xref: /llvm-project/llvm/test/Transforms/IndVarSimplify/exit_value_tests.ll (revision a56071ffb7f647a41e4b24ff4c2e70d6c63f40b7)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -passes='loop(indvars,loop-deletion),simplifycfg' -simplifycfg-require-and-preserve-domtree=1 -S | FileCheck %s
3
4; Test that we can evaluate the exit values of various expression types.  Since
5; these loops all have predictable exit values we can replace the use outside
6; of the loop with a closed-form computation.
7
8define i32 @polynomial_constant() {
9; <label>:0
10; CHECK-LABEL: @polynomial_constant(
11; CHECK-NEXT:  Out:
12; CHECK-NEXT:    ret i32 500500
13;
14  br label %Loop
15
16Loop:		; preds = %Loop, %0
17  %A1 = phi i32 [ 0, %0 ], [ %A2, %Loop ]		; <i32> [#uses=3]
18  %B1 = phi i32 [ 0, %0 ], [ %B2, %Loop ]		; <i32> [#uses=1]
19  %A2 = add i32 %A1, 1		; <i32> [#uses=1]
20  %B2 = add i32 %B1, %A1		; <i32> [#uses=2]
21  %C = icmp eq i32 %A1, 1000		; <i1> [#uses=1]
22  br i1 %C, label %Out, label %Loop
23
24Out:		; preds = %Loop
25  ret i32 %B2
26}
27
28define i32 @NSquare(i32 %N) {
29; <label>:0
30; CHECK-LABEL: @NSquare(
31; CHECK-NEXT:  Out:
32; CHECK-NEXT:    [[Y:%.*]] = mul i32 [[N:%.*]], [[N]]
33; CHECK-NEXT:    ret i32 [[Y]]
34;
35  br label %Loop
36
37Loop:		; preds = %Loop, %0
38  %X = phi i32 [ 0, %0 ], [ %X2, %Loop ]		; <i32> [#uses=4]
39  %X2 = add i32 %X, 1		; <i32> [#uses=1]
40  %c = icmp eq i32 %X, %N		; <i1> [#uses=1]
41  br i1 %c, label %Out, label %Loop
42
43Out:		; preds = %Loop
44  %Y = mul i32 %X, %X		; <i32> [#uses=1]
45  ret i32 %Y
46}
47
48define i32 @NSquareOver2(i32 %N) {
49; <label>:0
50; CHECK-LABEL: @NSquareOver2(
51; CHECK-NEXT:  Out:
52; CHECK-NEXT:    [[TMP0:%.*]] = zext i32 [[N:%.*]] to i33
53; CHECK-NEXT:    [[TMP1:%.*]] = add i32 [[N]], -1
54; CHECK-NEXT:    [[TMP2:%.*]] = zext i32 [[TMP1]] to i33
55; CHECK-NEXT:    [[TMP3:%.*]] = mul i33 [[TMP0]], [[TMP2]]
56; CHECK-NEXT:    [[TMP4:%.*]] = lshr i33 [[TMP3]], 1
57; CHECK-NEXT:    [[TMP5:%.*]] = trunc i33 [[TMP4]] to i32
58; CHECK-NEXT:    [[TMP6:%.*]] = add i32 [[N]], [[TMP5]]
59; CHECK-NEXT:    [[TMP7:%.*]] = add i32 [[TMP6]], 15
60; CHECK-NEXT:    ret i32 [[TMP7]]
61;
62  br label %Loop
63
64Loop:		; preds = %Loop, %0
65  %X = phi i32 [ 0, %0 ], [ %X2, %Loop ]		; <i32> [#uses=3]
66  %Y = phi i32 [ 15, %0 ], [ %Y2, %Loop ]		; <i32> [#uses=1]
67  %Y2 = add i32 %Y, %X		; <i32> [#uses=2]
68  %X2 = add i32 %X, 1		; <i32> [#uses=1]
69  %c = icmp eq i32 %X, %N		; <i1> [#uses=1]
70  br i1 %c, label %Out, label %Loop
71
72Out:		; preds = %Loop
73  ret i32 %Y2
74}
75
76define i32 @strength_reduced() {
77; <label>:0
78; CHECK-LABEL: @strength_reduced(
79; CHECK-NEXT:  Out:
80; CHECK-NEXT:    ret i32 500500
81;
82  br label %Loop
83
84Loop:		; preds = %Loop, %0
85  %A1 = phi i32 [ 0, %0 ], [ %A2, %Loop ]		; <i32> [#uses=3]
86  %B1 = phi i32 [ 0, %0 ], [ %B2, %Loop ]		; <i32> [#uses=1]
87  %A2 = add i32 %A1, 1		; <i32> [#uses=1]
