xref: /llvm-project/llvm/test/Transforms/LoopVectorize/invariant-store-vectorization-2.ll (revision f0d5104c944b329c479802788571ed6df41e0e86)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -aa-pipeline=basic-aa -passes='loop-mssa(licm),loop-vectorize,dce,instcombine,loop-mssa(licm)' -force-vector-width=4 -S | FileCheck %s
3
4; First licm pass is to hoist/sink invariant stores if possible. Today LICM does
5; not hoist/sink the invariant stores. Even if that changes, we should still
6; vectorize this loop in case licm is not run.
7
8; The next licm pass after vectorization is to hoist/sink loop invariant
9; instructions.
10target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
11
12; This file separates tests with auto-generated check lines from
13; invariant-store-vectorization.ll for maintenance.
14; all tests check that it is legal to vectorize the stores to invariant
15; address.
16
17; Instcombine'd version of @inv_val_store_to_inv_address_conditional_diff_values.
18; Now the store is no longer of invariant value.
19; scalar store the value extracted from the last element of the vector value.
20define void @inv_val_store_to_inv_address_conditional_diff_values_ic(ptr %a, i64 %n, ptr %b, i32 %k) {
21; CHECK-LABEL: @inv_val_store_to_inv_address_conditional_diff_values_ic(
22; CHECK-NEXT:  entry:
23; CHECK-NEXT:    [[NTRUNC:%.*]] = trunc i64 [[N:%.*]] to i32
24; CHECK-NEXT:    [[SMAX2:%.*]] = call i64 @llvm.smax.i64(i64 [[N]], i64 1)
25; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp slt i64 [[N]], 4
26; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_MEMCHECK:%.*]]
27; CHECK:       vector.memcheck:
28; CHECK-NEXT:    [[TMP0:%.*]] = shl i64 [[N]], 2
29; CHECK-NEXT:    [[SCEVGEP:%.*]] = getelementptr i8, ptr [[B:%.*]], i64 [[TMP0]]
30; CHECK-NEXT:    [[SCEVGEP1:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 4
31; CHECK-NEXT:    [[BOUND0:%.*]] = icmp ult ptr [[B]], [[SCEVGEP1]]
32; CHECK-NEXT:    [[BOUND1:%.*]] = icmp ult ptr [[A]], [[SCEVGEP]]
33; CHECK-NEXT:    [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
34; CHECK-NEXT:    br i1 [[FOUND_CONFLICT]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
35; CHECK:       vector.ph:
36; CHECK-NEXT:    [[N_VEC:%.*]] = and i64 [[SMAX2]], 9223372036854775804
37; CHECK-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x i32> poison, i32 [[K:%.*]], i64 0
38; CHECK-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT]], <4 x i32> poison, <4 x i32> zeroinitializer
39; CHECK-NEXT:    [[BROADCAST_SPLATINSERT3:%.*]] = insertelement <4 x i32> poison, i32 [[NTRUNC]], i64 0
40; CHECK-NEXT:    [[BROADCAST_SPLAT4:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT3]], <4 x i32> poison, <4 x i32> zeroinitializer
41; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
42; CHECK:       vector.body:
43; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
44; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX]]
45; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <4 x i32>, ptr [[TMP1]], align 8, !alias.scope [[META0:![0-9]+]], !noalias [[META3:![0-9]+]]
46; CHECK-NEXT:    [[DOTNOT:%.*]] = icmp eq <4 x i32> [[WIDE_LOAD]], [[BROADCAST_SPLAT]]
47; CHECK-NEXT:    store <4 x i32> [[BROADCAST_SPLAT4]], ptr [[TMP1]], align 4, !alias.scope [[META0]], !noalias [[META3]]
48; CHECK-NEXT:    [[PREDPHI:%.*]] = select <4 x i1> [[DOTNOT]], <4 x i32> [[BROADCAST_SPLAT4]], <4 x i32> [[BROADCAST_SPLAT]]
