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[X86][SSE] Fold (VSRAI (VSHLI X, C1), C1) --> X iff NumSignBits(X) > C1
authorSimon Pilgrim <llvm-dev@redking.me.uk>
Sat, 30 Sep 2017 17:57:34 +0000 (17:57 +0000)
committerSimon Pilgrim <llvm-dev@redking.me.uk>
Sat, 30 Sep 2017 17:57:34 +0000 (17:57 +0000)
commit206263fa1eedd9a578f6ab0bf1719b838e7d64df
tree9fe1084bec3ff8567e6bb127ef2ddf0024c7c9c0
parentc80e022c96d8a175af9edbea798d11545b061e4b
[X86][SSE] Fold (VSRAI (VSHLI X, C1), C1) --> X iff NumSignBits(X) > C1

Remove sign extend in register style pattern if the sign is already extended enough

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@314599 91177308-0d34-0410-b5e6-96231b3b80d8
lib/Target/X86/X86ISelLowering.cpp
test/CodeGen/X86/vector-trunc.ll