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-rw-r--r--lib/Transforms/Scalar/CodeGenPrepare.cpp29
1 files changed, 22 insertions, 7 deletions
diff --git a/lib/Transforms/Scalar/CodeGenPrepare.cpp b/lib/Transforms/Scalar/CodeGenPrepare.cpp
index cfca726f26..57a648f7b9 100644
--- a/lib/Transforms/Scalar/CodeGenPrepare.cpp
+++ b/lib/Transforms/Scalar/CodeGenPrepare.cpp
@@ -1174,17 +1174,32 @@ static bool isFormingBranchFromSelectProfitable(SelectInst *SI) {
}
+/// If we have a SelectInst that will likely profit from branch prediction,
+/// turn it into a branch.
bool CodeGenPrepare::OptimizeSelectInst(SelectInst *SI) {
- // If we have a SelectInst that will likely profit from branch prediction,
- // turn it into a branch.
- if (DisableSelectToBranch || OptSize || !TLI ||
- !TLI->isPredictableSelectExpensive())
- return false;
+ bool VectorCond = !SI->getCondition()->getType()->isIntegerTy(1);
- if (!SI->getCondition()->getType()->isIntegerTy(1) ||
- !isFormingBranchFromSelectProfitable(SI))
+ // Can we convert the 'select' to CF ?
+ if (DisableSelectToBranch || OptSize || !TLI || VectorCond)
return false;
+ TargetLowering::SelectSupportKind SelectKind;
+ if (VectorCond)
+ SelectKind = TargetLowering::VectorMaskSelect;
+ else if (SI->getType()->isVectorTy())
+ SelectKind = TargetLowering::ScalarCondVectorVal;
+ else
+ SelectKind = TargetLowering::ScalarValSelect;
+
+ // Do we have efficient codegen support for this kind of 'selects' ?
+ if (TLI->isSelectSupported(SelectKind)) {
+ // We have efficient codegen support for the select instruction.
+ // Check if it is profitable to keep this 'select'.
+ if (!TLI->isPredictableSelectExpensive() ||
+ !isFormingBranchFromSelectProfitable(SI))
+ return false;
+ }
+
ModifiedDT = true;
// First, we split the block containing the select into 2 blocks.