49; CHECK-NEXT:    [[TMP2:%.*]] = extractelement <4 x i32> [[PREDPHI]], i64 3
50; CHECK-NEXT:    store i32 [[TMP2]], ptr [[A]], align 4, !alias.scope [[META3]]
51; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
52; CHECK-NEXT:    [[TMP3:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
53; CHECK-NEXT:    br i1 [[TMP3]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP5:![0-9]+]]
54; CHECK:       middle.block:
55; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[SMAX2]], [[N_VEC]]
56; CHECK-NEXT:    br i1 [[CMP_N]], label [[FOR_END:%.*]], label [[SCALAR_PH]]
57; CHECK:       scalar.ph:
58; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[VECTOR_MEMCHECK]] ], [ 0, [[ENTRY:%.*]] ]
59; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
60; CHECK:       for.body:
61; CHECK-NEXT:    [[I:%.*]] = phi i64 [ [[I_NEXT:%.*]], [[LATCH:%.*]] ], [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ]
62; CHECK-NEXT:    [[I1:%.*]] = getelementptr inbounds nuw i32, ptr [[B]], i64 [[I]]
63; CHECK-NEXT:    [[I2:%.*]] = load i32, ptr [[I1]], align 8
64; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[I2]], [[K]]
65; CHECK-NEXT:    store i32 [[NTRUNC]], ptr [[I1]], align 4
66; CHECK-NEXT:    br i1 [[CMP]], label [[COND_STORE:%.*]], label [[COND_STORE_K:%.*]]
67; CHECK:       cond_store:
68; CHECK-NEXT:    br label [[LATCH]]
69; CHECK:       cond_store_k:
70; CHECK-NEXT:    br label [[LATCH]]
71; CHECK:       latch:
72; CHECK-NEXT:    [[STOREVAL:%.*]] = phi i32 [ [[NTRUNC]], [[COND_STORE]] ], [ [[K]], [[COND_STORE_K]] ]
73; CHECK-NEXT:    store i32 [[STOREVAL]], ptr [[A]], align 4
74; CHECK-NEXT:    [[I_NEXT]] = add nuw nsw i64 [[I]], 1
75; CHECK-NEXT:    [[COND:%.*]] = icmp slt i64 [[I_NEXT]], [[N]]
76; CHECK-NEXT:    br i1 [[COND]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop [[LOOP8:![0-9]+]]
77; CHECK:       for.end.loopexit:
78; CHECK-NEXT:    br label [[FOR_END]]
79; CHECK:       for.end:
80; CHECK-NEXT:    ret void
81;
82entry:
83  %ntrunc = trunc i64 %n to i32
84  br label %for.body
85
86for.body:                                         ; preds = %for.body, %entry
87  %i = phi i64 [ %i.next, %latch ], [ 0, %entry ]
88  %i1 = getelementptr inbounds i32, ptr %b, i64 %i
89  %i2 = load i32, ptr %i1, align 8
90  %cmp = icmp eq i32 %i2, %k
91  store i32 %ntrunc, ptr %i1
92  br i1 %cmp, label %cond_store, label %cond_store_k
93
94cond_store:
95  br label %latch
96
97cond_store_k:
98  br label %latch
99
100latch:
101  %storeval = phi i32 [ %ntrunc, %cond_store ], [ %k, %cond_store_k ]
102  store i32 %storeval, ptr %a
103  %i.next = add nuw nsw i64 %i, 1
104  %cond = icmp slt i64 %i.next, %n
105  br i1 %cond, label %for.body, label %for.end
106
107for.end:                                          ; preds = %for.body
108  ret void
109}
110
111; invariant val stored to invariant address predicated on invariant condition
112; This is not treated as a predicated store since the block the store belongs to
113; is the latch block (which doesn't need to be predicated).
114; variant/invariant values being stored to invariant address.
115; test checks that the last element of the phi is extracted and scalar stored
116; into the uniform address within the loop.
117; Since the condition and the phi is loop invariant, they are LICM'ed after
118; vectorization.
