[InstCombine] fold select X, (ext X), C
If we're going to canonicalize IR towards select of constants, try harder to create those.
Also, don't lose the metadata.
This is actually 4 related transforms in one patch:
// select X, (sext X), C --> select X, -1, C
// select X, (zext X), C --> select X, 1, C
// select X, C, (sext X) --> select X, C, 0
// select X, C, (zext X) --> select X, C, 0
Differential Revision: https://reviews.llvm.org/D25126
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@283575 91177308-0d34-0410-b5e6-96231b3b80d8
2 files changed