xref: /llvm-project/llvm/test/Analysis/ScalarEvolution/increasing-or-decreasing-iv.ll (revision 0d38f21e4ab7fe7cebe76a9d7c218ec54dba1e98)
1; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py
2; RUN: opt -disable-output "-passes=print<scalar-evolution>" < %s 2>&1 | FileCheck %s
3
4define void @f0(i1 %c) {
5; CHECK-LABEL: 'f0'
6; CHECK-NEXT:  Classifying expressions for: @f0
7; CHECK-NEXT:    %start = select i1 %c, i32 127, i32 0
8; CHECK-NEXT:    --> %start U: [0,128) S: [0,128)
9; CHECK-NEXT:    %step = select i1 %c, i32 -1, i32 1
10; CHECK-NEXT:    --> %step U: [1,0) S: [-2,2)
11; CHECK-NEXT:    %loop.iv = phi i32 [ 0, %entry ], [ %loop.iv.inc, %loop ]
12; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%loop> U: [0,128) S: [0,128) Exits: 127 LoopDispositions: { %loop: Computable }
13; CHECK-NEXT:    %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
14; CHECK-NEXT:    --> {%start,+,%step}<nsw><%loop> U: [0,128) S: [0,128) Exits: ((127 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
15; CHECK-NEXT:    %iv.next = add i32 %iv, %step
16; CHECK-NEXT:    --> {(%step + %start),+,%step}<nw><%loop> U: [-256,256) S: [-256,256) Exits: ((128 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
17; CHECK-NEXT:    %loop.iv.inc = add i32 %loop.iv, 1
18; CHECK-NEXT:    --> {1,+,1}<nuw><nsw><%loop> U: [1,129) S: [1,129) Exits: 128 LoopDispositions: { %loop: Computable }
19; CHECK-NEXT:  Determining loop execution counts for: @f0
20; CHECK-NEXT:  Loop %loop: backedge-taken count is i32 127
21; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i32 127
22; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is i32 127
23; CHECK-NEXT:  Loop %loop: Trip multiple is 128
24;
25entry:
26  %start = select i1 %c, i32 127, i32 0
27  %step  = select i1 %c, i32 -1,  i32 1
28  br label %loop
29
30loop:
31  %loop.iv = phi i32 [ 0, %entry ], [ %loop.iv.inc, %loop ]
32  %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
33  %iv.next = add i32 %iv, %step
34  %loop.iv.inc = add i32 %loop.iv, 1
35  %be.cond = icmp ne i32 %loop.iv.inc, 128
36  br i1 %be.cond, label %loop, label %leave
37
38leave:
39  ret void
40}
41
42define void @f1(i1 %c) {
43; CHECK-LABEL: 'f1'
44; CHECK-NEXT:  Classifying expressions for: @f1
45; CHECK-NEXT:    %start = select i1 %c, i32 120, i32 0
46; CHECK-NEXT:    --> %start U: [0,121) S: [0,121)
47; CHECK-NEXT:    %step = select i1 %c, i32 -8, i32 8
48; CHECK-NEXT:    --> %step U: [8,-7) S: [-16,16)
49; CHECK-NEXT:    %loop.iv = phi i32 [ 0, %entry ], [ %loop.iv.inc, %loop ]
50; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%loop> U: [0,16) S: [0,16) Exits: 15 LoopDispositions: { %loop: Computable }
51; CHECK-NEXT:    %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
52; CHECK-NEXT:    --> {%start,+,%step}<nsw><%loop> U: [0,121) S: [0,121) Exits: ((15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
53; CHECK-NEXT:    %iv.1 = add i32 %iv, 1
54; CHECK-NEXT:    --> {(1 + %start)<nuw><nsw>,+,%step}<nsw><%loop> U: [1,122) S: [1,122) Exits: (1 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
55; CHECK-NEXT:    %iv.2 = add i32 %iv, 2
