xref: /llvm-project/llvm/test/Transforms/LoopVectorize/unsupported_early_exit.ll (revision 5fae408d3a4c073ee43aec9906fa44ffe4026301)

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
; RUN: opt -S < %s -p loop-vectorize -enable-early-exit-vectorization  -force-vector-width=4 | FileCheck %s

declare void @init_mem(ptr, i64);


; The early exit (i.e. unknown exit-not-taken count) is the latch - we don't
; support this yet.
define i64 @early_exit_on_last_block() {
; CHECK-LABEL: define i64 @early_exit_on_last_block() {
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[P1:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    [[P2:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT:    call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT:    br label [[LAND_RHS:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[SEARCH:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT:    [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT:    [[CMP1:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT:    br i1 [[CMP1]], label [[SEARCH]], label [[FOR_END_LOOPEXIT:%.*]]
; CHECK:       search:
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT:    [[TMP41:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT:    [[ARRAYIDX1:%.*]] = getelementptr inbounds i8, ptr [[P2]], i64 [[INDEX]]
; CHECK-NEXT:    [[TMP42:%.*]] = load i8, ptr [[ARRAYIDX1]], align 1
; CHECK-NEXT:    [[CMP3:%.*]] = icmp eq i8 [[TMP41]], [[TMP42]]
; CHECK-NEXT:    br i1 [[CMP3]], label [[FOR_END_LOOPEXIT]], label [[LAND_RHS]]
; CHECK:       loop.end:
; CHECK-NEXT:    [[START_0_LCSSA:%.*]] = phi i64 [ 64, [[LAND_RHS]] ], [ [[INDEX]], [[SEARCH]] ]
; CHECK-NEXT:    ret i64 [[START_0_LCSSA]]
;
entry:
  %p1 = alloca [1024 x i8]
  %p2 = alloca [1024 x i8]
  call void @init_mem(ptr %p1, i64 1024)
  call void @init_mem(ptr %p2, i64 1024)
  br label %loop

loop:
  %index = phi i64 [ %index.next, %search ], [ 3, %entry ]
  %index.next = add i64 %index, 1
  %exitcond = icmp ne i64 %index.next, 67
  br i1 %exitcond, label %search, label %loop.end

search:
  %arrayidx = getelementptr inbounds i8, ptr %p1, i64 %index
  %ld1 = load i8, ptr %arrayidx, align 1
  %arrayidx1 = getelementptr inbounds i8, ptr %p2, i64 %index
  %ld2 = load i8, ptr %arrayidx1, align 1
  %cmp3 = icmp eq i8 %ld1, %ld2
  br i1 %cmp3, label %loop.end, label %loop

loop.end:
  %retval = phi i64 [ 64, %loop ], [ %index, %search ]
  ret i64 %retval
}


; We don't currently support multiple early exits.
define i64 @multiple_uncountable_exits() {
; CHECK-LABEL: define i64 @multiple_uncountable_exits() {
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[P1:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    [[P2:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT:    call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT:    br label [[SEARCH1:%.*]]
; CHECK:       search1:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD1:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT:    [[ARRAYIDX1:%.*]] = getelementptr inbounds i8, ptr [[P2]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD2:%.*]] = load i8, ptr [[ARRAYIDX1]], align 1
; CHECK-NEXT:    [[CMP1:%.*]] = icmp eq i8 [[LD1]], [[LD2]]
; CHECK-NEXT:    br i1 [[CMP1]], label [[LOOP_END:%.*]], label [[SEARCH2:%.*]]
; CHECK:       search2:
; CHECK-NEXT:    [[CMP2:%.*]] = icmp ult i8 [[LD1]], 34
; CHECK-NEXT:    br i1 [[CMP2]], label [[LOOP_END]], label [[LOOP_INC]]
; CHECK:       loop.inc:
; CHECK-NEXT:    [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[SEARCH1]], label [[LOOP_END]]
; CHECK:       loop.end:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[SEARCH1]] ], [ 100, [[SEARCH2]] ], [ 43, [[LOOP_INC]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  %p1 = alloca [1024 x i8]
  %p2 = alloca [1024 x i8]
  call void @init_mem(ptr %p1, i64 1024)
  call void @init_mem(ptr %p2, i64 1024)
  br label %search1