119define void @inv_val_store_to_inv_address_conditional_inv(ptr %a, i64 %n, ptr %b, i32 %k) {
120; CHECK-LABEL: @inv_val_store_to_inv_address_conditional_inv(
121; CHECK-NEXT:  entry:
122; CHECK-NEXT:    [[NTRUNC:%.*]] = trunc i64 [[N:%.*]] to i32
123; CHECK-NEXT:    [[CMP:%.*]] = icmp eq i32 [[K:%.*]], [[NTRUNC]]
124; CHECK-NEXT:    [[SMAX2:%.*]] = call i64 @llvm.smax.i64(i64 [[N]], i64 1)
125; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp slt i64 [[N]], 4
126; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_MEMCHECK:%.*]]
127; CHECK:       vector.memcheck:
128; CHECK-NEXT:    [[TMP0:%.*]] = shl i64 [[N]], 2
129; CHECK-NEXT:    [[SCEVGEP:%.*]] = getelementptr i8, ptr [[B:%.*]], i64 [[TMP0]]
130; CHECK-NEXT:    [[SCEVGEP1:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 4
131; CHECK-NEXT:    [[BOUND0:%.*]] = icmp ult ptr [[B]], [[SCEVGEP1]]
132; CHECK-NEXT:    [[BOUND1:%.*]] = icmp ult ptr [[A]], [[SCEVGEP]]
133; CHECK-NEXT:    [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
134; CHECK-NEXT:    br i1 [[FOUND_CONFLICT]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
135; CHECK:       vector.ph:
136; CHECK-NEXT:    [[N_VEC:%.*]] = and i64 [[SMAX2]], 9223372036854775804
137; CHECK-NEXT:    [[TMP1:%.*]] = insertelement <4 x i1> poison, i1 [[CMP]], i64 0
138; CHECK-NEXT:    [[BROADCAST_SPLATINSERT:%.*]] = insertelement <4 x i32> poison, i32 [[NTRUNC]], i64 0
139; CHECK-NEXT:    [[BROADCAST_SPLAT:%.*]] = shufflevector <4 x i32> [[BROADCAST_SPLATINSERT]], <4 x i32> poison, <4 x i32> zeroinitializer
140; CHECK-NEXT:    [[BROADCAST_SPLAT6:%.*]] = insertelement <4 x i32> poison, i32 [[K]], i64 0
141; CHECK-NEXT:    [[PREDPHI:%.*]] = select <4 x i1> [[TMP1]], <4 x i32> [[BROADCAST_SPLAT]], <4 x i32> [[BROADCAST_SPLAT6]]
142; CHECK-NEXT:    [[TMP2:%.*]] = extractelement <4 x i32> [[PREDPHI]], i64 0
143; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
144; CHECK:       vector.body:
145; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
146; CHECK-NEXT:    [[TMP3:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX]]
147; CHECK-NEXT:    store <4 x i32> [[BROADCAST_SPLAT]], ptr [[TMP3]], align 4, !alias.scope [[META9:![0-9]+]], !noalias [[META12:![0-9]+]]
148; CHECK-NEXT:    store i32 [[TMP2]], ptr [[A]], align 4, !alias.scope [[META12]]
149; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
150; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
151; CHECK-NEXT:    br i1 [[TMP4]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP14:![0-9]+]]
152; CHECK:       middle.block:
153; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[SMAX2]], [[N_VEC]]
154; CHECK-NEXT:    br i1 [[CMP_N]], label [[FOR_END:%.*]], label [[SCALAR_PH]]
155; CHECK:       scalar.ph:
156; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[VECTOR_MEMCHECK]] ], [ 0, [[ENTRY:%.*]] ]
157; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
158; CHECK:       for.body:
159; CHECK-NEXT:    [[I:%.*]] = phi i64 [ [[I_NEXT:%.*]], [[LATCH:%.*]] ], [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ]
160; CHECK-NEXT:    [[I1:%.*]] = getelementptr inbounds nuw i32, ptr [[B]], i64 [[I]]
161; CHECK-NEXT:    store i32 [[NTRUNC]], ptr [[I1]], align 4
162; CHECK-NEXT:    br i1 [[CMP]], label [[COND_STORE:%.*]], label [[COND_STORE_K:%.*]]
163; CHECK:       cond_store:
164; CHECK-NEXT:    br label [[LATCH]]
165; CHECK:       cond_store_k:
166; CHECK-NEXT:    br label [[LATCH]]
167; CHECK:       latch:
168; CHECK-NEXT:    [[STOREVAL:%.*]] = phi i32 [ [[NTRUNC]], [[COND_STORE]] ], [ [[K]], [[COND_STORE_K]] ]
169; CHECK-NEXT:    store i32 [[STOREVAL]], ptr [[A]], align 4
170; CHECK-NEXT:    [[I_NEXT]] = add nuw nsw i64 [[I]], 1
171; CHECK-NEXT:    [[COND:%.*]] = icmp slt i64 [[I_NEXT]], [[N]]
172; CHECK-NEXT:    br i1 [[COND]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop [[LOOP15:![0-9]+]]
173; CHECK:       for.end.loopexit:
174; CHECK-NEXT:    br label [[FOR_END]]
175; CHECK:       for.end:
176; CHECK-NEXT:    ret void
177;
178entry:
179  %ntrunc = trunc i64 %n to i32
180  %cmp = icmp eq i32 %ntrunc, %k
181  br label %for.body
182
183for.body:                                         ; preds = %for.body, %entry
184  %i = phi i64 [ %i.next, %latch ], [ 0, %entry ]
185  %i1 = getelementptr inbounds i32, ptr %b, i64 %i
186  %i2 = load i32, ptr %i1, align 8
187  store i32 %ntrunc, ptr %i1
188  br i1 %cmp, label %cond_store, label %cond_store_k
189
190cond_store:
191  br label %latch
192
193cond_store_k:
194  br label %latch
195
196latch:
197  %storeval = phi i32 [ %ntrunc, %cond_store ], [ %k, %cond_store_k ]
198  store i32 %storeval, ptr %a
199  %i.next = add nuw nsw i64 %i, 1
200  %cond = icmp slt i64 %i.next, %n
201  br i1 %cond, label %for.body, label %for.end
202
203for.end:                                          ; preds = %for.body
204  ret void
205}
206
207; variant value stored to uniform address tests that the code gen extracts the
208; last element from the variant vector and scalar stores it into the uniform
209; address.
