[PATCH] D156153: [RISCV] Generalize combineAddOfBooleanXor to support any boolean not just setcc.

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
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Instead of checking for setcc, look for any 0/1 value.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D156153

Files:
  llvm/lib/Target/RISCV/RISCVISelLowering.cpp
  llvm/test/CodeGen/RISCV/atomicrmw-uinc-udec-wrap.ll


Index: llvm/test/CodeGen/RISCV/atomicrmw-uinc-udec-wrap.ll
===================================================================
--- llvm/test/CodeGen/RISCV/atomicrmw-uinc-udec-wrap.ll
+++ llvm/test/CodeGen/RISCV/atomicrmw-uinc-udec-wrap.ll
@@ -481,8 +481,7 @@
 ; RV32I-NEXT:    addi a1, a4, 1
 ; RV32I-NEXT:    seqz a2, a1
 ; RV32I-NEXT:    add a3, a5, a2
-; RV32I-NEXT:    xori a0, a0, 1
-; RV32I-NEXT:    addi a0, a0, -1
+; RV32I-NEXT:    neg a0, a0
 ; RV32I-NEXT:    and a2, a0, a1
 ; RV32I-NEXT:    and a3, a0, a3
 ; RV32I-NEXT:    sw a4, 8(sp)
@@ -537,8 +536,7 @@
 ; RV32IA-NEXT:    addi a1, a4, 1
 ; RV32IA-NEXT:    seqz a2, a1
 ; RV32IA-NEXT:    add a3, a5, a2
-; RV32IA-NEXT:    xori a0, a0, 1
-; RV32IA-NEXT:    addi a0, a0, -1
+; RV32IA-NEXT:    neg a0, a0
 ; RV32IA-NEXT:    and a2, a0, a1
 ; RV32IA-NEXT:    and a3, a0, a3
 ; RV32IA-NEXT:    sw a4, 8(sp)
Index: llvm/lib/Target/RISCV/RISCVISelLowering.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -10533,7 +10533,7 @@
   return DAG.getNode(ISD::ADD, DL, VT, New1, DAG.getConstant(CB, DL, VT));
 }
 
-// Try to turn (add (xor (setcc X, Y), 1) -1) into (neg (setcc X, Y)).
+// Try to turn (add (xor bool, 1) -1) into (neg bool).
 static SDValue combineAddOfBooleanXor(SDNode *N, SelectionDAG &DAG) {
   SDValue N0 = N->getOperand(0);
   SDValue N1 = N->getOperand(1);
@@ -10544,9 +10544,13 @@
   if (!isAllOnesConstant(N1))
     return SDValue();
 
-  // Look for an (xor (setcc X, Y), 1).
-  if (N0.getOpcode() != ISD::XOR || !isOneConstant(N0.getOperand(1)) ||
-      N0.getOperand(0).getOpcode() != ISD::SETCC)
+  // Look for (xor X, 1).
+  if (N0.getOpcode() != ISD::XOR || !isOneConstant(N0.getOperand(1)))
+    return SDValue();
+
+  // Xor input should be 0 or 1.
+  APInt Mask = APInt::getBitsSetFrom(VT.getSizeInBits(), 1);
+  if (!DAG.MaskedValueIsZero(N0.getOperand(0), Mask))
     return SDValue();
 
   // Emit a negate of the setcc.


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