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
|
; REQUIRES: asserts
; RUN: llc < %s -O3 -march=x86-64 -mcpu=core2 -stress-ivchain | FileCheck %s -check-prefix=X64
; RUN: llc < %s -O3 -march=x86 -mcpu=core2 -stress-ivchain | FileCheck %s -check-prefix=X32
; @sharedidx is an unrolled variant of this loop:
; for (unsigned long i = 0; i < len; i += s) {
; c[i] = a[i] + b[i];
; }
; where 's' cannot be folded into the addressing mode.
;
; This is not quite profitable to chain. But with -stress-ivchain, we
; can form three address chains in place of the shared induction
; variable.
; X64: sharedidx:
; X64: %for.body.preheader
; X64-NOT: leal ({{.*}},4)
; X64: %for.body.1
; X32: sharedidx:
; X32: %for.body.2
; X32: add
; X32: add
; X32: add
; X32: add
; X32: add
; X32: %for.body.3
define void @sharedidx(i8* nocapture %a, i8* nocapture %b, i8* nocapture %c, i32 %s, i32 %len) nounwind ssp {
entry:
%cmp8 = icmp eq i32 %len, 0
br i1 %cmp8, label %for.end, label %for.body
for.body: ; preds = %entry, %for.body.3
%i.09 = phi i32 [ %add5.3, %for.body.3 ], [ 0, %entry ]
%arrayidx = getelementptr inbounds i8, i8* %a, i32 %i.09
%0 = load i8, i8* %arrayidx, align 1
%conv6 = zext i8 %0 to i32
%arrayidx1 = getelementptr inbounds i8, i8* %b, i32 %i.09
%1 = load i8, i8* %arrayidx1, align 1
%conv27 = zext i8 %1 to i32
%add = add nsw i32 %conv27, %conv6
%conv3 = trunc i32 %add to i8
%arrayidx4 = getelementptr inbounds i8, i8* %c, i32 %i.09
store i8 %conv3, i8* %arrayidx4, align 1
%add5 = add i32 %i.09, %s
%cmp = icmp ult i32 %add5, %len
br i1 %cmp, label %for.body.1, label %for.end
for.end: ; preds = %for.body, %for.body.1, %for.body.2, %for.body.3, %entry
ret void
for.body.1: ; preds = %for.body
%arrayidx.1 = getelementptr inbounds i8, i8* %a, i32 %add5
%2 = load i8, i8* %arrayidx.1, align 1
%conv6.1 = zext i8 %2 to i32
%arrayidx1.1 = getelementptr inbounds i8, i8* %b, i32 %add5
%3 = load i8, i8* %arrayidx1.1, align 1
%conv27.1 = zext i8 %3 to i32
%add.1 = add nsw i32 %conv27.1, %conv6.1
%conv3.1 = trunc i32 %add.1 to i8
%arrayidx4.1 = getelementptr inbounds i8, i8* %c, i32 %add5
store i8 %conv3.1, i8* %arrayidx4.1, align 1
%add5.1 = add i32 %add5, %s
%cmp.1 = icmp ult i32 %add5.1, %len
br i1 %cmp.1, label %for.body.2, label %for.end
for.body.2: ; preds = %for.body.1
%arrayidx.2 = getelementptr inbounds i8, i8* %a, i32 %add5.1
%4 = load i8, i8* %arrayidx.2, align 1
%conv6.2 = zext i8 %4 to i32
%arrayidx1.2 = getelementptr inbounds i8, i8* %b, i32 %add5.1
%5 = load i8, i8* %arrayidx1.2, align 1
%conv27.2 = zext i8 %5 to i32
%add.2 = add nsw i32 %conv27.2, %conv6.2
%conv3.2 = trunc i32 %add.2 to i8
%arrayidx4.2 = getelementptr inbounds i8, i8* %c, i32 %add5.1
store i8 %conv3.2, i8* %arrayidx4.2, align 1
%add5.2 = add i32 %add5.1, %s
%cmp.2 = icmp ult i32 %add5.2, %len
br i1 %cmp.2, label %for.body.3, label %for.end
for.body.3: ; preds = %for.body.2
%arrayidx.3 = getelementptr inbounds i8, i8* %a, i32 %add5.2
%6 = load i8, i8* %arrayidx.3, align 1
%conv6.3 = zext i8 %6 to i32
%arrayidx1.3 = getelementptr inbounds i8, i8* %b, i32 %add5.2
%7 = load i8, i8* %arrayidx1.3, align 1
%conv27.3 = zext i8 %7 to i32
%add.3 = add nsw i32 %conv27.3, %conv6.3
%conv3.3 = trunc i32 %add.3 to i8
%arrayidx4.3 = getelementptr inbounds i8, i8* %c, i32 %add5.2
store i8 %conv3.3, i8* %arrayidx4.3, align 1
%add5.3 = add i32 %add5.2, %s
%cmp.3 = icmp ult i32 %add5.3, %len
br i1 %cmp.3, label %for.body, label %for.end
}
|
