1; RUN: opt < %s -aa-pipeline=basic-aa -passes='require<phi-values>,aa-eval' -print-all-alias-modref-info -disable-output 2>&1 | FileCheck %s
2target 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"
3target triple = "x86_64-unknown-linux-gnu"
4
5; rdar://7282591
6
7@X = common global i32 0
8@Y = common global i32 0
9@Z = common global i32 0
10
11; CHECK-LABEL: foo
12; CHECK:  NoAlias: i32* %P, i32* @Z
13
14define void @foo(i32 %cond) nounwind {
15entry:
16  %"alloca point" = bitcast i32 0 to i32
17  %tmp = icmp ne i32 %cond, 0
18  br i1 %tmp, label %bb, label %bb1
19
20bb:
21  br label %bb2
22
23bb1:
24  br label %bb2
25
26bb2:
27  %P = phi i32* [ @X, %bb ], [ @Y, %bb1 ]
28  %tmp1 = load i32, i32* @Z, align 4
29  store i32 123, i32* %P, align 4
30  %tmp2 = load i32, i32* @Z, align 4
31  br label %return
32
33return:
34  ret void
35}
36
37; Pointers can vary in between iterations of loops.
38; PR18068
39
40; CHECK-LABEL: pr18068
41; CHECK: MayAlias: i32* %0, i32* %arrayidx5
42; CHECK: NoAlias: i32* %arrayidx13, i32* %arrayidx5
43
44define i32 @pr18068(i32* %jj7, i32* %j) {
45entry:
46  %oa5 = alloca [100 x i32], align 16
47  br label %codeRepl
48
49codeRepl:
50  %0 = phi i32* [ %arrayidx13, %for.body ], [ %j, %entry ]
51  %targetBlock = call i1 @cond(i32* %jj7)
52  br i1 %targetBlock, label %for.body, label %bye
53
54for.body:
55  %1 = load i32, i32* %jj7, align 4
56  %idxprom4 = zext i32 %1 to i64
57  %arrayidx5 = getelementptr inbounds [100 x i32], [100 x i32]* %oa5, i64 0, i64 %idxprom4
58  %2 = load i32, i32* %arrayidx5, align 4
59  %sub6 = sub i32 %2, 6
60  store i32 %sub6, i32* %arrayidx5, align 4
61  ; %0 and %arrayidx5 can alias! It is not safe to DSE the above store.
62  %3 = load i32, i32* %0, align 4
63  store i32 %3, i32* %arrayidx5, align 4
64  %sub11 = add i32 %1, -1
65  %idxprom12 = zext i32 %sub11 to i64
66  %arrayidx13 = getelementptr inbounds [100 x i32], [100 x i32]* %oa5, i64 0, i64 %idxprom12
67  load i32, i32* %arrayidx13
68  call void @inc(i32* %jj7)
69  br label %codeRepl
70
71bye:
72  %.reload = load i32, i32* %jj7, align 4
73  ret i32 %.reload
74}
75
76declare i1 @cond(i32*)
77
78declare void @inc(i32*)
79
80
81; When we have a chain of phis in nested loops we should recognise if there's
82; actually only one underlying value.
83; CHECK-LABEL: loop_phi_chain
84; CHECK: NoAlias: i32* %val1, i32* @Y
85; CHECK: NoAlias: i32* %val2, i32* @Y
86; CHECK: NoAlias: i32* %val3, i32* @Y
87define void @loop_phi_chain(i32 %a, i32 %b, i32 %c) {
88entry:
89  br label %loop1
90
91loop1:
92  %n1 = phi i32 [ 0, %entry ], [ %add1, %loop2 ]
93  %val1 = phi i32* [ @X, %entry ], [ %val2, %loop2 ]
94  load i32, i32* %val1
95  %add1 = add i32 %n1, 1
96  %cmp1 = icmp ne i32 %n1, 32
97  br i1 %cmp1, label %loop2, label %end
98
99loop2:
100  %n2 = phi i32 [ 0, %loop1 ], [ %add2, %loop3 ]
101  %val2 = phi i32* [ %val1, %loop1 ], [ %val3, %loop3 ]
102  load i32, i32* %val2
103  %add2 = add i32 %n2, 1
104  %cmp2 = icmp ne i32 %n2, 32
105  br i1 %cmp2, label %loop3, label %loop1
106
107loop3:
108  %n3 = phi i32 [ 0, %loop2 ], [ %add3, %loop3 ]
109  %val3 = phi i32* [ %val2, %loop2 ], [ %val3, %loop3 ]
110  store i32 0, i32* %val3, align 4
111  store i32 0, i32* @Y, align 4
112  %add3 = add i32 %n3, 1
113  %cmp3 = icmp ne i32 %n3, 32
114  br i1 %cmp3, label %loop3, label %loop2
115
116end:
117  ret void
118}
119
120; CHECK-LABEL: phi_and_select
