[PATCH] D155388: [RISCV] Make selectSETCC return SDValue instead of bool. NFC

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.
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We can use a null SDValue for the 'false' case. This avoids the
need for an output parameter. This is consistent with other
SelectionDAG code.


Repository:
  rG LLVM Github Monorepo

https://reviews.llvm.org/D155388

Files:
  llvm/lib/Target/RISCV/RISCVISelLowering.cpp


Index: llvm/lib/Target/RISCV/RISCVISelLowering.cpp
===================================================================
--- llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -5767,31 +5767,29 @@
 /// seteq/setne into something that can be compared with 0.
 /// Based on RISCVDAGToDAGISel::selectSETCC but modified to produce
 /// target-independent SelectionDAG nodes rather than machine nodes.
-static bool selectSETCC(SDValue N, ISD::CondCode ExpectedCCVal, SDValue &Val,
-                        SelectionDAG &DAG) {
+static SDValue selectSETCC(SDValue N, ISD::CondCode ExpectedCCVal,
+                           SelectionDAG &DAG) {
   assert(ISD::isIntEqualitySetCC(ExpectedCCVal) &&
          "Unexpected condition code!");
 
   // We're looking for a setcc.
   if (N->getOpcode() != ISD::SETCC)
-    return false;
+    return SDValue();
 
   // Must be an equality comparison.
   ISD::CondCode CCVal = cast<CondCodeSDNode>(N->getOperand(2))->get();
   if (CCVal != ExpectedCCVal)
-    return false;
+    return SDValue();
 
   SDValue LHS = N->getOperand(0);
   SDValue RHS = N->getOperand(1);
 
   if (!LHS.getValueType().isInteger())
-    return false;
+    return SDValue();
 
   // If the RHS side is 0, we don't need any extra instructions, return the LHS.
-  if (isNullConstant(RHS)) {
-    Val = LHS;
-    return true;
-  }
+  if (isNullConstant(RHS))
+    return LHS;
 
   SDLoc DL(N);
 
@@ -5799,24 +5797,19 @@
     int64_t CVal = C->getSExtValue();
     // If the RHS is -2048, we can use xori to produce 0 if the LHS is -2048 and
     // non-zero otherwise.
-    if (CVal == -2048) {
-      Val = DAG.getNode(ISD::XOR, DL, N->getValueType(0), LHS,
-                        DAG.getConstant(CVal, DL, N->getValueType(0)));
-      return true;
-    }
+    if (CVal == -2048)
+      return DAG.getNode(ISD::XOR, DL, N->getValueType(0), LHS,
+                         DAG.getConstant(CVal, DL, N->getValueType(0)));
     // If the RHS is [-2047,2048], we can use addi with -RHS to produce 0 if the
     // LHS is equal to the RHS and non-zero otherwise.
-    if (isInt<12>(CVal) || CVal == 2048) {
-      Val = DAG.getNode(ISD::ADD, DL, N->getValueType(0), LHS,
-                        DAG.getConstant(-CVal, DL, N->getValueType(0)));
-      return true;
-    }
+    if (isInt<12>(CVal) || CVal == 2048)
+      return DAG.getNode(ISD::ADD, DL, N->getValueType(0), LHS,
+                         DAG.getConstant(-CVal, DL, N->getValueType(0)));
   }
 
   // If nothing else we can XOR the LHS and RHS to produce zero if they are
   // equal and a non-zero value if they aren't.
-  Val = DAG.getNode(ISD::XOR, DL, N->getValueType(0), LHS, RHS);
-  return true;
+  return DAG.getNode(ISD::XOR, DL, N->getValueType(0), LHS, RHS);
 }
 
 // Transform `binOp (select cond, x, c0), c1` where `c0` and `c1` are constants
@@ -5905,8 +5898,7 @@
   // when CZERO_{EQZ/NEZ} are used vs another branchless sequence or
   // RISCVISD::SELECT_CC node (branch-based select).
   if (Subtarget.hasStdExtZicond() && VT.isInteger()) {
-    SDValue NewCondV;
-    if (selectSETCC(CondV, ISD::SETNE, NewCondV, DAG)) {
+    if (SDValue NewCondV = selectSETCC(CondV, ISD::SETNE, DAG)) {
       if (isNullConstant(FalseV))
         // (select (riscv_setne c), t, 0) -> (czero_eqz t, c)
         return DAG.getNode(RISCVISD::CZERO_EQZ, DL, VT, TrueV, NewCondV);
@@ -5920,7 +5912,7 @@
           DAG.getNode(RISCVISD::CZERO_EQZ, DL, VT, TrueV, NewCondV),
           DAG.getNode(RISCVISD::CZERO_NEZ, DL, VT, FalseV, NewCondV));
     }
-    if (selectSETCC(CondV, ISD::SETEQ, NewCondV, DAG)) {
+    if (SDValue NewCondV =  selectSETCC(CondV, ISD::SETEQ, DAG)) {
       if (isNullConstant(FalseV))
         // (select (riscv_seteq c), t, 0) -> (czero_nez t, c)
         return DAG.getNode(RISCVISD::CZERO_NEZ, DL, VT, TrueV, NewCondV);


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