llvm/test/Transforms/Mem2Reg/pr24179.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt -passes=mem2reg < %s -S | FileCheck %s

declare i32 @def(i32)
declare i1 @use(i32)

; Special case of a single-BB alloca does not apply here since the load
; is affected by the following store. Expect this case to be identified
; and a PHI node to be created.
define void @test1() {
; CHECK-LABEL: @test1(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[T_0:%.*]] = phi i32 [ undef, [[ENTRY:%.*]] ], [ [[N:%.*]], [[LOOP]] ]
; CHECK-NEXT:    [[C:%.*]] = call i1 @use(i32 [[T_0]])
; CHECK-NEXT:    [[N]] = call i32 @def(i32 7)
; CHECK-NEXT:    br i1 [[C]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK:       exit:
; CHECK-NEXT:    ret void
;
  entry:
  %t = alloca i32
  br label %loop

  loop:
  %v = load i32, ptr %t
  %c = call i1 @use(i32 %v)
  %n = call i32 @def(i32 7)
  store i32 %n, ptr %t
  br i1 %c, label %loop, label %exit

  exit:
  ret void
}

; Same as above, except there is no following store. The alloca should just be
; replaced with an undef
define void @test2() {
; CHECK-LABEL: @test2(
; CHECK-NEXT:  entry:
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[C:%.*]] = call i1 @use(i32 undef)
; CHECK-NEXT:    br i1 [[C]], label [[LOOP]], label [[EXIT:%.*]]
; CHECK:       exit:
; CHECK-NEXT:    ret void
;
  entry:
  %t = alloca i32
  br label %loop

  loop:
  %v = load i32, ptr %t
  %c = call i1 @use(i32 %v)
  br i1 %c, label %loop, label %exit

  exit:
  ret void
}