1; RUN: opt -S < %s -passes='print<scalar-evolution>,loop-simplify,print<scalar-evolution>' 2>&1 | FileCheck %s
2
3; Provide legal integer types.
4target datalayout = "n8:16:32:64"
5
6@maxStat = external global i32
7
8; LoopSimplify should invalidate SCEV when splitting out the
9; inner loop.
10;
11; First SCEV print:
12; CHECK-LABEL: Classifying expressions for: @test
13; CHECK: %[[PHI:.*]] = phi i32 [ 0, %entry ], [ %{{.*}}, %if.then5 ], [ %[[PHI]], %if.end ]
14; CHECK-LABEL: Determining loop execution counts for: @test
15; CHECK: Loop %for.body18: Unpredictable backedge-taken count.
16; CHECK: Loop %for.body18: max backedge-taken count is 2147483646
17; CHECK: Loop %for.body18: Unpredictable predicated backedge-taken count.
18; CHECK: Loop %for.cond: <multiple exits> Unpredictable backedge-taken count.
19; CHECK: Loop %for.cond: Unpredictable max backedge-taken count.
20; CHECK: Loop %for.cond: Unpredictable predicated backedge-taken count.
21;
22; Now simplify the loop, which should cause SCEV to re-compute more precise
23; info here in addition to having preheader PHIs. Second SCEV print:
24; CHECK-LABEL: Classifying expressions for: @test
25; CHECK: phi i32 [ %{{.*}}, %if.then5 ], [ 0, %entry ]
26; CHECK-LABEL: Determining loop execution counts for: @test
27; CHECK: Loop %for.body18: Unpredictable backedge-taken count.
28; CHECK: Loop %for.body18: max backedge-taken count is 2147483646
29; CHECK: Loop %for.body18: Unpredictable predicated backedge-taken count.
30; CHECK: Loop %for.cond: <multiple exits> Unpredictable backedge-taken count.
31; CHECK: Loop %for.cond: max backedge-taken count is -2147483647
32; CHECK: Loop %for.cond: Unpredictable predicated backedge-taken count.
33; CHECK: Loop %for.cond.outer: <multiple exits> Unpredictable backedge-taken count.
34; CHECK: Loop %for.cond.outer: Unpredictable max backedge-taken count.
35; CHECK: Loop %for.cond.outer: Unpredictable predicated backedge-taken count.
36define i32 @test() nounwind {
37entry:
38  br label %for.cond
39
40for.cond:                                         ; preds = %if.then5, %if.end, %entry
41  %cuts.1 = phi i32 [ 0, %entry ], [ %inc, %if.then5 ], [ %cuts.1, %if.end ]
42  %0 = phi i32 [ 0, %entry ], [ %add, %if.end ], [ %add, %if.then5 ]
43  %add = add i32 %0, 1
44  %cmp = icmp slt i32 %0, 1
45  %tmp1 = load i32, i32* @maxStat, align 4
46  br i1 %cmp, label %for.body, label %for.cond14.preheader
47
48for.cond14.preheader:                             ; preds = %for.cond
49  %cmp1726 = icmp sgt i32 %tmp1, 0
50  br i1 %cmp1726, label %for.body18, label %return
51
52for.body:                                         ; preds = %for.cond
53  %cmp2 = icmp sgt i32 %tmp1, 100
54  br i1 %cmp2, label %return, label %if.end
55
56if.end:                                           ; preds = %for.body
57  %cmp4 = icmp sgt i32 %tmp1, -1
58  br i1 %cmp4, label %if.then5, label %for.cond
59
60if.then5:                                         ; preds = %if.end
61  call void @foo() nounwind
62  %inc = add i32 %cuts.1, 1
63  br label %for.cond
64
65for.body18:                                       ; preds = %for.body18, %for.cond14.preheader
66  %i13.027 = phi i32 [ %1, %for.body18 ], [ 0, %for.cond14.preheader ]
67  call void @foo() nounwind
68  %1 = add nsw i32 %i13.027, 1
69  %tmp16 = load i32, i32* @maxStat, align 4
70  %cmp17 = icmp slt i32 %1, %tmp16
71  br i1 %cmp17, label %for.body18, label %return
72
73return:                                           ; preds = %for.body18, %for.body, %for.cond14.preheader
74  ret i32 0
75}
76
77declare void @foo() nounwind
78
79; Notify SCEV when removing an ExitingBlock. This only changes the
80; backedge-taken information.