210define i32 @variant_val_store_to_inv_address(ptr %a, i64 %n, ptr %b, i32 %k) {
211; CHECK-LABEL: @variant_val_store_to_inv_address(
212; CHECK-NEXT:  entry:
213; CHECK-NEXT:    [[SMAX2:%.*]] = call i64 @llvm.smax.i64(i64 [[N:%.*]], i64 1)
214; CHECK-NEXT:    [[MIN_ITERS_CHECK:%.*]] = icmp slt i64 [[N]], 4
215; CHECK-NEXT:    br i1 [[MIN_ITERS_CHECK]], label [[SCALAR_PH:%.*]], label [[VECTOR_MEMCHECK:%.*]]
216; CHECK:       vector.memcheck:
217; CHECK-NEXT:    [[SCEVGEP:%.*]] = getelementptr i8, ptr [[A:%.*]], i64 4
218; CHECK-NEXT:    [[TMP0:%.*]] = shl i64 [[N]], 2
219; CHECK-NEXT:    [[SCEVGEP1:%.*]] = getelementptr i8, ptr [[B:%.*]], i64 [[TMP0]]
220; CHECK-NEXT:    [[BOUND0:%.*]] = icmp ult ptr [[A]], [[SCEVGEP1]]
221; CHECK-NEXT:    [[BOUND1:%.*]] = icmp ult ptr [[B]], [[SCEVGEP]]
222; CHECK-NEXT:    [[FOUND_CONFLICT:%.*]] = and i1 [[BOUND0]], [[BOUND1]]
223; CHECK-NEXT:    br i1 [[FOUND_CONFLICT]], label [[SCALAR_PH]], label [[VECTOR_PH:%.*]]
224; CHECK:       vector.ph:
225; CHECK-NEXT:    [[N_VEC:%.*]] = and i64 [[SMAX2]], 9223372036854775804
226; CHECK-NEXT:    br label [[VECTOR_BODY:%.*]]
227; CHECK:       vector.body:
228; CHECK-NEXT:    [[INDEX:%.*]] = phi i64 [ 0, [[VECTOR_PH]] ], [ [[INDEX_NEXT:%.*]], [[VECTOR_BODY]] ]
229; CHECK-NEXT:    [[VEC_PHI:%.*]] = phi <4 x i32> [ zeroinitializer, [[VECTOR_PH]] ], [ [[TMP3:%.*]], [[VECTOR_BODY]] ]
230; CHECK-NEXT:    [[TMP1:%.*]] = getelementptr inbounds i32, ptr [[B]], i64 [[INDEX]]
231; CHECK-NEXT:    [[WIDE_LOAD:%.*]] = load <4 x i32>, ptr [[TMP1]], align 8, !alias.scope [[META16:![0-9]+]]
232; CHECK-NEXT:    [[TMP2:%.*]] = extractelement <4 x i32> [[WIDE_LOAD]], i64 3
233; CHECK-NEXT:    store i32 [[TMP2]], ptr [[A]], align 4, !alias.scope [[META19:![0-9]+]], !noalias [[META16]]
234; CHECK-NEXT:    [[TMP3]] = add <4 x i32> [[VEC_PHI]], [[WIDE_LOAD]]
235; CHECK-NEXT:    [[INDEX_NEXT]] = add nuw i64 [[INDEX]], 4
236; CHECK-NEXT:    [[TMP4:%.*]] = icmp eq i64 [[INDEX_NEXT]], [[N_VEC]]
237; CHECK-NEXT:    br i1 [[TMP4]], label [[MIDDLE_BLOCK:%.*]], label [[VECTOR_BODY]], !llvm.loop [[LOOP21:![0-9]+]]
238; CHECK:       middle.block:
239; CHECK-NEXT:    [[DOTLCSSA:%.*]] = phi <4 x i32> [ [[TMP3]], [[VECTOR_BODY]] ]
240; CHECK-NEXT:    [[TMP5:%.*]] = call i32 @llvm.vector.reduce.add.v4i32(<4 x i32> [[DOTLCSSA]])
