diff options
Diffstat (limited to 'llvm/lib/Transforms')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/LoopIndexSplit.cpp | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Scalar/LoopIndexSplit.cpp b/llvm/lib/Transforms/Scalar/LoopIndexSplit.cpp index 887a730e623..8234317444a 100644 --- a/llvm/lib/Transforms/Scalar/LoopIndexSplit.cpp +++ b/llvm/lib/Transforms/Scalar/LoopIndexSplit.cpp @@ -587,11 +587,37 @@ unsigned LoopIndexSplit::findSplitCost(Loop *L, SplitInfo &SD) { } 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. |
