1 files changed, 8 insertions, 23 deletions

diff --git a/llvm/lib/Target/X86/X86ISelLowering.cpp b/llvm/lib/Target/X86/X86ISelLowering.cpp
index d725fbd6f41..4590980aa1a 100644
--- a/llvm/lib/Target/X86/X86ISelLowering.cpp
+++ b/llvm/lib/Target/X86/X86ISelLowering.cpp
@@ -39995,18 +39995,6 @@ static SDValue combineADC(SDNode *N, SelectionDAG &DAG,
   return SDValue();
 }
 
-/// Materialize "setb reg" as "sbb reg,reg", since it produces an all-ones bit
-/// which is more useful than 0/1 in some cases.
-static SDValue materializeSBB(SDNode *N, SDValue EFLAGS, SelectionDAG &DAG) {
-  SDLoc DL(N);
-  // "Condition code B" is also known as "the carry flag" (CF).
-  SDValue CF = DAG.getConstant(X86::COND_B, DL, MVT::i8);
-  SDValue SBB = DAG.getNode(X86ISD::SETCC_CARRY, DL, MVT::i8, CF, EFLAGS);
-  MVT VT = N->getSimpleValueType(0);
-  assert(VT == MVT::i8 && "Unexpected type for SETCC node");
-  return DAG.getNode(ISD::AND, DL, VT, SBB, DAG.getConstant(1, DL, VT));
-}
-
 /// If this is an add or subtract where one operand is produced by a cmp+setcc,
 /// then try to convert it to an ADC or SBB. This replaces TEST+SET+{ADD/SUB}
 /// with CMP+{ADC, SBB}.
@@ -40077,13 +40065,11 @@ static SDValue combineAddOrSubToADCOrSBB(SDNode *N, SelectionDAG &DAG) {
   }
 
   if (CC == X86::COND_B) {
-    // X + SETB Z --> X + (mask SBB Z, Z)
-    // X - SETB Z --> X - (mask SBB Z, Z)
-    // TODO: Produce ADC/SBB here directly and avoid SETCC_CARRY?
-    SDValue SBB = materializeSBB(Y.getNode(), Y.getOperand(1), DAG);
-    if (SBB.getValueSizeInBits() != VT.getSizeInBits())
-      SBB = DAG.getZExtOrTrunc(SBB, DL, VT);
-    return DAG.getNode(IsSub ? ISD::SUB : ISD::ADD, DL, VT, X, SBB);
+    // X + SETB Z --> adc X, 0
+    // X - SETB Z --> sbb X, 0
+    return DAG.getNode(IsSub ? X86ISD::SBB : X86ISD::ADC, DL,
+                       DAG.getVTList(VT, MVT::i32), X,
+                       DAG.getConstant(0, DL, VT), Y.getOperand(1));
   }
 
   if (CC == X86::COND_A) {
@@ -40101,10 +40087,9 @@ static SDValue combineAddOrSubToADCOrSBB(SDNode *N, SelectionDAG &DAG) {
                                    EFLAGS.getNode()->getVTList(),
                                    EFLAGS.getOperand(1), EFLAGS.getOperand(0));
       SDValue NewEFLAGS = SDValue(NewSub.getNode(), EFLAGS.getResNo());
-      SDValue SBB = materializeSBB(Y.getNode(), NewEFLAGS, DAG);
-      if (SBB.getValueSizeInBits() != VT.getSizeInBits())
-        SBB = DAG.getZExtOrTrunc(SBB, DL, VT);
-      return DAG.getNode(IsSub ? ISD::SUB : ISD::ADD, DL, VT, X, SBB);
+      return DAG.getNode(IsSub ? X86ISD::SBB : X86ISD::ADC, DL,
+                         DAG.getVTList(VT, MVT::i32), X,
+                         DAG.getConstant(0, DL, VT), NewEFLAGS);
     }
   }