llvm/test/Transforms/LoopVectorize/X86/predicated-udiv.ll

; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --check-globals none --filter-out-after "^scalar.ph" --version 6
; RUN: opt -p loop-vectorize -force-vector-width=4 -force-vector-interleave=2 -S %s | FileCheck %s

target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

; Test case for https://github.com/llvm/llvm-project/issues/175295.
define void @simplify_udiv_1_in_replicate_region(i8 %arg, ptr %src) {
; CHECK-LABEL: define void @simplify_udiv_1_in_replicate_region(
; CHECK-SAME: i8 [[ARG:%.*]], ptr [[SRC:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    br label %[[VECTOR_PH:.*]]
; CHECK:       [[VECTOR_PH]]:
; CHECK-NEXT:    [[TMP0:%.*]] = or i8 [[ARG]], 1
; CHECK-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x i8> poison, i8 [[TMP0]], i64 0
; CHECK-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x i8> [[BROADCAST_SPLATINSERT]], <4 x i8> poison, <4 x i32> zeroinitializer
; CHECK-NEXT:    [[TMP1:%.*]] = lshr <4 x i8> [[BROADCAST_SPLAT]], zeroinitializer
; CHECK-NEXT:    br label %[[VECTOR_BODY:.*]]
; CHECK:       [[VECTOR_BODY]]:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i32 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[VECTOR_BODY]] ]
; CHECK-NEXT:    [[TMP2:%.*]] = getelementptr inbounds i8, ptr [[SRC]], i32 [[INDEX]]
; CHECK-NEXT:    [[TMP3:%.*]] = getelementptr inbounds i8, ptr [[TMP2]], i64 4
; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <4 x i8>, ptr [[TMP3]], align 1
; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i32 [[INDEX]], 8
; CHECK-NEXT:    [[TMP7:%.*]] = icmp eq i32 [[INDEX_NEXT]], 16
; CHECK-NEXT:    br i1 [[TMP7]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP0:![0-9]+]]
; CHECK:       [[MIDDLE_BLOCK]]:
; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq <4 x i8> [[WIDE_LOAD]], zeroinitializer
; CHECK-NEXT:    [[PREDPHI:%.*]] = select <4 x i1> [[TMP4]], <4 x i8> zeroinitializer, <4 x i8> [[TMP1]]
; CHECK-NEXT:    [[TMP5:%.*]] = icmp ne <4 x i8> [[PREDPHI]], zeroinitializer
; CHECK-NEXT:    [[TMP6:%.*]] = zext <4 x i1> [[TMP5]] to <4 x i32>
; CHECK-NEXT:    [[VECTOR_RECUR_EXTRACT:%.*]] = extractelement <4 x i32> [[TMP6]], i32 3
; CHECK-NEXT:    br label %[[LATCH:.*]]
; CHECK:       [[LATCH]]:
;
entry:
  br label %loop

loop:
  %iv = phi i32 [ 0, %entry ], [ %iv.next, %latch ]
  %recur = phi i32 [ 0, %entry ], [ %zext, %latch ]
  %gep.src = getelementptr inbounds i8, ptr %src, i32 %iv
  %l = load i8, ptr %gep.src
  %c = icmp eq i8 %l, 0
  br i1 %c, label %latch, label %then

then:
  %or = or i8 %arg, 1
  %udiv = udiv i8 %or, 1
  br label %latch

latch:
  %phi = phi i8 [ %udiv, %then ], [ 0, %loop ]
  %cmp = icmp ne i8 %phi, 0
  %zext = zext i1 %cmp to i32
  %iv.next = add i32 %iv, 1
  %ec = icmp eq i32 %iv, 18
  br i1 %ec, label %exit, label %loop

