[PATCH] D61129: [InstCombine][X86] Expand PACKSS/PACKUS if the operands won't saturate

[Simon Pilgrim via Phabricator via llvm-commits]

RKSimon planned changes to this revision.
RKSimon marked an inline comment as done.
RKSimon added inline comments.


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Comment at: test/Transforms/InstCombine/X86/x86-pack.ll:363
+; CHECK-NEXT:    [[TMP4:%.*]] = trunc <8 x i32> [[TMP3]] to <8 x i16>
+; CHECK-NEXT:    ret <8 x i16> [[TMP4]]
 ;
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It looks like we're actually better off truncating before shuffling - it creates more IR but gives us more scope for folding - I'll revert rL359191


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  rL LLVM

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  https://reviews.llvm.org/D61129/new/

https://reviews.llvm.org/D61129