241; CHECK-NEXT:    [[CMP_N:%.*]] = icmp eq i64 [[SMAX2]], [[N_VEC]]
242; CHECK-NEXT:    br i1 [[CMP_N]], label [[FOR_END:%.*]], label [[SCALAR_PH]]
243; CHECK:       scalar.ph:
244; CHECK-NEXT:    [[BC_RESUME_VAL:%.*]] = phi i64 [ [[N_VEC]], [[MIDDLE_BLOCK]] ], [ 0, [[VECTOR_MEMCHECK]] ], [ 0, [[ENTRY:%.*]] ]
245; CHECK-NEXT:    [[BC_MERGE_RDX:%.*]] = phi i32 [ [[TMP5]], [[MIDDLE_BLOCK]] ], [ 0, [[VECTOR_MEMCHECK]] ], [ 0, [[ENTRY]] ]
246; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
247; CHECK:       for.body:
248; CHECK-NEXT:    [[I:%.*]] = phi i64 [ [[I_NEXT:%.*]], [[FOR_BODY]] ], [ [[BC_RESUME_VAL]], [[SCALAR_PH]] ]
249; CHECK-NEXT:    [[I0:%.*]] = phi i32 [ [[I3:%.*]], [[FOR_BODY]] ], [ [[BC_MERGE_RDX]], [[SCALAR_PH]] ]
250; CHECK-NEXT:    [[I1:%.*]] = getelementptr inbounds nuw i32, ptr [[B]], i64 [[I]]
251; CHECK-NEXT:    [[I2:%.*]] = load i32, ptr [[I1]], align 8
252; CHECK-NEXT:    store i32 [[I2]], ptr [[A]], align 4
253; CHECK-NEXT:    [[I3]] = add i32 [[I0]], [[I2]]
254; CHECK-NEXT:    [[I_NEXT]] = add nuw nsw i64 [[I]], 1
255; CHECK-NEXT:    [[COND:%.*]] = icmp slt i64 [[I_NEXT]], [[N]]
256; CHECK-NEXT:    br i1 [[COND]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]], !llvm.loop [[LOOP22:![0-9]+]]
257; CHECK:       for.end.loopexit:
258; CHECK-NEXT:    [[I3_LCSSA:%.*]] = phi i32 [ [[I3]], [[FOR_BODY]] ]
259; CHECK-NEXT:    br label [[FOR_END]]
260; CHECK:       for.end:
261; CHECK-NEXT:    [[RDX_LCSSA:%.*]] = phi i32 [ [[TMP5]], [[MIDDLE_BLOCK]] ], [ [[I3_LCSSA]], [[FOR_END_LOOPEXIT]] ]
262; CHECK-NEXT:    ret i32 [[RDX_LCSSA]]
263;
264entry:
265  %ntrunc = trunc i64 %n to i32
266  %cmp = icmp eq i32 %ntrunc, %k
267  br label %for.body
268
269for.body:                                         ; preds = %for.body, %entry
270  %i = phi i64 [ %i.next, %for.body ], [ 0, %entry ]
271  %i0 = phi i32 [ %i3, %for.body ], [ 0, %entry ]
272  %i1 = getelementptr inbounds i32, ptr %b, i64 %i
273  %i2 = load i32, ptr %i1, align 8
274  store i32 %i2, ptr %a
275  %i3 = add i32 %i0, %i2
276  %i.next = add nuw nsw i64 %i, 1
277  %cond = icmp slt i64 %i.next, %n
278  br i1 %cond, label %for.body, label %for.end
279
280for.end:                                          ; preds = %for.body
281  %rdx.lcssa = phi i32 [ %i3, %for.body ]
282  ret i32 %rdx.lcssa
283}
284