exit:
  ret void
}

define void @simplify_udiv_4_in_replicate_region2(i8 %arg, ptr noalias %src, ptr %dst) {
; CHECK-LABEL: define void @simplify_udiv_4_in_replicate_region2(
; CHECK-SAME: i8 [[ARG:%.*]], ptr noalias [[SRC:%.*]], ptr [[DST:%.*]]) {
; CHECK-NEXT:  [[ENTRY:.*:]]
; CHECK-NEXT:    br label %[[VECTOR_PH:.*]]
; CHECK:       [[VECTOR_PH]]:
; CHECK-NEXT:    br label %[[VECTOR_BODY:.*]]
; CHECK:       [[VECTOR_BODY]]:
; CHECK-NEXT:    [[INDEX:%.*]] = phi i32 [ 0, %[[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], %[[PRED_STORE_CONTINUE29:.*]] ]
; CHECK-NEXT:    [[TMP0:%.*]] = add i32 [[INDEX]], 0
; CHECK-NEXT:    [[TMP1:%.*]] = add i32 [[INDEX]], 1
; CHECK-NEXT:    [[TMP2:%.*]] = add i32 [[INDEX]], 2
; CHECK-NEXT:    [[TMP3:%.*]] = add i32 [[INDEX]], 3
; CHECK-NEXT:    [[TMP4:%.*]] = add i32 [[INDEX]], 4
; CHECK-NEXT:    [[TMP5:%.*]] = add i32 [[INDEX]], 5
; CHECK-NEXT:    [[TMP6:%.*]] = add i32 [[INDEX]], 6
; CHECK-NEXT:    [[TMP7:%.*]] = add i32 [[INDEX]], 7
; CHECK-NEXT:    [[TMP8:%.*]] = getelementptr inbounds i8, ptr [[SRC]], i32 [[TMP0]]
; CHECK-NEXT:    [[TMP9:%.*]] = getelementptr inbounds i8, ptr [[TMP8]], i64 4
; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <4 x i8>, ptr [[TMP8]], align 1
; CHECK-NEXT:    [[WIDE_LOAD1:%.*]] = load <4 x i8>, ptr [[TMP9]], align 1
; CHECK-NEXT:    [[TMP10:%.*]] = icmp ne <4 x i8> [[WIDE_LOAD]], zeroinitializer
; CHECK-NEXT:    [[TMP11:%.*]] = icmp ne <4 x i8> [[WIDE_LOAD1]], zeroinitializer
; CHECK-NEXT:    [[TMP12:%.*]] = getelementptr inbounds i8, ptr [[DST]], i32 [[TMP0]]
; CHECK-NEXT:    [[TMP13:%.*]] = getelementptr inbounds i8, ptr [[DST]], i32 [[TMP1]]
; CHECK-NEXT:    [[TMP14:%.*]] = getelementptr inbounds i8, ptr [[DST]], i32 [[TMP2]]
; CHECK-NEXT:    [[TMP15:%.*]] = getelementptr inbounds i8, ptr [[DST]], i32 [[TMP3]]
; CHECK-NEXT:    [[TMP16:%.*]] = insertelement <4 x ptr> poison, ptr [[TMP12]], i32 0
; CHECK-NEXT:    [[TMP17:%.*]] = insertelement <4 x ptr> [[TMP16]], ptr [[TMP13]], i32 1
; CHECK-NEXT:    [[TMP18:%.*]] = insertelement <4 x ptr> [[TMP17]], ptr [[TMP14]], i32 2
; CHECK-NEXT:    [[TMP19:%.*]] = insertelement <4 x ptr> [[TMP18]], ptr [[TMP15]], i32 3
; CHECK-NEXT:    [[TMP20:%.*]] = getelementptr inbounds i8, ptr [[DST]], i32 [[TMP4]]
; CHECK-NEXT:    [[TMP21:%.*]] = getelementptr inbounds i8, ptr [[DST]], i32 [[TMP5]]
; CHECK-NEXT:    [[TMP22:%.*]] = getelementptr inbounds i8, ptr [[DST]], i32 [[TMP6]]
; CHECK-NEXT:    [[TMP23:%.*]] = getelementptr inbounds i8, ptr [[DST]], i32 [[TMP7]]
