Let StructRetPromotion check if all if its users are really calls or invokesn,

not other instructions. This fixes a crash with the added testcase.

llvm-svn: 51992

2 files changed, 24 insertions, 0 deletions

diff --git a/llvm/lib/Transforms/IPO/StructRetPromotion.cpp b/llvm/lib/Transforms/IPO/StructRetPromotion.cpp
index 97a532b8b11..94bf4c6d5f2 100644
--- a/llvm/lib/Transforms/IPO/StructRetPromotion.cpp
+++ b/llvm/lib/Transforms/IPO/StructRetPromotion.cpp
@@ -165,6 +165,10 @@ bool SRETPromotion::isSafeToUpdateAllCallers(Function *F) {
 
     CallSite CS = CallSite::get(*FnUseI);
     Instruction *Call = CS.getInstruction();
+    // The function is used by something else than a call or invoke instruction,
+    // we can't change it!
+    if (!Call)
+      return false;
     CallSite::arg_iterator AI = CS.arg_begin();
     Value *FirstArg = *AI;
 
diff --git a/llvm/test/Transforms/SRETPromotion/2008-06-05-non-call-use.ll b/llvm/test/Transforms/SRETPromotion/2008-06-05-non-call-use.ll
new file mode 100644
index 00000000000..10f92efc865
--- /dev/null
+++ b/llvm/test/Transforms/SRETPromotion/2008-06-05-non-call-use.ll
@@ -0,0 +1,20 @@
+; This test shows an sret function that is used as an operand to a bitcast.
+; StructRetPromotion used to assume that a function was only used by call or
+; invoke instructions, making this code cause an assertion failure.
+
+; We're mainly testing for opt not to crash, but we'll check to see if the sret
+; attribute is still there for good measure.
+; RUN: llvm-as < %s | opt -sretpromotion | llvm-dis | grep sret
+
+%struct.S = type <{ i32, i32 }>
+
+define i32 @main() {
+entry:
+        %bar = bitcast void (%struct.S*)* @foo to i32 ()*
+	ret i32 undef
+}
+
+define internal void @foo(%struct.S* sret) {
+entry:
+	ret void
+}