x86: use simd::intrinsics for bitshifts #2034
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okaneco wants to merge 6 commits intorust-lang:mainfrom
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x86: use simd::intrinsics for bitshifts #2034okaneco wants to merge 6 commits intorust-lang:mainfrom
simd::intrinsics for bitshifts #2034okaneco wants to merge 6 commits intorust-lang:mainfrom
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Use intrinsics in `sse2`, `avx2`, `avx512f`, and `avx512bw` Mark intrinsics and tests that call these functions as const
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r? @Amanieu rustbot has assigned @Amanieu. Use Why was this reviewer chosen?The reviewer was selected based on:
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Amanieu
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Feb 23, 2026
| pub const fn _mm_sll_epi16(a: __m128i, count: __m128i) -> __m128i { | ||
| let shift = count.as_u64x2().as_array()[0]; | ||
| unsafe { | ||
| if shift >= 16 { |
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Can you check that LLVM is actually able to eliminate this check and fold it into the psllw instruction? It might still be keeping the check and only doing a psllw on the else branch.
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sse2,avx2,avx512f, andavx512bwNothing notable about the implementation.
Intrinsics take
countas the shift argument with the shift being au64in the low 64-bits of an__m128i. The shift amount must be less than the bit width of the type being shifted.