./kernelbenchhardv3runsopencode · ?
opencode / ? session: ses_1fc291b7fffeg2suHnzgH1Qmre cwd: ?
harness
opencode
model
?
turns
120
tools called
54
events
173
input toks
2,339,275
output toks
46,277
cache hit
0
solution.py
final answer
benchmark.log
check.log
result.json
"""Optimized Triton kernel for multi-axis RoPE pre-attention prep.

Unified kernel: cos/sin loaded once per (b, t_tile, d_tile), reused across all H.
Tunable BLOCK_T, BLOCK_D, num_warps for each shape.
"""
import torch
import torch.nn as nn
import triton
import triton.language as tl


@triton.jit
def _rope_kernel(
    q_ptr, k_ptr,
    cos_cache, sin_cache,
    pos_t_ptr, pos_h_ptr, pos_w_ptr,
    q_out_ptr, k_out_ptr,
    B: tl.int64,
    T: tl.int64,
    Hq: tl.int64,
    Hkv: tl.int64,
    D: tl.int64,
    s0: tl.int64,
    s1: tl.int64,
    stride_qb, stride_qt, stride_qh, stride_qd,
    stride_kb, stride_kt, stride_kh, stride_kd,
    stride_pb, stride_pt,
    stride_ccb, stride_ccd,
    stride_qob, stride_qoh, stride_qot, stride_qod,
    stride_kob, stride_koh, stride_kot, stride_kod,
    BLOCK_T: tl.constexpr,
    BLOCK_D: tl.constexpr,
):
    pid = tl.program_id(0)
    pid_d = tl.program_id(1)

    R = tl.cdiv(T, BLOCK_T)
    D_tiles = tl.cdiv(D, BLOCK_D)

    r = pid % R
    b = pid // R
    d_off = pid_d * BLOCK_D

    if b >= B or pid_d >= D_tiles:
        return

    t_off = r * BLOCK_T
    half_d = D // 2

    _rt = tl.arange(0, BLOCK_T)
    _rd = tl.arange(0, BLOCK_D)
    t_rng = t_off + _rt
    d_rng = d_off + _rd
    t_mask = t_rng < T
    d_mask = d_rng < D
    td_mask = t_mask[:, None] & d_mask[None, :]

    # Positions
    po = b * stride_pb + t_rng * stride_pt
    p_t = tl.load(pos_t_ptr + po, mask=t_mask, other=0)
    p_h = tl.load(pos_h_ptr + po, mask=t_mask, other=0)
    p_w = tl.load(pos_w_ptr + po, mask=t_mask, other=0)

    # Axis select per d
    d_f = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
    is_t = d_f < s0
    is_h = (d_f >= s0) & (d_f < s0 + s1)
    pos_sel = tl.where(is_t[None, :], p_t[:, None],
                 tl.where(is_h[None, :], p_h[:, None], p_w[:, None]))

    # Cos/sin cache — loaded ONCE, reused for all heads
    cache_off = pos_sel * stride_ccb + d_rng[None, :] * stride_ccd
    cos = tl.load(cos_cache + cache_off, mask=td_mask, other=1.0)
    sin = tl.load(sin_cache + cache_off, mask=td_mask, other=0.0)

    # Rotate-half mirror indices (same for all heads)
    d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
    is_first_half = d_rng[None, :] < half_d

    # Process Q heads
    h = 0
    while h < Hq:
        q_base = b * stride_qb + h * stride_qh
        qx = tl.load(q_ptr + q_base + t_rng[:, None] * stride_qt + d_rng[None, :] * stride_qd,
                      mask=td_mask, other=0.0)
        qm = tl.load(q_ptr + q_base + t_rng[:, None] * stride_qt + d_mir[None, :] * stride_qd,
                      mask=td_mask, other=0.0)
        out = qx * cos + tl.where(is_first_half, -qm, qm) * sin
        tl.store(q_out_ptr + b * stride_qob + h * stride_qoh + t_rng[:, None] * stride_qot + d_rng[None, :] * stride_qod,
                 out, mask=td_mask)
        h += 1

    # Process K heads
    h = 0
    while h < Hkv:
        k_base = b * stride_kb + h * stride_kh
        kx = tl.load(k_ptr + k_base + t_rng[:, None] * stride_kt + d_rng[None, :] * stride_kd,
                      mask=td_mask, other=0.0)
        km = tl.load(k_ptr + k_base + t_rng[:, None] * stride_kt + d_mir[None, :] * stride_kd,
                      mask=td_mask, other=0.0)
        out = kx * cos + tl.where(is_first_half, -km, km) * sin
        tl.store(k_out_ptr + b * stride_kob + h * stride_koh + t_rng[:, None] * stride_kot + d_rng[None, :] * stride_kod,
                 out, mask=td_mask)
        h += 1


def apply_mrope_torch(q, k, cos_cache, sin_cache, pos_t, pos_h, pos_w, mrope_section):
    B, T, Hq, D = q.shape
    _, _, Hkv, _ = k.shape
    s0, s1, s2 = mrope_section

    q_rot = torch.empty(B, Hq, T, D, dtype=q.dtype, device=q.device)
    k_rot = torch.empty(B, Hkv, T, D, dtype=k.dtype, device=k.device)

    # Tunable configs — selected based on shape characteristics
    # Larger H benefits from smaller grid => larger BLOCK_T
    # Bandwidth-bound: want maximal memory throughput
    if D == 64:
        BLOCK_T, BLOCK_D, num_warps = 32, 64, 4
    elif T <= 4096:
        BLOCK_T, BLOCK_D, num_warps = 16, 64, 4
    else:
        BLOCK_T, BLOCK_D, num_warps = 16, 64, 8

    n_t = (T + BLOCK_T - 1) // BLOCK_T
    n_d = (D + BLOCK_D - 1) // BLOCK_D

    _rope_kernel[(B * n_t, n_d)](
        q, k, cos_cache, sin_cache,
        pos_t, pos_h, pos_w,
        q_rot, k_rot,
        B=B, T=T, Hq=Hq, Hkv=Hkv, D=D,
        s0=s0, s1=s1,
        stride_qb=q.stride(0), stride_qt=q.stride(1),
        stride_qh=q.stride(2), stride_qd=q.stride(3),
        stride_kb=k.stride(0), stride_kt=k.stride(1),
        stride_kh=k.stride(2), stride_kd=k.stride(3),
        stride_pb=pos_t.stride(0), stride_pt=pos_t.stride(1),
        stride_ccb=cos_cache.stride(0), stride_ccd=cos_cache.stride(1),
        stride_qob=q_rot.stride(0), stride_qoh=q_rot.stride(1),
        stride_qot=q_rot.stride(2), stride_qod=q_rot.stride(3),
        stride_kob=k_rot.stride(0), stride_koh=k_rot.stride(1),
        stride_kot=k_rot.stride(2), stride_kod=k_rot.stride(3),
        BLOCK_T=BLOCK_T, BLOCK_D=BLOCK_D,
        num_warps=num_warps,
    )

    return q_rot, k_rot


class Model(nn.Module):
    def __init__(self, B: int, T: int, Hq: int, Hkv: int, D: int,
                 mrope_section: tuple[int, int, int], max_pos: int):
        super().__init__()
        assert sum(mrope_section) == D // 2
        self.B, self.T = B, T
        self.Hq, self.Hkv, self.D = Hq, Hkv, D
        self.mrope_section = tuple(mrope_section)
        self.max_pos = max_pos

        inv_freq = 1.0 / (10000.0 ** (torch.arange(0, D, 2, dtype=torch.float32) / D))
        pos = torch.arange(max_pos, dtype=torch.float32)
        freqs = torch.outer(pos, inv_freq)
        emb = torch.cat([freqs, freqs], dim=-1)
        self.register_buffer("cos_cache", emb.cos().to(torch.bfloat16))
        self.register_buffer("sin_cache", emb.sin().to(torch.bfloat16))

    def forward(
        self,
        q: torch.Tensor, k: torch.Tensor,
        pos_t: torch.Tensor, pos_h: torch.Tensor, pos_w: torch.Tensor,
    ) -> tuple[torch.Tensor, torch.Tensor]:
        return apply_mrope_torch(
            q, k, self.cos_cache, self.sin_cache,
            pos_t, pos_h, pos_w, self.mrope_section,
        )


B = 1
T = 4096
Hq = 32
Hkv = 8
D = 128
MROPE_SECTION = (16, 24, 24)
MAX_POS = 32768


def get_inputs():
    q = torch.randn(B, T, Hq, D, dtype=torch.bfloat16) * 0.5
    k = torch.randn(B, T, Hkv, D, dtype=torch.bfloat16) * 0.5
    pos_t = torch.randint(0, MAX_POS, (B, T), dtype=torch.int64)
    pos_h = torch.randint(0, MAX_POS, (B, T), dtype=torch.int64)
    pos_w = torch.randint(0, MAX_POS, (B, T), dtype=torch.int64)
    return [q, k, pos_t, pos_h, pos_w]


def get_init_inputs():
    return [B, T, Hq, Hkv, D, MROPE_SECTION, MAX_POS]
Excellent progress! 0.422 → 0.478 (peak fraction). The unified kernel sharing cos/sin across heads is a big win. Now let me push further with config tuning:
shape=0 variant=eager tflops=0.177 gbps=253.345 ms=0.356
shape=0 variant=compiled tflops=0.509 gbps=729.915 ms=0.124
shape=0 variant=solution tflops=0.653 gbps=936.471 ms=0.096
shape=0 solution_peak_fraction=0.5203
shape=1 variant=eager tflops=0.165 gbps=241.030 ms=0.610
shape=1 variant=compiled tflops=0.459 gbps=670.412 ms=0.219
shape=1 variant=solution tflops=0.722 gbps=1054.439 ms=0.139
shape=1 solution_peak_fraction=0.5858
shape=2 variant=eager tflops=0.070 gbps=109.697 ms=0.202
shape=2 variant=compiled tflops=0.164 gbps=255.669 ms=0.087
shape=2 variant=solution tflops=0.260 gbps=405.634 ms=0.055
shape=2 solution_peak_fraction=0.2254
shape=3 variant=eager tflops=0.172 gbps=246.866 ms=1.463
shape=3 variant=compiled tflops=0.462 gbps=662.896 ms=0.545
shape=3 variant=solution tflops=0.658 gbps=943.913 ms=0.383
shape=3 solution_peak_fraction=0.5244
peak_fraction: 0.4356
RESULT: OK
PASS
{
    "problem": "09_fmha_preattn_mrope",
    "harness": "opencode",
    "model": "openrouter-pinned/qwen/qwen3.6-27b",
    "reasoning_effort": "",
    "has_solution": true,
    "correct": true,
    "peak_fraction": 0.4356,
    "elapsed_seconds": 1610,
    "harness_exit_code": 0,
    "session_complete": true,
    "usage": {"input_tokens": 2339275, "output_tokens": 46277, "cache_read_tokens": 0, "cache_creation_tokens": 0, "reasoning_tokens": 13925, "total_cost_usd": null}
}

timeline (173 events)

assistant
read /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope"
}
tool
stdout (215 chars)
<path>/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope</path>
<type>directory</type>
<entries>
benchmark.py
check.py
problem.yaml
PROMPT.txt
reference.py
shapes.py
sota.py

(7 entries)
</entries>
assistant
in 17793out 37cache_r 0cache_w 0
assistant
read /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/reference.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/reference.py"
}
tool
stdout (4884 chars) — TRUNCATED
<path>/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/reference.py</path>
<type>file</type>
<content>
1: """Naive multi-axis RoPE pre-attention reference (correctness only).
2: 
3: Mirrors the Qwen2-VL apply_multimodal_rotary_pos_emb semantics: three position
4: axes (temporal, height, width), each contributing a slice of the head_dim via
5: mrope_section. Standard rotate-half on q and k once per-axis cos/sin have been
6: mixed.
7: 
8: Layout convention:
9:   q: (B, T, Hq, D)   bf16
10:   k: (B, T, Hkv, D)  bf16
11:   pos_t, pos_h, pos_w: (B, T) int64
12: 
13: Output: q_rot, k_rot in (B, H, T, D) — i.e. the layout an attention kernel
14: expects (head dim second). The transpose is part of the "pre-attention prep".
15: """
16: import torch
17: import torch.nn as nn
18: 
19: OP_TYPE = "rope"
20: SUPPORTED_PRECISIONS = ["bf16"]
21: HARDWARE_REQUIRED = ["RTX_PRO_6000"]
22: 
23: 
24: def _build_inv_freq(D: int, base: float = 10000.0) -> torch.Tensor:
25:     return 1.0 / (base ** (torch.arange(0, D, 2, dtype=torch.float32) / D))
26: 
27: 
28: def _rotate_half(x: torch.Tensor) -> torch.Tensor:
29:     half = x.shape[-1] // 2
30:     return torch.cat((-x[..., half:], x[..., :half]), dim=-1)
31: 
32: 
33: class Model(nn.Module):
34:     def __init__(self, B: int, T: int, Hq: int, Hkv: int, D: int,
35:                  mrope_section: tuple[int, int, int], max_pos: int):
36:         super().__init__()
37:         assert sum(mrope_section) == D // 2, \
38:          

... (3384 more chars)
assistant
read /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/check.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/check.py"
}
tool
stdout (5019 chars) — TRUNCATED
<path>/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/check.py</path>
<type>file</type>
<content>
1: """Correctness runner for multi-axis RoPE pre-attention prep.
2: 
3: Runs solution.Model vs reference.Model across all shapes in shapes.py, 3 seeds
4: each, with per-dtype atol/rtol. Also rejects forbidden ops by grep.
5: """
6: import re
7: import sys
8: from pathlib import Path
9: 
10: import torch
11: import yaml
12: 
13: # Make the repo's src/ importable
14: REPO_ROOT = Path(__file__).resolve().parents[2]
15: sys.path.insert(0, str(REPO_ROOT))
16: 
17: from src.eval.correctness import check_correctness  # noqa: E402
18: 
19: 
20: def main():
21:     try:
22:         import reference
23:         import shapes
24:         import solution
25:     except Exception as e:
26:         print(f"FAIL: import error: {e}")
27:         sys.exit(1)
28: 
29:     problem_yaml = Path("problem.yaml")
30:     meta = yaml.safe_load(problem_yaml.read_text()) if problem_yaml.exists() else {}
31: 
32:     # --- Forbidden-op check ------------------------------------------------
33:     sol_src = Path("solution.py").read_text() if Path("solution.py").exists() else ""
34:     for forbidden in meta.get("forbidden", []):
35:         pat = re.escape(forbidden)
36:         if re.search(pat, sol_src):
37:             print(f"FAIL: forbidden op used: {forbidden}")
38:             sys.exit(1)
39: 
40:     device = torch.device("cuda:0")
41:     tol_override = meta.get("tolerance") or

... (3519 more chars)
assistant
read /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/benchmark.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/benchmark.py"
}
tool
stdout (5466 chars) — TRUNCATED
<path>/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/benchmark.py</path>
<type>file</type>
<content>
1: """Roofline benchmark for multi-axis RoPE pre-attention prep.
2: 
3: For each shape: times eager reference, compiled reference, SOTA (if available),
4: and the agent's solution. Reports achieved TFLOPS, GB/s, and peak_fraction.
5: 
6: Output lines the harness picks up:
7:   shape=<idx> variant=<name> tflops=<N> gbps=<N> ms=<N>
8:   peak_fraction: <N>  (geomean over shapes of solution's peak_fraction)
9: """
10: import sys
11: from math import exp, log
12: from pathlib import Path
13: 
14: import torch
15: import yaml
16: 
17: REPO_ROOT = Path(__file__).resolve().parents[2]
18: sys.path.insert(0, str(REPO_ROOT))
19: 
20: from src.eval.roofline import compute_gbps, compute_tflops, peak_fraction  # noqa: E402
21: from src.eval.timing import time_fn  # noqa: E402
22: from src.hardware import get as get_hw  # noqa: E402
23: 
24: 
25: def _eval_formula(expr: str, vars: dict) -> float:
26:     # Very small eval: only names from `vars` are valid.
27:     return float(eval(expr, {"__builtins__": {}}, vars))
28: 
29: 
30: def main():
31:     import reference
32:     import shapes
33:     import solution
34: 
35:     meta = yaml.safe_load(Path("problem.yaml").read_text())
36:     hw = get_hw(meta["hardware"][0])
37:     peak_tflops = hw.peak_tflops_dense.get(meta["peak_tflops_key"], 0.0)
38:     peak_gbps = hw.peak_bandwidth_gb_s
39:     regime = meta.get("regime

... (3966 more chars)
assistant
read /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/shapes.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/shapes.py"
}
tool
stdout (1187 chars)
<path>/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/shapes.py</path>
<type>file</type>
<content>
1: """Canonical shape sweep for multi-axis RoPE pre-attention.
2: 
3: Sized for Qwen2-VL-style vision-language inference: long T, GQA, mrope_section
4: splitting D/2 across temporal/height/width axes. Mix of base, long-context,
5: small-head-dim, and very-long-context.
6: """
7: 
8: SHAPES = [
9:     # Qwen2-VL base: T=4k, head_dim=128, GQA 32:8, mrope [16,24,24]
10:     {"B": 1, "T": 4096,  "Hq": 32, "Hkv": 8, "D": 128,
11:      "mrope_section": (16, 24, 24), "max_pos": 32768},
12: 
13:     # Qwen2-VL 7B-style long context, narrower kv heads
14:     {"B": 1, "T": 8192,  "Hq": 28, "Hkv": 4, "D": 128,
15:      "mrope_section": (16, 24, 24), "max_pos": 32768},
16: 
17:     # Smaller head_dim and B=2 (tests batch dim and reduced D)
18:     {"B": 2, "T": 2048,  "Hq": 16, "Hkv": 2, "D": 64,
19:      "mrope_section": (8, 12, 12), "max_pos": 16384},
20: 
21:     # Very long context (16k tokens)
22:     {"B": 1, "T": 16384, "Hq": 32, "Hkv": 8, "D": 128,
23:      "mrope_section": (16, 24, 24), "max_pos": 65536},
24: ]

(End of file - total 24 lines)
</content>
assistant
read /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/problem.yaml
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/problem.yaml"
}
tool
stdout (1784 chars) — TRUNCATED
<path>/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/problem.yaml</path>
<type>file</type>
<content>
1: name: 09_fmha_preattn_mrope
2: display_name: "Multi-axis RoPE Pre-attention Prep"
3: precision: bf16
4: regime: memory  # pointwise rotation + cache gather; bandwidth-bound
5: 
6: # FLOPs per call: rotate-half on q and k.
7: # Per element: out = a*cos + b*sin -> 3 flops/elem (1 mul + 1 mul + 1 add).
8: # We do this on q ((B*T*Hq*D) elems) and k ((B*T*Hkv*D) elems).
9: flops_formula: "3 * B * T * (Hq + Hkv) * D"
10: 
11: # Bytes moved (lower bound):
12: #   read q, k:                  2 * B*T*(Hq+Hkv)*D
13: #   read 3 position id arrays:  3 * B*T*8        (int64)
14: #   read cos/sin from cache:    6 * B*T*D*2      (3 axes, 2 caches, bf16)
15: #   write q_rot, k_rot:         2 * B*T*(Hq+Hkv)*D
16: bytes_formula: "4 * B * T * (Hq + Hkv) * D + 12 * B * T * D + 24 * B * T"
17: 
18: hardware: [RTX_PRO_6000]
19: peak_tflops_key: bf16    # informational; regime=memory uses bandwidth
20: peak_bandwidth_key: dram
21: 
22: tolerance:
23:   bfloat16: 0.02
24: 
25: # Forbidden ops -- agent must implement the gather + per-axis mix + rotation.
26: # Banning vendor mRoPE entry points and obvious shortcuts.
27: forbidden:
28:   - "transformers.models.qwen2_vl.modeling_qwen2_vl.apply_multimodal_rotary_pos_emb"
29:   - "apply_multimodal_rotary_pos_emb"
30:   - "flash_attn.layers.rotary"
31:   - "flashinfer.rope"
32:   - "flashinfer.apply_rope"
33: 
34: sota:
35:   name:

... (284 more chars)
assistant
read /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/sota.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/sota.py"
}
tool
stdout (1995 chars) — TRUNCATED
<path>/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/sota.py</path>
<type>file</type>
<content>
1: """SOTA reference for multi-axis RoPE pre-attention.
2: 
3: Wraps transformers' apply_multimodal_rotary_pos_emb. The full pipeline (gather
4: per-axis cos/sin from cache, then call the vendor rotation) is timed, matching
5: what the reference and the agent solution do.
6: 
7: If transformers isn't installed or the impl signature has drifted, returns
8: is_available()=False and the benchmark omits the SOTA line.
9: """
10: from __future__ import annotations
11: 
12: import torch
13: 
14: 
15: def _try_transformers():
16:     try:
17:         from transformers.models.qwen2_vl.modeling_qwen2_vl import (
18:             apply_multimodal_rotary_pos_emb as _impl,
19:         )
20:         return _impl
21:     except Exception:
22:         return None
23: 
24: 
25: def sota_forward(
26:     q: torch.Tensor, k: torch.Tensor,
27:     pos_t: torch.Tensor, pos_h: torch.Tensor, pos_w: torch.Tensor,
28:     cos_cache: torch.Tensor, sin_cache: torch.Tensor,
29:     mrope_section: tuple[int, int, int],
30: ):
31:     """q,k: (B, T, H, D); pos_*: (B, T); cos_cache,sin_cache: (max_pos, D)."""
32:     impl = _try_transformers()
33:     if impl is None:
34:         raise RuntimeError("transformers not available for SOTA")
35: 
36:     # Gather per-axis cos/sin and stack into (3, B, T, D) as transformers expects.
37:     cos = torch.stack([cos_cache[pos_t], cos_cache[pos_h], c

... (495 more chars)
assistant
in 17934out 303cache_r 0cache_w 0
assistant
read /home/infatoshi/cuda/KernelBench-Hard/CLAUDE.md
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/CLAUDE.md"
}
tool
stdout (7441 chars) — TRUNCATED
<path>/home/infatoshi/cuda/KernelBench-Hard/CLAUDE.md</path>
<type>file</type>
<content>
1: # KernelBench-Hard — Developer Instructions
2: 
3: Last updated: 2026-04-27.
4: 
5: This file is for **coding agents editing the repo** (you, via Claude Code). Do not confuse with `problems/<X>/PROMPT.txt` — those are the human-voice queries fed to agents _under test_.
6: 
7: For the journey behind the current design, read [DEVLOG.md](./DEVLOG.md).
8: 
9: ## What this repo is
10: 
11: Small kernel benchmark. Frontier coding agents are given URLs to SOTA implementations (sonic-moe, flashinfer, marlin) and asked to write a competitive kernel on RTX PRO 6000 Blackwell (SM120) in 45 minutes. Roofline-graded. Published artifact is the best kernel per (problem × model × harness), plus the agent trace.
12: 
13: See [SPEC.md](./SPEC.md) for methodology. See [README.md](./README.md) for the model matrix and quick start.
14: 
15: ## Non-negotiable rules
16: 
17: - **uv only.** No bare `python`, no `pip`. Use `uv run ...`, `uv add ...`, `uv pip install ...`.
18: - **Before committing:** `uv run ruff check . --fix && uv run pytest`.
19: - **Never edit `problems/*/solution.py`**. Those files are agent output; they're gitignored for a reason. If you need to inspect one, read it from `outputs/runs/<run>/<problem>/solution.py`.
20: - **Never modify `problems/*/reference.py`, `check.py`, `benchmark.py`, `problem.yaml`, `shapes.py`, or `PROMPT.txt`** once a sweep has been published. Those define the ben

... (5941 more chars)
assistant
read /home/infatoshi/cuda/KernelBench-Hard/src/eval/correctness.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/src/eval/correctness.py"
}
tool
stdout (4080 chars) — TRUNCATED
<path>/home/infatoshi/cuda/KernelBench-Hard/src/eval/correctness.py</path>
<type>file</type>
<content>
1: """Per-dtype correctness tolerance.
2: 
3: Stanford's KernelBench uses 1e-4 atol/rtol for fp32 and 1e-2 for fp16/bf16.
4: We extend to fp8 (0.1, permissive) and int (exact).
5: """
6: from __future__ import annotations
7: 
8: import torch
9: 
10: DEFAULT_TOLERANCE = {
11:     torch.float32: {"atol": 1e-4, "rtol": 1e-4},
12:     torch.float16: {"atol": 1e-2, "rtol": 1e-2},
13:     torch.bfloat16: {"atol": 1e-2, "rtol": 1e-2},
14:     torch.float8_e4m3fn: {"atol": 1e-1, "rtol": 1e-1},
15:     torch.float8_e5m2: {"atol": 1e-1, "rtol": 1e-1},
16:     torch.int8: {"atol": 0, "rtol": 0},
17:     torch.int32: {"atol": 0, "rtol": 0},
18:     torch.int64: {"atol": 0, "rtol": 0},
19: }
20: 
21: 
22: def _coerce_float(x):
23:     """Accept int/float/str scientific-notation as float; pass through dicts."""
24:     if isinstance(x, (int, float)):
25:         return float(x)
26:     if isinstance(x, str):
27:         try:
28:             return float(x)
29:         except ValueError:
30:             return x
31:     return x
32: 
33: 
34: def tolerance_for_dtype(dtype: torch.dtype, override: dict | None = None) -> dict:
35:     """Lookup atol/rtol for a given dtype, with optional per-problem override.
36: 
37:     The override dict is keyed by str(dtype). Values may be:
38:       - a single number (or a string parseable as float, e.g. "5e-2") -> used
39:         as both atol and rtol
4

... (2580 more chars)
assistant
read /home/infatoshi/cuda/KernelBench-Hard/src/eval/roofline.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/src/eval/roofline.py"
}
tool
stdout (1180 chars)
<path>/home/infatoshi/cuda/KernelBench-Hard/src/eval/roofline.py</path>
<type>file</type>
<content>
1: """Roofline math: achieved TFLOPS / GB/s, peak fraction.
2: 
3: FLOPS and bytes formulas come from the problem's `problem.yaml`. They are the
4: dense-equivalent algorithmic work; kernels that skip work (sparsity, early
5: exit) are still measured against the dense cost.
6: """
7: from __future__ import annotations
8: 
9: 
10: def compute_tflops(flops: float, time_ms: float) -> float:
11:     """flops per invocation and wall time in ms -> TFLOPS."""
12:     if time_ms <= 0:
13:         return 0.0
14:     return flops / (time_ms * 1e-3) / 1e12
15: 
16: 
17: def compute_gbps(bytes_moved: float, time_ms: float) -> float:
18:     """bytes per invocation and wall time in ms -> GB/s."""
19:     if time_ms <= 0:
20:         return 0.0
21:     return bytes_moved / (time_ms * 1e-3) / 1e9
22: 
23: 
24: def peak_fraction(
25:     achieved: float,
26:     peak: float,
27: ) -> float:
28:     """Return achieved / peak, clamped to [0, infinity)."""
29:     if peak <= 0:
30:         return 0.0
31:     return max(0.0, achieved / peak)

(End of file - total 31 lines)
</content>
assistant
read /home/infatoshi/cuda/KernelBench-Hard/src/hardware.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/src/hardware.py"
}
assistant
Let me also check the repo-level config and src modules.
assistant
in 25622out 181cache_r 0cache_w 0
assistant
read /home/infatoshi/cuda/KernelBench-Hard/src/hardware
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/src/hardware"
}
tool
stdout (171 chars)
<path>/home/infatoshi/cuda/KernelBench-Hard/src/hardware</path>
<type>directory</type>
<entries>
__init__.py
__pycache__/
m4_max.py
rtx_pro_6000.py

(4 entries)
</entries>
assistant
read /home/infatoshi/cuda/KernelBench-Hard/src/eval/timing.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/src/eval/timing.py"
}
tool
stdout (2978 chars) — TRUNCATED
<path>/home/infatoshi/cuda/KernelBench-Hard/src/eval/timing.py</path>
<type>file</type>
<content>
1: """Centralized GPU timing for benchmark.py files.
2: 
3: All problems' benchmark.py should call `time_fn` from here so we have one
4: implementation of warmup, L2 flush, and CUDA event capture to maintain.
5: 
6: Methodology:
7:   - 10 warmup calls absorb Triton autotune (typical ~7 configs) and
8:     torch.compile reduce-overhead CUDA-graph capture.
9:   - Between each timed call, `_l2_flush()` writes 128 MB to evict L2
10:     (Blackwell L2 is 96 MB; we want any prior L2 contents flushed so
11:     we measure HBM-load bandwidth, not L2-cached bandwidth).
12:   - GPU timing via cuda.Event with synchronize() AFTER record() but
13:     BEFORE elapsed_time() — the canonical NVIDIA pattern.
14:   - Reported value is the median of `iters` trials, robust to outliers.
15: 
16: Notes / known biases not addressed here:
17:   - torch.compile(mode="reduce-overhead") gets CUDA graphs which eliminate
18:     launch overhead. Custom Triton/CUDA kernels do NOT get this treatment.
19:     On small shapes where launch overhead matters, this gives compile an
20:     artificial advantage. We accept this as the cost of using the agreed
21:     "compiled" baseline policy.
22:   - cuBLAS / cuDNN allocate workspaces on first call. 10 warmup absorbs.
23:   - Median over a fairly small number of trials (default 30) is fine for
24:     headline numbers but won't catch bimodal distributions. Use --ext

... (1478 more chars)
assistant
in 30073out 84cache_r 0cache_w 0
assistant
read /home/infatoshi/cuda/KernelBench-Hard/src/hardware/rtx_pro_6000.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/src/hardware/rtx_pro_6000.py"
}
tool
stdout (1170 chars)
<path>/home/infatoshi/cuda/KernelBench-Hard/src/hardware/rtx_pro_6000.py</path>
<type>file</type>
<content>
1: """RTX PRO 6000 Blackwell Workstation — SM120, consumer-lineage Blackwell.
2: 
3: Peak tensor-core throughputs are dense-matrix advertised peaks. Actual kernels
4: will see 60-85% of peak on well-tuned code.
5: """
6: from dataclasses import dataclass
7: 
8: 
9: @dataclass(frozen=True)
10: class HardwareTarget:
11:     name: str
12:     sm: str
13:     vram_gb: int
14:     peak_bandwidth_gb_s: float  # DRAM
15:     peak_tflops_dense: dict[str, float]  # dtype -> TFLOPS
16: 
17: 
18: RTX_PRO_6000 = HardwareTarget(
19:     name="RTX PRO 6000 Blackwell Workstation",
20:     sm="sm_120a",
21:     vram_gb=96,
22:     peak_bandwidth_gb_s=1800.0,
23:     peak_tflops_dense={
24:         "fp4": 800.0,
25:         "nvfp4": 800.0,
26:         "mxfp4": 800.0,
27:         "fp6": 800.0,
28:         "fp8": 400.0,
29:         "bf16": 200.0,
30:         "fp16": 200.0,
31:         "tf32": 100.0,
32:         "fp32": 12.0,  # non-tensor-core SIMT fp32
33:         "int8": 400.0,
34:         "int4": 800.0,
35:     },
36: )

(End of file - total 36 lines)
</content>
assistant
read /home/infatoshi/cuda/KernelBench-Hard/src/hardware/__init__.py
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/src/hardware/__init__.py"
}
tool
stdout (558 chars)
<path>/home/infatoshi/cuda/KernelBench-Hard/src/hardware/__init__.py</path>
<type>file</type>
<content>
1: """Hardware peak-throughput lookup tables."""
2: from src.hardware.m4_max import M4_MAX
3: from src.hardware.rtx_pro_6000 import RTX_PRO_6000
4: 
5: TARGETS = {
6:     "RTX_PRO_6000": RTX_PRO_6000,
7:     "M4_MAX": M4_MAX,
8: }
9: 
10: 
11: def get(name: str):
12:     if name not in TARGETS:
13:         raise ValueError(f"Unknown hardware {name!r}; available: {list(TARGETS)}")
14:     return TARGETS[name]

(End of file - total 14 lines)
</content>
assistant
bash
args
{
  "command": "nvidia-smi --query-gpu=name,driver_version,memory.total --format=csv,noheader 2>/dev/null | head -1",
  "description": "Check GPU status"
}
tool
stdout (72 chars)
NVIDIA RTX PRO 6000 Blackwell Workstation Edition, 595.58.03, 97887 MiB
assistant
in 31211out 156cache_r 0cache_w 0
assistant
bash
args
{
  "command": "uv run python -c \"import triton; print(triton.__version__)\"",
  "description": "Check Triton version"
}
tool
stdout (6 chars)
3.6.0
assistant
Let me check the Triton version and CUDA setup, then look at a similar existing solution for reference patterns.
assistant
bash
args
{
  "command": "uv run python -c \"import torch; print(torch.__version__); print(torch.version.cuda)\"",
  "description": "Check torch version"
}
tool
stdout (18 chars)
2.11.0+cu130
13.0
assistant
in 32176out -530cache_r 0cache_w 0
assistant
todowrite
args
{
  "todos": [
    {
      "content": "Write initial Triton kernel solution.py",
      "status": "in_progress",
      "priority": "high"
    },
    {
      "content": "Run check.py for correctness",
      "status": "pending",
      "priority": "high"
    },
    {
      "content": "Run benchmark.py for performance baseline",
      "status": "pending",
      "priority": "high"
    },
    {
      "content": "Profile and optimize kernel",
      "status": "pending",
      "priority": "high"
    },
    {
      "content": "Verify final correctness + benchmark",
      "status": "pending",
      "prior

... (24 more chars)
tool
stdout (409 chars)
content: 'Write initial Triton kernel solution.py'
status: 'in_progress'
priority: 'high'
content: 'Run check.py for correctness'
status: 'pending'
priority: 'high'
content: 'Run benchmark.py for performance baseline'
status: 'pending'
priority: 'high'
content: 'Profile and optimize kernel'
status: 'pending'
priority: 'high'
content: 'Verify final correctness + benchmark'
status: 'pending'
priority: 'high'
assistant
in 32357out 194cache_r 0cache_w 0
assistant
Now let me write the initial Triton solution. I need to understand the exact math: - `rotate_half(x)`: for D-dim tensor, split at D/2: `[-x[..., D/2:], x[..., :D/2]]` - RoPE: `out = x * cos + rotate_half(x) * sin` - mRoPE mixing: assign different axis (t/h/w) cos/sin to different pairs based on mrope_section
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (604 lines — TRUNCATED)
--- /dev/null
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -0,0 +1,601 @@
+"""Triton kernel for multi-axis RoPE pre-attention prep.
+
+Fuses gather + per-axis mix + rotate-half + transpose into one kernel.
+Streams q/k once and emits the rotated (B, H, T, D) layout directly.
+"""
+import torch
+import torch.nn as nn
+import triton
+import triton.language as tl
+
+
+@triton.jit
+def _mrope_kernel(
+    q_ptr, k_ptr,
+    cos_cache, sin_cache,
+    pos_t, pos_h, pos_w,
+    q_rot, k_rot,
+    B: tl.int64, T: tl.int64, Hq: tl.int64, Hkv: tl.int64, D: tl.int64,
+    s0: tl.int64, s1: tl.int64, s2: tl.int64,
+    stride_qb, stride_qt, stride_qh, stride_qd,
+    stride_kb, stride_kt, stride_kh, stride_kd,
+    stride_pb, stride_pt,
+    stride_cocos, stride_cod,
+    stride_qrb, stride_qrr, stride_qrh, stride_qrd,
+    stride_krb, stride_krr, stride_krh, stride_krd,
+    BLOCK_TD: tl.constexpr,
+):
+    """Single kernel that processes one tensor (q or k).
+    
+    Each 1D program over (B*H*R) space. Within each program, a 2D grid
+    of threads handles tiles of (T, D).
+    
+    R = ceil(T / BLOCK_TD)  -- T tiles
+    """
+    # This program handles a specific (b, h, r) triple
+    # where r is the T-tile index
+    pid = tl.program_id(0)
+    
+    # Decompose pid into (b, h, r)
+    R = tl.cdiv(T, BLOCK_TD)
+    H = Hq  # set per call
+    r = pid % R
+    bh = pid // R
+    b = bh // H
+    h = bh % H
+    
+    if b >= B:
+        return
+    
+    # T offset and stride for output layout (B, H, T, D)
+    t_offset = r * BLOCK_TD
+    t_idx = t_offset + tl.arange(0, BLOCK_TD)
+    t_mask = t_idx < T
+    
+    # D indices - all threads in a warp handle different D elements
+    # We use a simple mapping: each thread handles one TD pair
+    d_idx = tl.arange(0, D)
+    
+    # We need threads = BLOCK_TD * D to cover the full tile, but that's too large.
+    # Instead, we'll process D serially in chunks.
+    # Actually let's use BLOCK_D as well.
+    # For now, let's just handle D elements sequentially per thread group.
+    pass  # placeholder
+
+
+@triton.jit
+def _mrope_fused(
+    q_ptr, k_ptr,
+    cos_cache_ptr, sin_cache_ptr,
+    pos_t_ptr, pos_h_ptr, pos_w_ptr,
+    q_rot_ptr, k_rot_ptr,
+    B: tl.int64, T: tl.int64, Hq: tl.int64, Hkv: tl.int64, D: tl.int64,
+    s0: tl.int64, s1: tl.int64, s2: tl.int64,
+    stride_qb, stride_qt, stride_qh, stride_qd,
+    stride_kb, stride_kt, stride_kh, stride_kd,
+    stride_pb, stride_pt,
+    stride_ccd,  # cos/sin cache: (max_pos, D)
+    stride_qrb, stride_qrr, stride_qrh, stride_qrd,
+    stride_krb, stride_krr, stride_krh, stride_krd,
+    BLOCK_DT: tl.constexpr,
+):
+    """
+    2D grid: (B*Hq*T//BLOCK_DT, D). Each program handles D elements for one (b,h,t) group.
+    
+    Actually we'll do TD tiling.
+    """
+    pass  # split below
+
+
+def _apply_mrope_kernel(q, k, cos_cache, sin_cache, pos_t, pos_h, pos_w, 
+                         mrope_section, D):
+    """Launch the fused mRoPE + transpose kernel."""
+    B, T, Hq, _ = q.shape
+    _, _, Hkv, _ = k.shape
+    s0, s1, s2 = mrope_section
+    
+    # Output buffers in (B, H, T, D) layout
+    q_rot = torch.empty(B, Hq, T, D, dtype=q.dtype, device=q.device)
+    k_rot = torch.empty(B, Hkv, T, D, dtype=k.dtype, device=k.device)
+    
+    # Process q and k separately but with same cos/sin
+    # Grid: each program handles (B*T*Hq) * D elements
+    # We'll use a simpler approach: (B * H) programs, each handles T * D
+    
+    BLOCK_D = 64
+    BLOCK_T = 64
+    
+    total_elements = B * T * (Hq + Hkv) * D
+    num_warps = 4
+    
+    # Launch for q
+    if q.numel() > 0:
+        _mrope_single_kernel[(B * Hq * triton.cdiv(T, BLOCK_T),)](
+            q, cos_cache, sin_cache, pos_t, pos_h, pos_w,
+            q_rot,
+            B=B, T=T, H=Hq, D=D,
+            s0=s0, s1=s1, s2=s2,
+            BLOCK_T=BLOCK_T,
+            num_warps=num_warps,
+        )
+    
+    # Launch for k 
+    if k.numel() > 0:
+        _mrope_single_kernel[(B * Hkv * triton.cdiv(T, BLOCK_T),)](
+            k, cos_cache, sin_cache, pos_t, pos_h, pos_w,
+            k_rot,
+            B=B, T=T, H=Hkv, D=D,
+            s0=s0, s1=s1, s2=s2,
+            BLOCK_T=BLOCK_T,
+            num_warps=num_warps,
+        )
+    
+    return q_rot, k_rot
+
+
+@triton.jit
+def _mrope_single_kernel(
+    x_ptr,        # (B, T, H, D) input
+    cos_cache_ptr,  # (max_pos, D)
+    sin_cache_ptr,
+    pos_t_ptr,    # (B, T)
+    pos_h_ptr,
+    pos_w_ptr,
+    out_ptr,      # (B, H, T, D) output
+    B: tl.int64, T: tl.int64, H: tl.int64, D: tl.int64,
+    s0: tl.int64, s1: tl.int64, s2: tl.int64,
+    stride_xb, stride_xt, stride_xh, stride_xd,
+    stride_outb, stride_outh, stride_outt, stride_outd,
+    stride_pb, stride_pt,
+    stride_cachepos, stride_cached,  # cos/sin cache strides
+    BLOCK_T: tl.constexpr,
+):
+    """
+    Each program handles one (b, h, t_tile) group.
+    Within the program, we process all D elements using thread mapping.
+    """
+    pid = tl.program_id(0)
+    R = tl.cdiv(T, BLOCK_T)
+    h_total = H
+    bh = pid // R
+    r = pid % R
+    b = bh // h_total
+    h = bh % h_total
+    
+    if b >= B:
+        return
+    
+    # T indices for this tile
+    t_off = r * BLOCK_T
+    t_idx = t_off + tl.arange(0, BLOCK_T)
+    t_mask = t_idx < T
+    
+    # D indices - we process ALL D across the program's threads
+    # With BLOCK_T=64 and num_warps=4 (128 threads), each thread handles D/128 elements
+    # For D=128, each thread handles 1 element. For D=64, we can have fewer threads.
+    stride = tl.num_programs(0)  # not needed
+    pid_d = tl.program_id(0) % D  # won't work - this is 1D grid
+    
+    # Better approach: make grid 2D or use a different strategy
+    # Let's use a 1D grid over (b, h, t_tile, d_chunk)
+    pass
+
+
+# Let me rewrite with proper tiling strategy
+@triton.jit
+def _mrope_kernel_v2(
+    x_ptr,
+    co

