xref: /llvm-project/llvm/test/Transforms/IndVarSimplify/lftr-reuse.ll (revision dce77a357948709e335910ddc07f9c3f2eb2ac4b)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -passes=indvars -S -indvars-predicate-loops=0 | FileCheck %s
3
4; Make sure that indvars can perform LFTR without a canonical IV.
5
6target 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"
7
8; Perform LFTR using the original pointer-type IV.
9
10declare void @use(double %x)
11
12;  for(char* p = base; p < base + n; ++p) {
13;    *p = p-base;
14;  }
15define void @ptriv(ptr %base, i32 %n) nounwind {
16; CHECK-LABEL: @ptriv(
17; CHECK-NEXT:  entry:
18; CHECK-NEXT:    [[IDX_EXT:%.*]] = sext i32 [[N:%.*]] to i64
19; CHECK-NEXT:    [[ADD_PTR:%.*]] = getelementptr inbounds i8, ptr [[BASE:%.*]], i64 [[IDX_EXT]]
20; CHECK-NEXT:    [[CMP1:%.*]] = icmp ult ptr [[BASE]], [[ADD_PTR]]
21; CHECK-NEXT:    br i1 [[CMP1]], label [[FOR_BODY_PREHEADER:%.*]], label [[FOR_END:%.*]]
22; CHECK:       for.body.preheader:
23; CHECK-NEXT:    br label [[FOR_BODY:%.*]]
24; CHECK:       for.body:
25; CHECK-NEXT:    [[P_02:%.*]] = phi ptr [ [[INCDEC_PTR:%.*]], [[FOR_BODY]] ], [ [[BASE]], [[FOR_BODY_PREHEADER]] ]
26; CHECK-NEXT:    [[SUB_PTR_LHS_CAST:%.*]] = ptrtoint ptr [[P_02]] to i64
27; CHECK-NEXT:    [[SUB_PTR_RHS_CAST:%.*]] = ptrtoint ptr [[BASE]] to i64
28; CHECK-NEXT:    [[SUB_PTR_SUB:%.*]] = sub i64 [[SUB_PTR_LHS_CAST]], [[SUB_PTR_RHS_CAST]]
29; CHECK-NEXT:    [[CONV:%.*]] = trunc i64 [[SUB_PTR_SUB]] to i8
30; CHECK-NEXT:    store i8 [[CONV]], ptr [[P_02]], align 1
31; CHECK-NEXT:    [[INCDEC_PTR]] = getelementptr inbounds i8, ptr [[P_02]], i32 1
32; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne ptr [[INCDEC_PTR]], [[ADD_PTR]]
33; CHECK-NEXT:    br i1 [[EXITCOND]], label [[FOR_BODY]], label [[FOR_END_LOOPEXIT:%.*]]
34; CHECK:       for.end.loopexit:
35; CHECK-NEXT:    br label [[FOR_END]]
36; CHECK:       for.end:
37; CHECK-NEXT:    ret void
38;
39entry:
40  %idx.ext = sext i32 %n to i64
41  %add.ptr = getelementptr inbounds i8, ptr %base, i64 %idx.ext
42  %cmp1 = icmp ult ptr %base, %add.ptr
43  br i1 %cmp1, label %for.body, label %for.end
44
45for.body:
46  %p.02 = phi ptr [ %base, %entry ], [ %incdec.ptr, %for.body ]
47  ; cruft to make the IV useful
48  %sub.ptr.lhs.cast = ptrtoint ptr %p.02 to i64
49  %sub.ptr.rhs.cast = ptrtoint ptr %base to i64
50  %sub.ptr.sub = sub i64 %sub.ptr.lhs.cast, %sub.ptr.rhs.cast
51  %conv = trunc i64 %sub.ptr.sub to i8
52  store i8 %conv, ptr %p.02
53  %incdec.ptr = getelementptr inbounds i8, ptr %p.02, i32 1
54  %cmp = icmp ult ptr %incdec.ptr, %add.ptr
55  br i1 %cmp, label %for.body, label %for.end
56
57for.end:
58  ret void
59}
60
61; This test checks that SCEVExpander can handle an outer loop that has been
62; simplified, and as a result the inner loop's exit test will be rewritten.
