xref: /llvm-project/llvm/test/Transforms/LoopVectorize/opaque-ptr.ll (revision 4ad0fdd1631eeae432714c03ede01a10dc00025d) 
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -S -passes=loop-vectorize -force-vector-width=2 < %s | FileCheck %s
3
4define void @test_ptr_iv_no_inbounds(ptr %p1.start, ptr %p2.start, ptr %p1.end) {
5; CHECK-LABEL: @test_ptr_iv_no_inbounds(
6; CHECK-NEXT:  entry:
7; CHECK-NEXT:    [[P1_START7:%.*]] = ptrtoint ptr [[P1_START:%.*]] to i64
8; CHECK-NEXT:    [[P1_END6:%.*]] = ptrtoint ptr [[P1_END:%.*]] to i64
9; CHECK-NEXT:    [[P1_START4:%.*]] = ptrtoint ptr [[P1_START]] to i64
10; CHECK-NEXT:    [[P1_END3:%.*]] = ptrtoint ptr [[P1_END]] to i64
11; CHECK-NEXT:    [[P1_START2:%.*]] = ptrtoint ptr [[P1_START]] to i64
12; CHECK-NEXT:    [[P1_END1:%.*]] = ptrtoint ptr [[P1_END]] to i64
13; CHECK-NEXT:    [[TMP0:%.*]] = add i64 [[P1_END6]], -4
14; CHECK-NEXT:    [[TMP1:%.*]] = sub i64 [[TMP0]], [[P1_START7]]
15; CHECK-NEXT:    [[TMP2:%.*]] = lshr i64 [[TMP1]], 2
16; CHECK-NEXT:    [[TMP3:%.*]] = add nuw nsw i64 [[TMP2]], 1
17; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP3]], 2
18; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_SCEVCHECK:%.*]]
19; CHECK:       vector.scevcheck:
20; CHECK-NEXT:    [[TMP4:%.*]] = trunc i64 [[P1_END1]] to i2
21; CHECK-NEXT:    [[TMP5:%.*]] = trunc i64 [[P1_START2]] to i2
22; CHECK-NEXT:    [[TMP6:%.*]] = sub i2 [[TMP4]], [[TMP5]]
23; CHECK-NEXT:    [[TMP7:%.*]] = zext i2 [[TMP6]] to i64
24; CHECK-NEXT:    [[IDENT_CHECK:%.*]] = icmp ne i64 [[TMP7]], 0
25; CHECK-NEXT:    br i1 [[IDENT_CHECK]], label [[SCALAR_PH]], label [[VECTOR_MEMCHECK:%.*]]
26; CHECK:       vector.memcheck:
27; CHECK-NEXT:    [[TMP8:%.*]] = add i64 [[P1_END3]], -4
28; CHECK-NEXT:    [[TMP9:%.*]] = sub i64 [[TMP8]], [[P1_START4]]
29; CHECK-NEXT:    [[TMP10:%.*]] = lshr i64 [[TMP9]], 2
30; CHECK-NEXT:    [[TMP11:%.*]] = shl nuw i64 [[TMP10]], 2
31; CHECK-NEXT:    [[TMP12:%.*]] = add i64 [[TMP11]], 4
32; CHECK-NEXT:    [[SCEVGEP:%.*]] = getelementptr i8, ptr [[P1_START]], i64 [[TMP12]]
33; CHECK-NEXT:    [[SCEVGEP5:%.*]] = getelementptr i8, ptr [[P2_START:%.*]], i64 [[TMP12]]
34; CHECK-NEXT:    [[BOUND0:%.*]] = icmp ult ptr [[P1_START]], [[SCEVGEP5]]
35; CHECK-NEXT:    [[BOUND1:%.*]] = icmp ult ptr [[P2_START]], [[SCEVGEP]]
36; CHECK-NEXT:    [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
37; CHECK-NEXT:    br i1 [[FOUND_CONFLICT]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
38; CHECK:       vector.ph:
39; CHECK-NEXT:    [[N_MOD_VF:%.*]] = urem i64 [[TMP3]], 2
40; CHECK-NEXT:    [[N_VEC:%.*]] = sub i64 [[TMP3]], [[N_MOD_VF]]
41; CHECK-NEXT:    [[TMP13:%.*]] = mul i64 [[N_VEC]], 4
42; CHECK-NEXT:    [[IND_END:%.*]] = getelementptr i8, ptr [[P1_START]], i64 [[TMP13]]
43; CHECK-NEXT:    [[TMP14:%.*]] = mul i64 [[N_VEC]], 4
44; CHECK-NEXT:    [[IND_END8:%.*]] = getelementptr i8, ptr [[P2_START]], i64 [[TMP14]]
45; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
46; CHECK:       vector.body:
47; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
48; CHECK-NEXT:    [[OFFSET_IDX:%.*]] = mul i64 [[INDEX]], 4
49; CHECK-NEXT:    [[TMP15:%.*]] = add i64 [[OFFSET_IDX]], 0
50; CHECK-NEXT:    [[NEXT_GEP:%.*]] = getelementptr i8, ptr [[P1_START]], i64 [[TMP15]]
51; CHECK-NEXT:    [[OFFSET_IDX10:%.*]] = mul i64 [[INDEX]], 4
52; CHECK-NEXT:    [[TMP16:%.*]] = add i64 [[OFFSET_IDX10]], 0
53; CHECK-NEXT:    [[NEXT_GEP11:%.*]] = getelementptr i8, ptr [[P2_START]], i64 [[TMP16]]
54; CHECK-NEXT:    [[TMP17:%.*]] = getelementptr float, ptr [[NEXT_GEP]], i32 0
55; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <2 x float>, ptr [[TMP17]], align 4, !alias.scope [[META0:![0-9]+]], !noalias [[META3:![0-9]+]]
56; CHECK-NEXT:    [[TMP18:%.*]] = getelementptr float, ptr [[NEXT_GEP11]], i32 0
57; CHECK-NEXT:    [[WIDE_LOAD12:%.*]] = load <2 x float>, ptr [[TMP18]], align 4, !alias.scope [[META3]]
58; CHECK-NEXT:    [[TMP19:%.*]] = fadd <2 x float> [[WIDE_LOAD]], [[WIDE_LOAD12]]
59; CHECK-NEXT:    store <2 x float> [[TMP19]], ptr [[TMP17]], align 4, !alias.scope [[META0]], !noalias [[META3]]
60; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 2
61; CHECK-NEXT:    [[TMP20:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
62; CHECK-NEXT:    br i1 [[TMP20]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP5:![0-9]+]]
63; CHECK:       middle.block:
64; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[TMP3]], [[N_VEC]]
65; CHECK-NEXT:    br i1 [[CMP_N]], label [[EXIT:%.*]], label [[SCALAR_PH]]
66; CHECK:       scalar.ph:
67; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi ptr [ [[IND_END]], [[MIDDLE_BLOCK]] ], [ [[P1_START]], [[VECTOR_MEMCHECK]] ], [ [[P1_START]], [[VECTOR_SCEVCHECK]] ], [ [[P1_START]], [[ENTRY:%.*]] ]
68; CHECK-NEXT:    [[BC_RESUME_VAL9:%.*]] = phi ptr [ [[IND_END8]], [[MIDDLE_BLOCK]] ], [ [[P2_START]], [[VECTOR_MEMCHECK]] ], [ [[P2_START]], [[VECTOR_SCEVCHECK]] ], [ [[P2_START]], [[ENTRY]] ]
69; CHECK-NEXT:    br label [[LOOP:%.*]]
70; CHECK:       loop:
71; CHECK-NEXT:    [[P1:%.*]] = phi ptr [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[P1_NEXT:%.*]], [[LOOP]] ]
72; CHECK-NEXT:    [[P2:%.*]] = phi ptr [ [[BC_RESUME_VAL9]], [[SCALAR_PH]] ], [ [[P2_NEXT:%.*]], [[LOOP]] ]
73; CHECK-NEXT:    [[P1_VAL:%.*]] = load float, ptr [[P1]], align 4
74; CHECK-NEXT:    [[P2_VAL:%.*]] = load float, ptr [[P2]], align 4
75; CHECK-NEXT:    [[SUM:%.*]] = fadd float [[P1_VAL]], [[P2_VAL]]
76; CHECK-NEXT:    store float [[SUM]], ptr [[P1]], align 4
77; CHECK-NEXT:    [[P1_NEXT]] = getelementptr float, ptr [[P1]], i64 1
78; CHECK-NEXT:    [[P2_NEXT]] = getelementptr float, ptr [[P2]], i64 1
79; CHECK-NEXT:    [[C:%.*]] = icmp ne ptr [[P1_NEXT]], [[P1_END]]
80; CHECK-NEXT:    br i1 [[C]], label [[LOOP]], label [[EXIT]], !llvm.loop [[LOOP8:![0-9]+]]
81; CHECK:       exit:
82; CHECK-NEXT:    ret void
83;
84entry:
85  br label %loop
86
87loop:
88  %p1 = phi ptr [ %p1.start, %entry ], [ %p1.next, %loop ]
89  %p2 = phi ptr [ %p2.start, %entry ], [ %p2.next, %loop ]
