diff options
| -rw-r--r-- | llvm/lib/Analysis/ScalarEvolution.cpp | 9 |
1 files changed, 6 insertions, 3 deletions
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp index 2dab2f367de..465807ecacb 100644 --- a/llvm/lib/Analysis/ScalarEvolution.cpp +++ b/llvm/lib/Analysis/ScalarEvolution.cpp @@ -3836,9 +3836,12 @@ HowManyLessThans(const SCEV *LHS, const SCEV *RHS, : getUMaxExpr(RHS, Start); // Determine the maximum constant end value. - SCEVHandle MaxEnd = isa<SCEVConstant>(End) ? End : - getConstant(isSigned ? APInt::getSignedMaxValue(BitWidth) : - APInt::getMaxValue(BitWidth)); + SCEVHandle MaxEnd = + isa<SCEVConstant>(End) ? End : + getConstant(isSigned ? APInt::getSignedMaxValue(BitWidth) + .ashr(GetMinSignBits(End) - 1) : + APInt::getMaxValue(BitWidth) + .lshr(GetMinLeadingZeros(End))); // Finally, we subtract these two values and divide, rounding up, to get // the number of times the backedge is executed. |