88  %B2 = add i32 %B1, %A1		; <i32> [#uses=2]
89  %C = icmp eq i32 %A1, 1000		; <i1> [#uses=1]
90  br i1 %C, label %Out, label %Loop
91
92Out:		; preds = %Loop
93  ret i32 %B2
94}
95
96define i32 @chrec_equals() {
97; CHECK-LABEL: @chrec_equals(
98; CHECK-NEXT:  entry:
99; CHECK-NEXT:    ret i32 101
100;
101entry:
102  br label %no_exit
103
104no_exit:		; preds = %no_exit, %entry
105  %i0 = phi i32 [ 0, %entry ], [ %i1, %no_exit ]		; <i32> [#uses=3]
106  %ISq = mul i32 %i0, %i0		; <i32> [#uses=1]
107  %i1 = add i32 %i0, 1		; <i32> [#uses=2]
108  %tmp.1 = icmp ne i32 %ISq, 10000		; <i1> [#uses=1]
109  br i1 %tmp.1, label %no_exit, label %loopexit
110
111loopexit:		; preds = %no_exit
112  ret i32 %i1
113}
114
115define i16 @cast_chrec_test() {
116; <label>:0
117; CHECK-LABEL: @cast_chrec_test(
118; CHECK-NEXT:  Out:
119; CHECK-NEXT:    ret i16 1000
120;
121  br label %Loop
122
123Loop:		; preds = %Loop, %0
124  %A1 = phi i32 [ 0, %0 ], [ %A2, %Loop ]		; <i32> [#uses=2]
125  %B1 = trunc i32 %A1 to i16		; <i16> [#uses=2]
126  %A2 = add i32 %A1, 1		; <i32> [#uses=1]
127  %C = icmp eq i16 %B1, 1000		; <i1> [#uses=1]
128  br i1 %C, label %Out, label %Loop
129
130Out:		; preds = %Loop
131  ret i16 %B1
132}
133
134define i32 @linear_div_fold() {
135; CHECK-LABEL: @linear_div_fold(
136; CHECK-NEXT:  entry:
137; CHECK-NEXT:    ret i32 34
138;
139entry:
140  br label %loop
141
142loop:		; preds = %loop, %entry
143  %i = phi i32 [ 4, %entry ], [ %i.next, %loop ]		; <i32> [#uses=3]
144  %i.next = add i32 %i, 8		; <i32> [#uses=1]
145  %RV = udiv i32 %i, 2		; <i32> [#uses=1]
146  %c = icmp ne i32 %i, 68		; <i1> [#uses=1]
147  br i1 %c, label %loop, label %loopexit
148
149loopexit:		; preds = %loop
150  ret i32 %RV
151}
152
153define i32 @unroll_phi_select_constant_nonzero(i32 %arg1, i32 %arg2) {
154; CHECK-LABEL: @unroll_phi_select_constant_nonzero(
155; CHECK-NEXT:  entry:
156; CHECK-NEXT:    ret i32 [[ARG2:%.*]]
157;
158entry:
159  br label %loop
160
161loop:
162  %i = phi i32 [ 0, %entry ], [ %i.next, %loop ]
163  %selector = phi i32 [%arg1, %entry], [%arg2, %loop]
164  %i.next = add nsw nuw i32 %i, 1
165  %c = icmp ult i32 %i, 4
166  br i1 %c, label %loop, label %loopexit
167
168loopexit:
169  ret i32 %selector
170}
171
172define i32 @unroll_phi_select_constant_nonzero_large_btc(i32 %arg1, i32 %arg2) {
173; CHECK-LABEL: @unroll_phi_select_constant_nonzero_large_btc(
174; CHECK-NEXT:  entry:
175; CHECK-NEXT:    ret i32 [[ARG2:%.*]]
176;
177entry:
178  br label %loop
179
180loop:
181  %i = phi i32 [ 0, %entry ], [ %i.next, %loop ]
182  %selector = phi i32 [%arg1, %entry], [%arg2, %loop]
183  %i.next = add nuw i32 %i, 1
184  %c = icmp ult i32 %i, -42
185  br i1 %c, label %loop, label %loopexit
186
187loopexit:
188  ret i32 %selector
189}
190
191declare i32 @f()
192
193; After LCSSA formation, there's no LCSSA phi for %f since it isn't directly
194; used outside the loop, and thus we can't directly replace %selector w/ %f.
