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
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
; RUN: llc %s -o - | FileCheck %s --check-prefix=CHECK
;
; This test checks that we do not use shrink-wrapping when
; the function does not have any frame pointer and may unwind.
; This is a workaround for a limitation in the emission of
; the CFI directives, that are not correct in such case.
; PR25614
;
; Note: This test cannot be merged with the shrink-wrapping tests
; because the booleans set on the command line take precedence on
; the target logic that disable shrink-wrapping.
target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
target triple = "x86_64-apple-macosx"
; No shrink-wrapping should occur here, until the CFI information are fixed.
; CHECK-LABEL: framelessUnwind:
;
; Prologue code.
; (What we push does not matter. It should be some random sratch register.)
; CHECK: pushq
;
; Compare the arguments and jump to exit.
; After the prologue is set.
; CHECK: movl %edi, [[ARG0CPY:%e[a-z]+]]
; CHECK-NEXT: cmpl %esi, [[ARG0CPY]]
; CHECK-NEXT: jge [[EXIT_LABEL:LBB[0-9_]+]]
;
; Store %a in the alloca.
; CHECK: movl [[ARG0CPY]], 4(%rsp)
; Set the alloca address in the second argument.
; CHECK-NEXT: leaq 4(%rsp), %rsi
; Set the first argument to zero.
; CHECK-NEXT: xorl %edi, %edi
; CHECK-NEXT: callq _doSomething
;
; CHECK: [[EXIT_LABEL]]:
;
; Without shrink-wrapping, epilogue is in the exit block.
; Epilogue code. (What we pop does not matter.)
; CHECK-NEXT: popq
;
; CHECK-NEXT: retq
define i32 @framelessUnwind(i32 %a, i32 %b) #0 {
%tmp = alloca i32, align 4
%tmp2 = icmp slt i32 %a, %b
br i1 %tmp2, label %true, label %false
true:
store i32 %a, i32* %tmp, align 4
%tmp4 = call i32 @doSomething(i32 0, i32* %tmp)
br label %false
false:
%tmp.0 = phi i32 [ %tmp4, %true ], [ %a, %0 ]
ret i32 %tmp.0
}
declare i32 @doSomething(i32, i32*)
attributes #0 = { "no-frame-pointer-elim"="false" }
; Shrink-wrapping should occur here. We have a frame pointer.
; CHECK-LABEL: frameUnwind:
;
; Compare the arguments and jump to exit.
; No prologue needed.
;
; Compare the arguments and jump to exit.
; After the prologue is set.
; CHECK: movl %edi, [[ARG0CPY:%e[a-z]+]]
; CHECK-NEXT: cmpl %esi, [[ARG0CPY]]
; CHECK-NEXT: jge [[EXIT_LABEL:LBB[0-9_]+]]
;
; Prologue code.
; CHECK: pushq %rbp
; CHECK: movq %rsp, %rbp
;
; Store %a in the alloca.
; CHECK: movl [[ARG0CPY]], -4(%rbp)
; Set the alloca address in the second argument.
; CHECK-NEXT: leaq -4(%rbp), %rsi
; Set the first argument to zero.
; CHECK-NEXT: xorl %edi, %edi
; CHECK-NEXT: callq _doSomething
;
; Epilogue code. (What we pop does not matter.)
; CHECK: popq %rbp
;
; CHECK: [[EXIT_LABEL]]:
; CHECK-NEXT: retq
define i32 @frameUnwind(i32 %a, i32 %b) #1 {
%tmp = alloca i32, align 4
%tmp2 = icmp slt i32 %a, %b
br i1 %tmp2, label %true, label %false
true:
store i32 %a, i32* %tmp, align 4
%tmp4 = call i32 @doSomething(i32 0, i32* %tmp)
br label %false
false:
%tmp.0 = phi i32 [ %tmp4, %true ], [ %a, %0 ]
ret i32 %tmp.0
}
attributes #1 = { "no-frame-pointer-elim"="true" }
; Shrink-wrapping should occur here. We do not have to unwind.
; CHECK-LABEL: framelessnoUnwind:
;
; Compare the arguments and jump to exit.
; No prologue needed.
;
; Compare the arguments and jump to exit.
; After the prologue is set.
; CHECK: movl %edi, [[ARG0CPY:%e[a-z]+]]
; CHECK-NEXT: cmpl %esi, [[ARG0CPY]]
; CHECK-NEXT: jge [[EXIT_LABEL:LBB[0-9_]+]]
;
; Prologue code.
; (What we push does not matter. It should be some random sratch register.)
; CHECK: pushq
;
; Store %a in the alloca.
; CHECK: movl [[ARG0CPY]], 4(%rsp)
; Set the alloca address in the second argument.
; CHECK-NEXT: leaq 4(%rsp), %rsi
; Set the first argument to zero.
; CHECK-NEXT: xorl %edi, %edi
; CHECK-NEXT: callq _doSomething
;
; Epilogue code.
; CHECK-NEXT: addq
;
; CHECK: [[EXIT_LABEL]]:
; CHECK-NEXT: retq
define i32 @framelessnoUnwind(i32 %a, i32 %b) #2 {
%tmp = alloca i32, align 4
%tmp2 = icmp slt i32 %a, %b
br i1 %tmp2, label %true, label %false
true:
store i32 %a, i32* %tmp, align 4
%tmp4 = call i32 @doSomething(i32 0, i32* %tmp)
br label %false
false:
%tmp.0 = phi i32 [ %tmp4, %true ], [ %a, %0 ]
ret i32 %tmp.0
}
attributes #2 = { "no-frame-pointer-elim"="false" nounwind }
|