56; CHECK-NEXT:    --> {(2 + %start)<nuw><nsw>,+,%step}<nsw><%loop> U: [2,123) S: [2,123) Exits: (2 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
57; CHECK-NEXT:    %iv.3 = add i32 %iv, 3
58; CHECK-NEXT:    --> {(3 + %start)<nuw><nsw>,+,%step}<nsw><%loop> U: [3,124) S: [3,124) Exits: (3 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
59; CHECK-NEXT:    %iv.4 = add i32 %iv, 4
60; CHECK-NEXT:    --> {(4 + %start)<nuw><nsw>,+,%step}<nsw><%loop> U: [4,125) S: [4,125) Exits: (4 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
61; CHECK-NEXT:    %iv.5 = add i32 %iv, 5
62; CHECK-NEXT:    --> {(5 + %start)<nuw><nsw>,+,%step}<nsw><%loop> U: [5,126) S: [5,126) Exits: (5 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
63; CHECK-NEXT:    %iv.6 = add i32 %iv, 6
64; CHECK-NEXT:    --> {(6 + %start)<nuw><nsw>,+,%step}<nsw><%loop> U: [6,127) S: [6,127) Exits: (6 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
65; CHECK-NEXT:    %iv.7 = add i32 %iv, 7
66; CHECK-NEXT:    --> {(7 + %start)<nuw><nsw>,+,%step}<nsw><%loop> U: [7,128) S: [7,128) Exits: (7 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
67; CHECK-NEXT:    %iv.m1 = sub i32 %iv, 1
68; CHECK-NEXT:    --> {(-1 + %start)<nsw>,+,%step}<nsw><%loop> U: [-1,120) S: [-1,120) Exits: (-1 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
69; CHECK-NEXT:    %iv.m2 = sub i32 %iv, 2
70; CHECK-NEXT:    --> {(-2 + %start)<nsw>,+,%step}<nsw><%loop> U: [0,-1) S: [-2,119) Exits: (-2 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
71; CHECK-NEXT:    %iv.m3 = sub i32 %iv, 3
72; CHECK-NEXT:    --> {(-3 + %start)<nsw>,+,%step}<nsw><%loop> U: [-3,118) S: [-3,118) Exits: (-3 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
73; CHECK-NEXT:    %iv.m4 = sub i32 %iv, 4
74; CHECK-NEXT:    --> {(-4 + %start)<nsw>,+,%step}<nsw><%loop> U: [0,-3) S: [-4,117) Exits: (-4 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
75; CHECK-NEXT:    %iv.m5 = sub i32 %iv, 5
76; CHECK-NEXT:    --> {(-5 + %start)<nsw>,+,%step}<nsw><%loop> U: [-5,116) S: [-5,116) Exits: (-5 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
77; CHECK-NEXT:    %iv.m6 = sub i32 %iv, 6
78; CHECK-NEXT:    --> {(-6 + %start)<nsw>,+,%step}<nsw><%loop> U: [0,-1) S: [-6,115) Exits: (-6 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
79; CHECK-NEXT:    %iv.m7 = sub i32 %iv, 7
80; CHECK-NEXT:    --> {(-7 + %start)<nsw>,+,%step}<nsw><%loop> U: [-7,114) S: [-7,114) Exits: (-7 + (15 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
81; CHECK-NEXT:    %iv.next = add i32 %iv, %step
82; CHECK-NEXT:    --> {(%step + %start),+,%step}<nw><%loop> U: [0,-7) S: [-256,361) Exits: ((16 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
83; CHECK-NEXT:    %loop.iv.inc = add i32 %loop.iv, 1
84; CHECK-NEXT:    --> {1,+,1}<nuw><nsw><%loop> U: [1,17) S: [1,17) Exits: 16 LoopDispositions: { %loop: Computable }
85; CHECK-NEXT:  Determining loop execution counts for: @f1
86; CHECK-NEXT:  Loop %loop: backedge-taken count is i32 15
87; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i32 15
88; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is i32 15