63define void @expandOuterRecurrence(i32 %arg) nounwind {
64; CHECK-LABEL: @expandOuterRecurrence(
65; CHECK-NEXT:  entry:
66; CHECK-NEXT:    [[SUB1:%.*]] = sub nsw i32 [[ARG:%.*]], 1
67; CHECK-NEXT:    [[CMP1:%.*]] = icmp slt i32 0, [[SUB1]]
68; CHECK-NEXT:    br i1 [[CMP1]], label [[OUTER_PREHEADER:%.*]], label [[EXIT:%.*]]
69; CHECK:       outer.preheader:
70; CHECK-NEXT:    br label [[OUTER:%.*]]
71; CHECK:       outer:
72; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i32 [ [[SUB1]], [[OUTER_PREHEADER]] ], [ [[INDVARS_IV_NEXT:%.*]], [[OUTER_INC:%.*]] ]
73; CHECK-NEXT:    [[I:%.*]] = phi i32 [ [[I_INC:%.*]], [[OUTER_INC]] ], [ 0, [[OUTER_PREHEADER]] ]
74; CHECK-NEXT:    [[SUB2:%.*]] = sub nsw i32 [[ARG]], [[I]]
75; CHECK-NEXT:    [[SUB3:%.*]] = sub nsw i32 [[SUB2]], 1
76; CHECK-NEXT:    [[CMP2:%.*]] = icmp slt i32 0, [[SUB3]]
77; CHECK-NEXT:    br i1 [[CMP2]], label [[INNER_PH:%.*]], label [[OUTER_INC]]
78; CHECK:       inner.ph:
79; CHECK-NEXT:    br label [[INNER:%.*]]
80; CHECK:       inner:
81; CHECK-NEXT:    [[J:%.*]] = phi i32 [ 0, [[INNER_PH]] ], [ [[J_INC:%.*]], [[INNER]] ]
82; CHECK-NEXT:    [[J_INC]] = add nuw nsw i32 [[J]], 1
83; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i32 [[J_INC]], [[INDVARS_IV]]
84; CHECK-NEXT:    br i1 [[EXITCOND]], label [[INNER]], label [[OUTER_INC_LOOPEXIT:%.*]]
85; CHECK:       outer.inc.loopexit:
86; CHECK-NEXT:    br label [[OUTER_INC]]
87; CHECK:       outer.inc:
88; CHECK-NEXT:    [[I_INC]] = add nuw nsw i32 [[I]], 1
89; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add i32 [[INDVARS_IV]], -1
90; CHECK-NEXT:    [[EXITCOND1:%.*]] = icmp ne i32 [[I_INC]], [[SUB1]]
91; CHECK-NEXT:    br i1 [[EXITCOND1]], label [[OUTER]], label [[EXIT_LOOPEXIT:%.*]]
92; CHECK:       exit.loopexit:
93; CHECK-NEXT:    br label [[EXIT]]
94; CHECK:       exit:
95; CHECK-NEXT:    ret void
96;
97entry:
98  %sub1 = sub nsw i32 %arg, 1
99  %cmp1 = icmp slt i32 0, %sub1
100  br i1 %cmp1, label %outer, label %exit
101
102outer:
103  %i = phi i32 [ 0, %entry ], [ %i.inc, %outer.inc ]
104  %sub2 = sub nsw i32 %arg, %i
105  %sub3 = sub nsw i32 %sub2, 1
106  %cmp2 = icmp slt i32 0, %sub3
107  br i1 %cmp2, label %inner.ph, label %outer.inc
108
109inner.ph:
110  br label %inner
111
112inner:
113  %j = phi i32 [ 0, %inner.ph ], [ %j.inc, %inner ]
114  %j.inc = add nsw i32 %j, 1
115  %cmp3 = icmp slt i32 %j.inc, %sub3
116  br i1 %cmp3, label %inner, label %outer.inc
117
118outer.inc:
119  %i.inc = add nsw i32 %i, 1
120  %cmp4 = icmp slt i32 %i.inc, %sub1
121  br i1 %cmp4, label %outer, label %exit
122
123exit:
124  ret void
125}
126
127; Force SCEVExpander to look for an existing well-formed phi.
