xref: /llvm-project/llvm/test/Analysis/ScalarEvolution/smax-br-phi-idioms.ll (revision 0d38f21e4ab7fe7cebe76a9d7c218ec54dba1e98)
1; NOTE: Assertions have been autogenerated by utils/update_analyze_test_checks.py UTC_ARGS: --version 2
2; RUN: opt -disable-output "-passes=print<scalar-evolution>" < %s 2>&1 | FileCheck %s
3
4define i32 @f0(i32 %x, i32 %y) {
5; CHECK-LABEL: 'f0'
6; CHECK-NEXT:  Classifying expressions for: @f0
7; CHECK-NEXT:    %sum = add i32 %x, %y
8; CHECK-NEXT:    --> (%x + %y) U: full-set S: full-set
9; CHECK-NEXT:    %v = phi i32 [ %sum, %add ], [ %x, %entry ]
10; CHECK-NEXT:    --> ((0 smax %y) + %x) U: full-set S: full-set
11; CHECK-NEXT:  Determining loop execution counts for: @f0
12;
13entry:
14  %c = icmp sgt i32 %y, 0
15  br i1 %c, label %add, label %merge
16
17add:
18  %sum = add i32 %x, %y
19  br label %merge
20
21merge:
22  %v = phi i32 [ %sum, %add ], [ %x, %entry ]
23  ret i32 %v
24}
25
26define i32 @f1(i32 %x, i32 %y) {
27; CHECK-LABEL: 'f1'
28; CHECK-NEXT:  Classifying expressions for: @f1
29; CHECK-NEXT:    %sum = add i32 %x, %y
30; CHECK-NEXT:    --> (%x + %y) U: full-set S: full-set
31; CHECK-NEXT:    %v = phi i32 [ %sum, %add ], [ %x, %entry ]
32; CHECK-NEXT:    --> ((0 smax %y) + %x) U: full-set S: full-set
33; CHECK-NEXT:  Determining loop execution counts for: @f1
34;
35entry:
36  %c = icmp sge i32 %y, 0
37  br i1 %c, label %add, label %merge
38
39add:
40  %sum = add i32 %x, %y
41  br label %merge
42
43merge:
44  %v = phi i32 [ %sum, %add ], [ %x, %entry ]
45  ret i32 %v
46}
47
48define i32 @f2(i32 %x, i32 %y, ptr %ptr) {
49; CHECK-LABEL: 'f2'
50; CHECK-NEXT:  Classifying expressions for: @f2
51; CHECK-NEXT:    %lv = load i32, ptr %ptr, align 4
52; CHECK-NEXT:    --> %lv U: full-set S: full-set
53; CHECK-NEXT:    %v = phi i32 [ %lv, %add ], [ %x, %entry ]
54; CHECK-NEXT:    --> %v U: full-set S: full-set
55; CHECK-NEXT:  Determining loop execution counts for: @f2
56;
57entry:
58  %c = icmp sge i32 %y, 0
59  br i1 %c, label %add, label %merge
60
61add:
62  %lv = load i32, ptr %ptr
63  br label %merge
64
65merge:
66  %v = phi i32 [ %lv, %add ], [ %x, %entry ]
67  ret i32 %v
68}
69
70define i32 @f3(i32 %x, i32 %init, i32 %lim) {
71; CHECK-LABEL: 'f3'
72; CHECK-NEXT:  Classifying expressions for: @f3
73; CHECK-NEXT:    %iv = phi i32 [ %init, %entry ], [ %iv.inc, %merge ]
74; CHECK-NEXT:    --> {%init,+,1}<%loop> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %loop: Computable }
75; CHECK-NEXT:    %iv.inc = add i32 %iv, 1
76; CHECK-NEXT:    --> {(1 + %init),+,1}<%loop> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %loop: Computable }
77; CHECK-NEXT:    %sum = add i32 %x, %iv
78; CHECK-NEXT:    --> {(%x + %init),+,1}<%loop> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %loop: Computable }
79; CHECK-NEXT:    %v = phi i32 [ %sum, %add ], [ %x, %loop ]
80; CHECK-NEXT:    --> ((0 smax {%init,+,1}<%loop>) + %x) U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %loop: Computable }
81; CHECK-NEXT:  Determining loop execution counts for: @f3
82; CHECK-NEXT:  Loop %loop: Unpredictable backedge-taken count.
83; CHECK-NEXT:  Loop %loop: Unpredictable constant max backedge-taken count.
84; CHECK-NEXT:  Loop %loop: Unpredictable symbolic max backedge-taken count.