90  %p1.val = load float, ptr %p1
91  %p2.val = load float, ptr %p2
92  %sum = fadd float %p1.val, %p2.val
93  store float %sum, ptr %p1
94  %p1.next = getelementptr float, ptr %p1, i64 1
95  %p2.next = getelementptr float, ptr %p2, i64 1
96  %c = icmp ne ptr %p1.next, %p1.end
97  br i1 %c, label %loop, label %exit
98
99exit:
100  ret void
101}
102
103define void @test_ptr_iv_with_inbounds(ptr %p1.start, ptr %p2.start, ptr %p1.end) {
104; CHECK-LABEL: @test_ptr_iv_with_inbounds(
105; CHECK-NEXT:  entry:
106; CHECK-NEXT:    [[P1_START5:%.*]] = ptrtoint ptr [[P1_START:%.*]] to i64
107; CHECK-NEXT:    [[P1_END4:%.*]] = ptrtoint ptr [[P1_END:%.*]] to i64
108; CHECK-NEXT:    [[P1_START2:%.*]] = ptrtoint ptr [[P1_START]] to i64
109; CHECK-NEXT:    [[P1_END1:%.*]] = ptrtoint ptr [[P1_END]] to i64
110; CHECK-NEXT:    [[TMP0:%.*]] = add i64 [[P1_END4]], -4
111; CHECK-NEXT:    [[TMP1:%.*]] = sub i64 [[TMP0]], [[P1_START5]]
112; CHECK-NEXT:    [[TMP2:%.*]] = lshr i64 [[TMP1]], 2
113; CHECK-NEXT:    [[TMP3:%.*]] = add nuw nsw i64 [[TMP2]], 1
114; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP3]], 2
115; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_MEMCHECK:%.*]]
116; CHECK:       vector.memcheck:
117; CHECK-NEXT:    [[TMP4:%.*]] = add i64 [[P1_END1]], -4
118; CHECK-NEXT:    [[TMP5:%.*]] = sub i64 [[TMP4]], [[P1_START2]]
119; CHECK-NEXT:    [[TMP6:%.*]] = lshr i64 [[TMP5]], 2
120; CHECK-NEXT:    [[TMP7:%.*]] = shl nuw i64 [[TMP6]], 2
121; CHECK-NEXT:    [[TMP8:%.*]] = add i64 [[TMP7]], 4
122; CHECK-NEXT:    [[SCEVGEP:%.*]] = getelementptr i8, ptr [[P1_START]], i64 [[TMP8]]
123; CHECK-NEXT:    [[SCEVGEP3:%.*]] = getelementptr i8, ptr [[P2_START:%.*]], i64 [[TMP8]]
124; CHECK-NEXT:    [[BOUND0:%.*]] = icmp ult ptr [[P1_START]], [[SCEVGEP3]]
125; CHECK-NEXT:    [[BOUND1:%.*]] = icmp ult ptr [[P2_START]], [[SCEVGEP]]
126; CHECK-NEXT:    [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
127; CHECK-NEXT:    br i1 [[FOUND_CONFLICT]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
128; CHECK:       vector.ph:
129; CHECK-NEXT:    [[N_MOD_VF:%.*]] = urem i64 [[TMP3]], 2
130; CHECK-NEXT:    [[N_VEC:%.*]] = sub i64 [[TMP3]], [[N_MOD_VF]]
131; CHECK-NEXT:    [[TMP9:%.*]] = mul i64 [[N_VEC]], 4
132; CHECK-NEXT:    [[IND_END:%.*]] = getelementptr i8, ptr [[P1_START]], i64 [[TMP9]]
133; CHECK-NEXT:    [[TMP10:%.*]] = mul i64 [[N_VEC]], 4
134; CHECK-NEXT:    [[IND_END6:%.*]] = getelementptr i8, ptr [[P2_START]], i64 [[TMP10]]
135; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
136; CHECK:       vector.body:
137; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
138; CHECK-NEXT:    [[OFFSET_IDX:%.*]] = mul i64 [[INDEX]], 4
139; CHECK-NEXT:    [[TMP11:%.*]] = add i64 [[OFFSET_IDX]], 0
140; CHECK-NEXT:    [[NEXT_GEP:%.*]] = getelementptr i8, ptr [[P1_START]], i64 [[TMP11]]
141; CHECK-NEXT:    [[OFFSET_IDX8:%.*]] = mul i64 [[INDEX]], 4
142; CHECK-NEXT:    [[TMP12:%.*]] = add i64 [[OFFSET_IDX8]], 0
143; CHECK-NEXT:    [[NEXT_GEP9:%.*]] = getelementptr i8, ptr [[P2_START]], i64 [[TMP12]]
