parallel-loops.ll
4.74 KB
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
; RUN: opt < %s -loop-vectorize -force-vector-interleave=1 -force-vector-width=4 -dce -instcombine -S | FileCheck %s
target 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"
target triple = "x86_64-unknown-linux-gnu"
; A tricky loop:
;
; void loop(int *a, int *b) {
; for (int i = 0; i < 512; ++i) {
; a[a[i]] = b[i];
; a[i] = b[i+1];
; }
;}
;CHECK-LABEL: @loop(
;CHECK-NOT: <4 x i32>
define void @loop(i32* nocapture %a, i32* nocapture %b) nounwind uwtable {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%arrayidx = getelementptr inbounds i32, i32* %b, i64 %indvars.iv
%0 = load i32, i32* %arrayidx, align 4
%arrayidx2 = getelementptr inbounds i32, i32* %a, i64 %indvars.iv
%1 = load i32, i32* %arrayidx2, align 4
%idxprom3 = sext i32 %1 to i64
%arrayidx4 = getelementptr inbounds i32, i32* %a, i64 %idxprom3
store i32 %0, i32* %arrayidx4, align 4
%indvars.iv.next = add i64 %indvars.iv, 1
%arrayidx6 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv.next
%2 = load i32, i32* %arrayidx6, align 4
store i32 %2, i32* %arrayidx2, align 4
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, 512
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body
ret void
}
; The same loop with parallel loop metadata added to the loop branch
; and the memory instructions.
;CHECK-LABEL: @parallel_loop(
;CHECK: <4 x i32>
define void @parallel_loop(i32* nocapture %a, i32* nocapture %b) nounwind uwtable {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%arrayidx = getelementptr inbounds i32, i32* %b, i64 %indvars.iv
%0 = load i32, i32* %arrayidx, align 4, !llvm.access.group !13
%arrayidx2 = getelementptr inbounds i32, i32* %a, i64 %indvars.iv
%1 = load i32, i32* %arrayidx2, align 4, !llvm.access.group !13
%idxprom3 = sext i32 %1 to i64
%arrayidx4 = getelementptr inbounds i32, i32* %a, i64 %idxprom3
; This store might have originated from inlining a function with a parallel
; loop. Refers to a list with the "original loop reference" (!4) also included.
store i32 %0, i32* %arrayidx4, align 4, !llvm.access.group !15
%indvars.iv.next = add i64 %indvars.iv, 1
%arrayidx6 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv.next
%2 = load i32, i32* %arrayidx6, align 4, !llvm.access.group !13
store i32 %2, i32* %arrayidx2, align 4, !llvm.access.group !13
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, 512
br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !3
for.end: ; preds = %for.body
ret void
}
; The same loop with an illegal parallel loop metadata: the memory
; accesses refer to a different loop's identifier.
;CHECK-LABEL: @mixed_metadata(
;CHECK-NOT: <4 x i32>
define void @mixed_metadata(i32* nocapture %a, i32* nocapture %b) nounwind uwtable {
entry:
br label %for.body
for.body: ; preds = %for.body, %entry
%indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ]
%arrayidx = getelementptr inbounds i32, i32* %b, i64 %indvars.iv
%0 = load i32, i32* %arrayidx, align 4, !llvm.access.group !16
%arrayidx2 = getelementptr inbounds i32, i32* %a, i64 %indvars.iv
%1 = load i32, i32* %arrayidx2, align 4, !llvm.access.group !16
%idxprom3 = sext i32 %1 to i64
%arrayidx4 = getelementptr inbounds i32, i32* %a, i64 %idxprom3
; This refers to the loop marked with !7 which we are not in at the moment.
; It should prevent detecting as a parallel loop.
store i32 %0, i32* %arrayidx4, align 4, !llvm.access.group !17
%indvars.iv.next = add i64 %indvars.iv, 1
%arrayidx6 = getelementptr inbounds i32, i32* %b, i64 %indvars.iv.next
%2 = load i32, i32* %arrayidx6, align 4, !llvm.access.group !16
store i32 %2, i32* %arrayidx2, align 4, !llvm.access.group !16
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, 512
br i1 %exitcond, label %for.end, label %for.body, !llvm.loop !6
for.end: ; preds = %for.body
ret void
}
!3 = !{!3, !{!"llvm.loop.parallel_accesses", !13, !15}}
!4 = !{!4, !{!"llvm.loop.parallel_accesses", !14, !15}}
!6 = !{!6, !{!"llvm.loop.parallel_accesses", !16}}
!7 = !{!7, !{!"llvm.loop.parallel_accesses", !17}}
!13 = distinct !{}
!14 = distinct !{}
!15 = distinct !{}
!16 = distinct !{}
!17 = distinct !{}