llvm/llvm-project

[X86] Recognise VPMADD52L/H patterns on AVX512IFMA/AVXIFMA targets

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#153,787 建立於 2025年8月15日

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backend:X86good first issuemissed-optimization

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描述

AVX512IFMA/AVXIFMA targets should be able to fold vXi64 mul-add patterns assuming the multiplicands are known to be u52 integers

X86ISD::VPMADD52L patterns can be matched for (X * Y) + Z if the upper 12 bits of X, Y AND (X * Y) are all known zero

X86ISD::VPMADD52H patterns are trickier as we extract the upper 52 bits of the (X * Y) 104-bit mulu extended result, but at least basic matching might be achievable

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