llvm/test/Analysis/ValueTracking/phi-self.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt -S -passes=instsimplify < %s | FileCheck %s

; Test `%r` can be replaced by `%nonpoison`.

define i32 @other_noundef(i32 noundef %arg) {
; CHECK-LABEL: define i32 @other_noundef(
; CHECK-SAME: i32 noundef [[ARG:%.*]]) {
; CHECK-NEXT:  [[START:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[NONPOISON:%.*]] = phi i32 [ 0, %[[START]] ], [ [[NONPOISON]], %[[BB0:.*]] ], [ [[ARG]], %[[BB1:.*]] ]
; CHECK-NEXT:    [[I:%.*]] = call i32 @opaque()
; CHECK-NEXT:    switch i32 [[I]], label %[[EXIT:.*]] [
; CHECK-NEXT:      i32 0, label %[[BB0]]
; CHECK-NEXT:      i32 1, label %[[BB1]]
; CHECK-NEXT:    ]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    ret i32 [[NONPOISON]]
; CHECK:       [[BB0]]:
; CHECK-NEXT:    br label %[[LOOP]]
; CHECK:       [[BB1]]:
; CHECK-NEXT:    br label %[[LOOP]]
;
start:
  br label %loop

loop:
  %nonpoison = phi i32 [ 0, %start ], [ %nonpoison, %bb0 ], [ %arg, %bb1 ]
  %i = call i32 @opaque()
  switch i32 %i, label %exit [
  i32 0, label %bb0
  i32 1, label %bb1
  ]

exit:
  %r = freeze i32 %nonpoison
  ret i32 %r

bb0:
  br label %loop

bb1:
  br label %loop
}

define i32 @other_poison(i32 %arg) {
; CHECK-LABEL: define i32 @other_poison(
; CHECK-SAME: i32 [[ARG:%.*]]) {
; CHECK-NEXT:  [[START:.*]]:
; CHECK-NEXT:    br label %[[LOOP:.*]]
; CHECK:       [[LOOP]]:
; CHECK-NEXT:    [[MAYPOISON:%.*]] = phi i32 [ 0, %[[START]] ], [ [[MAYPOISON]], %[[BB0:.*]] ], [ [[ARG]], %[[BB1:.*]] ]
; CHECK-NEXT:    [[I:%.*]] = call i32 @opaque()
; CHECK-NEXT:    switch i32 [[I]], label %[[EXIT:.*]] [
; CHECK-NEXT:      i32 0, label %[[BB0]]
; CHECK-NEXT:      i32 1, label %[[BB1]]
; CHECK-NEXT:    ]
; CHECK:       [[EXIT]]:
; CHECK-NEXT:    [[R:%.*]] = freeze i32 [[MAYPOISON]]
; CHECK-NEXT:    ret i32 [[R]]
; CHECK:       [[BB0]]:
; CHECK-NEXT:    br label %[[LOOP]]
; CHECK:       [[BB1]]:
; CHECK-NEXT:    br label %[[LOOP]]
;
start:
  br label %loop

loop:
  %maypoison = phi i32 [ 0, %start ], [ %maypoison, %bb0 ], [ %arg, %bb1 ]
  %i = call i32 @opaque()
  switch i32 %i, label %exit [
  i32 0, label %bb0
  i32 1, label %bb1
  ]

exit:
  %r = freeze i32 %maypoison
  ret i32 %r

bb0:
  br label %loop

bb1:
  br label %loop
}

declare i32 @opaque()