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1; RUN: opt -S -o - -basicaa -domtree -gvn %s | FileCheck %s
2
3target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
4
5%struct.S1 = type { i32, i32 }
6
7@a2 = common global i32* null, align 8
8@a = common global i32* null, align 8
9@s1 = common global %struct.S1 zeroinitializer, align 8
10
11; Check that GVN doesn't determine %2 is partially redundant.
12
13; CHECK-LABEL: define i32 @volatile_load
14; CHECK: for.body:
15; CHECK: %2 = load i32, i32*
16; CHECK: %3 = load volatile i32, i32*
17; CHECK: for.cond.for.end_crit_edge:
18
19define i32 @volatile_load(i32 %n) {
20entry:
21  %cmp6 = icmp sgt i32 %n, 0
22  br i1 %cmp6, label %for.body.lr.ph, label %for.end
23
24for.body.lr.ph:
25  %0 = load i32*, i32** @a2, align 8, !tbaa !1
26  %1 = load i32*, i32** @a, align 8, !tbaa !1
27  br label %for.body
28
29for.body:
30  %indvars.iv = phi i64 [ 0, %for.body.lr.ph ], [ %indvars.iv.next, %for.body ]
31  %s.09 = phi i32 [ 0, %for.body.lr.ph ], [ %add, %for.body ]
32  %p.08 = phi i32* [ %0, %for.body.lr.ph ], [ %incdec.ptr, %for.body ]
33  %2 = load i32, i32* %p.08, align 4, !tbaa !5
34  %arrayidx = getelementptr inbounds i32, i32* %1, i64 %indvars.iv
35  store i32 %2, i32* %arrayidx, align 4, !tbaa !5
36  %3 = load volatile i32, i32* %p.08, align 4, !tbaa !5
37  %add = add nsw i32 %3, %s.09
38  %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1
39  %incdec.ptr = getelementptr inbounds i32, i32* %p.08, i64 1
40  %lftr.wideiv = trunc i64 %indvars.iv.next to i32
41  %exitcond = icmp ne i32 %lftr.wideiv, %n
42  br i1 %exitcond, label %for.body, label %for.cond.for.end_crit_edge
43
44for.cond.for.end_crit_edge:
45  %add.lcssa = phi i32 [ %add, %for.body ]
46  br label %for.end
47
48for.end:
49  %s.0.lcssa = phi i32 [ %add.lcssa, %for.cond.for.end_crit_edge ], [ 0, %entry ]
50  ret i32 %s.0.lcssa
51}
52
53; %1 is partially redundant if %0 can be widened to a 64-bit load.
54
55; CHECK-LABEL: define i32 @overaligned_load
56; CHECK: if.then:
57; CHECK:   %0 = load i64
58; CHECK:   [[LSHR:%[0-9]+]] = lshr i64 %0, 32, !dbg [[LSHR_LOC:![0-9]+]]
59; CHECK:   trunc i64 [[LSHR]] to i32
60; CHECK: if.end:
61; CHECK-NOT: %1 = load i32, i32*
62; CHECK: [[LSHR_LOC]] = !DILocation(line: 101, column: 1, scope: !{{.*}})
63
64define i32 @overaligned_load(i32 %a, i32* nocapture %b) !dbg !13 {
65entry:
66  %cmp = icmp sgt i32 %a, 0, !dbg !14
67  br i1 %cmp, label %if.then, label %if.else, !dbg !14
68
69if.then:
70  %0 = load i32, i32* getelementptr inbounds (%struct.S1, %struct.S1* @s1, i64 0, i32 0), align 8, !tbaa !5, !dbg !15
71  br label %if.end, !dbg !15
72
73if.else:
74  %arrayidx = getelementptr inbounds i32, i32* %b, i64 2, !dbg !16
75  store i32 10, i32* %arrayidx, align 4, !tbaa !5, !dbg !16
76  br label %if.end, !dbg !16
77
78if.end:
79  %i.0 = phi i32 [ %0, %if.then ], [ 0, %if.else ]
80  %p.0 = phi i32* [ getelementptr inbounds (%struct.S1, %struct.S1* @s1, i64 0, i32 0), %if.then ], [ %b, %if.else ]
81  %add.ptr = getelementptr inbounds i32, i32* %p.0, i64 1, !dbg !17
82  %1 = load i32, i32* %add.ptr, align 4, !tbaa !5, !dbg !17
83  %add1 = add nsw i32 %1, %i.0, !dbg !17
84  ret i32 %add1, !dbg !17
85}
86
87!1 = !{!2, !2, i64 0}
88!2 = !{!"any pointer", !3, i64 0}
89!3 = !{!"omnipotent char", !4, i64 0}
90!4 = !{!"Simple C/C++ TBAA"}
91!5 = !{!6, !6, i64 0}
92!6 = !{!"int", !3, i64 0}
93
94!llvm.module.flags = !{!7, !8, !9}
95!llvm.dbg.cu = !{!18}
96!7 = !{i32 2, !"Dwarf Version", i32 4}
97!8 = !{i32 2, !"Debug Info Version", i32 3}
98!9 = !{i32 1, !"PIC Level", i32 2}
99
100!10 = !{}
101!11 = !DISubroutineType(types: !10)
102!12 = !DIFile(filename: "test.cpp", directory: "/tmp")
103!13 = distinct !DISubprogram(name: "test", scope: !12, file: !12, line: 99, type: !11, isLocal: false, isDefinition: true, scopeLine: 100, flags: DIFlagPrototyped, isOptimized: false, unit: !18, variables: !10)
104!14 = !DILocation(line: 100, column: 1, scope: !13)
105!15 = !DILocation(line: 101, column: 1, scope: !13)
106!16 = !DILocation(line: 102, column: 1, scope: !13)
107!17 = !DILocation(line: 103, column: 1, scope: !13)
108!18 = distinct !DICompileUnit(language: DW_LANG_C99, producer: "clang",
109                             file: !12,
110                             isOptimized: true, flags: "-O2",
111                             splitDebugFilename: "abc.debug", emissionKind: 2)
112