test/Transforms/MergeFunc/linkonce.ll

; RUN: opt -S -passes=mergefunc < %s | FileCheck %s -implicit-check-not=funA -implicit-check-not=funC

; 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.

define linkonce i32 @funC(i32 %x, i32 %y) {
  %sum = add i32 %x, %y
  %sum2 = add i32 %x, %sum
  %sum3 = add i32 %x, %sum2
  ret i32 %sum3
}

define linkonce 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 i32 @funA(i32 %x, i32 %y) {
  %sum = add i32 %x, %y
  %sum2 = add i32 %x, %sum
  %sum3 = add i32 %x, %sum2
  ret i32 %sum3
}

; This creates a use of @funB, preventing -passes=mergefunc from deleting it.
; @funC, however, can safely be deleted as it has no uses, and is discardable
; if unused.
@take_addr_of_funB = global ptr @funB
;.
; CHECK: @take_addr_of_funB = global ptr @funB
;.
; CHECK-LABEL: define private i32 @0(
; CHECK-SAME: i32 [[X:%.*]], i32 [[Y:%.*]]) {
; CHECK-NEXT:    [[SUM:%.*]] = add i32 [[X]], [[Y]]
; CHECK-NEXT:    [[SUM2:%.*]] = add i32 [[X]], [[SUM]]
; CHECK-NEXT:    [[SUM3:%.*]] = add i32 [[X]], [[SUM2]]
; CHECK-NEXT:    ret i32 [[SUM3]]
;
;
; CHECK-LABEL: define linkonce i32 @funB(
; CHECK-SAME: i32 [[TMP0:%.*]], i32 [[TMP1:%.*]]) {
; CHECK-NEXT:    [[TMP3:%.*]] = tail call i32 @0(i32 [[TMP0]], i32 [[TMP1]])
; CHECK-NEXT:    ret i32 [[TMP3]]
;