; CHECK-NEXT:    [[TMP24:%.*]] = insertelement <4 x ptr> poison, ptr [[TMP20]], i32 0
; CHECK-NEXT:    [[TMP25:%.*]] = insertelement <4 x ptr> [[TMP24]], ptr [[TMP21]], i32 1
; CHECK-NEXT:    [[TMP26:%.*]] = insertelement <4 x ptr> [[TMP25]], ptr [[TMP22]], i32 2
; CHECK-NEXT:    [[TMP27:%.*]] = insertelement <4 x ptr> [[TMP26]], ptr [[TMP23]], i32 3
; CHECK-NEXT:    [[TMP28:%.*]] = extractelement <4 x i1> [[TMP10]], i32 0
; CHECK-NEXT:    br i1 [[TMP28]], label %[[PRED_LOAD_IF:.*]], label %[[PRED_LOAD_CONTINUE:.*]]
; CHECK:       [[PRED_LOAD_IF]]:
; CHECK-NEXT:    [[TMP29:%.*]] = load i8, ptr [[TMP12]], align 1
; CHECK-NEXT:    [[TMP30:%.*]] = insertelement <4 x i8> poison, i8 [[TMP29]], i32 0
; CHECK-NEXT:    br label %[[PRED_LOAD_CONTINUE]]
; CHECK:       [[PRED_LOAD_CONTINUE]]:
; CHECK-NEXT:    [[TMP31:%.*]] = phi <4 x i8> [ poison, %[[VECTOR_BODY]] ], [ [[TMP30]], %[[PRED_LOAD_IF]] ]
; CHECK-NEXT:    [[TMP32:%.*]] = extractelement <4 x i1> [[TMP10]], i32 1
; CHECK-NEXT:    br i1 [[TMP32]], label %[[PRED_LOAD_IF2:.*]], label %[[PRED_LOAD_CONTINUE3:.*]]
; CHECK:       [[PRED_LOAD_IF2]]:
; CHECK-NEXT:    [[TMP33:%.*]] = load i8, ptr [[TMP13]], align 1
; CHECK-NEXT:    [[TMP34:%.*]] = insertelement <4 x i8> [[TMP31]], i8 [[TMP33]], i32 1
; CHECK-NEXT:    br label %[[PRED_LOAD_CONTINUE3]]
; CHECK:       [[PRED_LOAD_CONTINUE3]]:
; CHECK-NEXT:    [[TMP35:%.*]] = phi <4 x i8> [ [[TMP31]], %[[PRED_LOAD_CONTINUE]] ], [ [[TMP34]], %[[PRED_LOAD_IF2]] ]
; CHECK-NEXT:    [[TMP36:%.*]] = extractelement <4 x i1> [[TMP10]], i32 2
; CHECK-NEXT:    br i1 [[TMP36]], label %[[PRED_LOAD_IF4:.*]], label %[[PRED_LOAD_CONTINUE5:.*]]
; CHECK:       [[PRED_LOAD_IF4]]:
; CHECK-NEXT:    [[TMP37:%.*]] = load i8, ptr [[TMP14]], align 1
; CHECK-NEXT:    [[TMP38:%.*]] = insertelement <4 x i8> [[TMP35]], i8 [[TMP37]], i32 2
; CHECK-NEXT:    br label %[[PRED_LOAD_CONTINUE5]]
; CHECK:       [[PRED_LOAD_CONTINUE5]]:
; CHECK-NEXT:    [[TMP39:%.*]] = phi <4 x i8> [ [[TMP35]], %[[PRED_LOAD_CONTINUE3]] ], [ [[TMP38]], %[[PRED_LOAD_IF4]] ]
; CHECK-NEXT:    [[TMP40:%.*]] = extractelement <4 x i1> [[TMP10]], i32 3
; CHECK-NEXT:    br i1 [[TMP40]], label %[[PRED_LOAD_IF6:.*]], label %[[PRED_LOAD_CONTINUE7:.*]]
; CHECK:       [[PRED_LOAD_IF6]]:
; CHECK-NEXT:    [[TMP41:%.*]] = load i8, ptr [[TMP15]], align 1
; CHECK-NEXT:    [[TMP42:%.*]] = insertelement <4 x i8> [[TMP39]], i8 [[TMP41]], i32 3
; CHECK-NEXT:    br label %[[PRED_LOAD_CONTINUE7]]
