// Memory barriers
// TODO: Get this to fold the constant into the instruction.
-let isCodeGenOnly = 1 in
+let isCodeGenOnly = 1, Defs = [EFLAGS] in
def OR32mrLocked : I<0x09, MRMDestMem, (outs), (ins i32mem:$dst, GR32:$zero),
"lock\n\t"
"or{l}\t{$zero, $dst|$dst, $zero}",
--- /dev/null
+; RUN: llc < %s -mtriple=i686-linux -mattr=-sse | FileCheck %s
+; PR11768
+
+@ptr = external global i8*
+
+define void @baz() nounwind ssp {
+entry:
+ %0 = load i8** @ptr, align 4
+ %cmp = icmp eq i8* %0, null
+ fence seq_cst
+ br i1 %cmp, label %if.then, label %if.else
+
+; Make sure the fence comes before the comparison, since it
+; clobbers EFLAGS.
+
+; CHECK: lock
+; CHECK-NEXT: orl {{.*}}, (%esp)
+; CHECK-NEXT: cmpl $0
+
+if.then: ; preds = %entry
+ tail call void bitcast (void (...)* @foo to void ()*)() nounwind
+ br label %if.end
+
+if.else: ; preds = %entry
+ tail call void bitcast (void (...)* @bar to void ()*)() nounwind
+ br label %if.end
+
+if.end: ; preds = %if.else, %if.then
+ ret void
+}
+
+declare void @foo(...)
+
+declare void @bar(...)