89; CHECK-NEXT:  Loop %loop: Trip multiple is 16
90;
91entry:
92  %start = select i1 %c, i32 120, i32 0
93  %step  = select i1 %c, i32 -8,  i32 8
94  br label %loop
95
96loop:
97  %loop.iv = phi i32 [ 0, %entry ], [ %loop.iv.inc, %loop ]
98  %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
99
100
101  %iv.1 = add i32 %iv, 1
102  %iv.2 = add i32 %iv, 2
103  %iv.3 = add i32 %iv, 3
104  %iv.4 = add i32 %iv, 4
105  %iv.5 = add i32 %iv, 5
106  %iv.6 = add i32 %iv, 6
107  %iv.7 = add i32 %iv, 7
108
109
110  %iv.m1 = sub i32 %iv, 1
111  %iv.m2 = sub i32 %iv, 2
112  %iv.m3 = sub i32 %iv, 3
113  %iv.m4 = sub i32 %iv, 4
114  %iv.m5 = sub i32 %iv, 5
115  %iv.m6 = sub i32 %iv, 6
116  %iv.m7 = sub i32 %iv, 7
117
118  %iv.next = add i32 %iv, %step
119  %loop.iv.inc = add i32 %loop.iv, 1
120  %be.cond = icmp sgt i32 %loop.iv, 14
121  br i1 %be.cond, label %leave, label %loop
122
123leave:
124  ret void
125}
126
127define void @f2(i1 %c) {
128; CHECK-LABEL: 'f2'
129; CHECK-NEXT:  Classifying expressions for: @f2
130; CHECK-NEXT:    %start = select i1 %c, i32 127, i32 0
131; CHECK-NEXT:    --> %start U: [0,128) S: [0,128)
132; CHECK-NEXT:    %step = select i1 %c, i32 -1, i32 1
133; CHECK-NEXT:    --> %step U: [1,0) S: [-2,2)
134; CHECK-NEXT:    %loop.iv = phi i32 [ 0, %entry ], [ %loop.iv.inc, %loop ]
135; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%loop> U: [0,128) S: [0,128) Exits: 127 LoopDispositions: { %loop: Computable }
136; CHECK-NEXT:    %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
137; CHECK-NEXT:    --> {%start,+,%step}<nsw><%loop> U: [0,128) S: [0,128) Exits: ((127 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
138; CHECK-NEXT:    %iv.sext = sext i32 %iv to i64
139; CHECK-NEXT:    --> {(zext i32 %start to i64),+,(sext i32 %step to i64)}<nsw><%loop> U: [0,128) S: [0,128) Exits: ((zext i32 %start to i64) + (127 * (sext i32 %step to i64))<nsw>) LoopDispositions: { %loop: Computable }
140; CHECK-NEXT:    %iv.next = add i32 %iv, %step
141; CHECK-NEXT:    --> {(%step + %start),+,%step}<nw><%loop> U: [-256,256) S: [-256,256) Exits: ((128 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
142; CHECK-NEXT:    %loop.iv.inc = add i32 %loop.iv, 1
143; CHECK-NEXT:    --> {1,+,1}<nuw><nsw><%loop> U: [1,129) S: [1,129) Exits: 128 LoopDispositions: { %loop: Computable }
144; CHECK-NEXT:  Determining loop execution counts for: @f2
145; CHECK-NEXT:  Loop %loop: backedge-taken count is i32 127
146; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i32 127
147; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is i32 127
148; CHECK-NEXT:  Loop %loop: Trip multiple is 128
149;
150entry:
151  %start = select i1 %c, i32 127, i32 0
152  %step  = select i1 %c, i32 -1,  i32 1
153  br label %loop
154
155loop:
156  %loop.iv = phi i32 [ 0, %entry ], [ %loop.iv.inc, %loop ]
157  %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
158  %iv.sext = sext i32 %iv to i64
159  %iv.next = add i32 %iv, %step
160  %loop.iv.inc = add i32 %loop.iv, 1
161  %be.cond = icmp ne i32 %loop.iv.inc, 128
162  br i1 %be.cond, label %loop, label %leave
163
164leave:
165  ret void
166}
167
