Fix PR1780

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43893 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Transforms/Scalar/InstructionCombining.cpp b/lib/Transforms/Scalar/InstructionCombining.cpp
index 41485b203ecdacd398b672fee9072e083c55c7da..c8d03be2c008cbe0e045212c4873eb1169aab997 100644 (file)
--- a/lib/Transforms/Scalar/InstructionCombining.cpp
+++ b/lib/Transforms/Scalar/InstructionCombining.cpp
@@ -7582,7 +7582,7 @@ static unsigned GetOrEnforceKnownAlignment(Value *V, TargetData *TD,
                                            unsigned PrefAlign = 0) {
   if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V)) {
     unsigned Align = GV->getAlignment();
-    if (Align == 0 && TD) 
+    if (Align == 0 && TD && !isa<OpaqueType>(GV->getType()->getElementType())) 
       Align = TD->getPrefTypeAlignment(GV->getType()->getElementType());
 
     // If there is a large requested alignment and we can, bump up the alignment

diff --git a/test/Transforms/InstCombine/2007-11-07-OpaqueAlignCrash.ll b/test/Transforms/InstCombine/2007-11-07-OpaqueAlignCrash.ll
new file mode 100644 (file)
index 0000000..61e67ad
--- /dev/null
+++ b/test/Transforms/InstCombine/2007-11-07-OpaqueAlignCrash.ll
@@ -0,0 +1,19 @@
+; RUN: llvm-as < %s | opt -instcombine -disable-output
+; PR1780
+
+target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
+target triple = "i686-pc-linux-gnu"
+
+%opaque_t = type opaque
+
+@g = external global %opaque_t
+
+define i32 @foo() {
+entry:
+        %x = load i8* bitcast (%opaque_t* @g to i8*)
+        %y = load i32* bitcast (%opaque_t* @g to i32*)
+       %z = zext i8 %x to i32
+       %r = add i32 %y, %z
+        ret i32 %r
+}
+