81;
82; First SCEV print:
83; CHECK-LABEL: Determining loop execution counts for: @mergeExit
84; CHECK: Loop %while.cond191: <multiple exits> Unpredictable backedge-taken count.
85; CHECK: Loop %while.cond191: max backedge-taken count is -1
86; CHECK: Loop %while.cond191: Unpredictable predicated backedge-taken count.
87; CHECK: Loop %while.cond191.outer: <multiple exits> Unpredictable backedge-taken count.
88; CHECK: Loop %while.cond191.outer: Unpredictable max backedge-taken count.
89; CHECK: Loop %while.cond191.outer: Unpredictable predicated backedge-taken count.
90;
91; After simplifying, the max backedge count is refined.
92; Second SCEV print:
93; CHECK-LABEL: Determining loop execution counts for: @mergeExit
94; CHECK: Loop %while.cond191: <multiple exits> backedge-taken count is 0
95; CHECK: Loop %while.cond191: max backedge-taken count is 0
96; CHECK: Loop %while.cond191: Predicated backedge-taken count is 0
97; CHECK: Loop %while.cond191.outer: <multiple exits> Unpredictable backedge-taken count.
98; CHECK: Loop %while.cond191.outer: max backedge-taken count is false
99; CHECK: Loop %while.cond191.outer: Unpredictable predicated backedge-taken count.
100define void @mergeExit(i32 %MapAttrCount) nounwind uwtable ssp {
101entry:
102  br i1 undef, label %if.then124, label %if.end126
103
104if.then124:                                       ; preds = %entry
105  unreachable
106
107if.end126:                                        ; preds = %entry
108  br i1 undef, label %while.body.lr.ph, label %if.end591
109
110while.body.lr.ph:                                 ; preds = %if.end126
111  br i1 undef, label %if.end140, label %if.then137
112
113if.then137:                                       ; preds = %while.body.lr.ph
114  unreachable
115
116if.end140:                                        ; preds = %while.body.lr.ph
117  br i1 undef, label %while.cond191.outer, label %if.then148
118
119if.then148:                                       ; preds = %if.end140
120  unreachable
121
122while.cond191.outer:                              ; preds = %if.then205, %if.end140
123  br label %while.cond191
124
125while.cond191:                                    ; preds = %while.body197, %while.cond191.outer
126  %CppIndex.0 = phi i32 [ %inc, %while.body197 ], [ undef, %while.cond191.outer ]
127  br i1 undef, label %land.rhs, label %if.then216
128
129land.rhs:                                         ; preds = %while.cond191
130  %inc = add i32 %CppIndex.0, 1
131  %cmp196 = icmp ult i32 %inc, %MapAttrCount
132  br i1 %cmp196, label %while.body197, label %if.then216
133
134while.body197:                                    ; preds = %land.rhs
135  br i1 undef, label %if.then205, label %while.cond191
136
137if.then205:                                       ; preds = %while.body197
138  br label %while.cond191.outer
139
140if.then216:                                       ; preds = %land.rhs, %while.cond191
141  br i1 undef, label %if.else, label %if.then221
142
143if.then221:                                       ; preds = %if.then216
144  unreachable
145
146if.else:                                          ; preds = %if.then216
147  br i1 undef, label %if.then266, label %if.end340
148
149if.then266:                                       ; preds = %if.else
150  switch i32 undef, label %if.else329 [
151    i32 17, label %if.then285
152    i32 19, label %if.then285
153    i32 18, label %if.then285
154    i32 15, label %if.then285
155  ]
156
157if.then285:                                       ; preds = %if.then266, %if.then266, %if.then266, %if.then266
158  br i1 undef, label %if.then317, label %if.else324
159
160if.then317:                                       ; preds = %if.then285
161  br label %if.end340
162
163if.else324:                                       ; preds = %if.then285
164  unreachable
165
166if.else329:                                       ; preds = %if.then266
167  unreachable
168
169if.end340:                                        ; preds = %if.then317, %if.else
170  unreachable
171
172if.end591:                                        ; preds = %if.end126
173  br i1 undef, label %cond.end, label %cond.false
174
175cond.false:                                       ; preds = %if.end591
176  unreachable
177
178cond.end:                                         ; preds = %if.end591
179  ret void
180}
181