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Summary

  1. [CostModel][X86] Add CTLZ scalar costs (details)
Commit 1385b27e92d906dbce9dd10431c8c210d1f7ef45 by llvm-dev
[CostModel][X86] Add CTLZ scalar costs
Add specific scalar costs for CTLZ instructions, we can't discriminate
between CTLZ and CTLZ_ZERO_UNDEF so we have to assume the worst. Given
how BSR is often a microcoded nightmare on some older targets we might
still be underestimating it.
For targets supporting LZCNT (Intel Haswell+ or AMD Fam10+), we provide
overrides that assume 1cy costs.
llvm-svn: 374786
The file was modifiedllvm/test/Analysis/CostModel/X86/ctlz.ll
The file was modifiedllvm/lib/Target/X86/X86TargetTransformInfo.cpp
The file was modifiedllvm/test/Transforms/SLPVectorizer/X86/ctlz.ll