168define void @f3(i1 %c) {
169; CHECK-LABEL: 'f3'
170; CHECK-NEXT:  Classifying expressions for: @f3
171; CHECK-NEXT:    %start = select i1 %c, i16 1000, i16 0
172; CHECK-NEXT:    --> %start U: [0,1001) S: [0,1001)
173; CHECK-NEXT:    %step = select i1 %c, i16 1, i16 509
174; CHECK-NEXT:    --> %step U: [1,510) S: [1,510)
175; CHECK-NEXT:    %loop.iv = phi i16 [ 0, %entry ], [ %loop.iv.inc, %loop ]
176; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%loop> U: [0,128) S: [0,128) Exits: 127 LoopDispositions: { %loop: Computable }
177; CHECK-NEXT:    %iv = phi i16 [ %start, %entry ], [ %iv.next, %loop ]
178; CHECK-NEXT:    --> {%start,+,%step}<nuw><%loop> U: [0,-892) S: [0,-892) Exits: ((127 * %step)<nuw> + %start) LoopDispositions: { %loop: Computable }
179; CHECK-NEXT:    %iv.zext = zext i16 %iv to i64
180; CHECK-NEXT:    --> {(zext i16 %start to i64),+,(zext i16 %step to i64)}<nuw><%loop> U: [0,64644) S: [0,64644) Exits: ((zext i16 %start to i64) + (127 * (zext i16 %step to i64))<nuw><nsw>) LoopDispositions: { %loop: Computable }
181; CHECK-NEXT:    %iv.next = add i16 %iv, %step
182; CHECK-NEXT:    --> {(%step + %start),+,%step}<nw><%loop> U: full-set S: full-set Exits: ((128 * %step)<nuw> + %start) LoopDispositions: { %loop: Computable }
183; CHECK-NEXT:    %loop.iv.inc = add i16 %loop.iv, 1
184; CHECK-NEXT:    --> {1,+,1}<nuw><nsw><%loop> U: [1,129) S: [1,129) Exits: 128 LoopDispositions: { %loop: Computable }
185; CHECK-NEXT:  Determining loop execution counts for: @f3
186; CHECK-NEXT:  Loop %loop: backedge-taken count is i16 127
187; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i16 127
188; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is i16 127
189; CHECK-NEXT:  Loop %loop: Trip multiple is 128
190;
191entry:
192
193; NB! the i16 type (as opposed to i32), the choice of the constant 509
194; and the trip count are all related and not arbitrary.  We want an
195; add recurrence that will look like it can unsign-overflow *unless*
196; SCEV is able to see the correlation between the two selects feeding
197; into the initial value and the step increment.
198
199  %start = select i1 %c, i16 1000, i16 0
200  %step  = select i1 %c, i16 1,  i16 509
201  br label %loop
202
203loop:
204  %loop.iv = phi i16 [ 0, %entry ], [ %loop.iv.inc, %loop ]
205  %iv = phi i16 [ %start, %entry ], [ %iv.next, %loop ]
206  %iv.zext = zext i16 %iv to i64
207  %iv.next = add i16 %iv, %step
208  %loop.iv.inc = add i16 %loop.iv, 1
209  %be.cond = icmp ne i16 %loop.iv.inc, 128
210  br i1 %be.cond, label %loop, label %leave
211
212leave:
213  ret void
214}
215
216define void @f4(i1 %c) {
217; CHECK-LABEL: 'f4'
218; CHECK-NEXT:  Classifying expressions for: @f4
219; CHECK-NEXT:    %start = select i1 %c, i32 127, i32 0
220; CHECK-NEXT:    --> %start U: [0,128) S: [0,128)
221; CHECK-NEXT:    %step = select i1 %c, i32 -1, i32 1
222; CHECK-NEXT:    --> %step U: [1,0) S: [-2,2)
223; CHECK-NEXT:    %loop.iv = phi i32 [ 0, %entry ], [ %loop.iv.inc, %loop ]
224; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%loop> U: [0,128) S: [0,128) Exits: 127 LoopDispositions: { %loop: Computable }
