diff options
| -rw-r--r-- | lib/Transforms/Utils/LoopSimplify.cpp | 11 | ||||
| -rw-r--r-- | test/Transforms/LoopSimplify/preserve-scev.ll | 50 |
2 files changed, 60 insertions, 1 deletions
diff --git a/lib/Transforms/Utils/LoopSimplify.cpp b/lib/Transforms/Utils/LoopSimplify.cpp index 2f0a175..b3c4801 100644 --- a/lib/Transforms/Utils/LoopSimplify.cpp +++ b/lib/Transforms/Utils/LoopSimplify.cpp @@ -46,6 +46,7 @@ #include "llvm/LLVMContext.h" #include "llvm/Type.h" #include "llvm/Analysis/AliasAnalysis.h" +#include "llvm/Analysis/ScalarEvolution.h" #include "llvm/Analysis/Dominators.h" #include "llvm/Analysis/LoopPass.h" #include "llvm/Transforms/Utils/BasicBlockUtils.h" @@ -71,6 +72,7 @@ namespace { AliasAnalysis *AA; LoopInfo *LI; DominatorTree *DT; + ScalarEvolution *SE; Loop *L; virtual bool runOnLoop(Loop *L, LPPassManager &LPM); @@ -83,7 +85,7 @@ namespace { AU.addPreserved<LoopInfo>(); AU.addPreserved<AliasAnalysis>(); - AU.addPreserved("scalar-evolution"); + AU.addPreserved<ScalarEvolution>(); AU.addPreservedID(BreakCriticalEdgesID); // No critical edges added. AU.addPreserved<DominanceFrontier>(); AU.addPreservedID(LCSSAID); @@ -121,6 +123,7 @@ bool LoopSimplify::runOnLoop(Loop *l, LPPassManager &LPM) { LI = &getAnalysis<LoopInfo>(); AA = getAnalysisIfAvailable<AliasAnalysis>(); DT = &getAnalysis<DominatorTree>(); + SE = getAnalysisIfAvailable<ScalarEvolution>(); Changed |= ProcessLoop(L, LPM); @@ -532,6 +535,12 @@ Loop *LoopSimplify::SeparateNestedLoop(Loop *L, LPPassManager &LPM) { DEBUG(dbgs() << "LoopSimplify: Splitting out a new outer loop\n"); + // If ScalarEvolution is around and knows anything about values in + // this loop, tell it to forget them, because we're about to + // substantially change it. + if (SE) + SE->forgetLoop(L); + BasicBlock *Header = L->getHeader(); BasicBlock *NewBB = SplitBlockPredecessors(Header, &OuterLoopPreds[0], OuterLoopPreds.size(), diff --git a/test/Transforms/LoopSimplify/preserve-scev.ll b/test/Transforms/LoopSimplify/preserve-scev.ll new file mode 100644 index 0000000..017a0d2 --- /dev/null +++ b/test/Transforms/LoopSimplify/preserve-scev.ll @@ -0,0 +1,50 @@ +; RUN: opt -S < %s -indvars | opt -analyze -iv-users | grep {%cmp = icmp slt i32} | grep {= \{%\\.ph,+,1\}<%for.cond>} +; PR8079 + +; LoopSimplify should invalidate indvars when splitting out the +; inner loop. + +@maxStat = external global i32 + +define i32 @test() nounwind { +entry: + br label %for.cond + +for.cond: ; preds = %if.then5, %if.end, %entry + %cuts.1 = phi i32 [ 0, %entry ], [ %inc, %if.then5 ], [ %cuts.1, %if.end ] + %0 = phi i32 [ 0, %entry ], [ %add, %if.end ], [ %add, %if.then5 ] + %add = add i32 %0, 1 + %cmp = icmp slt i32 %0, 1 + %tmp1 = load i32* @maxStat, align 4 + br i1 %cmp, label %for.body, label %for.cond14.preheader + +for.cond14.preheader: ; preds = %for.cond + %cmp1726 = icmp sgt i32 %tmp1, 0 + br i1 %cmp1726, label %for.body18, label %return + +for.body: ; preds = %for.cond + %cmp2 = icmp sgt i32 %tmp1, 100 + br i1 %cmp2, label %return, label %if.end + +if.end: ; preds = %for.body + %cmp4 = icmp sgt i32 %tmp1, -1 + br i1 %cmp4, label %if.then5, label %for.cond + +if.then5: ; preds = %if.end + call void @foo() nounwind + %inc = add i32 %cuts.1, 1 + br label %for.cond + +for.body18: ; preds = %for.body18, %for.cond14.preheader + %i13.027 = phi i32 [ %1, %for.body18 ], [ 0, %for.cond14.preheader ] + call void @foo() nounwind + %1 = add nsw i32 %i13.027, 1 + %tmp16 = load i32* @maxStat, align 4 + %cmp17 = icmp slt i32 %1, %tmp16 + br i1 %cmp17, label %for.body18, label %return + +return: ; preds = %for.body18, %for.body, %for.cond14.preheader + ret i32 0 +} + +declare void @foo() nounwind |