diff options
Diffstat (limited to 'llvm/lib/Analysis/ScalarEvolution.cpp')
| -rw-r--r-- | llvm/lib/Analysis/ScalarEvolution.cpp | 4 |
1 files changed, 4 insertions, 0 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index bc2cfd6..8552d78 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -9833,6 +9833,10 @@ Optional<APInt> ScalarEvolution::computeConstantDifference(const SCEV *More, // We avoid subtracting expressions here because this function is usually // fairly deep in the call stack (i.e. is called many times). + // X - X = 0. + if (More == Less) + return APInt(getTypeSizeInBits(More->getType()), 0); + if (isa<SCEVAddRecExpr>(Less) && isa<SCEVAddRecExpr>(More)) { const auto *LAR = cast<SCEVAddRecExpr>(Less); const auto *MAR = cast<SCEVAddRecExpr>(More); |