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
|
; RUN: llc -mtriple=i686-unknown-linux-gnu -mattr=+cmov %s -o - | FileCheck %s --check-prefix=CHECK32
; RUN: llc -mtriple=x86_64-unknown-linux-gnu -mattr=+cmov %s -o - | FileCheck %s --check-prefix=CHECK64
; RUN: llc -mtriple=x86_64-pc-win32 -mattr=+cmov %s -o - | FileCheck %s --check-prefix=CHECKWIN64
define i32 @one32_nooptsize() {
entry:
ret i32 1
; When not optimizing for size, use mov.
; CHECK32-LABEL: one32_nooptsize:
; CHECK32: movl $1, %eax
; CHECK32-NEXT: retl
; CHECK64-LABEL: one32_nooptsize:
; CHECK64: movl $1, %eax
; CHECK64-NEXT: retq
}
define i32 @one32() optsize {
entry:
ret i32 1
; CHECK32-LABEL: one32:
; CHECK32: xorl %eax, %eax
; CHECK32-NEXT: incl %eax
; CHECK32-NEXT: retl
; FIXME: Figure out the best approach in 64-bit mode.
; CHECK64-LABEL: one32:
; CHECK64: movl $1, %eax
; CHECK64-NEXT: retq
}
define i32 @one32_minsize() minsize {
entry:
ret i32 1
; On 32-bit, xor-inc is preferred over push-pop.
; CHECK32-LABEL: one32_minsize:
; CHECK32: xorl %eax, %eax
; CHECK32-NEXT: incl %eax
; CHECK32-NEXT: retl
; On 64-bit we don't do xor-inc yet, so push-pop it is. Note that we have to
; pop into a 64-bit register even when we just need 32 bits.
; CHECK64-LABEL: one32_minsize:
; CHECK64: pushq $1
; CHECK64: .cfi_adjust_cfa_offset 8
; CHECK64: popq %rax
; CHECK64: .cfi_adjust_cfa_offset -8
; CHECK64-NEXT: retq
; On Win64 we can't adjust the stack unless there's a frame pointer.
; CHECKWIN64-LABEL: one32_minsize:
; CHECKWIN64: movl $1, %eax
; CHECKWIN64-NEXT: retq
}
define i32 @pr26023() minsize {
entry:
%x = alloca [120 x i8]
%0 = getelementptr inbounds [120 x i8], [120 x i8]* %x, i64 0, i64 0
call void asm sideeffect "", "imr,~{memory},~{dirflag},~{fpsr},~{flags}"(i8* %0)
%arrayidx = getelementptr inbounds [120 x i8], [120 x i8]* %x, i64 0, i64 119
store volatile i8 -2, i8* %arrayidx
call void asm sideeffect "", "r,~{dirflag},~{fpsr},~{flags}"(i32 5)
%1 = load volatile i8, i8* %arrayidx
%conv = sext i8 %1 to i32
ret i32 %conv
; The function writes to the redzone, so push/pop cannot be used.
; CHECK64-LABEL: pr26023:
; CHECK64: movl $5, %ecx
; CHECK64: retq
; 32-bit X86 doesn't have a redzone.
; CHECK32-LABEL: pr26023:
; CHECK32: pushl $5
; CHECK32: popl %ecx
; CHECK32: retl
}
define i64 @one64_minsize() minsize {
entry:
ret i64 1
; On 64-bit we don't do xor-inc yet, so push-pop it is.
; CHECK64-LABEL: one64_minsize:
; CHECK64: pushq $1
; CHECK64: .cfi_adjust_cfa_offset 8
; CHECK64: popq %rax
; CHECK64: .cfi_adjust_cfa_offset -8
; CHECK64-NEXT: retq
; On Win64 we can't adjust the stack unless there's a frame pointer.
; CHECKWIN64-LABEL: one64_minsize:
; CHECKWIN64: movl $1, %eax
; CHECKWIN64-NEXT: retq
}
define i32 @minus_one32() optsize {
entry:
ret i32 -1
; CHECK32-LABEL: minus_one32:
; CHECK32: xorl %eax, %eax
; CHECK32-NEXT: decl %eax
; CHECK32-NEXT: retl
}
define i32 @minus_one32_minsize() minsize {
entry:
ret i32 -1
; xor-dec is preferred over push-pop.
; CHECK32-LABEL: minus_one32_minsize:
; CHECK32: xorl %eax, %eax
; CHECK32-NEXT: decl %eax
; CHECK32-NEXT: retl
}
define i16 @one16() optsize {
entry:
ret i16 1
; CHECK32-LABEL: one16:
; CHECK32: xorl %eax, %eax
; CHECK32-NEXT: incl %eax
; CHECK32-NEXT: # kill
; CHECK32-NEXT: retl
}
define i16 @minus_one16() optsize {
entry:
ret i16 -1
; CHECK32-LABEL: minus_one16:
; CHECK32: xorl %eax, %eax
; CHECK32-NEXT: decl %eax
; CHECK32-NEXT: # kill
; CHECK32-NEXT: retl
}
define i32 @minus_five32() minsize {
entry:
ret i32 -5
; CHECK32-LABEL: minus_five32:
; CHECK32: pushl $-5
; CHECK32: popl %eax
; CHECK32: retl
}
define i64 @minus_five64() minsize {
entry:
ret i64 -5
; CHECK64-LABEL: minus_five64:
; CHECK64: pushq $-5
; CHECK64: .cfi_adjust_cfa_offset 8
; CHECK64: popq %rax
; CHECK64: .cfi_adjust_cfa_offset -8
; CHECK64: retq
}
define i32 @rematerialize_minus_one() optsize {
entry:
; Materialize -1 (thiscall forces it into %ecx).
tail call x86_thiscallcc void @f(i32 -1)
; Clobber all registers except %esp, leaving nowhere to store the -1 besides
; spilling it to the stack.
tail call void asm sideeffect "", "~{eax},~{ebx},~{ecx},~{edx},~{edi},~{esi},~{ebp},~{dirflag},~{fpsr},~{flags}"()
; -1 should be re-materialized here instead of getting spilled above.
ret i32 -1
; CHECK32-LABEL: rematerialize_minus_one
; CHECK32: xorl %ecx, %ecx
; CHECK32-NEXT: decl %ecx
; CHECK32: calll
; CHECK32: xorl %eax, %eax
; CHECK32-NEXT: decl %eax
; CHECK32-NOT: %eax
; CHECK32: retl
}
define i32 @rematerialize_minus_one_eflags(i32 %x) optsize {
entry:
; Materialize -1 (thiscall forces it into %ecx).
tail call x86_thiscallcc void @f(i32 -1)
; Clobber all registers except %esp, leaving nowhere to store the -1 besides
; spilling it to the stack.
tail call void asm sideeffect "", "~{eax},~{ebx},~{ecx},~{edx},~{edi},~{esi},~{ebp},~{dirflag},~{fpsr},~{flags}"()
; Define eflags.
%a = icmp ne i32 %x, 123
%b = zext i1 %a to i32
; Cause -1 to be rematerialized right in front of the cmov, which needs eflags.
; It must therefore not use the xor-dec lowering.
%c = select i1 %a, i32 %b, i32 -1
ret i32 %c
; CHECK32-LABEL: rematerialize_minus_one_eflags
; CHECK32: xorl %ecx, %ecx
; CHECK32-NEXT: decl %ecx
; CHECK32: calll
; CHECK32: cmpl
; CHECK32: setne
; CHECK32-NOT: xorl
; CHECK32: movl $-1
; CHECK32: cmov
; CHECK32: retl
}
declare x86_thiscallcc void @f(i32)
|