search1:
  %index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
  %arrayidx = getelementptr inbounds i8, ptr %p1, i64 %index
  %ld1 = load i8, ptr %arrayidx, align 1
  %arrayidx1 = getelementptr inbounds i8, ptr %p2, i64 %index
  %ld2 = load i8, ptr %arrayidx1, align 1
  %cmp1 = icmp eq i8 %ld1, %ld2
  br i1 %cmp1, label %loop.end, label %search2

search2:
  %cmp2 = icmp ult i8 %ld1, 34
  br i1 %cmp2, label %loop.end, label %loop.inc

loop.inc:
  %index.next = add i64 %index, 1
  %exitcond = icmp ne i64 %index.next, 67
  br i1 %exitcond, label %search1, label %loop.end

loop.end:
  %retval = phi i64 [ %index, %search1 ], [ 100, %search2 ], [ 43, %loop.inc ]
  ret i64 %retval
}


define i64 @uncountable_exit_infinite_loop() {
; CHECK-LABEL: define i64 @uncountable_exit_infinite_loop() {
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[P1:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    [[P2:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT:    call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD1:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT:    [[ARRAYIDX1:%.*]] = getelementptr inbounds i8, ptr [[P2]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD2:%.*]] = load i8, ptr [[ARRAYIDX1]], align 1
; CHECK-NEXT:    [[CMP3:%.*]] = icmp eq i8 [[LD1]], [[LD2]]
; CHECK-NEXT:    br i1 [[CMP3]], label [[LOOP_INC]], label [[LOOP_END:%.*]]
; CHECK:       loop.inc:
; CHECK-NEXT:    [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT:    br label [[LOOP]]
; CHECK:       loop.end:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[LOOP]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  %p1 = alloca [1024 x i8]
  %p2 = alloca [1024 x i8]
  call void @init_mem(ptr %p1, i64 1024)
  call void @init_mem(ptr %p2, i64 1024)
  br label %loop

loop:
  %index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
  %arrayidx = getelementptr inbounds i8, ptr %p1, i64 %index
  %ld1 = load i8, ptr %arrayidx, align 1
  %arrayidx1 = getelementptr inbounds i8, ptr %p2, i64 %index
  %ld2 = load i8, ptr %arrayidx1, align 1
  %cmp3 = icmp eq i8 %ld1, %ld2
  br i1 %cmp3, label %loop.inc, label %loop.end

loop.inc:
  %index.next = add i64 %index, 1
  %exitcond = icmp ne i64 %index.next, 67
  br label %loop

loop.end:
  %retval = phi i64 [ %index, %loop ]
  ret i64 %retval
}


define i64 @loop_contains_unsafe_call() {
; CHECK-LABEL: define i64 @loop_contains_unsafe_call() {
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[P1:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    [[P2:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT:    call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i32, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD1:%.*]] = load i32, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT:    [[BAD_CALL:%.*]] = call i32 @foo(i32 [[LD1]]) #[[ATTR1:[0-9]+]]
; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[BAD_CALL]], 34
; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP_INC]], label [[LOOP_END:%.*]]
; CHECK:       loop.inc:
; CHECK-NEXT:    [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[LOOP_END]]
; CHECK:       loop.end:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[LOOP]] ], [ 67, [[LOOP_INC]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  %p1 = alloca [1024 x i8]
  %p2 = alloca [1024 x i8]
  call void @init_mem(ptr %p1, i64 1024)
  call void @init_mem(ptr %p2, i64 1024)
  br label %loop

loop:
  %index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
  %arrayidx = getelementptr inbounds i32, ptr %p1, i64 %index
  %ld1 = load i32, ptr %arrayidx, align 1
  %bad_call = call i32 @foo(i32 %ld1) #0
  %cmp = icmp eq i32 %bad_call, 34
  br i1 %cmp, label %loop.inc, label %loop.end

loop.inc:
  %index.next = add i64 %index, 1
  %exitcond = icmp ne i64 %index.next, 67
  br i1 %exitcond, label %loop, label %loop.end