... (16484 more chars)
args
{
  "content": "<21764 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
in 32692out 7402cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (705 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -11,545 +11,185 @@
 
 @triton.jit
 def _mrope_kernel(
-    q_ptr, k_ptr,
-    cos_cache, sin_cache,
-    pos_t, pos_h, pos_w,
-    q_rot, k_rot,
-    B: tl.int64, T: tl.int64, Hq: tl.int64, Hkv: tl.int64, D: tl.int64,
-    s0: tl.int64, s1: tl.int64, s2: tl.int64,
-    stride_qb, stride_qt, stride_qh, stride_qd,
-    stride_kb, stride_kt, stride_kh, stride_kd,
-    stride_pb, stride_pt,
-    stride_cocos, stride_cod,
-    stride_qrb, stride_qrr, stride_qrh, stride_qrd,
-    stride_krb, stride_krr, stride_krh, stride_krd,
-    BLOCK_TD: tl.constexpr,
-):
-    """Single kernel that processes one tensor (q or k).
-    
-    Each 1D program over (B*H*R) space. Within each program, a 2D grid
-    of threads handles tiles of (T, D).
-    
-    R = ceil(T / BLOCK_TD)  -- T tiles
-    """
-    # This program handles a specific (b, h, r) triple
-    # where r is the T-tile index
-    pid = tl.program_id(0)
-    
-    # Decompose pid into (b, h, r)
-    R = tl.cdiv(T, BLOCK_TD)
-    H = Hq  # set per call
-    r = pid % R
-    bh = pid // R
-    b = bh // H
-    h = bh % H
-    
-    if b >= B:
-        return
-    
-    # T offset and stride for output layout (B, H, T, D)
-    t_offset = r * BLOCK_TD
-    t_idx = t_offset + tl.arange(0, BLOCK_TD)
-    t_mask = t_idx < T
-    
-    # D indices - all threads in a warp handle different D elements
-    # We use a simple mapping: each thread handles one TD pair
-    d_idx = tl.arange(0, D)
-    
-    # We need threads = BLOCK_TD * D to cover the full tile, but that's too large.
-    # Instead, we'll process D serially in chunks.
-    # Actually let's use BLOCK_D as well.
-    # For now, let's just handle D elements sequentially per thread group.
-    pass  # placeholder
-
-
-@triton.jit
-def _mrope_fused(
-    q_ptr, k_ptr,
-    cos_cache_ptr, sin_cache_ptr,
-    pos_t_ptr, pos_h_ptr, pos_w_ptr,
-    q_rot_ptr, k_rot_ptr,
-    B: tl.int64, T: tl.int64, Hq: tl.int64, Hkv: tl.int64, D: tl.int64,
-    s0: tl.int64, s1: tl.int64, s2: tl.int64,
-    stride_qb, stride_qt, stride_qh, stride_qd,
-    stride_kb, stride_kt, stride_kh, stride_kd,
-    stride_pb, stride_pt,
-    stride_ccd,  # cos/sin cache: (max_pos, D)
-    stride_qrb, stride_qrr, stride_qrh, stride_qrd,
-    stride_krb, stride_krr, stride_krh, stride_krd,
-    BLOCK_DT: tl.constexpr,
-):
-    """
-    2D grid: (B*Hq*T//BLOCK_DT, D). Each program handles D elements for one (b,h,t) group.
-    
-    Actually we'll do TD tiling.
-    """
-    pass  # split below
-
-
-def _apply_mrope_kernel(q, k, cos_cache, sin_cache, pos_t, pos_h, pos_w, 
-                         mrope_section, D):
-    """Launch the fused mRoPE + transpose kernel."""
-    B, T, Hq, _ = q.shape
-    _, _, Hkv, _ = k.shape
-    s0, s1, s2 = mrope_section
-    
-    # Output buffers in (B, H, T, D) layout
-    q_rot = torch.empty(B, Hq, T, D, dtype=q.dtype, device=q.device)
-    k_rot = torch.empty(B, Hkv, T, D, dtype=k.dtype, device=k.device)
-    
-    # Process q and k separately but with same cos/sin
-    # Grid: each program handles (B*T*Hq) * D elements
-    # We'll use a simpler approach: (B * H) programs, each handles T * D
-    
-    BLOCK_D = 64
-    BLOCK_T = 64
-    
-    total_elements = B * T * (Hq + Hkv) * D
-    num_warps = 4
-    
-    # Launch for q
-    if q.numel() > 0:
-        _mrope_single_kernel[(B * Hq * triton.cdiv(T, BLOCK_T),)](
-            q, cos_cache, sin_cache, pos_t, pos_h, pos_w,
-            q_rot,
-            B=B, T=T, H=Hq, D=D,
-            s0=s0, s1=s1, s2=s2,
-            BLOCK_T=BLOCK_T,
-            num_warps=num_warps,
-        )
-    
-    # Launch for k 
-    if k.numel() > 0:
-        _mrope_single_kernel[(B * Hkv * triton.cdiv(T, BLOCK_T),)](
-            k, cos_cache, sin_cache, pos_t, pos_h, pos_w,
-            k_rot,
-            B=B, T=T, H=Hkv, D=D,
-            s0=s0, s1=s1, s2=s2,
-            BLOCK_T=BLOCK_T,
-            num_warps=num_warps,
-        )
-    
-    return q_rot, k_rot
-
-
-@triton.jit
-def _mrope_single_kernel(
-    x_ptr,        # (B, T, H, D) input
-    cos_cache_ptr,  # (max_pos, D)
+    x_ptr,
+    cos_cache_ptr,
     sin_cache_ptr,
-    pos_t_ptr,    # (B, T)
+    pos_t_ptr,
     pos_h_ptr,
     pos_w_ptr,
-    out_ptr,      # (B, H, T, D) output
-    B: tl.int64, T: tl.int64, H: tl.int64, D: tl.int64,
-    s0: tl.int64, s1: tl.int64, s2: tl.int64,
-    stride_xb, stride_xt, stride_xh, stride_xd,
-    stride_outb, stride_outh, stride_outt, stride_outd,
-    stride_pb, stride_pt,
-    stride_cachepos, stride_cached,  # cos/sin cache strides
-    BLOCK_T: tl.constexpr,
-):
-    """
-    Each program handles one (b, h, t_tile) group.
-    Within the program, we process all D elements using thread mapping.
-    """
-    pid = tl.program_id(0)
-    R = tl.cdiv(T, BLOCK_T)
-    h_total = H
-    bh = pid // R
-    r = pid % R
-    b = bh // h_total
-    h = bh % h_total
-    
-    if b >= B:
-        return
-    
-    # T indices for this tile
-    t_off = r * BLOCK_T
-    t_idx = t_off + tl.arange(0, BLOCK_T)
-    t_mask = t_idx < T
-    
-    # D indices - we process ALL D across the program's threads
-    # With BLOCK_T=64 and num_warps=4 (128 threads), each thread handles D/128 elements
-    # For D=128, each thread handles 1 element. For D=64, we can have fewer threads.
-    stride = tl.num_programs(0)  # not needed
-    pid_d = tl.program_id(0) % D  # won't work - this is 1D grid
-    
-    # Better approach: make grid 2D or use a different strategy
-    # Let's use a 1D grid over (b, h, t_tile, d_chunk)
-    pass
-
-
-# Let me rewrite with proper tiling strategy
-@triton.jit
-def _mrope_kernel_v2(
-    x_ptr,
-    cos_cache_ptr, sin_cache_ptr,
-    pos_t_ptr, pos_h_ptr, pos_w_ptr,
     out_ptr,
-    B: tl.int64, T: tl.int64, H: tl.int64, D: tl.int64,
-    s0: tl.int64, s1: tl.int

... (20308 more chars)
args
{
  "content": "<8350 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
Let me rewrite with a cleaner, proper tiling approach:
assistant
in 40104out 2920cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard && ./scripts/patch_torch.sh 2>&1 | tail -5",
  "description": "Apply torch inductor hotfix"
}
tool
stdout (290 chars)
Applying torch inductor CSE typing hotfix...
  [skip] already patched: .venv/lib/python3.11/site-packages/torch/_inductor/codegen/cutedsl/cutedsl_kernel.py
  [skip] already patched: /home/infatoshi/.local/lib/python3.12/site-packages/torch/_inductor/codegen/cutedsl/cutedsl_kernel.py
Done.
assistant
in 43115out 102cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python check.py 2>&1",
  "description": "Run correctness check",
  "timeout": 120000
}
tool
stdout (5 chars)
PASS
assistant
in 43292out 93cache_r 0cache_w 0
assistant
todowrite
args
{
  "todos": [
    {
      "content": "Write initial Triton kernel solution.py",
      "status": "completed",
      "priority": "high"
    },
    {
      "content": "Run check.py for correctness",
      "status": "completed",
      "priority": "high"
    },
    {
      "content": "Run benchmark.py for performance baseline",
      "status": "in_progress",
      "priority": "high"
    },
    {
      "content": "Profile and optimize kernel",
      "status": "pending",
      "priority": "high"
    },
    {
      "content": "Verify final correctness + benchmark",
      "status": "pending",
      "p

... (28 more chars)
tool
stdout (413 chars)
content: 'Write initial Triton kernel solution.py'
status: 'completed'
priority: 'high'
content: 'Run check.py for correctness'
status: 'completed'
priority: 'high'
content: 'Run benchmark.py for performance baseline'
status: 'in_progress'
priority: 'high'
content: 'Profile and optimize kernel'
status: 'pending'
priority: 'high'
content: 'Verify final correctness + benchmark'
status: 'pending'
priority: 'high'
assistant
in 43403out 138cache_r 0cache_w 0
assistant
Correctness passes. Now let me benchmark:
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python benchmark.py 2>&1",
  "description": "Run benchmark for baseline",
  "timeout": 300000
}
tool
stdout (893 chars)
shape=0 variant=eager tflops=0.178 gbps=255.745 ms=0.353
shape=0 variant=compiled tflops=0.471 gbps=675.636 ms=0.134
shape=0 variant=solution tflops=0.397 gbps=569.866 ms=0.158
shape=0 solution_peak_fraction=0.3166
shape=1 variant=eager tflops=0.180 gbps=262.931 ms=0.559
shape=1 variant=compiled tflops=0.489 gbps=714.245 ms=0.206
shape=1 variant=solution tflops=0.387 gbps=564.506 ms=0.260
shape=1 solution_peak_fraction=0.3136
shape=2 variant=eager tflops=0.072 gbps=113.061 ms=0.196
shape=2 variant=compiled tflops=0.165 gbps=257.143 ms=0.086
shape=2 variant=solution tflops=0.490 gbps=765.025 ms=0.029
shape=2 solution_peak_fraction=0.4250
shape=3 variant=eager tflops=0.172 gbps=246.564 ms=1.465
shape=3 variant=compiled tflops=0.465 gbps=666.813 ms=0.542
shape=3 variant=solution tflops=0.293 gbps=420.655 ms=0.858
shape=3 solution_peak_fraction=0.2337
peak_fraction: 0.3151
RESULT: OK
assistant
in 43738out 101cache_r 0cache_w 0
assistant
Baseline results: ~420-765 GB/s across shapes, peak_fraction=0.315. The kernel is working but needs optimization. Let me profile and understand the bottleneck, then optimize the kernel. Key optimization opportunities: 1. **Reduce cos/sin cache loads**: Currently loading cos/sin 6 times (3 axes × 2 caches). We should load once per axis and then mix. 2. **Increase BLOCK_D** for less kernel launches 3. **Reduce grid size overhead**: For large T, the grid is huge 4. **Coalesced cache access**: The cache access pattern with variable positions per thread creates scattered reads 5. **Fuse both tensors into one kernel** to share cache loads 6. **Use larger thread counts for wider vectorized loads** Let me profile the kernel first to understand where time is spent:
assistant
bash
args
{
  "command": "<1426 chars \u2014 see below>",
  "description": "Profile the Triton kernel",
  "timeout": 120000
}
command (1426 chars)
cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python -c "
import torch, triton
import solution

B, T, Hq, Hkv, D = 1, 4096, 32, 8, 128
mrope_section = (16, 24, 24)
max_pos = 32768

device = 'cuda'
torch.manual_seed(42)

ref_model = __import__('reference').Model(B, T, Hq, Hkv, D, mrope_section, max_pos).to(device).eval()
sol_model = solution.Model(B, T, Hq, Hkv, D, mrope_section, max_pos).to(device).eval()
with torch.no_grad():
    sol_model.load_state_dict(ref_model.state_dict())

q = torch.randn(B, T, Hq, D, dtype=torch.bfloat16, device=device) * 0.5
k = torch.randn(B, T, Hkv, D, dtype=torch.bfloat16, device=device) * 0.5
pos_t = torch.randint(0, max_pos, (B, T), dtype=torch.int64, device=device)
pos_h = torch.randint(0, max_pos, (B, T), dtype=torch.int64, device=device)
pos_w = torch.randint(0, max_pos, (B, T), dtype=torch.int64, device=device)

# Profile
schedule = torch.profiler.schedule(wait=2, warmup=2, active=5)
with torch.profiler.profile(
    schedule=schedule,
    on_trace_ready=torch.profiler.tensorboard_trace_handler('./profile_output'),
    profile_memory=False,
    with_stack=True,
    record_shapes=True,
) as prof:
    for i in range(9):
        with torch.no_grad():
            sol_model(q, k, pos_t, pos_h, pos_w)
        prof.step()

prof.export_chrome_trace('./kernel_trace.json')
print('Profile written to profile_output and kernel_trace.json')
" 2>&1
tool
stdout (891 chars)
/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/torch/profiler/profiler.py:224: UserWarning: Warning: Profiler clears events at the end of each cycle.Only events from the current cycle will be reported.To keep events across cycles, set acc_events=True.
  _warn_once(
Traceback (most recent call last):
  File "<string>", line 37, in <module>
  File "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/torch/profiler/profiler.py", line 301, in export_chrome_trace
    return self.profiler.export_chrome_trace(path)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/torch/autograd/profiler.py", line 521, in export_chrome_trace
    self.kineto_results.save(path)  # type: ignore[union-attr]
    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
RuntimeError: Trace is already saved.
assistant
in 44313out 725cache_r 0cache_w 0
assistant
assistant
bash
args
{
  "command": "<1980 chars \u2014 see below>",
  "description": "Quick timing test",
  "timeout": 120000
}
command (1980 chars)
cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python -c "
import torch, solution, time

B, T, Hq, Hkv, D = 1, 4096, 32, 8, 128
mrope_section = (16, 24, 24)
max_pos = 32768
device = 'cuda'

sol_model = solution.Model(B, T, Hq, Hkv, D, mrope_section, max_pos).to(device).eval()

q = torch.randn(B, T, Hq, D, dtype=torch.bfloat16, device=device) * 0.5
k = torch.randn(B, T, Hkv, D, dtype=torch.bfloat16, device=device) * 0.5
pos_t = torch.randint(0, max_pos, (B, T), dtype=torch.int64, device=device)
pos_h = torch.randint(0, max_pos, (B, T), dtype=torch.int64, device=device)
pos_w = torch.randint(0, max_pos, (B, T), dtype=torch.int64, device=device)

# Warmup
for _ in range(10):
    with torch.no_grad():
        sol_model(q, k, pos_t, pos_h, pos_w)
torch.cuda.synchronize()

# Time it
times = []
for _ in range(30):
    s = torch.cuda.Event(enable_timing=True)
    e = torch.cuda.Event(enable_timing=True)
    s.record()
    with torch.no_grad():
        sol_model(q, k, pos_t, pos_h, pos_w)
    e.record()
    torch.cuda.synchronize()
    times.append(s.elapsed_time(e))
print(f'Median: {sorted(times)[15]:.3f}ms, Mean: {sum(times)/len(times):.3f}ms')
print(f'Total KB/s: {(4*B*T*Hq*D*2 + 4*B*T*Hkv*D*2 + 6*B*T*D*2)/1e6/sum(times)/30*1000:.1f}')

# Compute theoretical bandwidth 
# read q: B*T*Hq*D*2, read k: B*T*Hkv*D*2, write qrot: B*T*Hq*D*2, write krot: B*T*Hkv*D*2
# cos/sin: 6*B*T*D*2 (for our kernel which loads 6 times), pos: 3*B*T*8
# Total = 4*B*T*(Hq+Hkv)*D*2 + 12*B*T*D*2 + 24*B*T
total_bytes = 4*B*T*(Hq+Hkv)*2 + 12*B*T*2 + 24*B*T  # hmm this is wrong
# Actually bytes from problem.yaml: 4*B*T*(Hq+Hkv)*D + 12*B*T*D + 24*B*T
total_bytes = 4*B*T*(Hq+Hkv)*D + 12*B*T*D + 24*B*T  # note: factor of 2 for bf16 is in the formula
# No wait, the formula uses bf16 as 2 bytes already accounted for
gbps = total_bytes / (sum(times)/30 * 1e-3) / 1e9
print(f'GB/s (formula): {gbps:.1f}, Peak: 1800 GB/s, Fraction: {gbps/1800:.4f}')
" 2>&1
tool
stdout (107 chars)
Median: 0.109ms, Mean: 0.102ms
Total KB/s: 1888.0
GB/s (formula): 881.3, Peak: 1800 GB/s, Fraction: 0.4896
assistant
in 45314out 878cache_r 0cache_w 0
assistant
todowrite
args
{
  "todos": [
    {
      "content": "Write initial Triton kernel solution.py",
      "status": "completed",
      "priority": "high"
    },
    {
      "content": "Run check.py for correctness",
      "status": "completed",
      "priority": "high"
    },
    {
      "content": "Run benchmark.py for performance baseline",
      "status": "completed",
      "priority": "high"
    },
    {
      "content": "Profile and optimize kernel",
      "status": "in_progress",
      "priority": "high"
    },
    {
      "content": "Verify final correctness + benchmark",
      "status": "pending",
      

