diff options
| -rw-r--r-- | lib/Transforms/Scalar/IndVarSimplify.cpp | 21 |
1 files changed, 20 insertions, 1 deletions
diff --git a/lib/Transforms/Scalar/IndVarSimplify.cpp b/lib/Transforms/Scalar/IndVarSimplify.cpp index 3f7f5cefb4..0078abd4d5 100644 --- a/lib/Transforms/Scalar/IndVarSimplify.cpp +++ b/lib/Transforms/Scalar/IndVarSimplify.cpp @@ -1900,6 +1900,25 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) { // Clean up dead instructions. Changed |= DeleteDeadPHIs(L->getHeader()); // Check a post-condition. - assert(L->isLCSSAForm(*DT) && "Indvars did not leave the loop in lcssa form!"); + assert(L->isLCSSAForm(*DT) && + "Indvars did not leave the loop in lcssa form!"); + + // Verify that LFTR, and any other change have not interfered with SCEV's + // ability to compute trip count. +#ifndef NDEBUG + if (DisableIVRewrite && !isa<SCEVCouldNotCompute>(BackedgeTakenCount)) { + SE->forgetLoop(L); + const SCEV *NewBECount = SE->getBackedgeTakenCount(L); + if (SE->getTypeSizeInBits(BackedgeTakenCount->getType()) < + SE->getTypeSizeInBits(NewBECount->getType())) + NewBECount = SE->getTruncateOrNoop(NewBECount, + BackedgeTakenCount->getType()); + else + BackedgeTakenCount = SE->getTruncateOrNoop(BackedgeTakenCount, + NewBECount->getType()); + assert(BackedgeTakenCount == NewBECount && "indvars must preserve SCEV"); + } +#endif + return Changed; } |