144; CHECK-NEXT:    [[TMP13:%.*]] = getelementptr float, ptr [[NEXT_GEP]], i32 0
145; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <2 x float>, ptr [[TMP13]], align 4, !alias.scope [[META9:![0-9]+]], !noalias [[META12:![0-9]+]]
146; CHECK-NEXT:    [[TMP14:%.*]] = getelementptr float, ptr [[NEXT_GEP9]], i32 0
147; CHECK-NEXT:    [[WIDE_LOAD10:%.*]] = load <2 x float>, ptr [[TMP14]], align 4, !alias.scope [[META12]]
148; CHECK-NEXT:    [[TMP15:%.*]] = fadd <2 x float> [[WIDE_LOAD]], [[WIDE_LOAD10]]
149; CHECK-NEXT:    store <2 x float> [[TMP15]], ptr [[TMP13]], align 4, !alias.scope [[META9]], !noalias [[META12]]
150; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 2
151; CHECK-NEXT:    [[TMP16:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
152; CHECK-NEXT:    br i1 [[TMP16]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP14:![0-9]+]]
153; CHECK:       middle.block:
154; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[TMP3]], [[N_VEC]]
155; CHECK-NEXT:    br i1 [[CMP_N]], label [[EXIT:%.*]], label [[SCALAR_PH]]
156; CHECK:       scalar.ph:
157; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi ptr [ [[IND_END]], [[MIDDLE_BLOCK]] ], [ [[P1_START]], [[VECTOR_MEMCHECK]] ], [ [[P1_START]], [[ENTRY:%.*]] ]
158; CHECK-NEXT:    [[BC_RESUME_VAL7:%.*]] = phi ptr [ [[IND_END6]], [[MIDDLE_BLOCK]] ], [ [[P2_START]], [[VECTOR_MEMCHECK]] ], [ [[P2_START]], [[ENTRY]] ]
159; CHECK-NEXT:    br label [[LOOP:%.*]]
160; CHECK:       loop:
161; CHECK-NEXT:    [[P1:%.*]] = phi ptr [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[P1_NEXT:%.*]], [[LOOP]] ]
162; CHECK-NEXT:    [[P2:%.*]] = phi ptr [ [[BC_RESUME_VAL7]], [[SCALAR_PH]] ], [ [[P2_NEXT:%.*]], [[LOOP]] ]
163; CHECK-NEXT:    [[P1_VAL:%.*]] = load float, ptr [[P1]], align 4
164; CHECK-NEXT:    [[P2_VAL:%.*]] = load float, ptr [[P2]], align 4
165; CHECK-NEXT:    [[SUM:%.*]] = fadd float [[P1_VAL]], [[P2_VAL]]
166; CHECK-NEXT:    store float [[SUM]], ptr [[P1]], align 4
167; CHECK-NEXT:    [[P1_NEXT]] = getelementptr inbounds float, ptr [[P1]], i64 1
168; CHECK-NEXT:    [[P2_NEXT]] = getelementptr inbounds float, ptr [[P2]], i64 1
169; CHECK-NEXT:    [[C:%.*]] = icmp ne ptr [[P1_NEXT]], [[P1_END]]
170; CHECK-NEXT:    br i1 [[C]], label [[LOOP]], label [[EXIT]], !llvm.loop [[LOOP15:![0-9]+]]
171; CHECK:       exit:
172; CHECK-NEXT:    ret void
173;
174entry:
175  br label %loop
176
177loop:
178  %p1 = phi ptr [ %p1.start, %entry ], [ %p1.next, %loop ]
179  %p2 = phi ptr [ %p2.start, %entry ], [ %p2.next, %loop ]
180  %p1.val = load float, ptr %p1
181  %p2.val = load float, ptr %p2
182  %sum = fadd float %p1.val, %p2.val
183  store float %sum, ptr %p1
184  %p1.next = getelementptr inbounds float, ptr %p1, i64 1
185  %p2.next = getelementptr inbounds float, ptr %p2, i64 1
186  %c = icmp ne ptr %p1.next, %p1.end
187  br i1 %c, label %loop, label %exit
188
189exit:
190  ret void
191}
192
193define void @store_pointer_induction(ptr %start, ptr %end) {
