Minor perf improvements to quantized mat mul shader.

[trivedivivek]

Summary: The diff includes minor performance improvements to the quantized matrix multiplication shader.

Differential Revision: D84998542

[pytorch-bot]

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❗ 1 Active SEVs

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• [ROCm][CI] Machines under the label linux.rocm.gpu.2 are undergoing maintenance.

❌ 6 New Failures, 3 Unrelated Failures

As of commit a5081fc with merge base 419727c ():

NEW FAILURES - The following jobs have failed:

• pull / test-samsung-models-linux / linux-job (gh)
  RuntimeError: Command docker exec -t 10aad1e1f53048b67a6e9bfa24b7cb3d167b296ddc2a3201e08df5eaa8c76e99 /exec failed with exit code 1
• pull / unittest-arm-backend-with-no-fvp (test_pytest_models) / linux-job (gh)
  RuntimeError: Command docker exec -t 9e8d219d96394941b862951b3d32fa85e07a97f813efc86a6e34bccce0204fd2 /exec failed with exit code 1
• pull / unittest-nxp-neutron / linux-job (gh)
  RuntimeError: Command docker exec -t a65ff105469b5bab7396629137612b14a9083302491b2d7760a3b231899a06f2 /exec failed with exit code 1
• Test CUDA Builds / export-voxtral-cuda-non-quantized / linux-job (gh)
  RuntimeError: Command docker exec -t e684044f3d5c776a3e0aa115f8c4e6162a80ff563a86133f81dcefadf20a7295 /exec failed with exit code 2
• Test CUDA Builds / export-voxtral-cuda-quantized-int4-tile-packed / linux-job (gh)
  RuntimeError: Command docker exec -t bb8b03c1a31dfc9217cb662aadc64e4169c98d081b98f8987e8e22c61e57fca3 /exec failed with exit code 2
• Test CUDA Builds / export-voxtral-cuda-quantized-int4-weight-only / linux-job (gh)
  RuntimeError: Command docker exec -t 758f00ec0193958ffc3cb2fb0ee3bc11d1f61a484d6c53596d4e06abcfb83b3d /exec failed with exit code 2

BROKEN TRUNK - The following jobs failed but were present on the merge base:

👉 Rebase onto the `viable/strict` branch to avoid these failures

• pull / android / run-emulator (gh) (trunk failure)
  The process '/usr/bin/sh' failed with exit code 255
• pull / unittest / linux / linux-job (gh) (trunk failure)
• pull / unittest-editable / linux / linux-job (gh) (trunk failure)

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[meta-codesync]

@trivedivivek has exported this pull request. If you are a Meta employee, you can view the originating Diff in D84998542.

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