Commit Graph

3 Commits

Author SHA1 Message Date
Andrea Di Biagio 23df4e4a2d Teach the DAGCombiner how to fold 'vselect' dag nodes according
to the following two rules:
  1) fold (vselect (build_vector AllOnes), A, B) -> A
  2) fold (vselect (build_vector AllZeros), A, B) -> B

llvm-svn: 198777
2014-01-08 18:33:04 +00:00
NAKAMURA Takumi cf396cf82c llvm/test/CodeGen/X86/vselect.ll: Unbreak Windows x64 targets to add -mtriple=x86_64-unknown-unknown.
llvm-svn: 198114
2013-12-28 13:04:29 +00:00
Andrea Di Biagio 46dcddb350 Teach DAGCombiner how to fold a SIGN_EXTEND_INREG of a BUILD_VECTOR of
ConstantSDNodes (or UNDEFs) into a simple BUILD_VECTOR.

For example, given the following sequence of dag nodes:

  i32 C = Constant<1>
  v4i32 V = BUILD_VECTOR C, C, C, C
  v4i32 Result = SIGN_EXTEND_INREG V, ValueType:v4i1

The SIGN_EXTEND_INREG node can be folded into a build_vector since
the vector in input is a BUILD_VECTOR of constants.

The optimized sequence is:

  i32 C = Constant<-1>
  v4i32 Result = BUILD_VECTOR C, C, C, C

llvm-svn: 198084
2013-12-27 20:20:28 +00:00