diff options
Diffstat (limited to 'lib/Transforms/Scalar/Reassociate.cpp')
| -rw-r--r-- | lib/Transforms/Scalar/Reassociate.cpp | 6 |
1 files changed, 6 insertions, 0 deletions
diff --git a/lib/Transforms/Scalar/Reassociate.cpp b/lib/Transforms/Scalar/Reassociate.cpp index 29d1ba406ae4..e235e5eb1a06 100644 --- a/lib/Transforms/Scalar/Reassociate.cpp +++ b/lib/Transforms/Scalar/Reassociate.cpp @@ -1941,6 +1941,12 @@ Instruction *ReassociatePass::canonicalizeNegConstExpr(Instruction *I) { if (!User->isCommutative() && User->getOperand(1) != I) return nullptr; + // Don't canonicalize x + (-Constant * y) -> x - (Constant * y), if the + // resulting subtract will be broken up later. This can get us into an + // infinite loop during reassociation. + if (UserOpcode == Instruction::FAdd && ShouldBreakUpSubtract(User)) + return nullptr; + // Change the sign of the constant. APFloat Val = CF->getValueAPF(); Val.changeSign(); |