else if (Op1I->getOperand(1) == Op0) // X-(Y+X) == -Y
return BinaryOperator::CreateFNeg(Op1I->getOperand(0), I.getName());
}
-
- if (Op1I->hasOneUse()) {
- // Replace (x - (y - z)) with (x + (z - y)) if the (y - z) subexpression
- // is not used by anyone else...
- //
- if (Op1I->getOpcode() == Instruction::FSub) {
- // Swap the two operands of the subexpr...
- Value *IIOp0 = Op1I->getOperand(0), *IIOp1 = Op1I->getOperand(1);
- Op1I->setOperand(0, IIOp1);
- Op1I->setOperand(1, IIOp0);
-
- // Create the new top level fadd instruction...
- return BinaryOperator::CreateFAdd(Op0, Op1);
- }
- }
}
return 0;
--- /dev/null
+; RUN: llvm-as < %s | opt -instcombine | llvm-dis | grep fsub | count 2
+; PR4374
+
+define float @func(float %a, float %b) nounwind {
+ %tmp3 = fsub float %a, %b
+ %tmp4 = fsub float -0.000000e+00, %tmp3
+ ret float %tmp4
+}