xref: /llvm-project/llvm/test/Analysis/ValueTracking/deref-bitcast-of-gep.ll (revision 7fbbbfd63899331a47a0265c45f1a2a2ae6918d4)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt -S -passes=licm < %s | FileCheck %s
3
4; Note: the !invariant.load is there just solely to let us call @use()
5; to add a fake use, and still have the aliasing work out.  The call
6; to @use(0) is just to provide a may-unwind exit out of the loop, so
7; that LICM cannot hoist out the load simply because it is guaranteed
8; to execute.
9
10declare void @use(i32)
11
12define void @f_0(ptr align 4 dereferenceable(1024) %ptr) nofree nosync {
13; CHECK-LABEL: @f_0(
14; CHECK-NEXT:  entry:
15; CHECK-NEXT:    [[PTR_GEP:%.*]] = getelementptr i8, ptr [[PTR:%.*]], i32 32
16; CHECK-NEXT:    [[VAL:%.*]] = load i32, ptr [[PTR_GEP]], align 4
17; CHECK-NEXT:    br label [[LOOP:%.*]]
18; CHECK:       loop:
19; CHECK-NEXT:    call void @use(i32 0)
20; CHECK-NEXT:    call void @use(i32 [[VAL]])
21; CHECK-NEXT:    br label [[LOOP]]
22;
23
24
25entry:
26  %ptr.gep = getelementptr i8, ptr %ptr, i32 32
27  br label %loop
28
29loop:
30  call void @use(i32 0)
31  %val = load i32, ptr %ptr.gep, !invariant.load !{}
32  call void @use(i32 %val)
33  br label %loop
34}
35
36define void @f_1(ptr align 4 dereferenceable_or_null(1024) %ptr) nofree nosync {
37; CHECK-LABEL: @f_1(
38; CHECK-NEXT:  entry:
39; CHECK-NEXT:    [[PTR_GEP:%.*]] = getelementptr i8, ptr [[PTR:%.*]], i32 32
40; CHECK-NEXT:    [[PTR_IS_NULL:%.*]] = icmp eq ptr [[PTR]], null
41; CHECK-NEXT:    br i1 [[PTR_IS_NULL]], label [[LEAVE:%.*]], label [[LOOP_PREHEADER:%.*]]
42; CHECK:       loop.preheader:
43; CHECK-NEXT:    [[VAL:%.*]] = load i32, ptr [[PTR_GEP]], align 4
44; CHECK-NEXT:    br label [[LOOP:%.*]]
45; CHECK:       loop:
46; CHECK-NEXT:    call void @use(i32 0)
47; CHECK-NEXT:    call void @use(i32 [[VAL]])
48; CHECK-NEXT:    br label [[LOOP]]
49; CHECK:       leave:
50; CHECK-NEXT:    ret void
51;
52entry:
53  %ptr.gep = getelementptr i8, ptr %ptr, i32 32
54  %ptr_is_null = icmp eq ptr %ptr, null
55  br i1 %ptr_is_null, label %leave, label %loop
56
57
58loop:
59  call void @use(i32 0)
60  %val = load i32, ptr %ptr.gep, !invariant.load !{}
61  call void @use(i32 %val)
62  br label %loop
63
64leave:
65  ret void
66}
67
68define void @f_2(ptr align 4 dereferenceable_or_null(1024) %ptr) {
69; CHECK-LABEL: @f_2(
70; CHECK-NEXT:  entry:
71; CHECK-NEXT:    [[PTR_GEP:%.*]] = getelementptr i8, ptr [[PTR:%.*]], i32 30
72; CHECK-NEXT:    [[PTR_IS_NULL:%.*]] = icmp eq ptr [[PTR]], null
73; CHECK-NEXT:    br i1 [[PTR_IS_NULL]], label [[LEAVE:%.*]], label [[LOOP_PREHEADER:%.*]]
74; CHECK:       loop.preheader:
75; CHECK-NEXT:    br label [[LOOP:%.*]]
76; CHECK:       loop:
77; CHECK-NEXT:    call void @use(i32 0)
78; CHECK-NEXT:    [[VAL:%.*]] = load i32, ptr [[PTR_GEP]], align 4, !invariant.load !0
79; CHECK-NEXT:    call void @use(i32 [[VAL]])
80; CHECK-NEXT:    br label [[LOOP]]
81; CHECK:       leave:
82; CHECK-NEXT:    ret void
83;
84
85entry:
86  ;; Can't hoist, since the alignment does not work out -- (<4 byte
87  ;; aligned> + 30) is not necessarily 4 byte aligned.
88
89  %ptr.gep = getelementptr i8, ptr %ptr, i32 30
90  %ptr_is_null = icmp eq ptr %ptr, null
91  br i1 %ptr_is_null, label %leave, label %loop
92
93loop:
94  call void @use(i32 0)
95  %val = load i32, ptr %ptr.gep, !invariant.load !{}
96  call void @use(i32 %val)
97  br label %loop
98
99leave:
100  ret void
101}
102
103define void @checkLaunder(ptr align 4 dereferenceable(1024) %p) nofree nosync {
104; CHECK-LABEL: @checkLaunder(
105; CHECK-NEXT:  entry:
106; CHECK-NEXT:    [[L:%.*]] = call ptr @llvm.launder.invariant.group.p0(ptr [[P:%.*]])
107; CHECK-NEXT:    [[VAL:%.*]] = load i8, ptr [[L]], align 1
108; CHECK-NEXT:    br label [[LOOP:%.*]]
109; CHECK:       loop:
110; CHECK-NEXT:    call void @use(i32 0)
111; CHECK-NEXT:    call void @use8(i8 [[VAL]])
112; CHECK-NEXT:    br label [[LOOP]]
113;
114
115entry:
116  %l = call ptr @llvm.launder.invariant.group.p0(ptr %p)
117  br label %loop
118
119loop:
120  call void @use(i32 0)
121  %val = load i8, ptr %l, !invariant.load !{}
122  call void @use8(i8 %val)
123  br label %loop
124}
125
126declare ptr @llvm.launder.invariant.group.p0(ptr)
127
128declare void @use8(i8)
129