194; CHECK-LABEL: @store_pointer_induction(
195; CHECK-NEXT:  entry:
196; CHECK-NEXT:    [[START2:%.*]] = ptrtoint ptr [[START:%.*]] to i64
197; CHECK-NEXT:    [[END1:%.*]] = ptrtoint ptr [[END:%.*]] to i64
198; CHECK-NEXT:    [[TMP0:%.*]] = add i64 [[END1]], -8
199; CHECK-NEXT:    [[TMP1:%.*]] = sub i64 [[TMP0]], [[START2]]
200; CHECK-NEXT:    [[TMP2:%.*]] = lshr i64 [[TMP1]], 3
201; CHECK-NEXT:    [[TMP3:%.*]] = add nuw nsw i64 [[TMP2]], 1
202; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp ult i64 [[TMP3]], 2
203; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_PH:%.*]]
204; CHECK:       vector.ph:
205; CHECK-NEXT:    [[N_MOD_VF:%.*]] = urem i64 [[TMP3]], 2
206; CHECK-NEXT:    [[N_VEC:%.*]] = sub i64 [[TMP3]], [[N_MOD_VF]]
207; CHECK-NEXT:    [[TMP4:%.*]] = mul i64 [[N_VEC]], 8
208; CHECK-NEXT:    [[IND_END:%.*]] = getelementptr i8, ptr [[START]], i64 [[TMP4]]
209; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
210; CHECK:       vector.body:
211; CHECK-NEXT:    [[POINTER_PHI:%.*]] = phi ptr [ [[START]], [[VECTOR_PH]] ], [ [[PTR_IND:%.*]], [[VECTOR_BODY]] ]
212; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
213; CHECK-NEXT:    [[TMP5:%.*]] = getelementptr i8, ptr [[POINTER_PHI]], <2 x i64> <i64 0, i64 8>
214; CHECK-NEXT:    [[TMP6:%.*]] = extractelement <2 x ptr> [[TMP5]], i32 0
215; CHECK-NEXT:    [[TMP7:%.*]] = getelementptr ptr, ptr [[TMP6]], i32 0
216; CHECK-NEXT:    store <2 x ptr> [[TMP5]], ptr [[TMP7]], align 4
217; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 2
218; CHECK-NEXT:    [[PTR_IND]] = getelementptr i8, ptr [[POINTER_PHI]], i64 16
219; CHECK-NEXT:    [[TMP8:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
220; CHECK-NEXT:    br i1 [[TMP8]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP16:![0-9]+]]
221; CHECK:       middle.block:
222; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[TMP3]], [[N_VEC]]
223; CHECK-NEXT:    br i1 [[CMP_N]], label [[EXIT:%.*]], label [[SCALAR_PH]]
224; CHECK:       scalar.ph:
225; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi ptr [ [[IND_END]], [[MIDDLE_BLOCK]] ], [ [[START]], [[ENTRY:%.*]] ]
226; CHECK-NEXT:    br label [[LOOP:%.*]]
227; CHECK:       loop:
228; CHECK-NEXT:    [[IV:%.*]] = phi ptr [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ], [ [[IV_NEXT:%.*]], [[LOOP]] ]
229; CHECK-NEXT:    store ptr [[IV]], ptr [[IV]], align 4
230; CHECK-NEXT:    [[IV_NEXT]] = getelementptr inbounds ptr, ptr [[IV]], i32 1
231; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp eq ptr [[IV_NEXT]], [[END]]
232; CHECK-NEXT:    br i1 [[EXITCOND]], label [[EXIT]], label [[LOOP]], !llvm.loop [[LOOP17:![0-9]+]]
233; CHECK:       exit:
234; CHECK-NEXT:    ret void
235;
236entry:
237  br label %loop
238
239loop:
240  %iv = phi ptr [ %start, %entry ], [ %iv.next, %loop ]
241  store ptr %iv, ptr %iv, align 4
242  %iv.next = getelementptr inbounds ptr, ptr %iv, i32 1
243  %exitcond = icmp eq ptr %iv.next, %end
244  br i1 %exitcond, label %exit, label %loop
245
246exit:
247  ret void
248}
249