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[Bug target/85832] [AVX512] possible shorter code when comparing with vector of zeros


https://gcc.gnu.org/bugzilla/show_bug.cgi?id=85832

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Actually, vpcmpeq zmmX, zero and vptestm zmmX, zmmX perform exactly the
opposite, not the same thing, as vpcmpeq sets bits in the %kY register if zmmX
element is equal to 0, while vptestm if it is not equal to 0.
So we want to use vptestnm instead.

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