... (30 more chars)
tool
stdout (415 chars)
content: 'Write initial Triton kernel solution.py'
status: 'completed'
priority: 'high'
content: 'Run check.py for correctness'
status: 'completed'
priority: 'high'
content: 'Run benchmark.py for performance baseline'
status: 'completed'
priority: 'high'
content: 'Profile and optimize kernel'
status: 'in_progress'
priority: 'high'
content: 'Verify final correctness + benchmark'
status: 'pending'
priority: 'high'
assistant
The quick timing shows better numbers (~881 GB/s), but the benchmark's L2 flush reveals the real cache performance (~570 GB/s). Let me optimize by merging q+k into one kernel and improving tiling.
assistant
in 46270out 279cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (161 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -2,6 +2,10 @@
 
 Fuses gather + per-axis mix + rotate-half + transpose into one kernel.
 Streams q/k once and emits the rotated (B, H, T, D) layout directly.
+
+Optimization: each d maps to exactly one axis (t/h/w) based on mrope_section.
+Instead of loading cos/sin from all 3 axes, we select the position first
+and load cos/sin from the chosen axis only — 2 cache loads per (t,d) instead of 6.
 """
 import torch
 import torch.nn as nn
@@ -42,8 +46,10 @@
 ):
     """
     Grid: (B * H * ceil(T/BLOCK_T), ceil(D/BLOCK_D))
-    Each program handles a (BLOCK_T, BLOCK_D) tile in the (T, D) plane
-    for a single (b, h) pair.
+    Each program handles a (BLOCK_T, BLOCK_D) tile for one (b, h) pair.
+
+    Key optimization: each d maps to exactly one axis based on mrope_section.
+    Select the position first, then load cos/sin once per (t,d).
     """
     pid = tl.program_id(0)
     pid_d = tl.program_id(1)
@@ -70,68 +76,51 @@
 
     half = D // 2
 
+    # --- Select position index based on which axis each d belongs to ---
+    # d_first = d if d < half else d - half  (axis is determined by first-half index)
+    d_first = d_off + tl.arange(0, BLOCK_D)
+    d_first = tl.where(d_first < half, d_first, d_first - half)
+
+    axis_t = d_first < s0
+    axis_h = (d_first >= s0) & (d_first < s0 + s1)
+    # axis_w = not axis_t and not axis_h (implied)
+
+    pos_base = b * stride_pb
+    pt_vals = tl.load(pos_t_ptr + pos_base + t_rng[:, None] * stride_pt,
+                      mask=t_mask[:, None], other=0)
+    ph_vals = tl.load(pos_h_ptr + pos_base + t_rng[:, None] * stride_pt,
+                      mask=t_mask[:, None], other=0)
+    pw_vals = tl.load(pos_w_ptr + pos_base + t_rng[:, None] * stride_pt,
+                      mask=t_mask[:, None], other=0)
+
+    # Select position per d column
+    pos_mixed = tl.where(axis_t[None, :], pt_vals,
+                 tl.where(axis_h[None, :], ph_vals, pw_vals))
+
+    # --- Load cos/sin once from the selected position ---
+    cos_off = pos_mixed * stride_ccb + d_rng[None, :] * stride_ccd
+    sin_off = cos_off  # same offset, different base pointer
+
+    cos_tile = tl.load(cos_cache_ptr + cos_off, mask=td_mask, other=0.0)
+    sin_tile = tl.load(sin_cache_ptr + sin_off, mask=td_mask, other=0.0)
+
     # --- Load x[b, t, h, d] ---
     x_base_off = b * stride_xb + h * stride_xh
     x_offsets = x_base_off + t_rng[:, None] * stride_xt + d_rng[None, :] * stride_xd
     x_tile = tl.load(x_ptr + x_offsets, mask=td_mask, other=0.0)
 
-    # --- Load position indices (each T loads its position) ---
-    pos_base = b * stride_pb
-    pt_off = pos_base + t_rng * stride_pt
-    ph_off = pos_base + t_rng * stride_pt
-    pw_off = pos_base + t_rng * stride_pt
-
-    pos_t_vals = tl.load(pos_t_ptr + pt_off, mask=t_mask, other=0)
-    pos_h_vals = tl.load(pos_h_ptr + ph_off, mask=t_mask, other=0)
-    pos_w_vals = tl.load(pos_w_ptr + pw_off, mask=t_mask, other=0)
-
-    # --- Load cos for each axis ---
-    # cos_cache is (max_pos, D), contiguous. stride = (D, 1)
-    # offset for (pos, d) = pos * D + d
-    # pos_vals[:, None] * stride_ccb + d_rng[None, :] * stride_ccd
-    # shape: (BLOCK_T, BLOCK_D)
-    cos_t_off = pos_t_vals[:, None] * stride_ccb + d_rng[None, :] * stride_ccd
-    cos_h_off = pos_h_vals[:, None] * stride_ccb + d_rng[None, :] * stride_ccd
-    cos_w_off = pos_w_vals[:, None] * stride_ccb + d_rng[None, :] * stride_ccd
-
-    cos_t_tile = tl.load(cos_cache_ptr + cos_t_off, mask=td_mask, other=0.0)
-    cos_h_tile = tl.load(cos_cache_ptr + cos_h_off, mask=td_mask, other=0.0)
-    cos_w_tile = tl.load(cos_cache_ptr + cos_w_off, mask=td_mask, other=0.0)
-
-    sin_t_tile = tl.load(sin_cache_ptr + cos_t_off, mask=td_mask, other=0.0)
-    sin_h_tile = tl.load(sin_cache_ptr + cos_h_off, mask=td_mask, other=0.0)
-    sin_w_tile = tl.load(sin_cache_ptr + cos_w_off, mask=td_mask, other=0.0)
-
-    # --- Mix axes based on mrope_section ---
-    # d in [0, s0) -> temporal, [s0, s0+s1) -> height, [s0+s1, D//2) -> width
-    # d in [D//2, D) -> same scheme but with d and d-D//2 for cache column
-    # Key: cache column is ALWAYS d, not d_first.
-    # The axis determines WHICH position Row to use (pos_t vs pos_h vs pos_w).
-    # d_first determines axis, but actual cache col = d (mirror has same frequency)
-    d_first = tl.where(d_rng < half, d_rng, d_rng - half)
-    axis_mask_t = d_first < s0
-    axis_mask_h = (d_first >= s0) & (d_first < s0 + s1)
-
-    cos_mixed = tl.where(axis_mask_t, cos_t_tile,
-                 tl.where(axis_mask_h, cos_h_tile, cos_w_tile))
-    sin_mixed = tl.where(axis_mask_t, sin_t_tile,
-                 tl.where(axis_mask_h, sin_h_tile, sin_w_tile))
-
-    # --- Rotate half ---
-    # rotate_half(x)[d] = -x[d+half] if d < half else x[d-half]
-    d_mir = tl.where(d_rng < half, d_rng + half, d_rng - half)
-
-    # x_offsets for mirrored d: x[b, t, h, d_mir]
-    # d_mir might be outside [d_off, d_off+BLOCK_D), so this is a
-    # potentially non-contiguous load. Triton handles it as scalar addressed load.
+    # --- Load x at mirrored position for rotate_half ---
+    # d_mir = d + half if d < half else d - half
+    d_mir = d_rng + half
+    d_mir = tl.where(d_rng < half, d_mir, d_rng - half)
     x_mir_offsets = x_base_off + t_rng[:, None] * stride_xt + d_mir[None, :] * stride_xd
     x_mir_tile = tl.load(x_ptr + x_mir_offsets, mask=td_mask, other=0.0)
 
-    # Sign: negate if d < half (the d that's being moved from second half)
-    x_rot = tl.where(d_rng < half, -x_mir_tile, x_mir_tile)
+    # Sign: rotate_half[x at d] = -x[d+half] if d < half, +x[d-half] if d >= half
+    x_rot = tl.where(d_rng[None, :] < half, -x_mir_tile, x_mir_tile)
 
     # --- Apply RoPE ---
-    out_tile = x_tile * cos_mixed + x_rot * sin_mixed
+    out_tile = x_tile * cos_t

... (897 more chars)
args
{
  "content": "<7756 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
The key bottleneck is loading cos/sin 6 times (3 axes x 2 caches) when we only need 2 loads per d since each d maps to exactly one axis. Let me rewrite with this optimization:
assistant
in 46653out 2839cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python check.py 2>&1",
  "description": "Run correctness check",
  "timeout": 120000
}
tool
stdout (5 chars)
PASS
assistant
in 49447out 95cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python benchmark.py 2>&1",
  "description": "Run benchmark",
  "timeout": 300000
}
tool
stdout (893 chars)
shape=0 variant=eager tflops=0.182 gbps=260.551 ms=0.346
shape=0 variant=compiled tflops=0.481 gbps=689.676 ms=0.131
shape=0 variant=solution tflops=0.634 gbps=909.012 ms=0.099
shape=0 solution_peak_fraction=0.5050
shape=1 variant=eager tflops=0.181 gbps=264.004 ms=0.557
shape=1 variant=compiled tflops=0.487 gbps=711.534 ms=0.207
shape=1 variant=solution tflops=0.593 gbps=865.831 ms=0.170
shape=1 solution_peak_fraction=0.4810
shape=2 variant=eager tflops=0.073 gbps=114.798 ms=0.193
shape=2 variant=compiled tflops=0.165 gbps=257.095 ms=0.086
shape=2 variant=solution tflops=0.273 gbps=426.141 ms=0.052
shape=2 solution_peak_fraction=0.2367
shape=3 variant=eager tflops=0.172 gbps=247.505 ms=1.459
shape=3 variant=compiled tflops=0.462 gbps=662.935 ms=0.545
shape=3 variant=solution tflops=0.691 gbps=991.214 ms=0.364
shape=3 solution_peak_fraction=0.5507
peak_fraction: 0.4219
RESULT: OK
assistant
in 49558out 92cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (283 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -1,11 +1,8 @@
-"""Triton kernel for multi-axis RoPE pre-attention prep.
-
-Fuses gather + per-axis mix + rotate-half + transpose into one kernel.
-Streams q/k once and emits the rotated (B, H, T, D) layout directly.
-
-Optimization: each d maps to exactly one axis (t/h/w) based on mrope_section.
-Instead of loading cos/sin from all 3 axes, we select the position first
-and load cos/sin from the chosen axis only — 2 cache loads per (t,d) instead of 6.
+"""Optimized Triton kernel for multi-axis RoPE pre-attention prep.
+
+Fuses gather + per-axis mix + rotate-half + transpose for both q and k
+into a single kernel launch. Each thread block handles one (b, h, t_tile, d_tile),
+loading cos/sin once per (t,d) and applying rotation to both q and k heads.
 """
 import torch
 import torch.nn as nn
@@ -14,42 +11,37 @@
 
 
 @triton.jit
-def _mrope_kernel(
-    x_ptr,
+def _mrope_fused_kernel(
+    q_ptr,
+    k_ptr,
     cos_cache_ptr,
     sin_cache_ptr,
     pos_t_ptr,
     pos_h_ptr,
     pos_w_ptr,
-    out_ptr,
+    q_out_ptr,
+    k_out_ptr,
     B: tl.int64,
     T: tl.int64,
-    H: tl.int64,
+    Hq: tl.int64,
+    Hkv: tl.int64,
     D: tl.int64,
     s0: tl.int64,
     s1: tl.int64,
-    s2: tl.int64,
-    stride_xb,
-    stride_xt,
-    stride_xh,
-    stride_xd,
-    stride_pb,
-    stride_pt,
-    stride_ccb,
-    stride_ccd,
-    stride_outb,
-    stride_outh,
-    stride_outt,
-    stride_outd,
+    stride_qb, stride_qt, stride_qh, stride_qd,
+    stride_kb, stride_kt, stride_kh, stride_kd,
+    stride_pb, stride_pt,
+    stride_ccb, stride_ccd,
+    stride_qob, stride_qoh, stride_qot, stride_qod,
+    stride_kob, stride_koh, stride_kot, stride_kod,
     BLOCK_T: tl.constexpr,
     BLOCK_D: tl.constexpr,
+    HAS_K: tl.constexpr,
 ):
     """
-    Grid: (B * H * ceil(T/BLOCK_T), ceil(D/BLOCK_D))
-    Each program handles a (BLOCK_T, BLOCK_D) tile for one (b, h) pair.
-
-    Key optimization: each d maps to exactly one axis based on mrope_section.
-    Select the position first, then load cos/sin once per (t,d).
+    Grid: (B * (Hq + Hkv) * ceil(T/BLOCK_T), ceil(D/BLOCK_D))
+    Each program handles one (b, h, t_tile, d_tile).
+    h_is_q indicates whether this is a q head or k head.
     """
     pid = tl.program_id(0)
     pid_d = tl.program_id(1)
@@ -57,16 +49,34 @@
     R = tl.cdiv(T, BLOCK_T)
     D_tiles = tl.cdiv(D, BLOCK_D)
 
+    total_h = Hq + Hkv if HAS_K else Hq
     bh = pid // R
     r = pid % R
-    b = bh // H
-    h = bh % H
+    b = bh // total_h
+    h = bh % total_h
 
     if b >= B or pid_d >= D_tiles:
         return
 
+    h_is_q = h < Hq
+    h_idx = h if h_is_q else h - Hq
+
+    # Select pointers
+    stride_b = tl.where(h_is_q, stride_qb, tl.where(HAS_K, stride_kb, 0))
+    stride_t = tl.where(h_is_q, stride_qt, tl.where(HAS_K, stride_kt, 0))
+    stride_h = tl.where(h_is_q, stride_qh, tl.where(HAS_K, stride_kh, 0))
+    stride_d = tl.where(h_is_q, stride_qd, tl.where(HAS_K, stride_kd, 0))
+    x_ptr = tl.where(h_is_q, q_ptr, tl.where(HAS_K, k_ptr, 0))
+    
+    stride_ob = tl.where(h_is_q, stride_qob, tl.where(HAS_K, stride_kob, 0))
+    stride_oh = tl.where(h_is_q, stride_qoh, tl.where(HAS_K, stride_koh, 0))
+    stride_ot = tl.where(h_is_q, stride_qot, tl.where(HAS_K, stride_kot, 0))
+    stride_od = tl.where(h_is_q, stride_qod, tl.where(HAS_K, stride_kod, 0))
+    out_ptr = tl.where(h_is_q, q_out_ptr, tl.where(HAS_K, k_out_ptr, 0))
+
     t_off = r * BLOCK_T
     d_off = pid_d * BLOCK_D
+    half = D // 2
 
     t_rng = t_off + tl.arange(0, BLOCK_T)
     d_rng = d_off + tl.arange(0, BLOCK_D)
@@ -74,57 +84,63 @@
     d_mask = d_rng < D
     td_mask = t_mask[:, None] & d_mask[None, :]
 
-    half = D // 2
-
-    # --- Select position index based on which axis each d belongs to ---
-    # d_first = d if d < half else d - half  (axis is determined by first-half index)
-    d_first = d_off + tl.arange(0, BLOCK_D)
-    d_first = tl.where(d_first < half, d_first, d_first - half)
-
+    # Load x[b, t, h_idx, d]
+    x_base = b * stride_b + h_idx * stride_h
+    x_offsets = x_base + t_rng[:, None] * stride_t + d_rng[None, :] * stride_d
+    x_tile = tl.load(x_ptr + x_offsets, mask=td_mask, other=0.0)
+
+    # Load x at mirrored position for rotate_half
+    d_mir = tl.where(d_rng < half, d_rng + half, d_rng - half)
+    x_mir_offsets = x_base + t_rng[:, None] * stride_t + d_mir[None, :] * stride_d
+    x_mir_tile = tl.load(x_ptr + x_mir_offsets, mask=td_mask, other=0.0)
+    x_rot = tl.where(d_rng[None, :] < half, -x_mir_tile, x_mir_tile)
+
+    # Load positions
+    pos_base = b * stride_pb
+    pos_offsets = pos_base + t_rng * stride_pt
+    pos_t_vals = tl.load(pos_t_ptr + pos_offsets, mask=t_mask, other=0)
+    pos_h_vals = tl.load(pos_h_ptr + pos_offsets, mask=t_mask, other=0)
+    pos_w_vals = tl.load(pos_w_ptr + pos_offsets, mask=t_mask, other=0)
+
+    # Axis selection: d_first determines axis
+    d_first = tl.where(d_rng < half, d_rng, d_rng - half)
     axis_t = d_first < s0
     axis_h = (d_first >= s0) & (d_first < s0 + s1)
-    # axis_w = not axis_t and not axis_h (implied)
-
-    pos_base = b * stride_pb
-    pt_vals = tl.load(pos_t_ptr + pos_base + t_rng[:, None] * stride_pt,
-                      mask=t_mask[:, None], other=0)
-    ph_vals = tl.load(pos_h_ptr + pos_base + t_rng[:, None] * stride_pt,
-                      mask=t_mask[:, None], other=0)
-    pw_vals = tl.load(pos_w_ptr + pos_base + t_rng[:, None] * stride_pt,
-                      mask=t_mask[:, None], other=0)
-
-    # Select position per d column
-    pos_mixed = tl.where(axis_t[None, :], pt_vals,
-                 tl.where(axis_h[None, :], ph_vals, pw_vals))
-
-    # --- Load cos/sin once from the selected position ---
+
+    # Broadcast positions to (BLOCK_T, BLOCK_D)
+    pos_t_wide = pos_t_vals[:,

... (4909 more chars)
args
{
  "content": "<8324 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
Good improvement — 0.315 → 0.422 peak fraction. Now running at ~426-991 GB/s. The optimization helped. Further improvements: 1. Shape 2 (small) is still slow at 0.24 fraction — this could use fewer grid launches 2. Can fuse q+k into a single kernel launch to share cos/sin cache loads 3. Can try BLOCK_D=128 to load entire head dim at once 4. Can try more num_warps Let me try a fused q+k kernel with better parameters:
assistant
in 50121out 3151cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (390 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -1,8 +1,7 @@
 """Optimized Triton kernel for multi-axis RoPE pre-attention prep.
 
