aboutsummaryrefslogtreecommitdiffstats
path: root/test/Transforms/Inline/inline_constprop.ll
blob: b59a270468e09a13f9b0a64101d32c3bcb84cd5e (plain)
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
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
; RUN: opt < %s -inline -inline-threshold=20 -S | FileCheck %s

define internal i32 @callee1(i32 %A, i32 %B) {
  %C = sdiv i32 %A, %B
  ret i32 %C
}

define i32 @caller1() {
; CHECK-LABEL: define i32 @caller1(
; CHECK-NEXT: ret i32 3

  %X = call i32 @callee1( i32 10, i32 3 )
  ret i32 %X
}

define i32 @caller2() {
; Check that we can constant-prop through instructions after inlining callee21
; to get constants in the inlined callsite to callee22.
; FIXME: Currently, the threshold is fixed at 20 because we don't perform
; *recursive* cost analysis to realize that the nested call site will definitely
; inline and be cheap. We should eventually do that and lower the threshold here
; to 1.
;
; CHECK-LABEL: @caller2(
; CHECK-NOT: call void @callee2
; CHECK: ret

  %x = call i32 @callee21(i32 42, i32 48)
  ret i32 %x
}

define i32 @callee21(i32 %x, i32 %y) {
  %sub = sub i32 %y, %x
  %result = call i32 @callee22(i32 %sub)
  ret i32 %result
}

declare i8* @getptr()

define i32 @callee22(i32 %x) {
  %icmp = icmp ugt i32 %x, 42
  br i1 %icmp, label %bb.true, label %bb.false
bb.true:
  ; This block musn't be counted in the inline cost.
  %x1 = add i32 %x, 1
  %x2 = add i32 %x1, 1
  %x3 = add i32 %x2, 1
  %x4 = add i32 %x3, 1
  %x5 = add i32 %x4, 1
  %x6 = add i32 %x5, 1
  %x7 = add i32 %x6, 1
  %x8 = add i32 %x7, 1

  ret i32 %x8
bb.false:
  ret i32 %x
}

define i32 @caller3() {
; Check that even if the expensive path is hidden behind several basic blocks,
; it doesn't count toward the inline cost when constant-prop proves those paths
; dead.
;
; CHECK-LABEL: @caller3(
; CHECK-NOT: call
; CHECK: ret i32 6

entry:
  %x = call i32 @callee3(i32 42, i32 48)
  ret i32 %x
}

define i32 @callee3(i32 %x, i32 %y) {
  %sub = sub i32 %y, %x
  %icmp = icmp ugt i32 %sub, 42
  br i1 %icmp, label %bb.true, label %bb.false

bb.true:
  %icmp2 = icmp ult i32 %sub, 64
  br i1 %icmp2, label %bb.true.true, label %bb.true.false

bb.true.true:
  ; This block musn't be counted in the inline cost.
  %x1 = add i32 %x, 1
  %x2 = add i32 %x1, 1
  %x3 = add i32 %x2, 1
  %x4 = add i32 %x3, 1
  %x5 = add i32 %x4, 1
  %x6 = add i32 %x5, 1
  %x7 = add i32 %x6, 1
  %x8 = add i32 %x7, 1
  br label %bb.merge

bb.true.false:
  ; This block musn't be counted in the inline cost.
  %y1 = add i32 %y, 1
  %y2 = add i32 %y1, 1
  %y3 = add i32 %y2, 1
  %y4 = add i32 %y3, 1
  %y5 = add i32 %y4, 1
  %y6 = add i32 %y5, 1
  %y7 = add i32 %y6, 1
  %y8 = add i32 %y7, 1
  br label %bb.merge

bb.merge:
  %result = phi i32 [ %x8, %bb.true.true ], [ %y8, %bb.true.false ]
  ret i32 %result

bb.false:
  ret i32 %sub
}

declare {i8, i1} @llvm.uadd.with.overflow.i8(i8 %a, i8 %b)

define i8 @caller4(i8 %z) {
; Check that we can constant fold through intrinsics such as the
; overflow-detecting arithmetic instrinsics. These are particularly important
; as they are used heavily in standard library code and generic C++ code where
; the arguments are oftent constant but complete generality is required.
;
; CHECK-LABEL: @caller4(
; CHECK-NOT: call
; CHECK: ret i8 -1

entry:
  %x = call i8 @callee4(i8 254, i8 14, i8 %z)
  ret i8 %x
}

define i8 @callee4(i8 %x, i8 %y, i8 %z) {
  %uadd = call {i8, i1} @llvm.uadd.with.overflow.i8(i8 %x, i8 %y)
  %o = extractvalue {i8, i1} %uadd, 1
  br i1 %o, label %bb.true, label %bb.false

