[PATCH] D32273: [X86][AVX512] Make i1 illegal in the CodeGen

[Guy Blank via Phabricator via llvm-commits]

guyblank added inline comments.


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Comment at: test/CodeGen/X86/avx512-intrinsics.ll:125
+; CHECK-NEXT:    kxnorw %k0, %k0, %k1
+; CHECK-NEXT:    kxnorw %k1, %k0, %k0
 ; CHECK-NEXT:    kmovw %k0, %eax
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RKSimon wrote:
> guyblank wrote:
> > RKSimon wrote:
> > > Any ideas what is going on here?
> > SelectionDAG.cpp::FoldConstantArithmetic should eliminate this.
> > but there is a comment there...
> > // Avoid BUILD_VECTOR nodes that perform implicit truncation.
> > // FIXME: This is valid and could be handled by truncation.
> > 
> > without this patch the build vector was v16i1 = build vector i1, i1, ...
> > and with the patch it is v16i1 = build vector i8, i8, ...
> > so now it is unable to eliminate the xnor.
> > 
> > i've tried implementing proper handling for implicit truncation but i'm getting some failure in mips that i still need to investigate.
> > is it ok if I fix it in a separate commit?
> > 
> > 
> SelectionDAG::FoldConstantVectorArithmetic does the explicit truncation/extension - not sure if you can use that.
Thanks!


https://reviews.llvm.org/D32273