diff options
Diffstat (limited to 'llvm/lib/IR/ConstantRange.cpp')
| -rw-r--r-- | llvm/lib/IR/ConstantRange.cpp | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/llvm/lib/IR/ConstantRange.cpp b/llvm/lib/IR/ConstantRange.cpp index 309dfc33741..a202a2ebe35 100644 --- a/llvm/lib/IR/ConstantRange.cpp +++ b/llvm/lib/IR/ConstantRange.cpp @@ -713,6 +713,13 @@ ConstantRange::multiply(const ConstantRange &Other) const { this_max * Other_max + 1); ConstantRange UR = Result_zext.truncate(getBitWidth()); + // If the unsigned range doesn't wrap, and isn't negative then it's a range + // from one positive number to another which is as good as we can generate. + // In this case, skip the extra work of generating signed ranges which aren't + // going to be better than this range. + if (!UR.isWrappedSet() && UR.getLower().isNonNegative()) + return UR; + // Now the signed range. Because we could be dealing with negative numbers // here, the lower bound is the smallest of the cartesian product of the // lower and upper ranges; for example: |
