[llvm-commits] [llvm] r85786 - in /llvm/trunk: lib/Transforms/Utils/PromoteMemoryToRegister.cpp test/Transforms/Mem2Reg/crash.ll

[Chris Lattner]

Author: lattner
Date: Sun Nov  1 22:37:17 2009
New Revision: 85786

URL: http://llvm.org/viewvc/llvm-project?rev=85786&view=rev
Log:
fix a bug exposed by moving SRoA earlier which caused a crash building kc++

Modified:
    llvm/trunk/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
    llvm/trunk/test/Transforms/Mem2Reg/crash.ll

Modified: llvm/trunk/lib/Transforms/Utils/PromoteMemoryToRegister.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/PromoteMemoryToRegister.cpp?rev=85786&r1=85785&r2=85786&view=diff

==============================================================================
--- llvm/trunk/lib/Transforms/Utils/PromoteMemoryToRegister.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/PromoteMemoryToRegister.cpp Sun Nov  1 22:37:17 2009
@@ -749,7 +749,12 @@
     }
     
     // Otherwise, we *can* safely rewrite this load.
-    LI->replaceAllUsesWith(OnlyStore->getOperand(0));
+    Value *ReplVal = OnlyStore->getOperand(0);
+    // If the replacement value is the load, this must occur in unreachable
+    // code.
+    if (ReplVal == LI)
+      ReplVal = UndefValue::get(LI->getType());
+    LI->replaceAllUsesWith(ReplVal);
     if (AST && isa<PointerType>(LI->getType()))
       AST->deleteValue(LI);
     LI->eraseFromParent();

Modified: llvm/trunk/test/Transforms/Mem2Reg/crash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/Mem2Reg/crash.ll?rev=85786&r1=85785&r2=85786&view=diff

==============================================================================
--- llvm/trunk/test/Transforms/Mem2Reg/crash.ll (original)
+++ llvm/trunk/test/Transforms/Mem2Reg/crash.ll Sun Nov  1 22:37:17 2009
@@ -1,12 +1,12 @@
 ; RUN: opt < %s -mem2reg -S
 ; PR5023
 
-declare i32 @bar()
+declare i32 @test1f()
 
-define i32 @foo() {
+define i32 @test1() {
 entry:
   %whichFlag = alloca i32
-  %A = invoke i32 @bar()
+  %A = invoke i32 @test1f()
           to label %invcont2 unwind label %lpad86
 
 invcont2:
@@ -22,3 +22,20 @@
   
 }
 
+
+
+define i32 @test2() {
+entry:
+  %whichFlag = alloca i32
+  br label %bb15
+
+bb15:
+  %B = load i32* %whichFlag
+  ret i32 %B
+
+invcont2:
+  %C = load i32* %whichFlag
+  store i32 %C, i32* %whichFlag
+  br label %bb15
+}
+