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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
|
; RUN: llc %s -o - | FileCheck %s --check-prefix=CHECK
;
; 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"
; 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
;
; 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 }
; Check that we generate correct code for segmented stack.
; We used to emit the code at the entry point of the function
; instead of just before the prologue.
; For now, shrink-wrapping is disabled on segmented stack functions: PR26107.
;
; CHECK-LABEL: segmentedStack:
; CHECK: cmpq
; CHECK-NEXT: ja [[ENTRY_LABEL:LBB[0-9_]+]]
;
; CHECK: callq ___morestack
; CHECK-NEXT: retq
;
; CHECK: [[ENTRY_LABEL]]:
; Prologue
; CHECK: push
;
; In PR26107, we use to drop these two basic blocks, because
; the segmentedStack entry block was jumping directly to
; the place where the prologue is actually needed, which is
; the call to memcmp.
; Then, those two basic blocks did not have any predecessors
; anymore and were removed.
;
; Check if vk1 is null
; CHECK: testq %rdi, %rdi
; CHECK-NEXT: je [[STRINGS_EQUAL:LBB[0-9_]+]]
;
; Check if vk2 is null
; CHECK: testq %rsi, %rsi
; CHECK-NEXT: je [[STRINGS_EQUAL]]
;
; CHECK: [[STRINGS_EQUAL]]
; CHECK-NEXT: popq
define zeroext i1 @segmentedStack(i8* readonly %vk1, i8* readonly %vk2, i64 %key_size) #5 {
entry:
%cmp.i = icmp eq i8* %vk1, null
%cmp1.i = icmp eq i8* %vk2, null
%brmerge.i = or i1 %cmp.i, %cmp1.i
%cmp1.mux.i = and i1 %cmp.i, %cmp1.i
br i1 %brmerge.i, label %__go_ptr_strings_equal.exit, label %if.end4.i
if.end4.i: ; preds = %entry
%tmp = getelementptr inbounds i8, i8* %vk1, i64 8
%tmp1 = bitcast i8* %tmp to i64*
%tmp2 = load i64, i64* %tmp1, align 8
%tmp3 = getelementptr inbounds i8, i8* %vk2, i64 8
%tmp4 = bitcast i8* %tmp3 to i64*
%tmp5 = load i64, i64* %tmp4, align 8
%cmp.i.i = icmp eq i64 %tmp2, %tmp5
br i1 %cmp.i.i, label %land.rhs.i.i, label %__go_ptr_strings_equal.exit
land.rhs.i.i: ; preds = %if.end4.i
%tmp6 = bitcast i8* %vk2 to i8**
%tmp7 = load i8*, i8** %tmp6, align 8
%tmp8 = bitcast i8* %vk1 to i8**
%tmp9 = load i8*, i8** %tmp8, align 8
%call.i.i = tail call i32 @memcmp(i8* %tmp9, i8* %tmp7, i64 %tmp2) #5
%cmp4.i.i = icmp eq i32 %call.i.i, 0
br label %__go_ptr_strings_equal.exit
__go_ptr_strings_equal.exit: ; preds = %land.rhs.i.i, %if.end4.i, %entry
%retval.0.i = phi i1 [ %cmp1.mux.i, %entry ], [ false, %if.end4.i ], [ %cmp4.i.i, %land.rhs.i.i ]
ret i1 %retval.0.i
}
; Function Attrs: nounwind readonly
declare i32 @memcmp(i8* nocapture, i8* nocapture, i64) #5
attributes #5 = { nounwind readonly ssp uwtable "split-stack" }
|
