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
|
; RUN: llc -mtriple=aarch64-linux-gnu -mcpu=cortex-a57 -verify-machineinstrs < %s | FileCheck %s
; CHECK-LABEL: f_XX:
; CHECK: cbz x[[REG:[0-9]+]], [[BB:.LBB.*]]
; CHECK: [[BB]]:
; CHECK-NOT: mov x[[REG]], xzr
define i64 @f_XX(i64 %n, i64* nocapture readonly %P) {
entry:
%tobool = icmp eq i64 %n, 0
br i1 %tobool, label %if.end, label %if.then
if.then: ; preds = %entry
%0 = load i64, i64* %P
br label %if.end
if.end: ; preds = %entry, %if.then
%a.0 = phi i64 [ %0, %if.then ], [ 0, %entry ]
ret i64 %a.0
}
; CHECK-LABEL: f_WW:
; CHECK: cbz w[[REG:[0-9]+]], [[BB:.LBB.*]]
; CHECK: [[BB]]:
; CHECK-NOT: mov w[[REG]], wzr
define i32 @f_WW(i32 %n, i32* nocapture readonly %P) {
entry:
%tobool = icmp eq i32 %n, 0
br i1 %tobool, label %if.end, label %if.then
if.then: ; preds = %entry
%0 = load i32, i32* %P
br label %if.end
if.end: ; preds = %entry, %if.then
%a.0 = phi i32 [ %0, %if.then ], [ 0, %entry ]
ret i32 %a.0
}
; CHECK-LABEL: f_XW:
; CHECK: cbz x[[REG:[0-9]+]], [[BB:.LBB.*]]
; CHECK: [[BB]]:
; CHECK-NOT: mov w[[REG]], wzr
define i32 @f_XW(i64 %n, i32* nocapture readonly %P) {
entry:
%tobool = icmp eq i64 %n, 0
br i1 %tobool, label %if.end, label %if.then
if.then: ; preds = %entry
%0 = load i32, i32* %P
br label %if.end
if.end: ; preds = %entry, %if.then
%a.0 = phi i32 [ %0, %if.then ], [ 0, %entry ]
ret i32 %a.0
}
; CHECK-LABEL: f_WX:
; CHECK: cbz w[[REG:[0-9]+]], [[BB:.LBB.*]]
; CHECK: [[BB]]:
; CHECK: mov x[[REG]], xzr
; Do not remove the mov in this case because we do not know if the upper bits
; of the X register are zero.
define i64 @f_WX(i32 %n, i64* nocapture readonly %P) {
entry:
%tobool = icmp eq i32 %n, 0
br i1 %tobool, label %if.end, label %if.then
if.then: ; preds = %entry
%0 = load i64, i64* %P
br label %if.end
if.end: ; preds = %entry, %if.then
%a.0 = phi i64 [ %0, %if.then ], [ 0, %entry ]
ret i64 %a.0
}
; CHECK-LABEL: test_superreg:
; CHECK: cbz x[[REG:[0-9]+]], [[BB:.LBB.*]]
; CHECK: [[BB]]:
; CHECK: str x[[REG]], [x1]
; CHECK-NOT: mov w[[REG]], wzr
; Because we returned w0 but x0 was marked live-in to the block, we didn't
; remove the <kill> on the str leading to a verification failure.
define i32 @test_superreg(i64 %in, i64* %dest) {
%tst = icmp eq i64 %in, 0
br i1 %tst, label %true, label %false
false:
ret i32 42
true:
store volatile i64 %in, i64* %dest
ret i32 0
}
|