-Fuses gather + per-axis mix + rotate-half + transpose for both q and k
-into a single kernel launch. Each thread block handles one (b, h, t_tile, d_tile),
-loading cos/sin once per (t,d) and applying rotation to both q and k heads.
+Strategy: one kernel per tensor (q, k). Each block handles (BLOCK_T x BLOCK_D)
+for one (b, h) pair. Cos/sin loaded once per (t,d) via axis-selected position.
 """
 import torch
 import torch.nn as nn
@@ -11,20 +10,19 @@
 
 
 @triton.jit
-def _mrope_fused_kernel(
+def _mrope_kernel(
     q_ptr,
     k_ptr,
-    cos_cache_ptr,
-    sin_cache_ptr,
-    pos_t_ptr,
-    pos_h_ptr,
-    pos_w_ptr,
-    q_out_ptr,
-    k_out_ptr,
+    cos_cache,
+    sin_cache,
+    pos_t,
+    pos_h,
+    pos_w,
+    q_out,
+    k_out,
     B: tl.int64,
     T: tl.int64,
     Hq: tl.int64,
-    Hkv: tl.int64,
     D: tl.int64,
     s0: tl.int64,
     s1: tl.int64,
@@ -32,47 +30,44 @@
     stride_kb, stride_kt, stride_kh, stride_kd,
     stride_pb, stride_pt,
     stride_ccb, stride_ccd,
-    stride_qob, stride_qoh, stride_qot, stride_qod,
-    stride_kob, stride_koh, stride_kot, stride_kod,
+    stride_qob, stride_qot, stride_qod,
+    stride_kob, stride_kot, stride_kod,
     BLOCK_T: tl.constexpr,
     BLOCK_D: tl.constexpr,
-    HAS_K: tl.constexpr,
 ):
     """
-    Grid: (B * (Hq + Hkv) * ceil(T/BLOCK_T), ceil(D/BLOCK_D))
-    Each program handles one (b, h, t_tile, d_tile).
-    h_is_q indicates whether this is a q head or k head.
+    Grid: (B * H * ceil(T/BLOCK_T), ceil(D/BLOCK_D))
+    where H = Hq for q pass, Hkv for k pass.
+    
+    Actually this is a truly fused kernel: grid_0 over (b, h_or_hkv, t_tile),
+    grid_1 over d_tile. Each program computes RoPE for both q and k if applicable.
+    
+    Wait, q has Hq heads, k has Hkv heads. Different H means we can't simply fuse (b,h).
+    Let's keep things simple: each grid_0 program handles (b, h, t_tile), 
+    and within the kernel we compute for the appropriate tensor.
+    
+    We'll just use separate launches with shared code via constexpr HAS_KV flag.
+    Actually simpler: just two kernel calls, same kernel, different H and pointers.
     """
-    pid = tl.program_id(0)
-    pid_d = tl.program_id(1)
+    pid_t = tl.program_id(0)  # combined (b * H + h) * R + r
+    pid_d = tl.program_id(1)  # D tile
 
     R = tl.cdiv(T, BLOCK_T)
     D_tiles = tl.cdiv(D, BLOCK_D)
 
-    total_h = Hq + Hkv if HAS_K else Hq
-    bh = pid // R
-    r = pid % R
-    b = bh // total_h
-    h = bh % total_h
+    # Total heads depends on which tensor we're processing.
+    # We pass which_h_total to decide decomposition.
+    # Simplify: assume grid_0 = (B * H_total * R,) where H_total comes from
+    # the first argument.
+    H_total = Hq  # set per-caller
+    
+    bh = pid_t // R
+    r = pid_t % R
+    b = bh // H_total
+    h = bh % H_total
 
     if b >= B or pid_d >= D_tiles:
         return
-
-    h_is_q = h < Hq
-    h_idx = h if h_is_q else h - Hq
-
-    # Select pointers
-    stride_b = tl.where(h_is_q, stride_qb, tl.where(HAS_K, stride_kb, 0))
-    stride_t = tl.where(h_is_q, stride_qt, tl.where(HAS_K, stride_kt, 0))
-    stride_h = tl.where(h_is_q, stride_qh, tl.where(HAS_K, stride_kh, 0))
-    stride_d = tl.where(h_is_q, stride_qd, tl.where(HAS_K, stride_kd, 0))
-    x_ptr = tl.where(h_is_q, q_ptr, tl.where(HAS_K, k_ptr, 0))
-    
-    stride_ob = tl.where(h_is_q, stride_qob, tl.where(HAS_K, stride_kob, 0))
-    stride_oh = tl.where(h_is_q, stride_qoh, tl.where(HAS_K, stride_koh, 0))
-    stride_ot = tl.where(h_is_q, stride_qot, tl.where(HAS_K, stride_kot, 0))
-    stride_od = tl.where(h_is_q, stride_qod, tl.where(HAS_K, stride_kod, 0))
-    out_ptr = tl.where(h_is_q, q_out_ptr, tl.where(HAS_K, k_out_ptr, 0))
 
     t_off = r * BLOCK_T
     d_off = pid_d * BLOCK_D
@@ -84,71 +79,168 @@
     d_mask = d_rng < D
     td_mask = t_mask[:, None] & d_mask[None, :]
 
-    # Load x[b, t, h_idx, d]
-    x_base = b * stride_b + h_idx * stride_h
-    x_offsets = x_base + t_rng[:, None] * stride_t + d_rng[None, :] * stride_d
-    x_tile = tl.load(x_ptr + x_offsets, mask=td_mask, other=0.0)
-
-    # Load x at mirrored position for rotate_half
+    # Load position indices (broadcast per t column)
+    pos_off = b * stride_pb + t_rng * stride_pt
+    pos_t_vals = tl.load(pos_t + pos_off, mask=t_mask, other=0)
+    pos_h_vals = tl.load(pos_h + pos_off, mask=t_mask, other=0)
+    pos_w_vals = tl.load(pos_w + pos_off, mask=t_mask, other=0)
+
+    # Axis mask for each d column (independent of t)
+    d_first = tl.where(d_rng < half, d_rng, d_rng - half)
+    # axis_t[d] = d_first < s0
+    # axis_h[d] = s0 <= d_first < s0+s1
+    # axis_w[d] = d_first >= s0+s1
+    axis_t = d_first < s0
+    axis_h = (d_first >= s0) & (d_first < s0 + s1)
+    # axis_w = ~axis_t & ~axis_h (implied)
+
+    # Select position: for each (t, d), which of pos_t/pos_h/pos_w to use
+    # axis_t/axis_h are (BLOCK_D,) vectors, extend to (BLOCK_T, BLOCK_D)
+    pos_sel = tl.where(
+        axis_t[None, :],
+        pos_t_vals[:, None],
+        tl.where(axis_h[None, :], pos_h_vals[:, None], pos_w_vals[:, None])
+    )
+
+    # Load cos/sin from cache using selected position
+    # cache is contiguous (max_pos, D): offset = pos * D + d
+    cos_sin_off = pos_sel * stride_ccb + d_rng[None, :] * stride_ccd
+    cos_tile = tl.load(cos_cache + cos_sin_off, mask=td_mask, other=0.0)
+    sin_tile = tl.load(sin_cache + cos_sin_off, mask=td_mask, other=0.0)
+
+    # --- Q RoPE ---
+    q_base = b * stride_qb + h * stride_qh
+    q_offsets = q_base + t_rng[:, None] * stride_qt + d_rng[None, :] * stride_qd
+    q_tile = tl.load(q_ptr + q_offsets, mask=td_mask, other=0.0)
+
+    # Mirror d for rotate_half
     d_mir = tl.w

... (8826 more chars)
args
{
  "content": "<11263 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
The fused approach with `tl.where` on pointers won't compile in Triton. Let me go back to separate kernels but optimize the inner loop properly. The key bottleneck is the cos/sin cache access pattern.
assistant
in 53293out 4002cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python check.py 2>&1",
  "description": "Correctness check",
  "timeout": 120000
}
tool
stdout (5 chars)
PASS
assistant
in 57319out 93cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python benchmark.py 2>&1",
  "description": "Run benchmark",
  "timeout": 300000
}
tool
stdout (893 chars)
shape=0 variant=eager tflops=0.180 gbps=257.848 ms=0.350
shape=0 variant=compiled tflops=0.482 gbps=692.299 ms=0.130
shape=0 variant=solution tflops=0.565 gbps=811.016 ms=0.111
shape=0 solution_peak_fraction=0.4506
shape=1 variant=eager tflops=0.180 gbps=262.871 ms=0.559
shape=1 variant=compiled tflops=0.451 gbps=658.779 ms=0.223
shape=1 variant=solution tflops=0.595 gbps=868.860 ms=0.169
shape=1 solution_peak_fraction=0.4827
shape=2 variant=eager tflops=0.073 gbps=114.560 ms=0.193
shape=2 variant=compiled tflops=0.170 gbps=265.285 ms=0.083
shape=2 variant=solution tflops=0.292 gbps=455.636 ms=0.049
shape=2 solution_peak_fraction=0.2531
shape=3 variant=eager tflops=0.168 gbps=241.480 ms=1.495
shape=3 variant=compiled tflops=0.464 gbps=665.633 ms=0.542
shape=3 variant=solution tflops=0.686 gbps=984.469 ms=0.367
shape=3 solution_peak_fraction=0.5469
peak_fraction: 0.4166
RESULT: OK
assistant
in 57430out 93cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (320 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -1,7 +1,10 @@
 """Optimized Triton kernel for multi-axis RoPE pre-attention prep.
 
-Strategy: one kernel per tensor (q, k). Each block handles (BLOCK_T x BLOCK_D)
-for one (b, h) pair. Cos/sin loaded once per (t,d) via axis-selected position.
+Key optimizations:
+1. Each d maps to exactly one axis - load cos/sin ONCE per (t,d)
+2. Large D tiles (128) for coalesced loads
+3. num_warps=8 for better memory throughput
+4. Use TRITON_MAX Sunder for pointer arithmetic
 """
 import torch
 import torch.nn as nn
@@ -9,131 +12,6 @@
 import triton.language as tl
 
 
-@triton.jit
-def _mrope_kernel(
-    q_ptr,
-    k_ptr,
-    cos_cache,
-    sin_cache,
-    pos_t,
-    pos_h,
-    pos_w,
-    q_out,
-    k_out,
-    B: tl.int64,
-    T: tl.int64,
-    Hq: tl.int64,
-    D: tl.int64,
-    s0: tl.int64,
-    s1: tl.int64,
-    stride_qb, stride_qt, stride_qh, stride_qd,
-    stride_kb, stride_kt, stride_kh, stride_kd,
-    stride_pb, stride_pt,
-    stride_ccb, stride_ccd,
-    stride_qob, stride_qot, stride_qod,
-    stride_kob, stride_kot, stride_kod,
-    BLOCK_T: tl.constexpr,
-    BLOCK_D: tl.constexpr,
-):
-    """
-    Grid: (B * H * ceil(T/BLOCK_T), ceil(D/BLOCK_D))
-    where H = Hq for q pass, Hkv for k pass.
-    
-    Actually this is a truly fused kernel: grid_0 over (b, h_or_hkv, t_tile),
-    grid_1 over d_tile. Each program computes RoPE for both q and k if applicable.
-    
-    Wait, q has Hq heads, k has Hkv heads. Different H means we can't simply fuse (b,h).
-    Let's keep things simple: each grid_0 program handles (b, h, t_tile), 
-    and within the kernel we compute for the appropriate tensor.
-    
-    We'll just use separate launches with shared code via constexpr HAS_KV flag.
-    Actually simpler: just two kernel calls, same kernel, different H and pointers.
-    """
-    pid_t = tl.program_id(0)  # combined (b * H + h) * R + r
-    pid_d = tl.program_id(1)  # D tile
-
-    R = tl.cdiv(T, BLOCK_T)
-    D_tiles = tl.cdiv(D, BLOCK_D)
-
-    # Total heads depends on which tensor we're processing.
-    # We pass which_h_total to decide decomposition.
-    # Simplify: assume grid_0 = (B * H_total * R,) where H_total comes from
-    # the first argument.
-    H_total = Hq  # set per-caller
-    
-    bh = pid_t // R
-    r = pid_t % R
-    b = bh // H_total
-    h = bh % H_total
-
-    if b >= B or pid_d >= D_tiles:
-        return
-
-    t_off = r * BLOCK_T
-    d_off = pid_d * BLOCK_D
-    half = D // 2
-
-    t_rng = t_off + tl.arange(0, BLOCK_T)
-    d_rng = d_off + tl.arange(0, BLOCK_D)
-    t_mask = t_rng < T
-    d_mask = d_rng < D
-    td_mask = t_mask[:, None] & d_mask[None, :]
-
-    # Load position indices (broadcast per t column)
-    pos_off = b * stride_pb + t_rng * stride_pt
-    pos_t_vals = tl.load(pos_t + pos_off, mask=t_mask, other=0)
-    pos_h_vals = tl.load(pos_h + pos_off, mask=t_mask, other=0)
-    pos_w_vals = tl.load(pos_w + pos_off, mask=t_mask, other=0)
-
-    # Axis mask for each d column (independent of t)
-    d_first = tl.where(d_rng < half, d_rng, d_rng - half)
-    # axis_t[d] = d_first < s0
-    # axis_h[d] = s0 <= d_first < s0+s1
-    # axis_w[d] = d_first >= s0+s1
-    axis_t = d_first < s0
-    axis_h = (d_first >= s0) & (d_first < s0 + s1)
-    # axis_w = ~axis_t & ~axis_h (implied)
-
-    # Select position: for each (t, d), which of pos_t/pos_h/pos_w to use
-    # axis_t/axis_h are (BLOCK_D,) vectors, extend to (BLOCK_T, BLOCK_D)
-    pos_sel = tl.where(
-        axis_t[None, :],
-        pos_t_vals[:, None],
-        tl.where(axis_h[None, :], pos_h_vals[:, None], pos_w_vals[:, None])
-    )
-
-    # Load cos/sin from cache using selected position
-    # cache is contiguous (max_pos, D): offset = pos * D + d
-    cos_sin_off = pos_sel * stride_ccb + d_rng[None, :] * stride_ccd
-    cos_tile = tl.load(cos_cache + cos_sin_off, mask=td_mask, other=0.0)
-    sin_tile = tl.load(sin_cache + cos_sin_off, mask=td_mask, other=0.0)
-
-    # --- Q RoPE ---
-    q_base = b * stride_qb + h * stride_qh
-    q_offsets = q_base + t_rng[:, None] * stride_qt + d_rng[None, :] * stride_qd
-    q_tile = tl.load(q_ptr + q_offsets, mask=td_mask, other=0.0)
-
-    # Mirror d for rotate_half
-    d_mir = tl.where(d_rng < half, d_rng + half, d_rng - half)
-    q_mir_offsets = q_base + t_rng[:, None] * stride_qt + d_mir[None, :] * stride_qd
-    q_mir = tl.load(q_ptr + q_mir_offsets, mask=td_mask, other=0.0)
-    q_rot_half = tl.where(d_rng[None, :] < half, -q_mir, q_mir)
-
-    q_result = q_tile * cos_tile + q_rot_half * sin_tile
-
-    # Store q output (B, H, T, D)
-    q_out_base = b * stride_qob
-    q_out_off = q_out_base + h * q.stride(1).to(tl.int64) * 0 + t_rng[:, None] * stride_qot + d_rng[None, :] * stride_qod
-    # Wait, q.stride(1) is T stride in OUTPUT layout (B, H, T, D). Output strides are different.
-    tl.store(q_out + q_out_base + h * q_out.stride(1) + t_rng[:, None] * stride_qot + d_rng[None, :] * stride_qod, 
-             q_result, mask=td_mask)
-
-    # --- K RoPE (if this kernel also handles k) ---
-    # We'll vectorize over both by making K a separate launch for now.
-    pass  # handled by separate kernel call
-
-
-# Better to have one simple kernel and call it twice. Let me simplify:
 @triton.jit
 def _rope_kernel(
     x_ptr,
@@ -164,78 +42,77 @@
     BLOCK_T: tl.constexpr,
     BLOCK_D: tl.constexpr,
 ):
-    """
-    Grid: (B * H * ceil(T/BLOCK_T), ceil(D/BLOCK_D))
-    """
+    """2D grid: (B*H*ceil(T/BLOCK_T), ceil(D/BLOCK_D))"""
     pid = tl.program_id(0)
     pid_d = tl.program_id(1)
 
     R = tl.cdiv(T, BLOCK_T)
     D_tiles = tl.cdiv(D, BLOCK_D)
-    total_bh = B * H
 
     bh = pid // R
     r = pid % R
     b = bh // H
     h = bh % H
 
-    if bh >= total_bh or pid_d >= D_tiles:
+    if b >= B or pid_d >= D_tiles:
         return
 
     t_off = r

... (5715 more chars)
args
{
  "content": "<6472 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
Hmm, slightly worse. The previous version with BLOCK_T=16, BLOCK_D=64 was better. Let me go back to that but with further optimizations. The issue is likely the `d_first` computation with scalar operations. Let me try larger BLOCK_D and tune more aggressively:
assistant
in 57993out 2416cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python check.py 2>&1 && uv run python benchmark.py 2>&1",
  "description": "Check correctness and benchmark",
  "timeout": 300000
}
tool
stdout (192 chars)
FAIL: shape 0 {'B': 1, 'T': 4096, 'Hq': 32, 'Hkv': 8, 'D': 128, 'mrope_section': (16, 24, 24), 'max_pos': 32768} seed 42 q_rot: tolerance exceeded: max_abs_diff=4.34375 (atol=0.02, rtol=0.02)
assistant
in 60429out 105cache_r 0cache_w 0
assistant
edit /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (13 lines)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -80,8 +80,8 @@
 
     # Axis determination per d (BLOCK_D,)
     d_in_first = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
-    _bt = d_in_first < s0       # (BLOCK_D,)
-    _bh = d_in_first >= s0
+    _bt = d_in_first < s0
+    _bh = (d_in_first >= s0) & (d_in_first < s0 + s1)
     
     # pos mixing: (BLOCK_T, BLOCK_D)
     pos = tl.where(_bt[None, :],
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py",
  "oldString": "<71 chars \u2014 see below>",
  "newString": "<79 chars \u2014 see below>"
}
oldString (71 chars)
    _bt = d_in_first < s0       # (BLOCK_D,)
    _bh = d_in_first >= s0
newString (79 chars)
    _bt = d_in_first < s0
    _bh = (d_in_first >= s0) & (d_in_first < s0 + s1)
tool
stdout (26 chars)
Edit applied successfully.
assistant
The bug is in the axis mask — `_bh = d_in_first >= s0` catches both height AND width. Fix:
assistant
in 60660out 292cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python check.py 2>&1",
  "description": "Correctness check after fix",
  "timeout": 120000
}
tool
stdout (5 chars)
PASS
assistant
in 60846out 86cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python benchmark.py 2>&1",
  "description": "Benchmark after fix",
  "timeout": 300000
}
tool
stdout (893 chars)
shape=0 variant=eager tflops=0.179 gbps=257.179 ms=0.351
shape=0 variant=compiled tflops=0.500 gbps=717.386 ms=0.126
shape=0 variant=solution tflops=0.486 gbps=697.520 ms=0.129
shape=0 solution_peak_fraction=0.3875
shape=1 variant=eager tflops=0.181 gbps=264.034 ms=0.557
shape=1 variant=compiled tflops=0.479 gbps=699.081 ms=0.210
shape=1 variant=solution tflops=0.524 gbps=765.164 ms=0.192
shape=1 solution_peak_fraction=0.4251
shape=2 variant=eager tflops=0.074 gbps=115.915 ms=0.191
shape=2 variant=compiled tflops=0.169 gbps=263.415 ms=0.084
shape=2 variant=solution tflops=0.246 gbps=384.962 ms=0.057
shape=2 solution_peak_fraction=0.2139
shape=3 variant=eager tflops=0.169 gbps=242.881 ms=1.487
shape=3 variant=compiled tflops=0.457 gbps=656.322 ms=0.550
shape=3 variant=solution tflops=0.611 gbps=876.396 ms=0.412
shape=3 solution_peak_fraction=0.4869
peak_fraction: 0.3619
RESULT: OK
assistant
in 60959out 76cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (261 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -1,10 +1,8 @@
 """Optimized Triton kernel for multi-axis RoPE pre-attention prep.
 
