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
|
; RUN: opt < %s -indvars -S | FileCheck %s
;
; Make sure that indvars can perform LFTR without a canonical IV.
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
; Perform LFTR using the original pointer-type IV.
; for(char* p = base; p < base + n; ++p) {
; *p = p-base;
; }
define void @ptriv(i8* %base, i32 %n) nounwind {
entry:
%idx.ext = sext i32 %n to i64
%add.ptr = getelementptr inbounds i8* %base, i64 %idx.ext
%cmp1 = icmp ult i8* %base, %add.ptr
br i1 %cmp1, label %for.body, label %for.end
; CHECK: for.body:
; CHECK: phi i8*
; CHECK-NOT: phi
; CHECK-NOT: add
; CHECK: icmp ne i8*
; CHECK: br i1
for.body:
%p.02 = phi i8* [ %base, %entry ], [ %incdec.ptr, %for.body ]
; cruft to make the IV useful
%sub.ptr.lhs.cast = ptrtoint i8* %p.02 to i64
%sub.ptr.rhs.cast = ptrtoint i8* %base to i64
%sub.ptr.sub = sub i64 %sub.ptr.lhs.cast, %sub.ptr.rhs.cast
%conv = trunc i64 %sub.ptr.sub to i8
store i8 %conv, i8* %p.02
%incdec.ptr = getelementptr inbounds i8* %p.02, i32 1
%cmp = icmp ult i8* %incdec.ptr, %add.ptr
br i1 %cmp, label %for.body, label %for.end
for.end:
ret void
}
; This test checks that SCEVExpander can handle an outer loop that has been
; simplified, and as a result the inner loop's exit test will be rewritten.
define void @expandOuterRecurrence(i32 %arg) nounwind {
entry:
%sub1 = sub nsw i32 %arg, 1
%cmp1 = icmp slt i32 0, %sub1
br i1 %cmp1, label %outer, label %exit
; CHECK: outer:
; CHECK: icmp slt
outer:
%i = phi i32 [ 0, %entry ], [ %i.inc, %outer.inc ]
%sub2 = sub nsw i32 %arg, %i
%sub3 = sub nsw i32 %sub2, 1
%cmp2 = icmp slt i32 0, %sub3
br i1 %cmp2, label %inner.ph, label %outer.inc
inner.ph:
br label %inner
; CHECK: inner:
; CHECK: br i1
inner:
%j = phi i32 [ 0, %inner.ph ], [ %j.inc, %inner ]
%j.inc = add nsw i32 %j, 1
%cmp3 = icmp slt i32 %j.inc, %sub3
br i1 %cmp3, label %inner, label %outer.inc
; CHECK: outer.inc:
; CHECK: icmp ne
; CHECK: br i1
outer.inc:
%i.inc = add nsw i32 %i, 1
%cmp4 = icmp slt i32 %i.inc, %sub1
br i1 %cmp4, label %outer, label %exit
exit:
ret void
}
; Force SCEVExpander to look for an existing well-formed phi.
; Perform LFTR without generating extra preheader code.
define void @guardedloop([0 x double]* %matrix, [0 x double]* %vector,
i32 %irow, i32 %ilead) nounwind {
; CHECK-LABEL: @guardedloop(
; CHECK-LABEL: entry:
; CHECK-NEXT: %[[cmp:.*]] = icmp slt i32 1, %irow
; CHECK-NEXT: br i1 %[[cmp]], label %[[loop_preheader:.*]], label %[[return:.*]]
; CHECK: [[loop_preheader]]:
; CHECK-NEXT: %[[sext:.*]] = sext i32 %ilead to i64
; CHECK-NEXT: %[[add:.*]] = add i32 %irow, -1
; CHECK-NEXT: br label %[[loop:.*]]
; CHECK: [[loop]]:
; CHECK-NEXT: %[[indvars_iv2:.*]] = phi i64
; CHECK-NEXT: phi i64
; CHECK-NOT: phi
; CHECK: %[[lftr_wideiv:.*]] = trunc i64 %[[indvars_iv2]] to i32
; CHECK-NEXT: %[[exitcond:.*]] = icmp ne i32 %[[lftr_wideiv]], %[[add]]
; CHECK-NEXT: br i1 %[[exitcond]], label %[[loop]], label
entry:
%cmp = icmp slt i32 1, %irow
br i1 %cmp, label %loop, label %return
loop:
%rowidx = phi i32 [ 0, %entry ], [ %row.inc, %loop ]
%i = phi i32 [ 0, %entry ], [ %i.inc, %loop ]
%diagidx = add nsw i32 %rowidx, %i
%diagidxw = sext i32 %diagidx to i64
%matrixp = getelementptr inbounds [0 x double]* %matrix, i32 0, i64 %diagidxw
%v1 = load double* %matrixp
%iw = sext i32 %i to i64
%vectorp = getelementptr inbounds [0 x double]* %vector, i32 0, i64 %iw
%v2 = load double* %vectorp
%row.inc = add nsw i32 %rowidx, %ilead
%i.inc = add nsw i32 %i, 1
%cmp196 = icmp slt i32 %i.inc, %irow
br i1 %cmp196, label %loop, label %return
return:
ret void
}
; Avoid generating extra code to materialize a trip count. Skip LFTR.