; CHECK:       [[PRED_LOAD_CONTINUE7]]:
; CHECK-NEXT:    [[TMP43:%.*]] = phi <4 x i8> [ [[TMP39]], %[[PRED_LOAD_CONTINUE5]] ], [ [[TMP42]], %[[PRED_LOAD_IF6]] ]
; CHECK-NEXT:    [[TMP44:%.*]] = extractelement <4 x i1> [[TMP11]], i32 0
; CHECK-NEXT:    br i1 [[TMP44]], label %[[PRED_LOAD_IF8:.*]], label %[[PRED_LOAD_CONTINUE9:.*]]
; CHECK:       [[PRED_LOAD_IF8]]:
; CHECK-NEXT:    [[TMP45:%.*]] = load i8, ptr [[TMP20]], align 1
; CHECK-NEXT:    [[TMP46:%.*]] = insertelement <4 x i8> poison, i8 [[TMP45]], i32 0
; CHECK-NEXT:    br label %[[PRED_LOAD_CONTINUE9]]
; CHECK:       [[PRED_LOAD_CONTINUE9]]:
; CHECK-NEXT:    [[TMP47:%.*]] = phi <4 x i8> [ poison, %[[PRED_LOAD_CONTINUE7]] ], [ [[TMP46]], %[[PRED_LOAD_IF8]] ]
; CHECK-NEXT:    [[TMP48:%.*]] = extractelement <4 x i1> [[TMP11]], i32 1
; CHECK-NEXT:    br i1 [[TMP48]], label %[[PRED_LOAD_IF10:.*]], label %[[PRED_LOAD_CONTINUE11:.*]]
; CHECK:       [[PRED_LOAD_IF10]]:
; CHECK-NEXT:    [[TMP49:%.*]] = load i8, ptr [[TMP21]], align 1
; CHECK-NEXT:    [[TMP50:%.*]] = insertelement <4 x i8> [[TMP47]], i8 [[TMP49]], i32 1
; CHECK-NEXT:    br label %[[PRED_LOAD_CONTINUE11]]
; CHECK:       [[PRED_LOAD_CONTINUE11]]:
; CHECK-NEXT:    [[TMP51:%.*]] = phi <4 x i8> [ [[TMP47]], %[[PRED_LOAD_CONTINUE9]] ], [ [[TMP50]], %[[PRED_LOAD_IF10]] ]
; CHECK-NEXT:    [[TMP52:%.*]] = extractelement <4 x i1> [[TMP11]], i32 2
; CHECK-NEXT:    br i1 [[TMP52]], label %[[PRED_LOAD_IF12:.*]], label %[[PRED_LOAD_CONTINUE13:.*]]
; CHECK:       [[PRED_LOAD_IF12]]:
; CHECK-NEXT:    [[TMP53:%.*]] = load i8, ptr [[TMP22]], align 1
; CHECK-NEXT:    [[TMP54:%.*]] = insertelement <4 x i8> [[TMP51]], i8 [[TMP53]], i32 2
; CHECK-NEXT:    br label %[[PRED_LOAD_CONTINUE13]]
; CHECK:       [[PRED_LOAD_CONTINUE13]]:
; CHECK-NEXT:    [[TMP55:%.*]] = phi <4 x i8> [ [[TMP51]], %[[PRED_LOAD_CONTINUE11]] ], [ [[TMP54]], %[[PRED_LOAD_IF12]] ]
; CHECK-NEXT:    [[TMP56:%.*]] = extractelement <4 x i1> [[TMP11]], i32 3
; CHECK-NEXT:    br i1 [[TMP56]], label %[[PRED_LOAD_IF14:.*]], label %[[PRED_LOAD_CONTINUE15:.*]]
; CHECK:       [[PRED_LOAD_IF14]]:
; CHECK-NEXT:    [[TMP57:%.*]] = load i8, ptr [[TMP23]], align 1
; CHECK-NEXT:    [[TMP58:%.*]] = insertelement <4 x i8> [[TMP55]], i8 [[TMP57]], i32 3
; CHECK-NEXT:    br label %[[PRED_LOAD_CONTINUE15]]
; CHECK:       [[PRED_LOAD_CONTINUE15]]:
; CHECK-NEXT:    [[TMP59:%.*]] = phi <4 x i8> [ [[TMP55]], %[[PRED_LOAD_CONTINUE13]] ], [ [[TMP58]], %[[PRED_LOAD_IF14]] ]
; CHECK-NEXT:    [[TMP60:%.*]] = lshr <4 x i8> [[TMP43]], splat (i8 1)