85;
86entry:
87  br label %loop
88
89loop:
90  %iv = phi i32 [ %init, %entry ], [ %iv.inc, %merge ]
91  %iv.inc = add i32 %iv, 1
92  %c = icmp sge i32 %iv, 0
93  br i1 %c, label %add, label %merge
94
95add:
96  %sum = add i32 %x, %iv
97  br label %merge
98
99merge:
100  %v = phi i32 [ %sum, %add ], [ %x, %loop ]
101  %be.cond = icmp eq i32 %iv.inc, %lim
102  br i1 %be.cond, label %loop, label %leave
103
104leave:
105  ret i32 0
106}
107
108define i32 @f4(i32 %x, i32 %init, i32 %lim) {
109; CHECK-LABEL: 'f4'
110; CHECK-NEXT:  Classifying expressions for: @f4
111; CHECK-NEXT:    %iv = phi i32 [ %init, %add ], [ %iv.inc, %loop ]
112; CHECK-NEXT:    --> {%init,+,1}<%loop> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %loop: Computable }
113; CHECK-NEXT:    %iv.inc = add i32 %iv, 1
114; CHECK-NEXT:    --> {(1 + %init),+,1}<%loop> U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %loop: Computable }
115; CHECK-NEXT:    %sum = add i32 %x, %iv
116; CHECK-NEXT:    --> {(%x + %init),+,1}<%loop> U: full-set S: full-set
117; CHECK-NEXT:    %v = phi i32 [ %sum, %add.cont ], [ %x, %entry ]
118; CHECK-NEXT:    --> %v U: full-set S: full-set
119; CHECK-NEXT:  Determining loop execution counts for: @f4
120; CHECK-NEXT:  Loop %loop: Unpredictable backedge-taken count.
121; CHECK-NEXT:  Loop %loop: Unpredictable constant max backedge-taken count.
122; CHECK-NEXT:  Loop %loop: Unpredictable symbolic max backedge-taken count.
123;
124entry:
125  %c = icmp sge i32 %init, 0
126  br i1 %c, label %add, label %merge
127
128add:
129  br label %loop
130
131loop:
132  %iv = phi i32 [ %init, %add ], [ %iv.inc, %loop ]
133  %iv.inc = add i32 %iv, 1
134  %be.cond = icmp eq i32 %iv.inc, %lim
135  br i1 %be.cond, label %loop, label %add.cont
136
137add.cont:
138  %sum = add i32 %x, %iv
139  br label %merge
140
141merge:
142  %v = phi i32 [ %sum, %add.cont ], [ %x, %entry ]
143  ret i32 %v
144}
145
146; It's okay to match "through" %init, as SCEV expressions don't preserve LCSSA.
147define i32 @f5(ptr %val) {
148; CHECK-LABEL: 'f5'
149; CHECK-NEXT:  Classifying expressions for: @f5
150; CHECK-NEXT:    %inc = load i32, ptr %val, align 4
151; CHECK-NEXT:    --> %inc U: full-set S: full-set Exits: <<Unknown>> LoopDispositions: { %for.end: Variant }
152; CHECK-NEXT:    %init = phi i32 [ 0, %for.condt ], [ %inc, %for.end ]
153; CHECK-NEXT:    --> %inc U: full-set S: full-set
154; CHECK-NEXT:  Determining loop execution counts for: @f5
155; CHECK-NEXT:  Loop %for.end: <multiple exits> backedge-taken count is i1 false
156; CHECK-NEXT:    exit count for for.end: i1 false
157; CHECK-NEXT:    exit count for for.condt: i1 false
158; CHECK-NEXT:  Loop %for.end: constant max backedge-taken count is i1 false
159; CHECK-NEXT:  Loop %for.end: symbolic max backedge-taken count is i1 false
160; CHECK-NEXT:    symbolic max exit count for for.end: i1 false
161; CHECK-NEXT:    symbolic max exit count for for.condt: i1 false
162; CHECK-NEXT:  Loop %for.end: Trip multiple is 1
163;
164entry:
165  br label %for.end
166
167for.condt:
168  br i1 true, label %for.cond.0, label %for.end
169
170for.end:
171  %inc = load i32, ptr %val
172  br i1 false, label %for.condt, label %for.cond.0
173
174for.cond.0:
175  %init = phi i32 [ 0, %for.condt ], [ %inc, %for.end ]
176  ret i32 %init
177}
178
179; Do the right thing for unreachable code:
180define i32 @f6(i32 %x, i32 %y) {
181; CHECK-LABEL: 'f6'
182; CHECK-NEXT:  Classifying expressions for: @f6
183; CHECK-NEXT:    %sum = add i32 %x, %y
184; CHECK-NEXT:    --> (%x + %y) U: full-set S: full-set
185; CHECK-NEXT:    %v0 = phi i32 [ %sum, %entry ], [ %v1, %unreachable ]
186; CHECK-NEXT:    --> %v0 U: full-set S: full-set
187; CHECK-NEXT:    %v1 = phi i32 [ %v0, %merge ], [ 0, %leave_0_cond ]
188; CHECK-NEXT:    --> %v1 U: full-set S: full-set
189; CHECK-NEXT:  Determining loop execution counts for: @f6
190;
191entry:
192  %c0 = icmp sgt i32 %y, 0
193  %sum = add i32 %x, %y
194  br i1 %c0, label %merge, label %leave_1
195
196merge:
197  %v0 = phi i32 [ %sum, %entry ], [ %v1, %unreachable ]
198  %c1 = icmp slt i32 %y, 0
199  br i1 %c1, label %leave_0, label %leave_0_cond
200
201leave_0_cond:
202  br label %leave_0
203
204leave_0:
205  %v1 = phi i32 [ %v0, %merge ], [ 0, %leave_0_cond ]
206  ret i32 0
207
208leave_1:
209  ret i32 0
210
211unreachable:
212  br label %merge
213}
214