[PATCH] D36645: [X86] When handling addcarry intrinsic, create the flag result with the correct type so we don't crash if we use a memory instruction

[Craig Topper via Phabricator via llvm-commits]

craig.topper created this revision.

Previously we were creating the flag result with MVT::Other which is interpretted as a Chain node. If we used a memory form of the instruction we would end up with a copyToReg that consumed the chain result of the adcx instruction instead of the flag result.

Pretty sure we should be using MVT::i32 here, that's what we do other places we create these node types.

We should probably consider this for 5.0 as well.


https://reviews.llvm.org/D36645

Files:
  lib/Target/X86/X86ISelLowering.cpp
  test/CodeGen/X86/adx-intrinsics.ll


Index: test/CodeGen/X86/adx-intrinsics.ll
===================================================================
--- test/CodeGen/X86/adx-intrinsics.ll
+++ test/CodeGen/X86/adx-intrinsics.ll
@@ -75,3 +75,17 @@
   ret i8 %ret;
 }
 
+; Try a version with loads. Previously we crashed on this.
+define i32 @load_crash(i64* nocapture readonly %a, i64* nocapture readonly %b, i64* %res)  {
+; CHECK-LABEL: load_crash
+; CHECK: addb
+; ADX: adcxq
+; CHECK: setb
+; CHECK: retq
+  %1 = load i64, i64* %a, align 8
+  %2 = load i64, i64* %b, align 8
+  %3 = bitcast i64* %res to i8*
+  %4 = tail call i8 @llvm.x86.addcarryx.u64(i8 0, i64 %1, i64 %2, i8* %3)
+  %conv = zext i8 %4 to i32
+  ret i32 %conv
+}
Index: lib/Target/X86/X86ISelLowering.cpp
===================================================================
--- lib/Target/X86/X86ISelLowering.cpp
+++ lib/Target/X86/X86ISelLowering.cpp
@@ -20618,8 +20618,8 @@
   }
   // ADC/ADCX/SBB
   case ADX: {
-    SDVTList CFVTs = DAG.getVTList(Op->getValueType(0), MVT::Other);
-    SDVTList VTs = DAG.getVTList(Op.getOperand(3)->getValueType(0), MVT::Other);
+    SDVTList CFVTs = DAG.getVTList(Op->getValueType(0), MVT::i32);
+    SDVTList VTs = DAG.getVTList(Op.getOperand(3)->getValueType(0), MVT::i32);
     SDValue GenCF = DAG.getNode(X86ISD::ADD, dl, CFVTs, Op.getOperand(2),
                                 DAG.getConstant(-1, dl, MVT::i8));
     SDValue Res = DAG.getNode(IntrData->Opc0, dl, VTs, Op.getOperand(3),


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