bb.true:
  ret i8 -1

bb.false:
  ; This block musn't be counted in the inline cost.
  %z1 = add i8 %z, 1
  %z2 = add i8 %z1, 1
  %z3 = add i8 %z2, 1
  %z4 = add i8 %z3, 1
  %z5 = add i8 %z4, 1
  %z6 = add i8 %z5, 1
  %z7 = add i8 %z6, 1
  %z8 = add i8 %z7, 1
  ret i8 %z8
}

define i64 @caller5(i64 %y) {
; Check that we can round trip constants through various kinds of casts etc w/o
; losing track of the constant prop in the inline cost analysis.
;
; CHECK-LABEL: @caller5(
; CHECK-NOT: call
; CHECK: ret i64 -1

entry:
  %x = call i64 @callee5(i64 42, i64 %y)
  ret i64 %x
}

define i64 @callee5(i64 %x, i64 %y) {
  %inttoptr = inttoptr i64 %x to i8*
  %bitcast = bitcast i8* %inttoptr to i32*
  %ptrtoint = ptrtoint i32* %bitcast to i64
  %trunc = trunc i64 %ptrtoint to i32
  %zext = zext i32 %trunc to i64
  %cmp = icmp eq i64 %zext, 42
  br i1 %cmp, label %bb.true, label %bb.false

bb.true:
  ret i64 -1

bb.false:
  ; This block musn't be counted in the inline cost.
  %y1 = add i64 %y, 1
  %y2 = add i64 %y1, 1
  %y3 = add i64 %y2, 1
  %y4 = add i64 %y3, 1
  %y5 = add i64 %y4, 1
  %y6 = add i64 %y5, 1
  %y7 = add i64 %y6, 1
  %y8 = add i64 %y7, 1
  ret i64 %y8
}

define float @caller6() {
; Check that we can constant-prop through fcmp instructions
;
; CHECK-LABEL: @caller6(
; CHECK-NOT: call
; CHECK: ret
  %x = call float @callee6(float 42.0)
  ret float %x
}

define float @callee6(float %x) {
  %icmp = fcmp ugt float %x, 42.0
  br i1 %icmp, label %bb.true, label %bb.false

bb.true:
  ; This block musn't be counted in the inline cost.
  %x1 = fadd float %x, 1.0
  %x2 = fadd float %x1, 1.0
  %x3 = fadd float %x2, 1.0
  %x4 = fadd float %x3, 1.0
  %x5 = fadd float %x4, 1.0
  %x6 = fadd float %x5, 1.0
  %x7 = fadd float %x6, 1.0
  %x8 = fadd float %x7, 1.0
  ret float %x8

bb.false:
  ret float %x
}



define i32 @PR13412.main() {
; This is a somewhat complicated three layer subprogram that was reported to
; compute the wrong value for a branch due to assuming that an argument
; mid-inline couldn't be equal to another pointer.
;
; After inlining, the branch should point directly to the exit block, not to
; the intermediate block.
; CHECK: @PR13412.main
; CHECK: br i1 true, label %[[TRUE_DEST:.*]], label %[[FALSE_DEST:.*]]
; CHECK: [[FALSE_DEST]]:
; CHECK-NEXT: call void @PR13412.fail()
; CHECK: [[TRUE_DEST]]:
; CHECK-NEXT: ret i32 0

entry:
  %i1 = alloca i64
  store i64 0, i64* %i1
  %arraydecay = bitcast i64* %i1 to i32*
  %call = call i1 @PR13412.first(i32* %arraydecay, i32* %arraydecay)
  br i1 %call, label %cond.end, label %cond.false

cond.false:
  call void @PR13412.fail()
  br label %cond.end

cond.end:
  ret i32 0
}

define internal i1 @PR13412.first(i32* %a, i32* %b) {
entry:
  %call = call i32* @PR13412.second(i32* %a, i32* %b)
  %cmp = icmp eq i32* %call, %b
  ret i1 %cmp
}

declare void @PR13412.fail()

define internal i32* @PR13412.second(i32* %a, i32* %b) {
entry:
  %sub.ptr.lhs.cast = ptrtoint i32* %b to i64
  %sub.ptr.rhs.cast = ptrtoint i32* %a to i64
  %sub.ptr.sub = sub i64 %sub.ptr.lhs.cast, %sub.ptr.rhs.cast
  %sub.ptr.div = ashr exact i64 %sub.ptr.sub, 2
  %cmp = icmp ugt i64 %sub.ptr.div, 1
  br i1 %cmp, label %if.then, label %if.end3

if.then:
  %0 = load i32* %a
  %1 = load i32* %b
  %cmp1 = icmp eq i32 %0, %1
  br i1 %cmp1, label %return, label %if.end3

if.end3:
  br label %return

return:
  %retval.0 = phi i32* [ %b, %if.end3 ], [ %a, %if.then ]
  ret i32* %retval.0
}