llvm/builtin_mul_overflow.patch
2021-01-18 17:06:17 +01:00

26 lines
1.3 KiB
Diff

diff --git a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
index cf02ef1e83f3..e370f8c34809 100644
--- a/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
+++ b/llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp
@@ -3885,8 +3885,8 @@ void LSRInstance::GenerateICmpZeroScales(LSRUse &LU, unsigned LUIdx,
// Check that the multiplication doesn't overflow.
if (Base.BaseOffset == std::numeric_limits<int64_t>::min() && Factor == -1)
continue;
- int64_t NewBaseOffset = (uint64_t)Base.BaseOffset * Factor;
- if (NewBaseOffset / Factor != Base.BaseOffset)
+ int64_t NewBaseOffset;
+ if(__builtin_mul_overflow(Base.BaseOffset, Factor, &NewBaseOffset))
continue;
// If the offset will be truncated at this use, check that it is in bounds.
if (!IntTy->isPointerTy() &&
@@ -3897,8 +3897,7 @@ void LSRInstance::GenerateICmpZeroScales(LSRUse &LU, unsigned LUIdx,
int64_t Offset = LU.MinOffset;
if (Offset == std::numeric_limits<int64_t>::min() && Factor == -1)
continue;
- Offset = (uint64_t)Offset * Factor;
- if (Offset / Factor != LU.MinOffset)
+ if(__builtin_mul_overflow(Offset, Factor, &Offset))
continue;
// If the offset will be truncated at this use, check that it is in bounds.
if (!IntTy->isPointerTy() &&