loop.end:
  %retval = phi i64 [ %index, %loop ], [ 67, %loop.inc ]
  ret i64 %retval
}


define i64 @loop_contains_unsafe_div() {
; CHECK-LABEL: define i64 @loop_contains_unsafe_div() {
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[P1:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    [[P2:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT:    call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD1:%.*]] = load i32, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT:    [[DIV:%.*]] = udiv i32 20000, [[LD1]]
; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[DIV]], 1
; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP_INC]], label [[LOOP_END:%.*]]
; CHECK:       loop.inc:
; CHECK-NEXT:    [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[LOOP_END]]
; CHECK:       loop.end:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[LOOP]] ], [ 67, [[LOOP_INC]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  %p1 = alloca [1024 x i8]
  %p2 = alloca [1024 x i8]
  call void @init_mem(ptr %p1, i64 1024)
  call void @init_mem(ptr %p2, i64 1024)
  br label %loop

loop:
  %index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
  %arrayidx = getelementptr inbounds i8, ptr %p1, i64 %index
  %ld1 = load i32, ptr %arrayidx, align 1
  %div = udiv i32 20000, %ld1
  %cmp = icmp eq i32 %div, 1
  br i1 %cmp, label %loop.inc, label %loop.end

loop.inc:
  %index.next = add i64 %index, 1
  %exitcond = icmp ne i64 %index.next, 67
  br i1 %exitcond, label %loop, label %loop.end

loop.end:
  %retval = phi i64 [ %index, %loop ], [ 67, %loop.inc ]
  ret i64 %retval
}


define i64 @loop_contains_store(ptr %dest) {
; CHECK-LABEL: define i64 @loop_contains_store(
; CHECK-SAME: ptr [[DEST:%.*]]) {
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[P1:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i32, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD1:%.*]] = load i32, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT:    [[ARRAYIDX2:%.*]] = getelementptr inbounds i32, ptr [[DEST]], i64 [[INDEX]]
; CHECK-NEXT:    store i32 [[LD1]], ptr [[ARRAYIDX2]], align 4
; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[LD1]], 1
; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP_INC]], label [[LOOP_END:%.*]]
; CHECK:       loop.inc:
; CHECK-NEXT:    [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[LOOP_END]]
; CHECK:       loop.end:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[LOOP]] ], [ 67, [[LOOP_INC]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  %p1 = alloca [1024 x i8]
  call void @init_mem(ptr %p1, i64 1024)
  br label %loop

loop:
  %index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
  %arrayidx = getelementptr inbounds i32, ptr %p1, i64 %index
  %ld1 = load i32, ptr %arrayidx, align 1
  %arrayidx2 = getelementptr inbounds i32, ptr %dest, i64 %index
  store i32 %ld1, ptr %arrayidx2, align 4
  %cmp = icmp eq i32 %ld1, 1
  br i1 %cmp, label %loop.inc, label %loop.end

loop.inc:
  %index.next = add i64 %index, 1
  %exitcond = icmp ne i64 %index.next, 67
  br i1 %exitcond, label %loop, label %loop.end

loop.end:
  %retval = phi i64 [ %index, %loop ], [ 67, %loop.inc ]
  ret i64 %retval
}