225; CHECK-NEXT:    %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
226; CHECK-NEXT:    --> {%start,+,%step}<nsw><%loop> U: [0,128) S: [0,128) Exits: ((127 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
227; CHECK-NEXT:    %iv.trunc = trunc i32 %iv to i16
228; CHECK-NEXT:    --> {(trunc i32 %start to i16),+,(trunc i32 %step to i16)}<%loop> U: [0,128) S: [0,128) Exits: ((trunc i32 %start to i16) + (127 * (trunc i32 %step to i16))<nsw>) LoopDispositions: { %loop: Computable }
229; CHECK-NEXT:    %iv.next = add i32 %iv, %step
230; CHECK-NEXT:    --> {(%step + %start),+,%step}<nw><%loop> U: [-256,256) S: [-256,256) Exits: ((128 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
231; CHECK-NEXT:    %loop.iv.inc = add i32 %loop.iv, 1
232; CHECK-NEXT:    --> {1,+,1}<nuw><nsw><%loop> U: [1,129) S: [1,129) Exits: 128 LoopDispositions: { %loop: Computable }
233; CHECK-NEXT:  Determining loop execution counts for: @f4
234; CHECK-NEXT:  Loop %loop: backedge-taken count is i32 127
235; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i32 127
236; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is i32 127
237; CHECK-NEXT:  Loop %loop: Trip multiple is 128
238;
239
240entry:
241  %start = select i1 %c, i32 127, i32 0
242  %step  = select i1 %c, i32 -1,  i32 1
243  br label %loop
244
245loop:
246  %loop.iv = phi i32 [ 0, %entry ], [ %loop.iv.inc, %loop ]
247  %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
248  %iv.trunc = trunc i32 %iv to i16
249  %iv.next = add i32 %iv, %step
250  %loop.iv.inc = add i32 %loop.iv, 1
251  %be.cond = icmp ne i32 %loop.iv.inc, 128
252  br i1 %be.cond, label %loop, label %leave
253
254leave:
255  ret void
256}
257
258define void @f5(i1 %c) {
259; CHECK-LABEL: 'f5'
260; CHECK-NEXT:  Classifying expressions for: @f5
261; CHECK-NEXT:    %start = select i1 %c, i32 127, i32 0
262; CHECK-NEXT:    --> %start U: [0,128) S: [0,128)
263; CHECK-NEXT:    %step = select i1 %c, i32 -1, i32 1
264; CHECK-NEXT:    --> %step U: [1,0) S: [-2,2)
265; CHECK-NEXT:    %loop.iv = phi i16 [ 0, %entry ], [ %loop.iv.inc, %loop ]
266; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%loop> U: [0,128) S: [0,128) Exits: 127 LoopDispositions: { %loop: Computable }
267; CHECK-NEXT:    %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
268; CHECK-NEXT:    --> {%start,+,%step}<nsw><%loop> U: [0,128) S: [0,128) Exits: ((127 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
269; CHECK-NEXT:    %iv.trunc = trunc i32 %iv to i16
270; CHECK-NEXT:    --> {(trunc i32 %start to i16),+,(trunc i32 %step to i16)}<%loop> U: [0,128) S: [0,128) Exits: ((trunc i32 %start to i16) + (127 * (trunc i32 %step to i16))<nsw>) LoopDispositions: { %loop: Computable }
271; CHECK-NEXT:    %iv.next = add i32 %iv, %step
272; CHECK-NEXT:    --> {(%step + %start),+,%step}<nw><%loop> U: [-256,256) S: [-256,256) Exits: ((128 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
273; CHECK-NEXT:    %loop.iv.inc = add i16 %loop.iv, 1
274; CHECK-NEXT:    --> {1,+,1}<nuw><nsw><%loop> U: [1,129) S: [1,129) Exits: 128 LoopDispositions: { %loop: Computable }
275; CHECK-NEXT:  Determining loop execution counts for: @f5