define void @unguardedloop([0 x double]* %matrix, [0 x double]* %vector,
i32 %irow, i32 %ilead) nounwind {
entry:
br label %loop
; CHECK: entry:
; CHECK-NOT: zext
; CHECK-NOT: add
; CHECK: loop:
; CHECK: phi i64
; CHECK: phi i64
; CHECK-NOT: phi
; CHECK: icmp slt
; CHECK: br i1
loop:
%rowidx = phi i32 [ 0, %entry ], [ %row.inc, %loop ]
%i = phi i32 [ 0, %entry ], [ %i.inc, %loop ]
%diagidx = add nsw i32 %rowidx, %i
%diagidxw = sext i32 %diagidx to i64
%matrixp = getelementptr inbounds [0 x double]* %matrix, i32 0, i64 %diagidxw
%v1 = load double* %matrixp
%iw = sext i32 %i to i64
%vectorp = getelementptr inbounds [0 x double]* %vector, i32 0, i64 %iw
%v2 = load double* %vectorp
%row.inc = add nsw i32 %rowidx, %ilead
%i.inc = add nsw i32 %i, 1
%cmp196 = icmp slt i32 %i.inc, %irow
br i1 %cmp196, label %loop, label %return
return:
ret void
}
; Remove %i which is only used by the exit test.
; Verify that SCEV can still compute a backedge count from the sign
; extended %n, used for pointer comparison by LFTR.
;
; TODO: Fix for PR13371 currently makes this impossible. See
; IndVarSimplify.cpp hasConcreteDef(). We may want to change to undef rules.
define void @geplftr(i8* %base, i32 %x, i32 %y, i32 %n) nounwind {
entry:
%x.ext = sext i32 %x to i64
%add.ptr = getelementptr inbounds i8* %base, i64 %x.ext
%y.ext = sext i32 %y to i64
%add.ptr10 = getelementptr inbounds i8* %add.ptr, i64 %y.ext
%lim = add i32 %x, %n
%cmp.ph = icmp ult i32 %x, %lim
br i1 %cmp.ph, label %loop, label %exit
; CHECK-LABEL: @geplftr(
; CHECK: loop:
; CHECK: phi i8*
; DISABLE-NOT: phi // This check is currently disabled
; CHECK: getelementptr
; CHECK: store
; DISABLE: icmp ne i8* // This check is currently disabled
; CHECK: br i1
loop:
%i = phi i32 [ %x, %entry ], [ %inc, %loop ]
%aptr = phi i8* [ %add.ptr10, %entry ], [ %incdec.ptr, %loop ]
%incdec.ptr = getelementptr inbounds i8* %aptr, i32 1
store i8 3, i8* %aptr
%inc = add i32 %i, 1
%cmp = icmp ult i32 %inc, %lim
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
; Exercise backedge taken count verification with a never-taken loop.
define void @nevertaken() nounwind uwtable ssp {
entry:
br label %loop
; CHECK-LABEL: @nevertaken(
; CHECK: loop:
; CHECK-NOT: phi
; CHECK-NOT: add
; CHECK-NOT: icmp
; CHECK: exit:
loop:
%i = phi i32 [ 0, %entry ], [ %inc, %loop ]
%inc = add nsw i32 %i, 1
%cmp = icmp sle i32 %inc, 0
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
; Test LFTR on an IV whose recurrence start is a non-unit pointer type.
define void @aryptriv([256 x i8]* %base, i32 %n) nounwind {
entry:
%ivstart = getelementptr inbounds [256 x i8]* %base, i32 0, i32 0
%ivend = getelementptr inbounds [256 x i8]* %base, i32 0, i32 %n
%cmp.ph = icmp ult i8* %ivstart, %ivend
br i1 %cmp.ph, label %loop, label %exit
; CHECK: loop:
; CHECK: phi i8*
; CHECK-NOT: phi
; CHECK: getelementptr
; CHECK: store
; CHECK: icmp ne i8*
; CHECK: br i1
loop:
%aptr = phi i8* [ %ivstart, %entry ], [ %incdec.ptr, %loop ]
%incdec.ptr = getelementptr inbounds i8* %aptr, i32 1
store i8 3, i8* %aptr
%cmp = icmp ult i8* %incdec.ptr, %ivend
br i1 %cmp, label %loop, label %exit
exit:
ret void
}
|
