MergeFunctions: Impose a total order on the replacement of functions

[oota-llvm.git] / test / Transforms / MergeFunc / linkonce_odr.ll

diff --git a/test/Transforms/MergeFunc/linkonce_odr.ll b/test/Transforms/MergeFunc/linkonce_odr.ll
new file mode 100644 (file)
index 0000000..1ad0d72
--- /dev/null
+++ b/test/Transforms/MergeFunc/linkonce_odr.ll
@@ -0,0 +1,30 @@
+; RUN: opt -S -mergefunc < %s | FileCheck %s
+
+; Replacments should be totally ordered on the function name.
+; If we don't do this we  can end up with one module defining a thunk for @funA
+; and another module defining a thunk for @funB.
+;
+; The problem with this is that the linker could then choose these two stubs
+; each of the two modules and we end up with two stubs calling each other.
+
+; CHECK-LABEL: define linkonce_odr i32 @funA
+; CHECK-NEXT:    add
+; CHECK:         ret
+
+; CHECK-LABEL: define linkonce_odr i32 @funB
+; CHECK-NEXT:    tail call i32 @funA(i32 %0, i32 %1)
+; CHECK-NEXT:    ret
+
+define linkonce_odr i32 @funB(i32 %x, i32 %y) {
+  %sum = add i32 %x, %y
+  %sum2 = add i32 %x, %sum
+  %sum3 = add i32 %x, %sum2
+  ret i32 %sum3
+}
+
+define linkonce_odr i32 @funA(i32 %x, i32 %y) {
+  %sum = add i32 %x, %y
+  %sum2 = add i32 %x, %sum
+  %sum3 = add i32 %x, %sum2
+  ret i32 %sum3
+}