276; CHECK-NEXT:  Loop %loop: backedge-taken count is i16 127
277; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i16 127
278; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is i16 127
279; CHECK-NEXT:  Loop %loop: Trip multiple is 128
280;
281entry:
282  %start = select i1 %c, i32 127, i32 0
283  %step  = select i1 %c, i32 -1,  i32 1
284  br label %loop
285
286loop:
287  %loop.iv = phi i16 [ 0, %entry ], [ %loop.iv.inc, %loop ]
288  %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
289  %iv.trunc = trunc i32 %iv to i16
290  %iv.next = add i32 %iv, %step
291
292  %loop.iv.inc = add i16 %loop.iv, 1
293  %be.cond = icmp ne i16 %loop.iv.inc, 128
294  br i1 %be.cond, label %loop, label %leave
295
296leave:
297  ret void
298}
299
300define void @f6(i1 %c) {
301; CHECK-LABEL: 'f6'
302; CHECK-NEXT:  Classifying expressions for: @f6
303; CHECK-NEXT:    %start = select i1 %c, i32 127, i32 0
304; CHECK-NEXT:    --> %start U: [0,128) S: [0,128)
305; CHECK-NEXT:    %step = select i1 %c, i32 -2, i32 0
306; CHECK-NEXT:    --> %step U: [0,-1) S: [-2,2)
307; CHECK-NEXT:    %loop.iv = phi i16 [ 0, %entry ], [ %loop.iv.inc, %loop ]
308; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%loop> U: [0,128) S: [0,128) Exits: 127 LoopDispositions: { %loop: Computable }
309; CHECK-NEXT:    %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
310; CHECK-NEXT:    --> {%start,+,(1 + %step)<nuw><nsw>}<nsw><%loop> U: [0,128) S: [0,128) Exits: (127 + (127 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
311; CHECK-NEXT:    %step.plus.one = add i32 %step, 1
312; CHECK-NEXT:    --> (1 + %step)<nuw><nsw> U: [1,0) S: [-1,3) Exits: (1 + %step)<nuw><nsw> LoopDispositions: { %loop: Invariant }
313; CHECK-NEXT:    %iv.next = add i32 %iv, %step.plus.one
314; CHECK-NEXT:    --> {(1 + %step + %start),+,(1 + %step)<nuw><nsw>}<nw><%loop> U: [-128,384) S: [-128,384) Exits: (128 + (128 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
315; CHECK-NEXT:    %iv.sext = sext i32 %iv to i64
316; CHECK-NEXT:    --> {(zext i32 %start to i64),+,(1 + (sext i32 %step to i64))<nuw><nsw>}<nsw><%loop> U: [0,128) S: [0,128) Exits: (127 + (zext i32 %start to i64) + (127 * (sext i32 %step to i64))<nsw>) LoopDispositions: { %loop: Computable }
317; CHECK-NEXT:    %loop.iv.inc = add i16 %loop.iv, 1
318; CHECK-NEXT:    --> {1,+,1}<nuw><nsw><%loop> U: [1,129) S: [1,129) Exits: 128 LoopDispositions: { %loop: Computable }
319; CHECK-NEXT:  Determining loop execution counts for: @f6
320; CHECK-NEXT:  Loop %loop: backedge-taken count is i16 127
321; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i16 127
322; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is i16 127
323; CHECK-NEXT:  Loop %loop: Trip multiple is 128
324;
325entry:
326  %start = select i1 %c, i32 127, i32 0
327  %step  = select i1 %c, i32 -2,  i32 0
328  br label %loop
329
330loop:
331  %loop.iv = phi i16 [ 0, %entry ], [ %loop.iv.inc, %loop ]
332  %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
333
334  %step.plus.one = add i32 %step, 1
335  %iv.next = add i32 %iv, %step.plus.one
336  %iv.sext = sext i32 %iv to i64
