Fix a compiler crash where a Glue value had multiple uses. Radar 9049552.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127198 91177308-0d34-0410-b5e6-96231b3b80d8

Author: bob-wilson

lib/Target/ARM/ARMISelLowering.cpp

@@ -2527,6 +2527,27 @@ ARMTargetLowering::getVFPCmp(SDValue LHS, SDValue RHS, SelectionDAG &DAG,
   return DAG.getNode(ARMISD::FMSTAT, dl, MVT::Glue, Cmp);
 }
 
+/// duplicateCmp - Glue values can have only one use, so this function
+/// duplicates a comparison node.
+SDValue
+ARMTargetLowering::duplicateCmp(SDValue Cmp, SelectionDAG &DAG) const {
+  unsigned Opc = Cmp.getOpcode();
+  DebugLoc DL = Cmp.getDebugLoc();
+  if (Opc == ARMISD::CMP || Opc == ARMISD::CMPZ)
+    return DAG.getNode(Opc, DL, MVT::Glue, Cmp.getOperand(0),Cmp.getOperand(1));
+
+  assert(Opc == ARMISD::FMSTAT && "unexpected comparison operation");
+  Cmp = Cmp.getOperand(0);
+  Opc = Cmp.getOpcode();
+  if (Opc == ARMISD::CMPFP)
+    Cmp = DAG.getNode(Opc, DL, MVT::Glue, Cmp.getOperand(0),Cmp.getOperand(1));
+  else {
+    assert(Opc == ARMISD::CMPFPw0 && "unexpected operand of FMSTAT");
+    Cmp = DAG.getNode(Opc, DL, MVT::Glue, Cmp.getOperand(0));
+  }
+  return DAG.getNode(ARMISD::FMSTAT, DL, MVT::Glue, Cmp);
+}
+
 SDValue ARMTargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const {
   SDValue Cond = Op.getOperand(0);
   SDValue SelectTrue = Op.getOperand(1);
@@ -2562,7 +2583,7 @@ SDValue ARMTargetLowering::LowerSELECT(SDValue Op, SelectionDAG &DAG) const {
         EVT VT = Cond.getValueType();
         SDValue ARMcc = Cond.getOperand(2);
         SDValue CCR = Cond.getOperand(3);
-        SDValue Cmp = Cond.getOperand(4);
+        SDValue Cmp = duplicateCmp(Cond.getOperand(4), DAG);
         return DAG.getNode(ARMISD::CMOV, dl, VT, True, False, ARMcc, CCR, Cmp);
       }
     }

lib/Target/ARM/ARMISelLowering.h

@@ -459,6 +459,7 @@ namespace llvm {
                       SDValue &ARMcc, SelectionDAG &DAG, DebugLoc dl) const;
     SDValue getVFPCmp(SDValue LHS, SDValue RHS,
                       SelectionDAG &DAG, DebugLoc dl) const;
+    SDValue duplicateCmp(SDValue Cmp, SelectionDAG &DAG) const;
 
     SDValue OptimizeVFPBrcond(SDValue Op, SelectionDAG &DAG) const;
 

test/CodeGen/ARM/select.ll

@@ -90,3 +90,26 @@ define arm_apcscc float @f8(i32 %a) nounwind {
   %tmp1 = select i1 %tmp, float 0x3FF3BE76C0000000, float 0x40030E9A20000000
   ret float %tmp1
 }
+
+; <rdar://problem/9049552>
+; Glue values can only have a single use, but the following test exposed a
+; case where a SELECT was lowered with 2 uses of a comparison, causing the
+; scheduler to assert.
+; CHECK-VFP: f9:
+
+declare i8* @objc_msgSend(i8*, i8*, ...)
+define void @f9() optsize {
+entry:
+  %cmp = icmp eq i8* undef, inttoptr (i32 4 to i8*)
+  %conv191 = select i1 %cmp, float -3.000000e+00, float 0.000000e+00
+  %conv195 = select i1 %cmp, double -1.000000e+00, double 0.000000e+00
+  %add = fadd double %conv195, 1.100000e+01
+  %conv196 = fptrunc double %add to float
+  %add201 = fadd float undef, %conv191
+  %tmp484 = bitcast float %conv196 to i32
+  %tmp478 = bitcast float %add201 to i32
+  %tmp490 = insertvalue [2 x i32] undef, i32 %tmp484, 0
+  %tmp493 = insertvalue [2 x i32] %tmp490, i32 %tmp478, 1
+  call void bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to void (i8*, i8*, [2 x i32], i32, float)*)(i8* undef, i8* undef, [2 x i32] %tmp493, i32 0, float 1.000000e+00) optsize
+  ret void
+}