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
|
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
; RUN: opt < %s -simplifycfg -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
; ModuleID = '<stdin>'
declare i1 @foo()
declare i1 @bar(i32)
; This function can't be merged
define void @a() {
; CHECK-LABEL: @a(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[BB_NOMERGE:%.*]]
; CHECK: BB.nomerge:
; CHECK-NEXT: [[A:%.*]] = phi i32 [ 1, [[ENTRY:%.*]] ], [ 0, [[COMMON:%.*]] ]
; CHECK-NEXT: br label [[SUCC:%.*]]
; CHECK: Succ:
; CHECK-NEXT: [[B:%.*]] = phi i32 [ [[A]], [[BB_NOMERGE]] ], [ 2, [[COMMON]] ]
; CHECK-NEXT: [[CONDE:%.*]] = call i1 @foo()
; CHECK-NEXT: br i1 [[CONDE]], label [[COMMON]], label [[EXIT:%.*]]
; CHECK: Common:
; CHECK-NEXT: [[COND:%.*]] = call i1 @foo()
; CHECK-NEXT: br i1 [[COND]], label [[BB_NOMERGE]], label [[SUCC]]
; CHECK: Exit:
; CHECK-NEXT: ret void
;
entry:
br label %BB.nomerge
BB.nomerge: ; preds = %Common, %entry
; This phi has a conflicting value (0) with below phi (2), so blocks
; can't be merged.
%a = phi i32 [ 1, %entry ], [ 0, %Common ] ; <i32> [#uses=1]
br label %Succ
Succ: ; preds = %Common, %BB.nomerge
%b = phi i32 [ %a, %BB.nomerge ], [ 2, %Common ] ; <i32> [#uses=0]
%conde = call i1 @foo( ) ; <i1> [#uses=1]
br i1 %conde, label %Common, label %Exit
Common: ; preds = %Succ
%cond = call i1 @foo( ) ; <i1> [#uses=1]
br i1 %cond, label %BB.nomerge, label %Succ
Exit: ; preds = %Succ
ret void
}
; This function can't be merged
define void @b() {
; CHECK-LABEL: @b(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[BB_NOMERGE:%.*]]
; CHECK: BB.nomerge:
; CHECK-NEXT: br label [[SUCC:%.*]]
; CHECK: Succ:
; CHECK-NEXT: [[B:%.*]] = phi i32 [ 1, [[BB_NOMERGE]] ], [ 2, [[COMMON:%.*]] ]
; CHECK-NEXT: [[CONDE:%.*]] = call i1 @foo()
; CHECK-NEXT: br i1 [[CONDE]], label [[COMMON]], label [[EXIT:%.*]]
; CHECK: Common:
; CHECK-NEXT: [[COND:%.*]] = call i1 @foo()
; CHECK-NEXT: br i1 [[COND]], label [[BB_NOMERGE]], label [[SUCC]]
; CHECK: Exit:
; CHECK-NEXT: ret void
;
entry:
br label %BB.nomerge
BB.nomerge: ; preds = %Common, %entry
br label %Succ
Succ: ; preds = %Common, %BB.nomerge
; This phi has confliction values for Common and (through BB) Common,
; blocks can't be merged
%b = phi i32 [ 1, %BB.nomerge ], [ 2, %Common ] ; <i32> [#uses=0]
%conde = call i1 @foo( ) ; <i1> [#uses=1]
br i1 %conde, label %Common, label %Exit
Common: ; preds = %Succ
%cond = call i1 @foo( ) ; <i1> [#uses=1]
br i1 %cond, label %BB.nomerge, label %Succ
Exit: ; preds = %Succ
ret void
}
; This function can't be merged (for keeping canonical loop structures)
define void @c() {
; CHECK-LABEL: @c(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[BB_NOMERGE:%.*]]
; CHECK: BB.nomerge:
; CHECK-NEXT: br label [[SUCC:%.*]]
; CHECK: Succ:
; CHECK-NEXT: [[B:%.*]] = phi i32 [ 1, [[BB_NOMERGE]] ], [ 1, [[COMMON:%.*]] ], [ 2, [[PRE_EXIT:%.*]] ]
; CHECK-NEXT: [[CONDE:%.*]] = call i1 @foo()
; CHECK-NEXT: br i1 [[CONDE]], label [[COMMON]], label [[PRE_EXIT]]
; CHECK: Common:
; CHECK-NEXT: [[COND:%.*]] = call i1 @foo()
; CHECK-NEXT: br i1 [[COND]], label [[BB_NOMERGE]], label [[SUCC]]