195define i32 @neg_unroll_phi_select_constant_nonzero(i32 %arg) {
196; CHECK-LABEL: @neg_unroll_phi_select_constant_nonzero(
197; CHECK-NEXT:  entry:
198; CHECK-NEXT:    br label [[LOOP:%.*]]
199; CHECK:       loop:
200; CHECK-NEXT:    [[I:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[I_NEXT:%.*]], [[LOOP]] ]
201; CHECK-NEXT:    [[SELECTOR:%.*]] = phi i32 [ [[ARG:%.*]], [[ENTRY]] ], [ [[F:%.*]], [[LOOP]] ]
202; CHECK-NEXT:    [[F]] = call i32 @f()
203; CHECK-NEXT:    [[I_NEXT]] = add nuw nsw i32 [[I]], 1
204; CHECK-NEXT:    [[C:%.*]] = icmp ult i32 [[I]], 4
205; CHECK-NEXT:    br i1 [[C]], label [[LOOP]], label [[LOOPEXIT:%.*]]
206; CHECK:       loopexit:
207; CHECK-NEXT:    [[SELECTOR_LCSSA:%.*]] = phi i32 [ [[SELECTOR]], [[LOOP]] ]
208; CHECK-NEXT:    ret i32 [[SELECTOR_LCSSA]]
209;
210entry:
211  br label %loop
212
213loop:
214  %i = phi i32 [ 0, %entry ], [ %i.next, %loop ]
215  %selector = phi i32 [%arg, %entry], [%f, %loop]
216  %f = call i32 @f()
217  %i.next = add nsw nuw i32 %i, 1
218  %c = icmp ult i32 %i, 4
219  br i1 %c, label %loop, label %loopexit
220
221loopexit:
222  ret i32 %selector
223}
224
225
226define i32 @unroll_phi_select_constant_zero(i32 %arg1, i32 %arg2) {
227; CHECK-LABEL: @unroll_phi_select_constant_zero(
228; CHECK-NEXT:  entry:
229; CHECK-NEXT:    ret i32 [[ARG1:%.*]]
230;
231entry:
232  br label %loop
233
234loop:
235  %i = phi i32 [ 0, %entry ], [ %i.next, %loop ]
236  %selector = phi i32 [%arg1, %entry], [%arg2, %loop]
237  %i.next = add i32 %i, 1
238  %c = icmp ne i32 %i, 0
239  br i1 %c, label %loop, label %loopexit
240
241loopexit:
242  ret i32 %selector
243}
244
245define i32 @unroll_phi_select(i32 %arg1, i32 %arg2, i16 %len) {
246; CHECK-LABEL: @unroll_phi_select(
247; CHECK-NEXT:  entry:
248; CHECK-NEXT:    ret i32 [[ARG2:%.*]]
249;
250entry:
251  %length = zext i16 %len to i32
252  br label %loop
253
254loop:
255  %i = phi i32 [ -1, %entry ], [ %i.next, %loop ]
256  %selector = phi i32 [%arg1, %entry], [%arg2, %loop]
257  %i.next = add nsw i32 %i, 1
258  %c = icmp slt i32 %i, %length
259  br i1 %c, label %loop, label %loopexit
260
261loopexit:
262  ret i32 %selector
263}
264
265