[llvm-commits] [llvm] r103419 - in /llvm/trunk: lib/CodeGen/SelectionDAG/DAGCombiner.cpp test/CodeGen/X86/2010-05-10-DAGCombinerBug.ll

[Evan Cheng]

Author: evancheng
Date: Mon May 10 14:03:57 2010
New Revision: 103419

URL: http://llvm.org/viewvc/llvm-project?rev=103419&view=rev
Log:
Be careful with operand promotion. For a binary operation, the source operands may be the same. PR7018. rdar://7939869.

Added:
    llvm/trunk/test/CodeGen/X86/2010-05-10-DAGCombinerBug.ll
Modified:
    llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp

Modified: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp?rev=103419&r1=103418&r2=103419&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp (original)
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp Mon May 10 14:03:57 2010
@@ -760,12 +760,18 @@
 
     bool Replace1 = false;
     SDValue N1 = Op.getOperand(1);
-    SDValue NN1 = PromoteOperand(N1, PVT, Replace1);
-    if (NN1.getNode() == 0)
-      return SDValue();
+    SDValue NN1;
+    if (N0 == N1)
+      NN1 = NN0;
+    else {
+      NN1 = PromoteOperand(N1, PVT, Replace1);
+      if (NN1.getNode() == 0)
+        return SDValue();
+    }
 
     AddToWorkList(NN0.getNode());
-    AddToWorkList(NN1.getNode());
+    if (NN1.getNode())
+      AddToWorkList(NN1.getNode());
 
     if (Replace0)
       ReplaceLoadWithPromotedLoad(N0.getNode(), NN0.getNode());

Added: llvm/trunk/test/CodeGen/X86/2010-05-10-DAGCombinerBug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/2010-05-10-DAGCombinerBug.ll?rev=103419&view=auto
==============================================================================
--- llvm/trunk/test/CodeGen/X86/2010-05-10-DAGCombinerBug.ll (added)
+++ llvm/trunk/test/CodeGen/X86/2010-05-10-DAGCombinerBug.ll Mon May 10 14:03:57 2010
@@ -0,0 +1,11 @@
+; RUN: llc < %s -mtriple=i386-apple-darwin10
+; PR7018
+; rdar://7939869
+
+define i32 @CXB30130(i32 %num1, i16* nocapture %num2, float* nocapture %num3, double* nocapture %num4) nounwind ssp {
+entry:
+  %0 = load i16* %num2, align 2                   ; <i16> [#uses=2]
+  %1 = mul nsw i16 %0, %0                         ; <i16> [#uses=1]
+  store i16 %1, i16* %num2, align 2
+  ret i32 undef
+}