define i64 @uncountable_exit_in_conditional_block(ptr %mask) {
; CHECK-LABEL: define i64 @uncountable_exit_in_conditional_block(
; CHECK-SAME: ptr [[MASK:%.*]]) {
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[P1:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    [[P2:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT:    call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT:    [[ARRAYIDX1:%.*]] = getelementptr inbounds i8, ptr [[MASK]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD1:%.*]] = load i8, ptr [[ARRAYIDX1]], align 1
; CHECK-NEXT:    [[CMP1:%.*]] = icmp ne i8 [[LD1]], 0
; CHECK-NEXT:    br i1 [[CMP1]], label [[LOOP_SEARCH:%.*]], label [[LOOP_INC]]
; CHECK:       loop.search:
; CHECK-NEXT:    [[ARRAYIDX2:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD2:%.*]] = load i8, ptr [[ARRAYIDX2]], align 1
; CHECK-NEXT:    [[ARRAYIDX3:%.*]] = getelementptr inbounds i8, ptr [[P2]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD3:%.*]] = load i8, ptr [[ARRAYIDX3]], align 1
; CHECK-NEXT:    [[CMP2:%.*]] = icmp eq i8 [[LD2]], [[LD3]]
; CHECK-NEXT:    br i1 [[CMP2]], label [[LOOP_INC]], label [[LOOP_END:%.*]]
; CHECK:       loop.inc:
; CHECK-NEXT:    [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[LOOP_END]]
; CHECK:       loop.end:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[LOOP_SEARCH]] ], [ 67, [[LOOP_INC]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  %p1 = alloca [1024 x i8]
  %p2 = alloca [1024 x i8]
  call void @init_mem(ptr %p1, i64 1024)
  call void @init_mem(ptr %p2, i64 1024)
  br label %loop

loop:
  %index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
  %arrayidx1 = getelementptr inbounds i8, ptr %mask, i64 %index
  %ld1 = load i8, ptr %arrayidx1, align 1
  %cmp1 = icmp ne i8 %ld1, 0
  br i1 %cmp1, label %loop.search, label %loop.inc

loop.search:
  %arrayidx2 = getelementptr inbounds i8, ptr %p1, i64 %index
  %ld2 = load i8, ptr %arrayidx2, align 1
  %arrayidx3 = getelementptr inbounds i8, ptr %p2, i64 %index
  %ld3 = load i8, ptr %arrayidx3, align 1
  %cmp2 = icmp eq i8 %ld2, %ld3
  br i1 %cmp2, label %loop.inc, label %loop.end

loop.inc:
  %index.next = add i64 %index, 1
  %exitcond = icmp ne i64 %index.next, 67
  br i1 %exitcond, label %loop, label %loop.end

loop.end:
  %retval = phi i64 [ %index, %loop.search ], [ 67, %loop.inc ]
  ret i64 %retval
}


define i64 @same_exit_block_pre_inc_use1_with_reduction() {
; CHECK-LABEL: define i64 @same_exit_block_pre_inc_use1_with_reduction() {
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[P1:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    [[P2:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT:    call void @init_mem(ptr [[P2]], i64 1024)
; CHECK-NEXT:    br label [[LAND_RHS:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[FOR_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT:    [[RED:%.*]] = phi i64 [ [[RED_NEXT:%.*]], [[FOR_INC]] ], [ 0, [[ENTRY]] ]
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT:    [[TMP38:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT:    [[ARRAYIDX1:%.*]] = getelementptr inbounds i8, ptr [[P2]], i64 [[INDEX]]
; CHECK-NEXT:    [[TMP39:%.*]] = load i8, ptr [[ARRAYIDX1]], align 1
; CHECK-NEXT:    [[LD2_ZEXT:%.*]] = zext i8 [[TMP39]] to i64
; CHECK-NEXT:    [[RED_NEXT]] = add i64 [[RED]], [[LD2_ZEXT]]
; CHECK-NEXT:    [[CMP3:%.*]] = icmp eq i8 [[TMP38]], [[TMP39]]
; CHECK-NEXT:    br i1 [[CMP3]], label [[FOR_INC]], label [[FOR_END_LOOPEXIT:%.*]]
; CHECK:       loop.inc:
; CHECK-NEXT:    [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LAND_RHS]], label [[FOR_END_LOOPEXIT]]
; CHECK:       loop.end:
; CHECK-NEXT:    [[RED_NEXT_LCSSA:%.*]] = phi i64 [ [[RED_NEXT]], [[FOR_INC]] ], [ [[RED_NEXT]], [[LAND_RHS]] ]
; CHECK-NEXT:    [[FINAL_IND:%.*]] = phi i64 [ [[INDEX]], [[LAND_RHS]] ], [ 67, [[FOR_INC]] ]
; CHECK-NEXT:    [[START_0_LCSSA:%.*]] = add i64 [[RED_NEXT_LCSSA]], [[FINAL_IND]]
; CHECK-NEXT:    ret i64 [[START_0_LCSSA]]
;
entry:
  %p1 = alloca [1024 x i8]
  %p2 = alloca [1024 x i8]
  call void @init_mem(ptr %p1, i64 1024)
  call void @init_mem(ptr %p2, i64 1024)
  br label %loop