-Key optimizations:
-1. Each d maps to exactly one axis - load cos/sin ONCE per (t,d)
-2. Large D tiles (128) for coalesced loads
-3. num_warps=8 for better memory throughput
-4. Use TRITON_MAX Sunder for pointer arithmetic
+Strategy: each block handles one (b, h, t) — all of D in SRAM.
+Grid = B * H * T programs. Each program has 128 threads for D=128.
+Single cos/sin load per (t,d) via axis-selected position.
 """
 import torch
 import torch.nn as nn
@@ -39,80 +37,130 @@
     stride_outh,
     stride_outt,
     stride_outd,
-    BLOCK_T: tl.constexpr,
+    D_PADDED: tl.constexpr,
+):
+    """
+    Grid: (B * H * T,)
+    Each program loads the full D for one (b, h, t).
+    Thread idx = tid within block maps to D index.
+    D_PADDED should be a power of 2 >= D for efficient thread mapping.
+    """
+    pid = tl.program_id(0)
+    R = B * H * T
+    if pid >= R:
+        return
+
+    t = pid % T
+    bh = (pid // T) % (B * H)
+    b = bh // H
+    h = bh % H
+
+    tid = tl.program_id(0) % D_PADDED
+    d_rng = tid + tl.arange(0, D_PADDED)
+    # Actually in Triton, we use tl.arange for vector operations.
+    # The program handles all D.
+    # With 1D grid, tl.program_id(0) = pid. Each program = one (b,h,t).
+    # Threads handle D via tl.arange.
+    pass
+
+
+# Actually better to use proper Triton patterns. Let me do 1D grid with
+# td-range within each program. Triton handles this via tl.arange(0, N)
+# where N = threads per block / warps.
+
+@triton.jit
+def _rope_per_token(
+    x_ptr,
+    cos_cache,
+    sin_cache,
+    pos_t_ptr,
+    pos_h_ptr,
+    pos_w_ptr,
+    out_ptr,
+    B: tl.int64,
+    T: tl.int64,
+    H: tl.int64,
+    D: tl.int64,
+    s0: tl.int64,
+    s1: tl.int64,
+    stride_xb,
+    stride_xt,
+    stride_xh,
+    stride_xd,
+    stride_pb,
+    stride_pt,
+    stride_cachepos,
+    stride_cached,
+    stride_outb,
+    stride_outh,
+    stride_outt,
+    stride_outd,
     BLOCK_D: tl.constexpr,
 ):
-    """2D grid: (B*H*ceil(T/BLOCK_T), ceil(D/BLOCK_D))"""
+    """
+    Each program handles one (b, h, t) and processes D in tiles of BLOCK_D.
+    Total programs = B * H * T. But that's huge (1*32*4096 = 131072).
+    Each program loops over D tiles.
+    """
     pid = tl.program_id(0)
-    pid_d = tl.program_id(1)
-
-    R = tl.cdiv(T, BLOCK_T)
-    D_tiles = tl.cdiv(D, BLOCK_D)
-
-    bh = pid // R
-    r = pid % R
+
+    t = pid % T
+    bh = (pid // T) % (B * H)
     b = bh // H
     h = bh % H
 
-    if b >= B or pid_d >= D_tiles:
+    if pid >= B * H * T:
         return
 
-    t_off = r * BLOCK_T
-    d_off = pid_d * BLOCK_D
-    half_d = D // 2
-
-    # Thread-local indices
-    _range_t = tl.arange(0, BLOCK_T)
-    _range_d = tl.arange(0, BLOCK_D)
-    
-    t_rng = t_off + _range_t
-    d_rng = d_off + _range_d
-    
-    t_mask = t_rng < T
-    d_mask = d_rng < D
-    td_mask = t_mask[:, None] & d_mask[None, :]
-
-    # --- Position gathering ---
-    pos_off = b * stride_pb + t_rng * stride_pt
-    p_t = tl.load(pos_t_ptr + pos_off, mask=t_mask, other=0)
-    p_h = tl.load(pos_h_ptr + pos_off, mask=t_mask, other=0)
-    p_w = tl.load(pos_w_ptr + pos_off, mask=t_mask, other=0)
-
-    # Axis determination per d (BLOCK_D,)
-    d_in_first = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
-    _bt = d_in_first < s0
-    _bh = (d_in_first >= s0) & (d_in_first < s0 + s1)
-    
-    # pos mixing: (BLOCK_T, BLOCK_D)
-    pos = tl.where(_bt[None, :],
-                   p_t[:, None],
-                   tl.where(_bh[None, :], p_h[:, None], p_w[:, None])
-                   )
-
-    # --- Single cos/sin load per (t,d) ---
-    cache_off = pos * stride_cachepos + d_rng[None, :] * stride_cached
-    cos = tl.load(cos_cache + cache_off, mask=td_mask, other=1.0)
-    sin = tl.load(sin_cache + cache_off, mask=td_mask, other=0.0)
-
-    # --- Load x and x_mirror ---
-    x_base = b * stride_xb + h * stride_xh
-    
-    x_off = x_base + t_rng[:, None] * stride_xt + d_rng[None, :] * stride_xd
-    x = tl.load(x_ptr + x_off, mask=td_mask, other=0.0)
-
-    # Mirror index for rotate_half
-    d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
-    x_mir_off = x_base + t_rng[:, None] * stride_xt + d_mir[None, :] * stride_xd
-    x_mir = tl.load(x_ptr + x_mir_off, mask=td_mask, other=0.0)
-    x_rot = tl.where(d_rng[None, :] < half_d, -x_mir, x_mir)
-
-    # --- RoPE ---
-    out = x * cos + x_rot * sin
-
-    # --- Store (B, H, T, D) ---
-    o_base = b * stride_outb + h * stride_outh
-    o_off = o_base + t_rng[:, None] * stride_outt + d_rng[None, :] * stride_outd
-    tl.store(out_ptr + o_off, out, mask=td_mask)
+    half = D // 2
+
+    # Base offsets
+    x_base = b * stride_xb + t * stride_xt + h * stride_xh
+    out_base = b * stride_outb + h * stride_outh + t * stride_outt
+    pos_off = b * stride_pb + t * stride_pt
+
+    # Load positions (scalar or small vector)
+    pos_t_val = tl.load(pos_t_ptr + pos_off)
+    pos_h_val = tl.load(pos_h_ptr + pos_off)
+    pos_w_val = tl.load(pos_w_ptr + pos_off)
+
+    # Process D in blocks
+    d_off = 0
+    while d_off < D:
+        d_rng = d_off + tl.arange(0, BLOCK_D)
+        d_mask = d_rng < D
+
+        # Axis determination
+        d_in_first = tl.where(d_rng < half, d_rng, d_rng - half)
+        is_t = d_in_first < s0
+        is_h = (d_in_first >= s0) & (d_in_first < s0 + s1)
+
+        # Select position
+        pos_sel = tl.where(is_t, pos_t_val, tl.where(is_h, pos_h_val, pos_w_val))
+
+        # Load cos/sin
+        cos_off = cos_cache + pos_sel * stride_cachepos + d_rng * stride_cached
+        sin_off = sin_cache + pos_sel * stride_cachepos + d_rng * stride_cached
+        cos_val = tl.load(cos_off, mask=d_mask, other=1.0)
+      

... (2504 more chars)
args
{
  "content": "<7487 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
Worse than the previous version (BLOCK_T=16 was 0.422). Let me try BLOCK_T=16 again and experiment: The previous winning config was BLOCK_T=16, BLOCK_D=64, num_warps=4 at 0.422. Let me go back to that and iterate from there. The key issue: the cos/sin cache loads with variable positions are non-coalesced and dominating. Let me try a fundamentally different approach: process D=128 in one block, using all 128 threads to load the full head dimension at once.
assistant
in 61523out 2815cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python check.py 2>&1",
  "description": "Check correctness",
  "timeout": 120000
}
tool
stdout (5 chars)
PASS
assistant
in 64358out 108cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python benchmark.py 2>&1",
  "description": "Benchmark per-token approach",
  "timeout": 300000
}
tool
stdout (893 chars)
shape=0 variant=eager tflops=0.178 gbps=255.040 ms=0.354
shape=0 variant=compiled tflops=0.478 gbps=686.571 ms=0.131
shape=0 variant=solution tflops=0.321 gbps=460.516 ms=0.196
shape=0 solution_peak_fraction=0.2558
shape=1 variant=eager tflops=0.182 gbps=266.099 ms=0.552
shape=1 variant=compiled tflops=0.669 gbps=976.337 ms=0.151
shape=1 variant=solution tflops=0.327 gbps=477.140 ms=0.308
shape=1 solution_peak_fraction=0.2651
shape=2 variant=eager tflops=0.071 gbps=111.628 ms=0.198
shape=2 variant=compiled tflops=0.240 gbps=374.634 ms=0.059
shape=2 variant=solution tflops=0.160 gbps=249.306 ms=0.089
shape=2 solution_peak_fraction=0.1385
shape=3 variant=eager tflops=0.179 gbps=256.471 ms=1.408
shape=3 variant=compiled tflops=0.528 gbps=757.475 ms=0.477
shape=3 variant=solution tflops=0.331 gbps=475.597 ms=0.759
shape=3 solution_peak_fraction=0.2642
peak_fraction: 0.2232
RESULT: OK
assistant
in 64468out 95cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (265 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -1,8 +1,7 @@
 """Optimized Triton kernel for multi-axis RoPE pre-attention prep.
 
-Strategy: each block handles one (b, h, t) — all of D in SRAM.
-Grid = B * H * T programs. Each program has 128 threads for D=128.
-Single cos/sin load per (t,d) via axis-selected position.
+Winning config from prior iteration: BLOCK_T=16, BLOCK_D=64, num_warps=4.
+Now pushing for better memory throughput with autotuning.
 """
 import torch
 import torch.nn as nn
@@ -10,6 +9,19 @@
 import triton.language as tl
 
 
+@triton.autotune(
+    configs=[
+        triton.Config({"BLOCK_T": 16, "BLOCK_D": 64}, num_warps=4),
+        triton.Config({"BLOCK_T": 16, "BLOCK_D": 64}, num_warps=8),
+        triton.Config({"BLOCK_T": 32, "BLOCK_D": 64}, num_warps=4),
+        triton.Config({"BLOCK_T": 32, "BLOCK_D": 32}, num_warps=4),
+        triton.Config({"BLOCK_T": 64, "BLOCK_D": 32}, num_warps=4),
+        triton.Config({"BLOCK_T": 64, "BLOCK_D": 32}, num_warps=8),
+        triton.Config({"BLOCK_T": 8, "BLOCK_D": 64}, num_warps=2),
+        triton.Config({"BLOCK_T": 8, "BLOCK_D": 64}, num_warps=4),
+    ],
+    key=["B", "T", "H", "D"],
+)
 @triton.jit
 def _rope_kernel(
     x_ptr,
@@ -37,130 +49,70 @@
     stride_outh,
     stride_outt,
     stride_outd,
-    D_PADDED: tl.constexpr,
+    BLOCK_T: tl.constexpr,
+    BLOCK_D: tl.constexpr,
 ):
-    """
-    Grid: (B * H * T,)
-    Each program loads the full D for one (b, h, t).
-    Thread idx = tid within block maps to D index.
-    D_PADDED should be a power of 2 >= D for efficient thread mapping.
-    """
     pid = tl.program_id(0)
-    R = B * H * T
-    if pid >= R:
-        return
-
-    t = pid % T
-    bh = (pid // T) % (B * H)
+    pid_d = tl.program_id(1)
+
+    R = tl.cdiv(T, BLOCK_T)
+    D_tiles = tl.cdiv(D, BLOCK_D)
+
+    bh = pid // R
+    r = pid % R
     b = bh // H
     h = bh % H
 
-    tid = tl.program_id(0) % D_PADDED
-    d_rng = tid + tl.arange(0, D_PADDED)
-    # Actually in Triton, we use tl.arange for vector operations.
-    # The program handles all D.
-    # With 1D grid, tl.program_id(0) = pid. Each program = one (b,h,t).
-    # Threads handle D via tl.arange.
-    pass
-
-
-# Actually better to use proper Triton patterns. Let me do 1D grid with
-# td-range within each program. Triton handles this via tl.arange(0, N)
-# where N = threads per block / warps.
-
-@triton.jit
-def _rope_per_token(
-    x_ptr,
-    cos_cache,
-    sin_cache,
-    pos_t_ptr,
-    pos_h_ptr,
-    pos_w_ptr,
-    out_ptr,
-    B: tl.int64,
-    T: tl.int64,
-    H: tl.int64,
-    D: tl.int64,
-    s0: tl.int64,
-    s1: tl.int64,
-    stride_xb,
-    stride_xt,
-    stride_xh,
-    stride_xd,
-    stride_pb,
-    stride_pt,
-    stride_cachepos,
-    stride_cached,
-    stride_outb,
-    stride_outh,
-    stride_outt,
-    stride_outd,
-    BLOCK_D: tl.constexpr,
-):
-    """
-    Each program handles one (b, h, t) and processes D in tiles of BLOCK_D.
-    Total programs = B * H * T. But that's huge (1*32*4096 = 131072).
-    Each program loops over D tiles.
-    """
-    pid = tl.program_id(0)
-
-    t = pid % T
-    bh = (pid // T) % (B * H)
-    b = bh // H
-    h = bh % H
-
-    if pid >= B * H * T:
+    if b >= B or pid_d >= D_tiles:
         return
 
-    half = D // 2
-
-    # Base offsets
-    x_base = b * stride_xb + t * stride_xt + h * stride_xh
-    out_base = b * stride_outb + h * stride_outh + t * stride_outt
-    pos_off = b * stride_pb + t * stride_pt
-
-    # Load positions (scalar or small vector)
-    pos_t_val = tl.load(pos_t_ptr + pos_off)
-    pos_h_val = tl.load(pos_h_ptr + pos_off)
-    pos_w_val = tl.load(pos_w_ptr + pos_off)
-
-    # Process D in blocks
-    d_off = 0
-    while d_off < D:
-        d_rng = d_off + tl.arange(0, BLOCK_D)
-        d_mask = d_rng < D
-
-        # Axis determination
-        d_in_first = tl.where(d_rng < half, d_rng, d_rng - half)
-        is_t = d_in_first < s0
-        is_h = (d_in_first >= s0) & (d_in_first < s0 + s1)
-
-        # Select position
-        pos_sel = tl.where(is_t, pos_t_val, tl.where(is_h, pos_h_val, pos_w_val))
-
-        # Load cos/sin
-        cos_off = cos_cache + pos_sel * stride_cachepos + d_rng * stride_cached
-        sin_off = sin_cache + pos_sel * stride_cachepos + d_rng * stride_cached
-        cos_val = tl.load(cos_off, mask=d_mask, other=1.0)
-        sin_val = tl.load(sin_off, mask=d_mask, other=0.0)
-
-        # Load x and x_mirror
-        x_off = x_ptr + x_base + d_rng * stride_xd
-        x_val = tl.load(x_off, mask=d_mask, other=0.0)
-
-        d_mir = tl.where(d_rng < half, d_rng + half, d_rng - half)
-        x_mir_off = x_ptr + x_base + d_mir * stride_xd
-        x_mir_val = tl.load(x_mir_off, mask=d_mask, other=0.0)
-        x_rot = tl.where(d_rng < half, -x_mir_val, x_mir_val)
-
-        # RoPE
-        out_val = x_val * cos_val + x_rot * sin_val
-
-        # Store
-        out_off = out_ptr + out_base + d_rng * stride_outd
-        tl.store(out_off, out_val, mask=d_mask)
-
-        d_off += BLOCK_D
+    t_off = r * BLOCK_T
+    d_off = pid_d * BLOCK_D
+    half_d = D // 2
+
+    t_rng = t_off + tl.arange(0, BLOCK_T)
+    d_rng = d_off + tl.arange(0, BLOCK_D)
+    t_mask = t_rng < T
+    d_mask = d_rng < D
+    td_mask = t_mask[:, None] & d_mask[None, :]
+
+    # Position indices
+    pos_off = b * stride_pb + t_rng * stride_pt
+    p_t = tl.load(pos_t_ptr + pos_off, mask=t_mask, other=0)
+    p_h = tl.load(pos_h_ptr + pos_off, mask=t_mask, other=0)
+    p_w = tl.load(pos_w_ptr + pos_off, mask=t_mask, other=0)
+
+    # Axis per d
+    d_in_first = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
+    _bt = d_in_first < s0
+    _bh = (d_in_first >= s0) & (d_in_first < s0 + s1)
+
+    # Select position per (t,d)
+    pos_sel = tl.where(_bt[None, :], p_t[:, None],
+                 tl.where(_bh[N

... (2767 more chars)
args
{
  "content": "<6623 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
Much worse — the per-token approach with grid = B*H*T creates too many kernel launches. The 2D tiling approach was better. Let me go back to the winning config (BLOCK_T=16, BLOCK_D=64) and think about what else can be optimized. The fundamental bottleneck is that cos/sin cache access is __completely random__ per (t,d) pair since each token has different position indices. The best we can do is 2 cache loads per (t,d). Let me return to the 2D tiling approach and push harder on the kernel config:
assistant
in 65033out 2590cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (306 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -1,7 +1,8 @@
 """Optimized Triton kernel for multi-axis RoPE pre-attention prep.
 
-Winning config from prior iteration: BLOCK_T=16, BLOCK_D=64, num_warps=4.
-Now pushing for better memory throughput with autotuning.
+Strategy: single kernel handles both q and k. Each program covers one (b, h_q_or_k, t_tile, d_tile).
+By processing q-heads first then k-heads in the same kernel, we share code and
+potentially benefit from SM occupancy.
 """
 import torch
 import torch.nn as nn
@@ -9,21 +10,10 @@
 import triton.language as tl
 
 
-@triton.autotune(
-    configs=[
-        triton.Config({"BLOCK_T": 16, "BLOCK_D": 64}, num_warps=4),
-        triton.Config({"BLOCK_T": 16, "BLOCK_D": 64}, num_warps=8),
-        triton.Config({"BLOCK_T": 32, "BLOCK_D": 64}, num_warps=4),
-        triton.Config({"BLOCK_T": 32, "BLOCK_D": 32}, num_warps=4),
-        triton.Config({"BLOCK_T": 64, "BLOCK_D": 32}, num_warps=4),
-        triton.Config({"BLOCK_T": 64, "BLOCK_D": 32}, num_warps=8),
-        triton.Config({"BLOCK_T": 8, "BLOCK_D": 64}, num_warps=2),
-        triton.Config({"BLOCK_T": 8, "BLOCK_D": 64}, num_warps=4),
-    ],
-    key=["B", "T", "H", "D"],
-)
+# Kernel for one tensor: q or k.
+# Uses num_stages for async load pipeline (Blackwell feature).
 @triton.jit
-def _rope_kernel(
+def _rope_tensor(
     x_ptr,
     cos_cache,
     sin_cache,
@@ -37,18 +27,10 @@
     D: tl.int64,
     s0: tl.int64,
     s1: tl.int64,
-    stride_xb,
-    stride_xt,
-    stride_xh,
-    stride_xd,
-    stride_pb,
-    stride_pt,
-    stride_cachepos,
-    stride_cached,
-    stride_outb,
-    stride_outh,
-    stride_outt,
-    stride_outd,
+    stride_xb, stride_xt, stride_xh, stride_xd,
+    stride_pb, stride_pt,
+    stride_ccb, stride_ccd,
+    stride_ob, stride_oh, stride_ot, stride_od,
     BLOCK_T: tl.constexpr,
     BLOCK_D: tl.constexpr,
 ):
@@ -70,83 +52,193 @@
     d_off = pid_d * BLOCK_D
     half_d = D // 2
 
-    t_rng = t_off + tl.arange(0, BLOCK_T)
-    d_rng = d_off + tl.arange(0, BLOCK_D)
+    _rt = tl.arange(0, BLOCK_T)
+    _rd = tl.arange(0, BLOCK_D)
+    t_rng = t_off + _rt
+    d_rng = d_off + _rd
     t_mask = t_rng < T
     d_mask = d_rng < D
     td_mask = t_mask[:, None] & d_mask[None, :]
 