337  %loop.iv.inc = add i16 %loop.iv, 1
338  %be.cond = icmp ne i16 %loop.iv.inc, 128
339  br i1 %be.cond, label %loop, label %leave
340
341leave:
342  ret void
343}
344
345define void @f7(i1 %c) {
346; CHECK-LABEL: 'f7'
347; CHECK-NEXT:  Classifying expressions for: @f7
348; CHECK-NEXT:    %start = select i1 %c, i32 127, i32 0
349; CHECK-NEXT:    --> %start U: [0,128) S: [0,128)
350; CHECK-NEXT:    %step = select i1 %c, i32 -1, i32 1
351; CHECK-NEXT:    --> %step U: [1,0) S: [-2,2)
352; CHECK-NEXT:    %loop.iv = phi i16 [ 0, %entry ], [ %loop.iv.inc, %loop ]
353; CHECK-NEXT:    --> {0,+,1}<nuw><nsw><%loop> U: [0,128) S: [0,128) Exits: 127 LoopDispositions: { %loop: Computable }
354; CHECK-NEXT:    %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
355; CHECK-NEXT:    --> {%start,+,%step}<nsw><%loop> U: [0,128) S: [0,128) Exits: ((127 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
356; CHECK-NEXT:    %iv.trunc = trunc i32 %iv to i16
357; CHECK-NEXT:    --> {(trunc i32 %start to i16),+,(trunc i32 %step to i16)}<%loop> U: [0,128) S: [0,128) Exits: ((trunc i32 %start to i16) + (127 * (trunc i32 %step to i16))<nsw>) LoopDispositions: { %loop: Computable }
358; CHECK-NEXT:    %iv.next = add i32 %iv, %step
359; CHECK-NEXT:    --> {(%step + %start),+,%step}<nw><%loop> U: [-256,256) S: [-256,256) Exits: ((128 * %step)<nsw> + %start) LoopDispositions: { %loop: Computable }
360; CHECK-NEXT:    %iv.trunc.plus.one = add i16 %iv.trunc, 1
361; CHECK-NEXT:    --> {(1 + (trunc i32 %start to i16))<nuw><nsw>,+,(trunc i32 %step to i16)}<%loop> U: [1,129) S: [1,129) Exits: (1 + (trunc i32 %start to i16) + (127 * (trunc i32 %step to i16))<nsw>) LoopDispositions: { %loop: Computable }
362; CHECK-NEXT:    %iv.trunc.plus.two = add i16 %iv.trunc, 2
363; CHECK-NEXT:    --> {(2 + (trunc i32 %start to i16))<nuw><nsw>,+,(trunc i32 %step to i16)}<%loop> U: [2,130) S: [2,130) Exits: (2 + (trunc i32 %start to i16) + (127 * (trunc i32 %step to i16))<nsw>) LoopDispositions: { %loop: Computable }
364; CHECK-NEXT:    %loop.iv.inc = add i16 %loop.iv, 1
365; CHECK-NEXT:    --> {1,+,1}<nuw><nsw><%loop> U: [1,129) S: [1,129) Exits: 128 LoopDispositions: { %loop: Computable }
366; CHECK-NEXT:  Determining loop execution counts for: @f7
367; CHECK-NEXT:  Loop %loop: backedge-taken count is i16 127
368; CHECK-NEXT:  Loop %loop: constant max backedge-taken count is i16 127
369; CHECK-NEXT:  Loop %loop: symbolic max backedge-taken count is i16 127
370; CHECK-NEXT:  Loop %loop: Trip multiple is 128
371;
372entry:
373  %start = select i1 %c, i32 127, i32 0
374  %step  = select i1 %c, i32 -1,  i32 1
375  br label %loop
376
377loop:
378  %loop.iv = phi i16 [ 0, %entry ], [ %loop.iv.inc, %loop ]
379  %iv = phi i32 [ %start, %entry ], [ %iv.next, %loop ]
380  %iv.trunc = trunc i32 %iv to i16
381  %iv.next = add i32 %iv, %step
382
383  %iv.trunc.plus.one = add i16 %iv.trunc, 1
384
385  %iv.trunc.plus.two = add i16 %iv.trunc, 2
386
387  %loop.iv.inc = add i16 %loop.iv, 1
388  %be.cond = icmp ne i16 %loop.iv.inc, 128
389  br i1 %be.cond, label %loop, label %leave
390
391leave:
392  ret void
393}
394