X86: when replacing SUB with TEST in ISelDAGToDAG, only replace uses of the
second output of SUB with first output of TEST.
PR13966
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164835 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Target/X86/X86ISelDAGToDAG.cpp b/lib/Target/X86/X86ISelDAGToDAG.cpp
index 40605af..b4c7154 100644
--- a/lib/Target/X86/X86ISelDAGToDAG.cpp
+++ b/lib/Target/X86/X86ISelDAGToDAG.cpp
@@ -2525,7 +2525,13 @@
MVT::i8, Reg);
// Emit a testb.
- return CurDAG->getMachineNode(X86::TEST8ri, dl, MVT::i32, Subreg, Imm);
+ SDNode *NewNode = CurDAG->getMachineNode(X86::TEST8ri, dl, MVT::i32,
+ Subreg, Imm);
+ // Replace SUB|CMP with TEST, since SUB has two outputs while TEST has
+ // one, do not call ReplaceAllUsesWith.
+ ReplaceUses(SDValue(Node, (Opcode == X86ISD::SUB ? 1 : 0)),
+ SDValue(NewNode, 0));
+ return NULL;
}
// For example, "testl %eax, $2048" to "testb %ah, $8".
@@ -2556,8 +2562,13 @@
// Emit a testb. The EXTRACT_SUBREG becomes a COPY that can only
// target GR8_NOREX registers, so make sure the register class is
// forced.
- return CurDAG->getMachineNode(X86::TEST8ri_NOREX, dl, MVT::i32,
- Subreg, ShiftedImm);
+ SDNode *NewNode = CurDAG->getMachineNode(X86::TEST8ri_NOREX, dl,
+ MVT::i32, Subreg, ShiftedImm);
+ // Replace SUB|CMP with TEST, since SUB has two outputs while TEST has
+ // one, do not call ReplaceAllUsesWith.
+ ReplaceUses(SDValue(Node, (Opcode == X86ISD::SUB ? 1 : 0)),
+ SDValue(NewNode, 0));
+ return NULL;
}
// For example, "testl %eax, $32776" to "testw %ax, $32776".
@@ -2573,7 +2584,13 @@
MVT::i16, Reg);
// Emit a testw.
- return CurDAG->getMachineNode(X86::TEST16ri, dl, MVT::i32, Subreg, Imm);
+ SDNode *NewNode = CurDAG->getMachineNode(X86::TEST16ri, dl, MVT::i32,
+ Subreg, Imm);
+ // Replace SUB|CMP with TEST, since SUB has two outputs while TEST has
+ // one, do not call ReplaceAllUsesWith.
+ ReplaceUses(SDValue(Node, (Opcode == X86ISD::SUB ? 1 : 0)),
+ SDValue(NewNode, 0));
+ return NULL;
}
// For example, "testq %rax, $268468232" to "testl %eax, $268468232".
@@ -2589,7 +2606,13 @@
MVT::i32, Reg);
// Emit a testl.
- return CurDAG->getMachineNode(X86::TEST32ri, dl, MVT::i32, Subreg, Imm);
+ SDNode *NewNode = CurDAG->getMachineNode(X86::TEST32ri, dl, MVT::i32,
+ Subreg, Imm);
+ // Replace SUB|CMP with TEST, since SUB has two outputs while TEST has
+ // one, do not call ReplaceAllUsesWith.
+ ReplaceUses(SDValue(Node, (Opcode == X86ISD::SUB ? 1 : 0)),
+ SDValue(NewNode, 0));
+ return NULL;
}
}
break;