loop:
  %index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
  %red = phi i64 [ %red.next, %loop.inc ], [ 0, %entry ]
  %arrayidx = getelementptr inbounds i8, ptr %p1, i64 %index
  %ld1 = load i8, ptr %arrayidx, align 1
  %arrayidx1 = getelementptr inbounds i8, ptr %p2, i64 %index
  %ld2 = load i8, ptr %arrayidx1, align 1
  %ld2.zext = zext i8 %ld2 to i64
  %red.next = add i64 %red, %ld2.zext
  %cmp3 = icmp eq i8 %ld1, %ld2
  br i1 %cmp3, label %loop.inc, label %loop.end

loop.inc:
  %index.next = add i64 %index, 1
  %exitcond = icmp ne i64 %index.next, 67
  br i1 %exitcond, label %loop, label %loop.end

loop.end:
  %final.ind = phi i64 [ %index, %loop ], [ 67, %loop.inc ]
  %retval = add i64 %red.next, %final.ind
  ret i64 %retval
}


define i64 @uncountable_exit_has_multiple_outside_successors() {
; CHECK-LABEL: define i64 @uncountable_exit_has_multiple_outside_successors() {
; CHECK-NEXT:  entry:
; CHECK-NEXT:    [[P1:%.*]] = alloca [1024 x i8], align 1
; CHECK-NEXT:    call void @init_mem(ptr [[P1]], i64 1024)
; CHECK-NEXT:    br label [[LOOP:%.*]]
; CHECK:       loop:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ [[INDEX_NEXT:%.*]], [[LOOP_INC:%.*]] ], [ 3, [[ENTRY:%.*]] ]
; CHECK-NEXT:    [[ARRAYIDX:%.*]] = getelementptr inbounds i8, ptr [[P1]], i64 [[INDEX]]
; CHECK-NEXT:    [[LD1:%.*]] = load i8, ptr [[ARRAYIDX]], align 1
; CHECK-NEXT:    switch i8 [[LD1]], label [[LOOP_INC]] [
; CHECK-NEXT:      i8 2, label [[LOOP_END:%.*]]
; CHECK-NEXT:      i8 3, label [[LOOP_SURPRISE:%.*]]
; CHECK-NEXT:    ]
; CHECK:       loop.inc:
; CHECK-NEXT:    [[INDEX_NEXT]] = add i64 [[INDEX]], 1
; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDEX_NEXT]], 67
; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[LOOP_END]]
; CHECK:       loop.surprise:
; CHECK-NEXT:    ret i64 3
; CHECK:       loop.end:
; CHECK-NEXT:    [[RETVAL:%.*]] = phi i64 [ [[INDEX]], [[LOOP]] ], [ 67, [[LOOP_INC]] ]
; CHECK-NEXT:    ret i64 [[RETVAL]]
;
entry:
  %p1 = alloca [1024 x i8]
  call void @init_mem(ptr %p1, i64 1024)
  br label %loop

loop:
  %index = phi i64 [ %index.next, %loop.inc ], [ 3, %entry ]
  %arrayidx = getelementptr inbounds i8, ptr %p1, i64 %index
  %ld1 = load i8, ptr %arrayidx, align 1
  switch i8 %ld1, label %loop.inc [
  i8 2, label %loop.end
  i8 3, label %loop.surprise
  ]

loop.inc:
  %index.next = add i64 %index, 1
  %exitcond = icmp ne i64 %index.next, 67
  br i1 %exitcond, label %loop, label %loop.end

loop.surprise:
  ret i64 3

loop.end:
  %retval = phi i64 [ %index, %loop ], [ 67, %loop.inc ]
  ret i64 %retval
}


declare i32 @foo(i32) readonly
declare <vscale x 4 x i32> @foo_vec(<vscale x 4 x i32>)

attributes #0 = { "vector-function-abi-variant"="_ZGVsNxv_foo(foo_vec)" }