fix PR6533 by updating the br(xor) code to remember the case

when it looked past a trunc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98203 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 22 insertions, 5 deletions

diff --git a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
index 82bf478..aa283ad 100644
--- a/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ b/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -4605,7 +4605,7 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) {
 
   SDNode *Trunc = 0;
   if (N1.getOpcode() == ISD::TRUNCATE && N1.hasOneUse()) {
-    // Look pass truncate.
+    // Look past truncate.
     Trunc = N1.getNode();
     N1 = N1.getOperand(0);
   }
@@ -4700,7 +4700,9 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) {
           Equal = true;
         }
 
-      EVT SetCCVT = N1.getValueType();
+      SDValue NodeToReplace = Trunc ? SDValue(Trunc, 0) : N1;
+      
+      EVT SetCCVT = NodeToReplace.getValueType();
       if (LegalTypes)
         SetCCVT = TLI.getSetCCResultType(SetCCVT);
       SDValue SetCC = DAG.getSetCC(TheXor->getDebugLoc(),
@@ -4709,9 +4711,9 @@ SDValue DAGCombiner::visitBRCOND(SDNode *N) {
                                    Equal ? ISD::SETEQ : ISD::SETNE);
       // Replace the uses of XOR with SETCC
       WorkListRemover DeadNodes(*this);
-      DAG.ReplaceAllUsesOfValueWith(N1, SetCC, &DeadNodes);
-      removeFromWorkList(N1.getNode());
-      DAG.DeleteNode(N1.getNode());
+      DAG.ReplaceAllUsesOfValueWith(NodeToReplace, SetCC, &DeadNodes);
+      removeFromWorkList(NodeToReplace.getNode());
+      DAG.DeleteNode(NodeToReplace.getNode());
       return DAG.getNode(ISD::BRCOND, N->getDebugLoc(),
                          MVT::Other, Chain, SetCC, N2);
     }
diff --git a/test/CodeGen/X86/crash.ll b/test/CodeGen/X86/crash.ll
index 1e13046..b9037f3 100644
--- a/test/CodeGen/X86/crash.ll
+++ b/test/CodeGen/X86/crash.ll
@@ -18,3 +18,18 @@ entry:
   volatile store i32 %conv19.i, i32* undef
   ret i32 undef
 }
+
+; PR6533
+define void @test2(i1 %x, i32 %y) nounwind {
+  %land.ext = zext i1 %x to i32                   ; <i32> [#uses=1]
+  %and = and i32 %y, 1                        ; <i32> [#uses=1]
+  %xor = xor i32 %and, %land.ext                  ; <i32> [#uses=1]
+  %cmp = icmp eq i32 %xor, 1                      ; <i1> [#uses=1]
+  br i1 %cmp, label %if.end, label %if.then
+
+if.then:                                          ; preds = %land.end
+  ret void
+
+if.end:                                           ; preds = %land.end
+  ret void
+}