; CHECK: Pre-Exit:
; CHECK-NEXT: [[COND2:%.*]] = call i1 @foo()
; CHECK-NEXT: br i1 [[COND2]], label [[SUCC]], label [[EXIT:%.*]]
; CHECK: Exit:
; CHECK-NEXT: ret void
;
entry:
br label %BB.nomerge
BB.nomerge: ; preds = %Common, %entry
br label %Succ
Succ: ; preds = %Common, %BB.tomerge, %Pre-Exit
; This phi has identical values for Common and (through BB) Common,
; blocks can't be merged
%b = phi i32 [ 1, %BB.nomerge ], [ 1, %Common ], [ 2, %Pre-Exit ]
%conde = call i1 @foo( ) ; <i1> [#uses=1]
br i1 %conde, label %Common, label %Pre-Exit
Common: ; preds = %Succ
%cond = call i1 @foo( ) ; <i1> [#uses=1]
br i1 %cond, label %BB.nomerge, label %Succ
Pre-Exit: ; preds = %Succ
; This adds a backedge, so the %b phi node gets a third branch and is
; not completely trivial
%cond2 = call i1 @foo( ) ; <i1> [#uses=1]
br i1 %cond2, label %Succ, label %Exit
Exit: ; preds = %Pre-Exit
ret void
}
; This function can't be merged (for keeping canonical loop structures)
define void @d() {
; CHECK-LABEL: @d(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[BB_NOMERGE:%.*]]
; CHECK: BB.nomerge:
; CHECK-NEXT: [[A:%.*]] = phi i32 [ 1, [[ENTRY:%.*]] ], [ 0, [[COMMON:%.*]] ]
; CHECK-NEXT: br label [[SUCC:%.*]]
; CHECK: Succ:
; CHECK-NEXT: [[B:%.*]] = phi i32 [ [[A]], [[BB_NOMERGE]] ], [ 0, [[COMMON]] ]
; CHECK-NEXT: [[CONDE:%.*]] = call i1 @foo()
; CHECK-NEXT: br i1 [[CONDE]], label [[COMMON]], label [[EXIT:%.*]]
; CHECK: Common:
; CHECK-NEXT: [[COND:%.*]] = call i1 @foo()
; CHECK-NEXT: br i1 [[COND]], label [[BB_NOMERGE]], label [[SUCC]]
; CHECK: Exit:
; CHECK-NEXT: ret void
;
entry:
br label %BB.nomerge
BB.nomerge: ; preds = %Common, %entry
; This phi has a matching value (0) with below phi (0), so blocks
; can be merged.
%a = phi i32 [ 1, %entry ], [ 0, %Common ] ; <i32> [#uses=1]
br label %Succ
Succ: ; preds = %Common, %BB.tomerge
%b = phi i32 [ %a, %BB.nomerge ], [ 0, %Common ] ; <i32> [#uses=0]
%conde = call i1 @foo( ) ; <i1> [#uses=1]
br i1 %conde, label %Common, label %Exit
Common: ; preds = %Succ
%cond = call i1 @foo( ) ; <i1> [#uses=1]
br i1 %cond, label %BB.nomerge, label %Succ
Exit: ; preds = %Succ
ret void
}
; This function can be merged
define void @e() {
; CHECK-LABEL: @e(
; CHECK-NEXT: entry:
; CHECK-NEXT: br label [[SUCC:%.*]]
; CHECK: Succ:
; CHECK-NEXT: [[A:%.*]] = phi i32 [ 1, [[ENTRY:%.*]] ], [ 0, [[USE:%.*]] ]
; CHECK-NEXT: [[CONDE:%.*]] = call i1 @foo()
; CHECK-NEXT: br i1 [[CONDE]], label [[USE]], label [[EXIT:%.*]]
; CHECK: Use:
; CHECK-NEXT: [[COND:%.*]] = call i1 @bar(i32 [[A]])
; CHECK-NEXT: br i1 [[COND]], label [[SUCC]], label [[EXIT]]
; CHECK: Exit:
; CHECK-NEXT: ret void
;
entry:
br label %Succ
Succ: ; preds = %Use, %entry
; This phi is used somewhere else than Succ, but this should not prevent
; merging this block
%a = phi i32 [ 1, %entry ], [ 0, %Use ] ; <i32> [#uses=1]
br label %BB.tomerge
BB.tomerge: ; preds = %BB.tomerge
%conde = call i1 @foo( ) ; <i1> [#uses=1]
br i1 %conde, label %Use, label %Exit
Use: ; preds = %Succ
%cond = call i1 @bar( i32 %a ) ; <i1> [#uses=1]
br i1 %cond, label %Succ, label %Exit
Exit: ; preds = %Use, %Succ
ret void
}
|