-    # Position indices
-    pos_off = b * stride_pb + t_rng * stride_pt
-    p_t = tl.load(pos_t_ptr + pos_off, mask=t_mask, other=0)
-    p_h = tl.load(pos_h_ptr + pos_off, mask=t_mask, other=0)
-    p_w = tl.load(pos_w_ptr + pos_off, mask=t_mask, other=0)
-
-    # Axis per d
-    d_in_first = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
-    _bt = d_in_first < s0
-    _bh = (d_in_first >= s0) & (d_in_first < s0 + s1)
-
-    # Select position per (t,d)
-    pos_sel = tl.where(_bt[None, :], p_t[:, None],
-                 tl.where(_bh[None, :], p_h[:, None], p_w[:, None]))
-
-    # Cos/sin from cache (ONE load per axis position)
-    cache_off = pos_sel * stride_cachepos + d_rng[None, :] * stride_cached
-    cos = tl.load(cos_cache + cache_off, mask=td_mask, other=1.0)
-    sin = tl.load(sin_cache + cache_off, mask=td_mask, other=0.0)
-
-    # x[b, t, h, d]
-    x_base = b * stride_xb + h * stride_xh
-    x_off = x_base + t_rng[:, None] * stride_xt + d_rng[None, :] * stride_xd
-    x = tl.load(x_ptr + x_off, mask=td_mask, other=0.0)
-
-    # x mirror for rotate_half
+    # --- Stage 1: Load positions ---
+    po = b * stride_pb + t_rng * stride_pt
+    p_t = tl.load(pos_t_ptr + po, mask=t_mask, other=0)
+    p_h = tl.load(pos_h_ptr + po, mask=t_mask, other=0)
+    p_w = tl.load(pos_w_ptr + po, mask=t_mask, other=0)
+
+    # --- Stage 2: Axis select + cos/sin ---
+    d_f = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
+    _bt = d_f < s0
+    _bh = (d_f >= s0) & (d_f < s0 + s1)
+    ps = tl.where(_bt[None, :], p_t[:, None],
+             tl.where(_bh[None, :], p_h[:, None], p_w[:, None]))
+
+    co = ps * stride_ccb + d_rng[None, :] * stride_ccd
+    cos = tl.load(cos_cache + co, mask=td_mask, other=1.0)
+    sin = tl.load(sin_cache + co, mask=td_mask, other=0.0)
+
+    # --- Stage 3: Load x + x_mirror, compute, store ---
+    xb = b * stride_xb + h * stride_xh
+    xo = xb + t_rng[:, None] * stride_xt + d_rng[None, :] * stride_xd
+    x = tl.load(x_ptr + xo, mask=td_mask, other=0.0)
+
     d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
-    x_mir_off = x_base + t_rng[:, None] * stride_xt + d_mir[None, :] * stride_xd
-    x_mir = tl.load(x_ptr + x_mir_off, mask=td_mask, other=0.0)
-    x_rot = tl.where(d_rng[None, :] < half_d, -x_mir, x_mir)
-
-    out = x * cos + x_rot * sin
-
-    # Store to (B, H, T, D)
-    out_base = b * stride_outb + h * stride_outh
-    out_off = out_base + t_rng[:, None] * stride_outt + d_rng[None, :] * stride_outd
-    tl.store(out_ptr + out_off, out, mask=td_mask)
-
+    xmo = xb + t_rng[:, None] * stride_xt + d_mir[None, :] * stride_xd
+    xm = tl.load(x_ptr + xmo, mask=td_mask, other=0.0)
+    xr = tl.where(d_rng[None, :] < half_d, -xm, xm)
+
+    out = x * cos + xr * sin
+
+    ob = b * stride_ob + h * stride_oh
+    oo = ob + t_rng[:, None] * stride_ot + d_rng[None, :] * stride_od
+    tl.store(out_ptr + oo, out, mask=td_mask)
+
+
+# Unified kernel: each program knows if it's processing a q-head or k-head.
+# Grid_0 = B * (Hq + Hkv) * ceil(T/BLOCK_T), Grid_1 = ceil(D/BLOCK_D)
+@triton.jit
+def _rope_unified(
+    q_ptr, k_ptr,
+    cos_cache, sin_cache,
+    pos_t_ptr, pos_h_ptr, pos_w_ptr,
+    q_out_ptr, k_out_ptr,
+    B: tl.int64,
+    T: tl.int64,
+    Hq: tl.int64,
+    Hkv: tl.int64,
+    D: tl.int64,
+    s0: tl.int64,
+    s1: tl.int64,
+    stride_qb, stride_qt, stride_qh, stride_qd,
+    stride_kb, stride_kt, stride_kh, stride_kd,
+    stride_pb, stride_pt,
+    stride_ccb, stride_ccd,
+    stride_qob, stride_qot, stride_qod,
+    stride_kob, stride_kot, stride_kod

... (5401 more chars)
args
{
  "content": "<9706 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
The autotune will have issues with grid computation depending on BLOCK_T. Let me take a more direct approach — the previous winning config was BLOCK_T=16, BLOCK_D=64. Let me focus on real optimizations: 1. Merge q+k into one kernel to halve the cos/sin cache loads 2. Use `num_stages` for async memory on Blackwell 3. Try different configurations empirically
assistant
in 67644out 3572cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (282 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -1,8 +1,10 @@
 """Optimized Triton kernel for multi-axis RoPE pre-attention prep.
 
-Strategy: single kernel handles both q and k. Each program covers one (b, h_q_or_k, t_tile, d_tile).
-By processing q-heads first then k-heads in the same kernel, we share code and
-potentially benefit from SM occupancy.
+Unified kernel: grid_0 = B * (Hq + Hkv) * ceil(T/BLOCK_T), grid_1 = ceil(D/BLOCK_D).
+Each program handles one (b, h_combined, t_tile, d_tile).
+head index < Hq -> process q; head index >= Hq -> process k.
+
+No conditional branching on head type — instead we use tl.where for all operations.
 """
 import torch
 import torch.nn as nn
@@ -10,92 +12,6 @@
 import triton.language as tl
 
 
-# Kernel for one tensor: q or k.
-# Uses num_stages for async load pipeline (Blackwell feature).
-@triton.jit
-def _rope_tensor(
-    x_ptr,
-    cos_cache,
-    sin_cache,
-    pos_t_ptr,
-    pos_h_ptr,
-    pos_w_ptr,
-    out_ptr,
-    B: tl.int64,
-    T: tl.int64,
-    H: tl.int64,
-    D: tl.int64,
-    s0: tl.int64,
-    s1: tl.int64,
-    stride_xb, stride_xt, stride_xh, stride_xd,
-    stride_pb, stride_pt,
-    stride_ccb, stride_ccd,
-    stride_ob, stride_oh, stride_ot, stride_od,
-    BLOCK_T: tl.constexpr,
-    BLOCK_D: tl.constexpr,
-):
-    pid = tl.program_id(0)
-    pid_d = tl.program_id(1)
-
-    R = tl.cdiv(T, BLOCK_T)
-    D_tiles = tl.cdiv(D, BLOCK_D)
-
-    bh = pid // R
-    r = pid % R
-    b = bh // H
-    h = bh % H
-
-    if b >= B or pid_d >= D_tiles:
-        return
-
-    t_off = r * BLOCK_T
-    d_off = pid_d * BLOCK_D
-    half_d = D // 2
-
-    _rt = tl.arange(0, BLOCK_T)
-    _rd = tl.arange(0, BLOCK_D)
-    t_rng = t_off + _rt
-    d_rng = d_off + _rd
-    t_mask = t_rng < T
-    d_mask = d_rng < D
-    td_mask = t_mask[:, None] & d_mask[None, :]
-
-    # --- Stage 1: Load positions ---
-    po = b * stride_pb + t_rng * stride_pt
-    p_t = tl.load(pos_t_ptr + po, mask=t_mask, other=0)
-    p_h = tl.load(pos_h_ptr + po, mask=t_mask, other=0)
-    p_w = tl.load(pos_w_ptr + po, mask=t_mask, other=0)
-
-    # --- Stage 2: Axis select + cos/sin ---
-    d_f = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
-    _bt = d_f < s0
-    _bh = (d_f >= s0) & (d_f < s0 + s1)
-    ps = tl.where(_bt[None, :], p_t[:, None],
-             tl.where(_bh[None, :], p_h[:, None], p_w[:, None]))
-
-    co = ps * stride_ccb + d_rng[None, :] * stride_ccd
-    cos = tl.load(cos_cache + co, mask=td_mask, other=1.0)
-    sin = tl.load(sin_cache + co, mask=td_mask, other=0.0)
-
-    # --- Stage 3: Load x + x_mirror, compute, store ---
-    xb = b * stride_xb + h * stride_xh
-    xo = xb + t_rng[:, None] * stride_xt + d_rng[None, :] * stride_xd
-    x = tl.load(x_ptr + xo, mask=td_mask, other=0.0)
-
-    d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
-    xmo = xb + t_rng[:, None] * stride_xt + d_mir[None, :] * stride_xd
-    xm = tl.load(x_ptr + xmo, mask=td_mask, other=0.0)
-    xr = tl.where(d_rng[None, :] < half_d, -xm, xm)
-
-    out = x * cos + xr * sin
-
-    ob = b * stride_ob + h * stride_oh
-    oo = ob + t_rng[:, None] * stride_ot + d_rng[None, :] * stride_od
-    tl.store(out_ptr + oo, out, mask=td_mask)
-
-
-# Unified kernel: each program knows if it's processing a q-head or k-head.
-# Grid_0 = B * (Hq + Hkv) * ceil(T/BLOCK_T), Grid_1 = ceil(D/BLOCK_D)
 @triton.jit
 def _rope_unified(
     q_ptr, k_ptr,
@@ -113,8 +29,8 @@
     stride_kb, stride_kt, stride_kh, stride_kd,
     stride_pb, stride_pt,
     stride_ccb, stride_ccd,
-    stride_qob, stride_qot, stride_qod,
-    stride_kob, stride_kot, stride_kod,
+    stride_qob, stride_qoh, stride_qot, stride_qod,
+    stride_kob, stride_koh, stride_kot, stride_kod,
     BLOCK_T: tl.constexpr,
     BLOCK_D: tl.constexpr,
 ):
@@ -128,7 +44,7 @@
     bh = pid // R
     r = pid % R
     b = bh // total_h
-    h = bh % total_h
+    h_combined = bh % total_h
 
     if b >= B or pid_d >= D_tiles:
         return
@@ -145,60 +61,60 @@
     d_mask = d_rng < D
     td_mask = t_mask[:, None] & d_mask[None, :]
 
-    # Positions (broadcast across q and k since same pos)
+    # --- Load positions (shared for q and k since pos is per-token) ---
     po = b * stride_pb + t_rng * stride_pt
     p_t = tl.load(pos_t_ptr + po, mask=t_mask, other=0)
     p_h = tl.load(pos_h_ptr + po, mask=t_mask, other=0)
     p_w = tl.load(pos_w_ptr + po, mask=t_mask, other=0)
 
-    # Axis select
+    # --- Axis select per d ---
     d_f = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
-    _bt = d_f < s0
-    _bh = (d_f >= s0) & (d_f < s0 + s1)
-    ps = tl.where(_bt[None, :], p_t[:, None],
-             tl.where(_bh[None, :], p_h[:, None], p_w[:, None]))
-
-    co = ps * stride_ccb + d_rng[None, :] * stride_ccd
-    cos = tl.load(cos_cache + co, mask=td_mask, other=1.0)
-    sin = tl.load(sin_cache + co, mask=td_mask, other=0.0)
-
-    # Determine if this is a q-head or k-head, and apply RoPE accordingly
-    is_q = h < Hq
-    h_idx = tl.where(is_q, h, h - Hq)
-
-    # Q processing
-    if is_q:
-        qb = b * stride_qb + h * stride_qh
-        qo = qb + t_rng[:, None] * stride_qt + d_rng[None, :] * stride_qd
-        qx = tl.load(q_ptr + qo, mask=td_mask, other=0.0)
-
-        d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
-        qmo = qb + t_rng[:, None] * stride_qt + d_mir[None, :] * stride_qd
-        qm = tl.load(q_ptr + qmo, mask=td_mask, other=0.0)
-        qr = tl.where(d_rng[None, :] < half_d, -qm, qm)
-
-        qout = qx * cos + qr * sin
-
-        qob = b * stride_qob
-        qoo = qob + h * stride_qot * 0 + t_rng[:, None] * stride_qot + d_rng[None, :] * stride_qod
-        Wait this is wrong. Let me use actual stride values.
-        # Out stride for (B, H, T, D): stride_qob = T*D*2, stride for h = D*2, stride for t = D*2, stride for d = 2
-    

... (4832 more chars)
args
{
  "content": "<6864 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
Let me take a step back and think about this more carefully. The unified kernel approach with no conditional branching is key. Let me write the unified kernel properly where q and k heads are interleaved:
assistant
in 71264out 2539cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (206 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -1,10 +1,7 @@
 """Optimized Triton kernel for multi-axis RoPE pre-attention prep.
 
-Unified kernel: grid_0 = B * (Hq + Hkv) * ceil(T/BLOCK_T), grid_1 = ceil(D/BLOCK_D).
-Each program handles one (b, h_combined, t_tile, d_tile).
-head index < Hq -> process q; head index >= Hq -> process k.
-
-No conditional branching on head type — instead we use tl.where for all operations.
+Separate kernels for q and k (pointers can't be tl.where'd in Triton).
+Each kernel: grid_0 = B*H*ceil(T/BLOCK_T), grid_1 = ceil(D/BLOCK_D).
 """
 import torch
 import torch.nn as nn
@@ -13,24 +10,32 @@
 
 
 @triton.jit
-def _rope_unified(
-    q_ptr, k_ptr,
-    cos_cache, sin_cache,
-    pos_t_ptr, pos_h_ptr, pos_w_ptr,
-    q_out_ptr, k_out_ptr,
+def _rope_kernel(
+    x_ptr,
+    cos_cache,
+    sin_cache,
+    pos_t_ptr,
+    pos_h_ptr,
+    pos_w_ptr,
+    out_ptr,
     B: tl.int64,
     T: tl.int64,
-    Hq: tl.int64,
-    Hkv: tl.int64,
+    H: tl.int64,
     D: tl.int64,
     s0: tl.int64,
     s1: tl.int64,
-    stride_qb, stride_qt, stride_qh, stride_qd,
-    stride_kb, stride_kt, stride_kh, stride_kd,
-    stride_pb, stride_pt,
-    stride_ccb, stride_ccd,
-    stride_qob, stride_qoh, stride_qot, stride_qod,
-    stride_kob, stride_koh, stride_kot, stride_kod,
+    stride_xb,
+    stride_xt,
+    stride_xh,
+    stride_xd,
+    stride_pb,
+    stride_pt,
+    stride_ccb,
+    stride_ccd,
+    stride_ob,
+    stride_oh,
+    stride_ot,
+    stride_od,
     BLOCK_T: tl.constexpr,
     BLOCK_D: tl.constexpr,
 ):
@@ -39,12 +44,11 @@
 
     R = tl.cdiv(T, BLOCK_T)
     D_tiles = tl.cdiv(D, BLOCK_D)
-    total_h = Hq + Hkv
 
     bh = pid // R
     r = pid % R
-    b = bh // total_h
-    h_combined = bh % total_h
+    b = bh // H
+    h = bh % H
 
     if b >= B or pid_d >= D_tiles:
         return
@@ -61,59 +65,62 @@
     d_mask = d_rng < D
     td_mask = t_mask[:, None] & d_mask[None, :]
 
-    # --- Load positions (shared for q and k since pos is per-token) ---
+    # Position indices
     po = b * stride_pb + t_rng * stride_pt
     p_t = tl.load(pos_t_ptr + po, mask=t_mask, other=0)
     p_h = tl.load(pos_h_ptr + po, mask=t_mask, other=0)
     p_w = tl.load(pos_w_ptr + po, mask=t_mask, other=0)
 
-    # --- Axis select per d ---
+    # Axis select per d
     d_f = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
-    is_axis_t = d_f < s0
-    is_axis_h = (d_f >= s0) & (d_f < s0 + s1)
-    pos_sel = tl.where(is_axis_t[None, :], p_t[:, None],
-                 tl.where(is_axis_h[None, :], p_h[:, None], p_w[:, None]))
+    is_t = d_f < s0
+    is_h = (d_f >= s0) & (d_f < s0 + s1)
+    pos_sel = tl.where(is_t[None, :], p_t[:, None],
+                 tl.where(is_h[None, :], p_h[:, None], p_w[:, None]))
 
-    # --- Cos/sin cache load (shared) ---
+    # Single cos/sin load
     cache_off = pos_sel * stride_ccb + d_rng[None, :] * stride_ccd
     cos = tl.load(cos_cache + cache_off, mask=td_mask, other=1.0)
     sin = tl.load(sin_cache + cache_off, mask=td_mask, other=0.0)
 
-    # --- Determine if this program handles q or k ---
-    is_q = h_combined < Hq
-    h_idx = tl.where(is_q, h_combined, h_combined - Hq)
+    # x[b, t, h, d]
+    x_base = b * stride_xb + h * stride_xh
+    x_off = x_base + t_rng[:, None] * stride_xt + d_rng[None, :] * stride_xd
+    x = tl.load(x_ptr + x_off, mask=td_mask, other=0.0)
 
-    # Select strides and pointers based on is_q
-    stride_b = tl.where(is_q, stride_qb, stride_kb)
-    stride_t = tl.where(is_q, stride_qt, stride_kt)
-    stride_h = tl.where(is_q, stride_qh, stride_kh)
-    stride_d = tl.where(is_q, stride_qd, stride_kd)
-    in_ptr = tl.where(is_q, q_ptr, k_ptr)
-
-    stride_ob = tl.where(is_q, stride_qob, stride_kob)
-    stride_oh = tl.where(is_q, stride_qoh, stride_koh)
-    stride_ot = tl.where(is_q, stride_qot, stride_kot)
-    stride_od = tl.where(is_q, stride_qod, stride_kod)
-    out_ptr = tl.where(is_q, q_out_ptr, k_out_ptr)
-
-    # Load x
-    x_base = b * stride_b + h_idx * stride_h
-    x_off = x_base + t_rng[:, None] * stride_t + d_rng[None, :] * stride_d
-    x = tl.load(in_ptr + x_off, mask=td_mask, other=0.0)
-
-    # Load x_mirror
+    # Mirror for rotate_half
     d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
-    x_mir_off = x_base + t_rng[:, None] * stride_t + d_mir[None, :] * stride_d
-    x_mir = tl.load(in_ptr + x_mir_off, mask=td_mask, other=0.0)
+    x_mir_off = x_base + t_rng[:, None] * stride_xt + d_mir[None, :] * stride_xd
+    x_mir = tl.load(x_ptr + x_mir_off, mask=td_mask, other=0.0)
     x_rot = tl.where(d_rng[None, :] < half_d, -x_mir, x_mir)
 
     # RoPE
     out = x * cos + x_rot * sin
 
-    # Store
-    out_base = b * stride_ob + h_idx * stride_oh
+    # Store to (B, H, T, D)
+    out_base = b * stride_ob + h * stride_oh
     out_off = out_base + t_rng[:, None] * stride_ot + d_rng[None, :] * stride_od
     tl.store(out_ptr + out_off, out, mask=td_mask)
+
+
+def _run_kernel(x, cos_cache, sin_cache, pos_t, pos_h, pos_w, out, H, D,
+                s0, s1, BLOCK_T, BLOCK_D, num_warps):
+    B, T = x.shape[0], x.shape[1]
+    n_t = (T + BLOCK_T - 1) // BLOCK_T
+    n_d = (D + BLOCK_D - 1) // BLOCK_D
+
+    _rope_kernel[(B * H * n_t, n_d)](
+        x, cos_cache, sin_cache, pos_t, pos_h, pos_w, out,
+        B=B, T=T, H=H, D=D, s0=s0, s1=s1,
+        stride_xb=x.stride(0), stride_xt=x.stride(1),
+        stride_xh=x.stride(2), stride_xd=x.stride(3),
+        stride_pb=pos_t.stride(0), stride_pt=pos_t.stride(1),
+        stride_ccb=cos_cache.stride(0), stride_ccd=cos_cache.stride(1),
+        stride_ob=out.stride(0), stride_oh=out.stride(1),
+        stride_ot=out.stride(2), stride_od=out.stride(3),
+        BLOCK_T=BLOCK_T, BLOCK_D=BLOCK_D,
+        num_warps=num_warps,
+    )
 
 
 def apply_mrope_torch(q, k, cos_cache, sin_cache, pos_t, p

... (1504 more chars)
args
{
  "content": "<5874 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
`tl.where` on pointers won't compile. Need separate kernels. Let me go back to what works and push optimization.
assistant
in 73823out 2232cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python check.py 2>&1",
  "description": "Check correctness",
  "timeout": 120000
}
tool
stdout (5 chars)
PASS
assistant
in 76081out 85cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (229 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -1,7 +1,9 @@
 """Optimized Triton kernel for multi-axis RoPE pre-attention prep.
 
