diff options
Diffstat (limited to 'llvm/lib/Transforms/Scalar/IndVarSimplify.cpp')
| -rw-r--r-- | llvm/lib/Transforms/Scalar/IndVarSimplify.cpp | 7 |
1 files changed, 5 insertions, 2 deletions
diff --git a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp index 558ea27659c..66b079f6b2e 100644 --- a/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp +++ b/llvm/lib/Transforms/Scalar/IndVarSimplify.cpp @@ -635,9 +635,12 @@ bool IndVarSimplify::rewriteLoopExitValues(Loop *L, SCEVExpander &Rewriter) { // Computing the value outside of the loop brings no benefit if it is // definitely used inside the loop in a way which can not be optimized - // away. + // away. Avoid doing so unless we know we have a value which computes + // the ExitValue already. TODO: This should be merged into SCEV + // expander to leverage its knowledge of existing expressions. if (ReplaceExitValue != AlwaysRepl && - !isa<SCEVConstant>(ExitValue) && hasHardUserWithinLoop(L, Inst)) + !isa<SCEVConstant>(ExitValue) && !isa<SCEVUnknown>(ExitValue) && + hasHardUserWithinLoop(L, Inst)) continue; bool HighCost = Rewriter.isHighCostExpansion(ExitValue, L, Inst); |
