Transform (xor (setcc), (setcc)) == / != 1 to
(xor (setcc), (setcc)) != / == 1.
e.g. On x86_64
%0 = icmp eq i32 %x, 0
%1 = icmp eq i32 %y, 0
%2 = xor i1 %1, %0
br i1 %2, label %bb, label %return
=>
testl %edi, %edi
sete %al
testl %esi, %esi
sete %cl
cmpb %al, %cl
je LBB1_2
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96640 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/CodeGen/SelectionDAG/TargetLowering.cpp b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
index 9f9d8b0..2cb4fc9 100644
--- a/lib/CodeGen/SelectionDAG/TargetLowering.cpp
+++ b/lib/CodeGen/SelectionDAG/TargetLowering.cpp
@@ -1855,9 +1855,19 @@
SDValue Op0 = N0;
if (Op0.getOpcode() == ISD::TRUNCATE)
Op0 = Op0.getOperand(0);
- if (Op0.getOpcode() == ISD::AND &&
- isa<ConstantSDNode>(Op0.getOperand(1)) &&
- cast<ConstantSDNode>(Op0.getOperand(1))->getAPIntValue() == 1) {
+
+ if ((Op0.getOpcode() == ISD::XOR || Op0.getOpcode() == ISD::AND) &&
+ Op0.getOperand(0).getOpcode() == ISD::SETCC &&
+ Op0.getOperand(1).getOpcode() == ISD::SETCC) {
+ // (and (setcc), (setcc)) == / != 1 -> (setcc) == / != (setcc)
+ // (xor (setcc), (setcc)) == / != 1 -> (setcc) != / == (setcc)
+ if (Op0.getOpcode() == ISD::XOR)
+ Cond = (Cond == ISD::SETEQ) ? ISD::SETNE : ISD::SETEQ;
+ return DAG.getSetCC(dl, VT, Op0.getOperand(0), Op0.getOperand(1),
+ Cond);
+ } else if (Op0.getOpcode() == ISD::AND &&
+ isa<ConstantSDNode>(Op0.getOperand(1)) &&
+ cast<ConstantSDNode>(Op0.getOperand(1))->getAPIntValue() == 1) {
if (Op0.getValueType() != VT)
Op0 = DAG.getNode(ISD::AND, dl, VT,
DAG.getNode(ISD::TRUNCATE, dl, VT, Op0.getOperand(0)),