128; Perform LFTR without generating extra preheader code.
129; TODO: Recover regression after not strengthening AddRec flags during
130; get[Sign,Zero]ExtendExpr for INDVARS_IV_NEXT.
131define void @guardedloop(ptr %matrix, ptr %vector,
132;
133; CHECK-LABEL: @guardedloop(
134; CHECK-NEXT:  entry:
135; CHECK-NEXT:    [[CMP:%.*]] = icmp slt i32 1, [[IROW:%.*]]
136; CHECK-NEXT:    br i1 [[CMP]], label [[LOOP_PREHEADER:%.*]], label [[RETURN:%.*]]
137; CHECK:       loop.preheader:
138; CHECK-NEXT:    [[TMP0:%.*]] = sext i32 [[ILEAD:%.*]] to i64
139; CHECK-NEXT:    [[WIDE_TRIP_COUNT:%.*]] = zext i32 [[IROW]] to i64
140; CHECK-NEXT:    br label [[LOOP:%.*]]
141; CHECK:       loop:
142; CHECK-NEXT:    [[INDVARS_IV2:%.*]] = phi i64 [ 0, [[LOOP_PREHEADER]] ], [ [[INDVARS_IV_NEXT3:%.*]], [[LOOP]] ]
143; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ 0, [[LOOP_PREHEADER]] ], [ [[INDVARS_IV_NEXT:%.*]], [[LOOP]] ]
144; CHECK-NEXT:    [[TMP1:%.*]] = add nsw i64 [[INDVARS_IV]], [[INDVARS_IV2]]
145; CHECK-NEXT:    [[MATRIXP:%.*]] = getelementptr inbounds [0 x double], ptr [[MATRIX:%.*]], i32 0, i64 [[TMP1]]
146; CHECK-NEXT:    [[V1:%.*]] = load double, ptr [[MATRIXP]], align 8
147; CHECK-NEXT:    call void @use(double [[V1]])
148; CHECK-NEXT:    [[VECTORP:%.*]] = getelementptr inbounds [0 x double], ptr [[VECTOR:%.*]], i32 0, i64 [[INDVARS_IV2]]
149; CHECK-NEXT:    [[V2:%.*]] = load double, ptr [[VECTORP]], align 8
150; CHECK-NEXT:    call void @use(double [[V2]])
151; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nsw i64 [[INDVARS_IV]], [[TMP0]]
152; CHECK-NEXT:    [[INDVARS_IV_NEXT3]] = add nuw nsw i64 [[INDVARS_IV2]], 1
153; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDVARS_IV_NEXT3]], [[WIDE_TRIP_COUNT]]
154; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[RETURN_LOOPEXIT:%.*]]
155; CHECK:       return.loopexit:
156; CHECK-NEXT:    br label [[RETURN]]
157; CHECK:       return:
158; CHECK-NEXT:    ret void
159;
160  i32 %irow, i32 %ilead) nounwind {
161entry:
162  %cmp = icmp slt i32 1, %irow
163  br i1 %cmp, label %loop, label %return
164
165loop:
166  %rowidx = phi i32 [ 0, %entry ], [ %row.inc, %loop ]
167  %i = phi i32 [ 0, %entry ], [ %i.inc, %loop ]
168  %diagidx = add nsw i32 %rowidx, %i
169  %diagidxw = sext i32 %diagidx to i64
170  %matrixp = getelementptr inbounds [0 x double], ptr %matrix, i32 0, i64 %diagidxw
171  %v1 = load double, ptr %matrixp
172  call void @use(double %v1)
173  %iw = sext i32 %i to i64
174  %vectorp = getelementptr inbounds [0 x double], ptr %vector, i32 0, i64 %iw
175  %v2 = load double, ptr %vectorp
176  call void @use(double %v2)
177  %row.inc = add nsw i32 %rowidx, %ilead
178  %i.inc = add nsw i32 %i, 1
179  %cmp196 = icmp slt i32 %i.inc, %irow
180  br i1 %cmp196, label %loop, label %return
181
182return:
183  ret void
184}
185
186; Avoid generating extra code to materialize a trip count. Skip LFTR.
