Calculate exit and start value of true loop and false loop respectively.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40978 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/LoopIndexSplit.cpp b/lib/Transforms/Scalar/LoopIndexSplit.cpp
index 887a730..8234317 100644
--- a/lib/Transforms/Scalar/LoopIndexSplit.cpp
+++ b/lib/Transforms/Scalar/LoopIndexSplit.cpp
@@ -587,11 +587,37 @@
}
bool LoopIndexSplit::splitLoop(SplitInfo &SD) {
+
+ BasicBlock *Preheader = L->getLoopPreheader();
+
// True loop is original loop. False loop is cloned loop.
+
+ bool SignedPredicate = ExitCondition->isSignedPredicate();
//[*] Calculate True loop's new Exit Value in loop preheader.
- // NewExitValue = min(SplitValue, ExitValue)
+ // TLExitValue = min(SplitValue, ExitValue)
//[*] Calculate False loop's new Start Value in loop preheader.
- // NewStartValue = min(SplitValue, TrueLoop.StartValue)
+ // FLStartValue = min(SplitValue, TrueLoop.StartValue)
+ Value *TLExitValue = NULL;
+ Value *FLStartValue = NULL;
+ if (isa<ConstantInt>(SD.SplitValue)) {
+ TLExitValue = SD.SplitValue;
+ FLStartValue = SD.SplitValue;
+ }
+ else {
+ Value *C1 = new ICmpInst(SignedPredicate ?
+ ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
+ SD.SplitValue, ExitValue, "lsplit.ev",
+ Preheader->getTerminator());
+ TLExitValue = new SelectInst(C1, SD.SplitValue, ExitValue,
+ "lsplit.ev", Preheader->getTerminator());
+
+ Value *C2 = new ICmpInst(SignedPredicate ?
+ ICmpInst::ICMP_SLT : ICmpInst::ICMP_ULT,
+ SD.SplitValue, StartValue, "lsplit.sv",
+ Preheader->getTerminator());
+ FLStartValue = new SelectInst(C2, SD.SplitValue, StartValue,
+ "lsplit.sv", Preheader->getTerminator());
+ }
//[*] Split Exit Edge.
//[*] Clone loop. Avoid true destination of split condition and
// the blocks dominated by true destination.