[PATCH] D33983: update add\sub costs of vectors of 64 in X86\SLM arch

[Eli Friedman via Phabricator via llvm-commits]

efriedma added inline comments.


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Comment at: test/Transforms/LoopVectorize/X86/slm-no-vectorize.ll:1
+; This test should not be vectorized in X86\SLM arch
+; this test has a bad performance (regression of -70%) if vectorized on SLM arch
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The vectorizer is clearly doing something wrong if it's generating a 64-bit multiply for this loop... might want to clarify the comment.


https://reviews.llvm.org/D33983