; CHECK-NEXT:    [[TMP61:%.*]] = lshr <4 x i8> [[TMP59]], splat (i8 1)
; CHECK-NEXT:    [[TMP62:%.*]] = extractelement <4 x i1> [[TMP10]], i32 0
; CHECK-NEXT:    br i1 [[TMP62]], label %[[PRED_STORE_IF:.*]], label %[[PRED_STORE_CONTINUE:.*]]
; CHECK:       [[PRED_STORE_IF]]:
; CHECK-NEXT:    [[TMP63:%.*]] = extractelement <4 x i8> [[TMP60]], i32 0
; CHECK-NEXT:    store i8 [[TMP63]], ptr [[TMP12]], align 1
; CHECK-NEXT:    br label %[[PRED_STORE_CONTINUE]]
; CHECK:       [[PRED_STORE_CONTINUE]]:
; CHECK-NEXT:    [[TMP64:%.*]] = extractelement <4 x i1> [[TMP10]], i32 1
; CHECK-NEXT:    br i1 [[TMP64]], label %[[PRED_STORE_IF16:.*]], label %[[PRED_STORE_CONTINUE17:.*]]
; CHECK:       [[PRED_STORE_IF16]]:
; CHECK-NEXT:    [[TMP65:%.*]] = extractelement <4 x i8> [[TMP60]], i32 1
; CHECK-NEXT:    store i8 [[TMP65]], ptr [[TMP13]], align 1
; CHECK-NEXT:    br label %[[PRED_STORE_CONTINUE17]]
; CHECK:       [[PRED_STORE_CONTINUE17]]:
; CHECK-NEXT:    [[TMP66:%.*]] = extractelement <4 x i1> [[TMP10]], i32 2
; CHECK-NEXT:    br i1 [[TMP66]], label %[[PRED_STORE_IF18:.*]], label %[[PRED_STORE_CONTINUE19:.*]]
; CHECK:       [[PRED_STORE_IF18]]:
; CHECK-NEXT:    [[TMP67:%.*]] = extractelement <4 x i8> [[TMP60]], i32 2
; CHECK-NEXT:    store i8 [[TMP67]], ptr [[TMP14]], align 1
; CHECK-NEXT:    br label %[[PRED_STORE_CONTINUE19]]
; CHECK:       [[PRED_STORE_CONTINUE19]]:
; CHECK-NEXT:    [[TMP68:%.*]] = extractelement <4 x i1> [[TMP10]], i32 3
; CHECK-NEXT:    br i1 [[TMP68]], label %[[PRED_STORE_IF20:.*]], label %[[PRED_STORE_CONTINUE21:.*]]
; CHECK:       [[PRED_STORE_IF20]]:
; CHECK-NEXT:    [[TMP69:%.*]] = extractelement <4 x i8> [[TMP60]], i32 3
; CHECK-NEXT:    store i8 [[TMP69]], ptr [[TMP15]], align 1
; CHECK-NEXT:    br label %[[PRED_STORE_CONTINUE21]]
; CHECK:       [[PRED_STORE_CONTINUE21]]:
; CHECK-NEXT:    [[TMP70:%.*]] = extractelement <4 x i1> [[TMP11]], i32 0
; CHECK-NEXT:    br i1 [[TMP70]], label %[[PRED_STORE_IF22:.*]], label %[[PRED_STORE_CONTINUE23:.*]]
; CHECK:       [[PRED_STORE_IF22]]:
; CHECK-NEXT:    [[TMP71:%.*]] = extractelement <4 x i8> [[TMP61]], i32 0
; CHECK-NEXT:    store i8 [[TMP71]], ptr [[TMP20]], align 1
; CHECK-NEXT:    br label %[[PRED_STORE_CONTINUE23]]
; CHECK:       [[PRED_STORE_CONTINUE23]]:
; CHECK-NEXT:    [[TMP72:%.*]] = extractelement <4 x i1> [[TMP11]], i32 1
; CHECK-NEXT:    br i1 [[TMP72]], label %[[PRED_STORE_IF24:.*]], label %[[PRED_STORE_CONTINUE25:.*]]
; CHECK:       [[PRED_STORE_IF24]]:
; CHECK-NEXT:    [[TMP73:%.*]] = extractelement <4 x i8> [[TMP61]], i32 1
; CHECK-NEXT:    store i8 [[TMP73]], ptr [[TMP21]], align 1
; CHECK-NEXT:    br label %[[PRED_STORE_CONTINUE25]]
; CHECK:       [[PRED_STORE_CONTINUE25]]:
; CHECK-NEXT:    [[TMP74:%.*]] = extractelement <4 x i1> [[TMP11]], i32 2
; CHECK-NEXT:    br i1 [[TMP74]], label %[[PRED_STORE_IF26:.*]], label %[[PRED_STORE_CONTINUE27:.*]]
; CHECK:       [[PRED_STORE_IF26]]:
; CHECK-NEXT:    [[TMP75:%.*]] = extractelement <4 x i8> [[TMP61]], i32 2
; CHECK-NEXT:    store i8 [[TMP75]], ptr [[TMP22]], align 1
; CHECK-NEXT:    br label %[[PRED_STORE_CONTINUE27]]
; CHECK:       [[PRED_STORE_CONTINUE27]]:
; CHECK-NEXT:    [[TMP76:%.*]] = extractelement <4 x i1> [[TMP11]], i32 3
; CHECK-NEXT:    br i1 [[TMP76]], label %[[PRED_STORE_IF28:.*]], label %[[PRED_STORE_CONTINUE29]]
; CHECK:       [[PRED_STORE_IF28]]:
; CHECK-NEXT:    [[TMP77:%.*]] = extractelement <4 x i8> [[TMP61]], i32 3
; CHECK-NEXT:    store i8 [[TMP77]], ptr [[TMP23]], align 1
; CHECK-NEXT:    br label %[[PRED_STORE_CONTINUE29]]
; CHECK:       [[PRED_STORE_CONTINUE29]]:
; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i32 [[INDEX]], 8
; CHECK-NEXT:    [[TMP80:%.*]] = icmp eq i32 [[INDEX_NEXT]], 16
; CHECK-NEXT:    br i1 [[TMP80]], label %[[MIDDLE_BLOCK:.*]], label %[[VECTOR_BODY]], !llvm.loop [[LOOP4:![0-9]+]]
; CHECK:       [[MIDDLE_BLOCK]]:
; CHECK-NEXT:    [[PREDPHI:%.*]] = select <4 x i1> [[TMP11]], <4 x i8> [[TMP61]], <4 x i8> zeroinitializer
; CHECK-NEXT:    [[TMP78:%.*]] = icmp ne <4 x i8> [[PREDPHI]], zeroinitializer
; CHECK-NEXT:    [[TMP79:%.*]] = zext <4 x i1> [[TMP78]] to <4 x i32>
; CHECK-NEXT:    [[VECTOR_RECUR_EXTRACT:%.*]] = extractelement <4 x i32> [[TMP79]], i32 3
; CHECK-NEXT:    br label %[[LATCH:.*]]
; CHECK:       [[LATCH]]:
;
entry:
  br label %loop

loop:
  %iv = phi i32 [ 0, %entry ], [ %iv.next, %latch ]
  %recur = phi i32 [ 0, %entry ], [ %zext, %latch ]
  %gep.src = getelementptr inbounds i8, ptr %src, i32 %iv
  %l = load i8, ptr %gep.src
  %c = icmp eq i8 %l, 0
  br i1 %c, label %latch, label %then

then:
  %or = or i8 %arg, 1
  %gep = getelementptr inbounds i8, ptr %dst, i32 %iv
  %l.2 = load i8, ptr %gep
  %udiv = udiv i8 %l.2, 2
  store i8 %udiv, ptr %gep
  br label %latch

latch:
  %phi = phi i8 [ %udiv, %then ], [ 0, %loop ]
  %cmp = icmp ne i8 %phi, 0
  %zext = zext i1 %cmp to i32
  %iv.next = add i32 %iv, 1
  %ec = icmp eq i32 %iv, 18
  br i1 %ec, label %exit, label %loop

exit:
  ret void
}