121; CHECK: MustAlias: i32* %p, i32* %s
122define void @phi_and_select(i1 %c, i1 %c2, i32* %x, i32* %y) {
123entry:
124  br i1 %c, label %true, label %false
125
126true:
127  br label %exit
128
129false:
130  br label %exit
131
132exit:
133  %p = phi i32* [ %x, %true ], [ %y, %false ]
134  %s = select i1 %c2, i32* %p, i32* %p
135  store i32 0, i32* %p
136  store i32 0, i32* %s
137  ret void
138}
139
140; CHECK-LABEL: phi_and_phi_cycle
141; CHECK: NoAlias: i32* %p1, i32* %p2
142define void @phi_and_phi_cycle(i32* noalias %x, i32* noalias %y) {
143entry:
144  br label %loop
145
146loop:
147  %p1 = phi i32* [ %x, %entry ], [ %p1.next, %loop ]
148  %p2 = phi i32* [ %y, %entry ], [ %p2.next, %loop ]
149  %p1.next = getelementptr i32, i32* %p1, i64 1
150  %p2.next = getelementptr i32, i32* %p1, i64 2
151  store i32 0, i32* %p1
152  store i32 0, i32* %p2
153  br label %loop
154}
155
156; CHECK-LABEL: phi_and_gep_unknown_size
157; CHECK: Just Mod:   call void @llvm.memset.p0i8.i32(i8* %g, i8 0, i32 %size, i1 false) <->   call void @llvm.memset.p0i8.i32(i8* %z, i8 0, i32 %size, i1 false)
158; TODO: This should be NoModRef.
159define void @phi_and_gep_unknown_size(i1 %c, i8* %x, i8* %y, i8* noalias %z, i32 %size) {
160entry:
161  br i1 %c, label %true, label %false
162
163true:
164  br label %exit
165
166false:
167  br label %exit
168
169exit:
170  %p = phi i8* [ %x, %true ], [ %y, %false ]
171  %g = getelementptr inbounds i8, i8* %p, i64 1
172  call void @llvm.memset.p0i8.i32(i8* %g, i8 0, i32 %size, i1 false)
173  call void @llvm.memset.p0i8.i32(i8* %z, i8 0, i32 %size, i1 false)
174  ret void
175}
176
177declare void @llvm.memset.p0i8.i32(i8*, i8, i32, i1)
178
179; CHECK-LABEL: unsound_inequality
180; CHECK: MayAlias:  i32* %arrayidx5, i32* %phi
181; CHECK: MayAlias:  i32* %arrayidx13, i32* %phi
182; CHECK: NoAlias:   i32* %arrayidx13, i32* %arrayidx5
183
184; When recursively reasoning about phis, we can't use predicates between
185; two values as we might be comparing the two from different iterations.
186define i32 @unsound_inequality(i32* %jj7, i32* %j) {
187entry:
188  %oa5 = alloca [100 x i32], align 16
189  br label %for.body
190
191for.body:                                         ; preds = %for.body, %entry
192  %phi = phi i32* [ %arrayidx13, %for.body ], [ %j, %entry ]
193  load i32, i32* %phi
194  %idx = load i32, i32* %jj7, align 4
195  %arrayidx5 = getelementptr inbounds [100 x i32], [100 x i32]* %oa5, i64 0, i32 %idx
196  store i32 0, i32* %arrayidx5, align 4
197  store i32 0, i32* %phi, align 4
198  %notequal = add i32 %idx, 1
199  %arrayidx13 = getelementptr inbounds [100 x i32], [100 x i32]* %oa5, i64 0, i32 %notequal
200  store i32 0, i32* %arrayidx13, align 4
201  br label %for.body
202}
203
204; CHECK-LABEL: single_arg_phi
205; CHECK: NoAlias: i32* %ptr, i32* %ptr.next
206; CHECK: MustAlias: i32* %ptr, i32* %ptr.phi
207; CHECK: MustAlias: i32* %ptr.next, i32* %ptr.next.phi
208define void @single_arg_phi(i32* %ptr.base) {
209entry:
210  br label %loop
211
212loop:
213  %ptr = phi i32* [ %ptr.base, %entry ], [ %ptr.next, %split ]
214  %ptr.next = getelementptr inbounds i32, i32* %ptr, i64 1
215  load i32, i32* %ptr
216  load i32, i32* %ptr.next
217  br label %split
218
219split:
220  %ptr.phi = phi i32* [ %ptr, %loop ]
221  %ptr.next.phi = phi i32* [ %ptr.next, %loop ]
222  load i32, i32* %ptr.phi
223  load i32, i32* %ptr.next.phi
224  br label %loop
225}
226