-Separate kernels for q and k (pointers can't be tl.where'd in Triton).
-Each kernel: grid_0 = B*H*ceil(T/BLOCK_T), grid_1 = ceil(D/BLOCK_D).
+Key optimization: cos/sin depends only on (b, t, d), NOT on h.
+Grid over (B * ceil(T/BLOCK_T), ceil(D/BLOCK_D)).
+Each program loads cos/sin ONCE, then loops over all H (both q and k heads).
+This saves Hq+Hkv factor in random cache reads — critical for bandwidth.
 """
 import torch
 import torch.nn as nn
@@ -11,50 +13,45 @@
 
 @triton.jit
 def _rope_kernel(
-    x_ptr,
-    cos_cache,
-    sin_cache,
-    pos_t_ptr,
-    pos_h_ptr,
-    pos_w_ptr,
-    out_ptr,
+    q_ptr, k_ptr,
+    cos_cache, sin_cache,
+    pos_t_ptr, pos_h_ptr, pos_w_ptr,
+    q_out_ptr, k_out_ptr,
     B: tl.int64,
     T: tl.int64,
-    H: tl.int64,
+    Hq: tl.int64,
+    Hkv: tl.int64,
     D: tl.int64,
     s0: tl.int64,
     s1: tl.int64,
-    stride_xb,
-    stride_xt,
-    stride_xh,
-    stride_xd,
-    stride_pb,
-    stride_pt,
-    stride_ccb,
-    stride_ccd,
-    stride_ob,
-    stride_oh,
-    stride_ot,
-    stride_od,
+    stride_qb, stride_qt, stride_qh, stride_qd,
+    stride_kb, stride_kt, stride_kh, stride_kd,
+    stride_pb, stride_pt,
+    stride_ccb, stride_ccd,
+    stride_qob, stride_qoh, stride_qot, stride_qod,
+    stride_kob, stride_koh, stride_kot, stride_kod,
     BLOCK_T: tl.constexpr,
     BLOCK_D: tl.constexpr,
 ):
+    """
+    Grid: (B * ceil(T/BLOCK_T), ceil(D/BLOCK_D))
+    Each program handles one (b, t_tile, d_tile) and ALL heads.
+    cos/sin loaded once, then RoPE applied to each head.
+    """
     pid = tl.program_id(0)
     pid_d = tl.program_id(1)
 
     R = tl.cdiv(T, BLOCK_T)
     D_tiles = tl.cdiv(D, BLOCK_D)
 
-    bh = pid // R
     r = pid % R
-    b = bh // H
-    h = bh % H
+    b = pid // R
+    d_off = pid_d * BLOCK_D
 
     if b >= B or pid_d >= D_tiles:
         return
 
     t_off = r * BLOCK_T
-    d_off = pid_d * BLOCK_D
     half_d = D // 2
 
     _rt = tl.arange(0, BLOCK_T)
@@ -65,62 +62,65 @@
     d_mask = d_rng < D
     td_mask = t_mask[:, None] & d_mask[None, :]
 
-    # Position indices
+    # --- Load positions ---
     po = b * stride_pb + t_rng * stride_pt
     p_t = tl.load(pos_t_ptr + po, mask=t_mask, other=0)
     p_h = tl.load(pos_h_ptr + po, mask=t_mask, other=0)
     p_w = tl.load(pos_w_ptr + po, mask=t_mask, other=0)
 
-    # Axis select per d
+    # --- Axis select per d ---
     d_f = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
     is_t = d_f < s0
     is_h = (d_f >= s0) & (d_f < s0 + s1)
     pos_sel = tl.where(is_t[None, :], p_t[:, None],
                  tl.where(is_h[None, :], p_h[:, None], p_w[:, None]))
 
-    # Single cos/sin load
+    # --- Cos/sin cache (loaded ONCE per program, reused for all H) ---
     cache_off = pos_sel * stride_ccb + d_rng[None, :] * stride_ccd
     cos = tl.load(cos_cache + cache_off, mask=td_mask, other=1.0)
     sin = tl.load(sin_cache + cache_off, mask=td_mask, other=0.0)
 
-    # x[b, t, h, d]
-    x_base = b * stride_xb + h * stride_xh
-    x_off = x_base + t_rng[:, None] * stride_xt + d_rng[None, :] * stride_xd
-    x = tl.load(x_ptr + x_off, mask=td_mask, other=0.0)
-
-    # Mirror for rotate_half
-    d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
-    x_mir_off = x_base + t_rng[:, None] * stride_xt + d_mir[None, :] * stride_xd
-    x_mir = tl.load(x_ptr + x_mir_off, mask=td_mask, other=0.0)
-    x_rot = tl.where(d_rng[None, :] < half_d, -x_mir, x_mir)
-
-    # RoPE
-    out = x * cos + x_rot * sin
-
-    # Store to (B, H, T, D)
-    out_base = b * stride_ob + h * stride_oh
-    out_off = out_base + t_rng[:, None] * stride_ot + d_rng[None, :] * stride_od
-    tl.store(out_ptr + out_off, out, mask=td_mask)
-
-
-def _run_kernel(x, cos_cache, sin_cache, pos_t, pos_h, pos_w, out, H, D,
-                s0, s1, BLOCK_T, BLOCK_D, num_warps):
-    B, T = x.shape[0], x.shape[1]
-    n_t = (T + BLOCK_T - 1) // BLOCK_T
-    n_d = (D + BLOCK_D - 1) // BLOCK_D
-
-    _rope_kernel[(B * H * n_t, n_d)](
-        x, cos_cache, sin_cache, pos_t, pos_h, pos_w, out,
-        B=B, T=T, H=H, D=D, s0=s0, s1=s1,
-        stride_xb=x.stride(0), stride_xt=x.stride(1),
-        stride_xh=x.stride(2), stride_xd=x.stride(3),
-        stride_pb=pos_t.stride(0), stride_pt=pos_t.stride(1),
-        stride_ccb=cos_cache.stride(0), stride_ccd=cos_cache.stride(1),
-        stride_ob=out.stride(0), stride_oh=out.stride(1),
-        stride_ot=out.stride(2), stride_od=out.stride(3),
-        BLOCK_T=BLOCK_T, BLOCK_D=BLOCK_D,
-        num_warps=num_warps,
-    )
+    # --- Process Q heads ---
+    h = tl.arange(0, Hq)
+    # Loop over Hq heads — use scalar loop since Triton can handle it
+    h_idx = 0
+    while h_idx < Hq:
+        qb = b * stride_qb + h_idx * stride_qh
+        q_off = qb + t_rng[:, None] * stride_qt + d_rng[None, :] * stride_qd
+        qx = tl.load(q_ptr + q_off, mask=td_mask, other=0.0)
+
+        d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
+        q_mir_off = qb + t_rng[:, None] * stride_qt + d_mir[None, :] * stride_qd
+        qm = tl.load(q_ptr + q_mir_off, mask=td_mask, other=0.0)
+        qr = tl.where(d_rng[None, :] < half_d, -qm, qm)
+
+        qout = qx * cos + qr * sin
+
+        q_out_base = b * stride_qob + h_idx * stride_qoh
+        q_out_off = q_out_base + t_rng[:, None] * stride_qot + d_rng[None, :] * stride_qod
+        tl.store(q_out_ptr + q_out_off, qout, mask=td_mask)
+
+        h_idx += 1
+
+    # --- Process K heads ---
+    h_idx = 0
+    while h_idx < Hkv:
+        kb = b * stride_kb + h_idx * stride_kh
+        k_off = kb + t_rng[:, None] * stride_kt + d_rng[None, :] * stride_kd
+        kx = tl.load(k_ptr + k_off, mask=td_mask, other=0.0)
+
+    

... (2113 more chars)
args
{
  "content": "<7084 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
Now I need to push past ~0.42 peak fraction. Key insight: cos/sin are the SAME for all heads. We can compute them once per (b,t_tile,d_tile) and reuse across all H. Let me restructure the kernel:
assistant
in 76191out 2695cache_r 0cache_w 0
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python check.py 2>&1",
  "description": "Check correctness",
  "timeout": 120000
}
tool
stdout (3972 chars) — TRUNCATED
Traceback (most recent call last):
  File "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/triton/language/core.py", line 43, in wrapper
    return fn(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^
  File "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/triton/language/core.py", line 1644, in arange
    return _semantic.arange(start, end)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/triton/language/semantic.py", line 574, in arange
    raise ValueError("arange's arguments must be of type tl.constexpr")
ValueError: arange's arguments must be of type tl.constexpr

The above exception was the direct cause of the following exception:

Traceback (most recent call last):
  File "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/check.py", line 119, in <module>
    main()
  File "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/check.py", line 76, in main
    sol_out = sol_model(*inputs)
              ^^^^^^^^^^^^^^^^^^
  File "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/torch/nn/modules/module.py", line 1779, in _wrapped_call_impl
    return self._call_impl(*args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/home/infatoshi/cuda/KernelBench-Hard/.venv/lib/python3.11/site-packages/torch/nn/modules/module.py", line 1790, in _call_impl
    return forward_call(*args, **kwargs)


... (2472 more chars)
assistant
in 78848out 93cache_r 0cache_w 0
assistant
edit /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (11 lines)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -81,8 +81,6 @@
     sin = tl.load(sin_cache + cache_off, mask=td_mask, other=0.0)
 
     # --- Process Q heads ---
-    h = tl.arange(0, Hq)
-    # Loop over Hq heads — use scalar loop since Triton can handle it
     h_idx = 0
     while h_idx < Hq:
         qb = b * stride_qb + h_idx * stride_qh
args
{
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py",
  "oldString": "<138 chars \u2014 see below>",
  "newString": "<43 chars \u2014 see below>"
}
oldString (138 chars)
    # --- Process Q heads ---
    h = tl.arange(0, Hq)
    # Loop over Hq heads — use scalar loop since Triton can handle it
    h_idx = 0
newString (43 chars)
    # --- Process Q heads ---
    h_idx = 0
tool
stdout (26 chars)
Edit applied successfully.
assistant
`Hq` isn't constexpr. Let me fix — remove the unused `tl.arange(0, Hq)`:
assistant
in 80194out 174cache_r 0cache_w 0
assistant
Let me test if this compiles with the while loop:
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python check.py 2>&1",
  "description": "Check correctness with H loop",
  "timeout": 120000
}
tool
stdout (5 chars)
PASS
assistant
in 80375out 175cache_r 0cache_w 0
assistant
Wait — it passes?! Let me check: the while loop compiles but actually unrolls to iterate Hq=32 times, each with BLOCK_T=16 * BLOCK_D=64=1024 elements. That's 32*1024 = 32K bf16 loads/stores per (b,t_tile,d_tile). The cos/sin cache is only loaded once though — that's the key optimization. Let me benchmark:
assistant
bash
args
{
  "command": "cd /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope && uv run python benchmark.py 2>&1",
  "description": "Benchmark unified kernel",
  "timeout": 300000
}
tool
stdout (895 chars)
shape=0 variant=eager tflops=0.174 gbps=250.255 ms=0.361
shape=0 variant=compiled tflops=0.506 gbps=725.690 ms=0.124
shape=0 variant=solution tflops=0.663 gbps=950.672 ms=0.095
shape=0 solution_peak_fraction=0.5282
shape=1 variant=eager tflops=0.179 gbps=260.789 ms=0.564
shape=1 variant=compiled tflops=0.473 gbps=690.777 ms=0.213
shape=1 variant=solution tflops=0.752 gbps=1098.043 ms=0.134
shape=1 solution_peak_fraction=0.6100
shape=2 variant=eager tflops=0.075 gbps=117.511 ms=0.188
shape=2 variant=compiled tflops=0.170 gbps=266.358 ms=0.083
shape=2 variant=solution tflops=0.304 gbps=475.542 ms=0.047
shape=2 solution_peak_fraction=0.2642
shape=3 variant=eager tflops=0.171 gbps=245.104 ms=1.473
shape=3 variant=compiled tflops=0.465 gbps=667.523 ms=0.541
shape=3 variant=solution tflops=0.768 gbps=1102.108 ms=0.328
shape=3 solution_peak_fraction=0.6123
peak_fraction: 0.4778
RESULT: OK
assistant
in 80501out 193cache_r 0cache_w 0
assistant
write /home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
diff (151 lines — TRUNCATED)
--- a//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
+++ b//home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py
@@ -1,9 +1,7 @@
 """Optimized Triton kernel for multi-axis RoPE pre-attention prep.
 
-Key optimization: cos/sin depends only on (b, t, d), NOT on h.
-Grid over (B * ceil(T/BLOCK_T), ceil(D/BLOCK_D)).
-Each program loads cos/sin ONCE, then loops over all H (both q and k heads).
-This saves Hq+Hkv factor in random cache reads — critical for bandwidth.
+Unified kernel: cos/sin loaded once per (b, t_tile, d_tile), reused across all H.
+Tunable BLOCK_T, BLOCK_D, num_warps for each shape.
 """
 import torch
 import torch.nn as nn
@@ -33,11 +31,6 @@
     BLOCK_T: tl.constexpr,
     BLOCK_D: tl.constexpr,
 ):
-    """
-    Grid: (B * ceil(T/BLOCK_T), ceil(D/BLOCK_D))
-    Each program handles one (b, t_tile, d_tile) and ALL heads.
-    cos/sin loaded once, then RoPE applied to each head.
-    """
     pid = tl.program_id(0)
     pid_d = tl.program_id(1)
 
@@ -62,63 +55,53 @@
     d_mask = d_rng < D
     td_mask = t_mask[:, None] & d_mask[None, :]
 
-    # --- Load positions ---
+    # Positions
     po = b * stride_pb + t_rng * stride_pt
     p_t = tl.load(pos_t_ptr + po, mask=t_mask, other=0)
     p_h = tl.load(pos_h_ptr + po, mask=t_mask, other=0)
     p_w = tl.load(pos_w_ptr + po, mask=t_mask, other=0)
 
-    # --- Axis select per d ---
+    # Axis select per d
     d_f = tl.where(d_rng < half_d, d_rng, d_rng - half_d)
     is_t = d_f < s0
     is_h = (d_f >= s0) & (d_f < s0 + s1)
     pos_sel = tl.where(is_t[None, :], p_t[:, None],
                  tl.where(is_h[None, :], p_h[:, None], p_w[:, None]))
 
-    # --- Cos/sin cache (loaded ONCE per program, reused for all H) ---
+    # Cos/sin cache — loaded ONCE, reused for all heads
     cache_off = pos_sel * stride_ccb + d_rng[None, :] * stride_ccd
     cos = tl.load(cos_cache + cache_off, mask=td_mask, other=1.0)
     sin = tl.load(sin_cache + cache_off, mask=td_mask, other=0.0)
 
-    # --- Process Q heads ---
-    h_idx = 0
-    while h_idx < Hq:
-        qb = b * stride_qb + h_idx * stride_qh
-        q_off = qb + t_rng[:, None] * stride_qt + d_rng[None, :] * stride_qd
-        qx = tl.load(q_ptr + q_off, mask=td_mask, other=0.0)
+    # Rotate-half mirror indices (same for all heads)
+    d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
+    is_first_half = d_rng[None, :] < half_d
 
-        d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
-        q_mir_off = qb + t_rng[:, None] * stride_qt + d_mir[None, :] * stride_qd
-        qm = tl.load(q_ptr + q_mir_off, mask=td_mask, other=0.0)
-        qr = tl.where(d_rng[None, :] < half_d, -qm, qm)
+    # Process Q heads
+    h = 0
+    while h < Hq:
+        q_base = b * stride_qb + h * stride_qh
+        qx = tl.load(q_ptr + q_base + t_rng[:, None] * stride_qt + d_rng[None, :] * stride_qd,
+                      mask=td_mask, other=0.0)
+        qm = tl.load(q_ptr + q_base + t_rng[:, None] * stride_qt + d_mir[None, :] * stride_qd,
+                      mask=td_mask, other=0.0)
+        out = qx * cos + tl.where(is_first_half, -qm, qm) * sin
+        tl.store(q_out_ptr + b * stride_qob + h * stride_qoh + t_rng[:, None] * stride_qot + d_rng[None, :] * stride_qod,
+                 out, mask=td_mask)
+        h += 1
 
-        qout = qx * cos + qr * sin
-
-        q_out_base = b * stride_qob + h_idx * stride_qoh
-        q_out_off = q_out_base + t_rng[:, None] * stride_qot + d_rng[None, :] * stride_qod
-        tl.store(q_out_ptr + q_out_off, qout, mask=td_mask)
-
-        h_idx += 1
-
-    # --- Process K heads ---
-    h_idx = 0
-    while h_idx < Hkv:
-        kb = b * stride_kb + h_idx * stride_kh
-        k_off = kb + t_rng[:, None] * stride_kt + d_rng[None, :] * stride_kd
-        kx = tl.load(k_ptr + k_off, mask=td_mask, other=0.0)
-
-        d_mir = tl.where(d_rng < half_d, d_rng + half_d, d_rng - half_d)
-        k_mir_off = kb + t_rng[:, None] * stride_kt + d_mir[None, :] * stride_kd
-        km = tl.load(k_ptr + k_mir_off, mask=td_mask, other=0.0)
-        kr = tl.where(d_rng[None, :] < half_d, -km, km)
-
-        kout = kx * cos + kr * sin
-
-        k_out_base = b * stride_kob + h_idx * stride_koh
-        k_out_off = k_out_base + t_rng[:, None] * stride_kot + d_rng[None, :] * stride_kod
-        tl.store(k_out_ptr + k_out_off, kout, mask=td_mask)
-
-        h_idx += 1
+    # Process K heads
+    h = 0
+    while h < Hkv:
+        k_base = b * stride_kb + h * stride_kh
+        kx = tl.load(k_ptr + k_base + t_rng[:, None] * stride_kt + d_rng[None, :] * stride_kd,
+                      mask=td_mask, other=0.0)
+        km = tl.load(k_ptr + k_base + t_rng[:, None] * stride_kt + d_mir[None, :] * stride_kd,
+                      mask=td_mask, other=0.0)
+        out = kx * cos + tl.where(is_first_half, -km, km) * sin
+        tl.store(k_out_ptr + b * stride_kob + h * stride_koh + t_rng[:, None] * stride_kot + d_rng[None, :] * stride_kod,
+                 out, mask=td_mask)
+        h += 1
 
 
 def apply_mrope_torch(q, k, cos_cache, sin_cache, pos_t, pos_h, pos_w, mrope_section):
@@ -126,11 +109,18 @@
     _, _, Hkv, _ = k.shape
     s0, s1, s2 = mrope_section
 
-    BLOCK_T = 16
-    BLOCK_D = 64
-
     q_rot = torch.empty(B, Hq, T, D, dtype=q.dtype, device=q.device)
     k_rot = torch.empty(B, Hkv, T, D, dtype=k.dtype, device=k.device)
+
+    # Tunable configs — selected based on shape characteristics
+    # Larger H benefits from smaller grid => larger BLOCK_T
+    # Bandwidth-bound: want maximal memory throughput
+    if D == 64:
+        BLOCK_T, BLOCK_D, num_warps = 32, 64, 4
+    elif T <= 4096:
+        BLOCK_T, BLOCK_D, num_warps = 16, 64, 4
+    else:
+        BLOCK_T, BLOCK_D, num_warps = 16, 64, 8
 
     n_t = (T + BLOCK_T - 1) // BLOCK_T
     n_d = (D + BLOCK_D - 1) // BLOCK_D
@@ -152,7 +142,7 @@
         stride_kob=k_rot.stride(0), stride_koh=k_rot.stride(1),
         

... (185 more chars)
args
{
  "content": "<6799 chars \u2014 see diff>",
  "filePath": "/home/infatoshi/cuda/KernelBench-Hard/problems/09_fmha_preattn_mrope/solution.py"
}
tool
stdout (24 chars)
Wrote file successfully.
assistant
Excellent progress! 0.422 → 0.478 (peak fraction). The unified kernel sharing cos/sin across heads is a big win. Now let me push further with config tuning:
assistant
in 81165out 2507cache_r 0cache_w 0
assistant
in 83692out 1cache_r 0cache_w 0