diff options
| -rw-r--r-- | lib/Analysis/ScalarEvolution.cpp | 10 | ||||
| -rw-r--r-- | test/Analysis/ScalarEvolution/2008-07-29-SGTTripCount.ll | 27 |
2 files changed, 34 insertions, 3 deletions
diff --git a/lib/Analysis/ScalarEvolution.cpp b/lib/Analysis/ScalarEvolution.cpp index 737d9b3823..14c1389b43 100644 --- a/lib/Analysis/ScalarEvolution.cpp +++ b/lib/Analysis/ScalarEvolution.cpp @@ -1976,8 +1976,8 @@ SCEVHandle ScalarEvolutionsImpl::ComputeIterationCount(const Loop *L) { break; } case ICmpInst::ICMP_SGT: { - SCEVHandle TC = HowManyLessThans(SE.getNegativeSCEV(LHS), - SE.getNegativeSCEV(RHS), L, true); + SCEVHandle TC = HowManyLessThans(SE.getNotSCEV(LHS), + SE.getNotSCEV(RHS), L, true); if (!isa<SCEVCouldNotCompute>(TC)) return TC; break; } @@ -2724,7 +2724,11 @@ bool ScalarEvolutionsImpl::executesAtLeastOnce(const Loop *L, bool isSigned, if (!PreCondLHS->getType()->isInteger()) return false; - return LHS == getSCEV(PreCondLHS) && RHS == getSCEV(PreCondRHS); + SCEVHandle PreCondLHSSCEV = getSCEV(PreCondLHS); + SCEVHandle PreCondRHSSCEV = getSCEV(PreCondRHS); + return (LHS == PreCondLHSSCEV && RHS == PreCondRHSSCEV) || + (LHS == SE.getNotSCEV(PreCondRHSSCEV) && + RHS == SE.getNotSCEV(PreCondLHSSCEV)); } /// HowManyLessThans - Return the number of times a backedge containing the diff --git a/test/Analysis/ScalarEvolution/2008-07-29-SGTTripCount.ll b/test/Analysis/ScalarEvolution/2008-07-29-SGTTripCount.ll new file mode 100644 index 0000000000..307439f7b8 --- /dev/null +++ b/test/Analysis/ScalarEvolution/2008-07-29-SGTTripCount.ll @@ -0,0 +1,27 @@ +; RUN: llvm-as < %s | opt -analyze -scalar-evolution -disable-output \ +; RUN: -scalar-evolution-max-iterations=0 | \ +; RUN: grep -F "( -1 + ( -1 * %j)) iterations" +; PR2607 + +define i32 @_Z1aj(i32 %j) nounwind { +entry: + icmp sgt i32 0, %j ; <i1>:0 [#uses=1] + br i1 %0, label %bb.preheader, label %return + +bb.preheader: ; preds = %entry + br label %bb + +bb: ; preds = %bb, %bb.preheader + %i.01 = phi i32 [ %1, %bb ], [ 0, %bb.preheader ] ; <i32> [#uses=1] + add i32 %i.01, -1 ; <i32>:1 [#uses=3] + icmp sgt i32 %1, %j ; <i1>:2 [#uses=1] + br i1 %2, label %bb, label %return.loopexit + +return.loopexit: ; preds = %bb + br label %return + +return: ; preds = %return.loopexit, %entry + %i.0.lcssa = phi i32 [ 0, %entry ], [ %1, %return.loopexit ] ; <i32> [#uses=1] + ret i32 %i.0.lcssa +} + |