scanon created this revision.
scanon added reviewers: hfinkel, resistor, lhames.
scanon added a subscriber: cfe-commits.
r253269 exposed a pre-existing issue in tryEmitFMulAdd, where we would assert
if a fusable operation had operands with multiple uses (we didn't see it
previously because FP_CONTRACT was off by default). Fix this issue by changing
the assert into an early-out where we simply won't try to fuse.
Once this is done, we can try again at enabling FP_CONTRACT ON as a default.
http://reviews.llvm.org/D14891
Files:
lib/CodeGen/CGExprScalar.cpp
Index: lib/CodeGen/CGExprScalar.cpp
===================================================================
--- lib/CodeGen/CGExprScalar.cpp
+++ lib/CodeGen/CGExprScalar.cpp
@@ -2563,22 +2563,19 @@
if (CGF.CGM.getCodeGenOpts().getFPContractMode() != CodeGenOptions::FPC_On)
return nullptr;
- // We have a potentially fusable op. Look for a mul on one of the operands.
+ // We have a potentially fusable op. Look for a mul on one of the operands
+ // that does not have any other uses.
if (llvm::BinaryOperator* LHSBinOp = dyn_cast<llvm::BinaryOperator>(op.LHS))
{
- if (LHSBinOp->getOpcode() == llvm::Instruction::FMul) {
- assert(LHSBinOp->getNumUses() == 0 &&
- "Operations with multiple uses shouldn't be contracted.");
+ if (LHSBinOp->getOpcode() == llvm::Instruction::FMul &&
+ LHSBinOp->hasNUses(0))
return buildFMulAdd(LHSBinOp, op.RHS, CGF, Builder, false, isSub);
- }
- } else if (llvm::BinaryOperator* RHSBinOp =
- dyn_cast<llvm::BinaryOperator>(op.RHS)) {
- if (RHSBinOp->getOpcode() == llvm::Instruction::FMul) {
- assert(RHSBinOp->getNumUses() == 0 &&
- "Operations with multiple uses shouldn't be contracted.");
+ }
+ if (llvm::BinaryOperator* RHSBinOp = dyn_cast<llvm::BinaryOperator>(op.RHS))
{
+ if (RHSBinOp->getOpcode() == llvm::Instruction::FMul &&
+ RHSBinOp->hasNUses(0))
return buildFMulAdd(RHSBinOp, op.LHS, CGF, Builder, isSub, false);
- }
}
-
+
return nullptr;
}
Index: lib/CodeGen/CGExprScalar.cpp
===================================================================
--- lib/CodeGen/CGExprScalar.cpp
+++ lib/CodeGen/CGExprScalar.cpp
@@ -2563,22 +2563,19 @@
if (CGF.CGM.getCodeGenOpts().getFPContractMode() != CodeGenOptions::FPC_On)
return nullptr;
- // We have a potentially fusable op. Look for a mul on one of the operands.
+ // We have a potentially fusable op. Look for a mul on one of the operands
+ // that does not have any other uses.
if (llvm::BinaryOperator* LHSBinOp = dyn_cast<llvm::BinaryOperator>(op.LHS)) {
- if (LHSBinOp->getOpcode() == llvm::Instruction::FMul) {
- assert(LHSBinOp->getNumUses() == 0 &&
- "Operations with multiple uses shouldn't be contracted.");
+ if (LHSBinOp->getOpcode() == llvm::Instruction::FMul &&
+ LHSBinOp->hasNUses(0))
return buildFMulAdd(LHSBinOp, op.RHS, CGF, Builder, false, isSub);
- }
- } else if (llvm::BinaryOperator* RHSBinOp =
- dyn_cast<llvm::BinaryOperator>(op.RHS)) {
- if (RHSBinOp->getOpcode() == llvm::Instruction::FMul) {
- assert(RHSBinOp->getNumUses() == 0 &&
- "Operations with multiple uses shouldn't be contracted.");
+ }
+ if (llvm::BinaryOperator* RHSBinOp = dyn_cast<llvm::BinaryOperator>(op.RHS)) {
+ if (RHSBinOp->getOpcode() == llvm::Instruction::FMul &&
+ RHSBinOp->hasNUses(0))
return buildFMulAdd(RHSBinOp, op.LHS, CGF, Builder, isSub, false);
- }
}
-
+
return nullptr;
}
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