187define void @unguardedloop(ptr %matrix, ptr %vector,
188;
189; CHECK-LABEL: @unguardedloop(
190; CHECK-NEXT:  entry:
191; CHECK-NEXT:    [[SMAX:%.*]] = call i32 @llvm.smax.i32(i32 [[IROW:%.*]], i32 1)
192; CHECK-NEXT:    [[WIDE_TRIP_COUNT:%.*]] = zext i32 [[SMAX]] to i64
193; CHECK-NEXT:    br label [[LOOP:%.*]]
194; CHECK:       loop:
195; CHECK-NEXT:    [[INDVARS_IV2:%.*]] = phi i64 [ [[INDVARS_IV_NEXT3:%.*]], [[LOOP]] ], [ 0, [[ENTRY:%.*]] ]
196; CHECK-NEXT:    [[INDVARS_IV_NEXT3]] = add nuw nsw i64 [[INDVARS_IV2]], 1
197; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i64 [[INDVARS_IV_NEXT3]], [[WIDE_TRIP_COUNT]]
198; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[RETURN:%.*]]
199; CHECK:       return:
200; CHECK-NEXT:    ret void
201;
202  i32 %irow, i32 %ilead) nounwind {
203entry:
204  br label %loop
205
206loop:
207  %rowidx = phi i32 [ 0, %entry ], [ %row.inc, %loop ]
208  %i = phi i32 [ 0, %entry ], [ %i.inc, %loop ]
209  %diagidx = add nsw i32 %rowidx, %i
210  %diagidxw = sext i32 %diagidx to i64
211  %matrixp = getelementptr inbounds [0 x double], ptr %matrix, i32 0, i64 %diagidxw
212  %v1 = load double, ptr %matrixp
213  %iw = sext i32 %i to i64
214  %vectorp = getelementptr inbounds [0 x double], ptr %vector, i32 0, i64 %iw
215  %v2 = load double, ptr %vectorp
216  %row.inc = add nsw i32 %rowidx, %ilead
217  %i.inc = add nsw i32 %i, 1
218  %cmp196 = icmp slt i32 %i.inc, %irow
219  br i1 %cmp196, label %loop, label %return
220
221return:
222  ret void
223}
224
225; Remove %i which is only used by the exit test.
226; Verify that SCEV can still compute a backedge count from the sign
227; extended %n, used for pointer comparison by LFTR.
228;
229; TODO: Fix for PR13371 currently makes this impossible. See
230; IndVarSimplify.cpp hasConcreteDef(). We may want to change to undef rules.
231define void @geplftr(ptr %base, i32 %x, i32 %y, i32 %n) nounwind {
232; CHECK-LABEL: @geplftr(
233; CHECK-NEXT:  entry:
234; CHECK-NEXT:    [[X_EXT:%.*]] = sext i32 [[X:%.*]] to i64
235; CHECK-NEXT:    [[ADD_PTR:%.*]] = getelementptr inbounds i8, ptr [[BASE:%.*]], i64 [[X_EXT]]
236; CHECK-NEXT:    [[Y_EXT:%.*]] = sext i32 [[Y:%.*]] to i64
237; CHECK-NEXT:    [[ADD_PTR10:%.*]] = getelementptr inbounds i8, ptr [[ADD_PTR]], i64 [[Y_EXT]]
238; CHECK-NEXT:    [[LIM:%.*]] = add i32 [[X]], [[N:%.*]]
239; CHECK-NEXT:    [[CMP_PH:%.*]] = icmp ult i32 [[X]], [[LIM]]
240; CHECK-NEXT:    br i1 [[CMP_PH]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
241; CHECK:       loop.preheader:
242; CHECK-NEXT:    br label [[LOOP:%.*]]
243; CHECK:       loop:
244; CHECK-NEXT:    [[I:%.*]] = phi i32 [ [[INC:%.*]], [[LOOP]] ], [ [[X]], [[LOOP_PREHEADER]] ]
245; CHECK-NEXT:    [[APTR:%.*]] = phi ptr [ [[INCDEC_PTR:%.*]], [[LOOP]] ], [ [[ADD_PTR10]], [[LOOP_PREHEADER]] ]
246; CHECK-NEXT:    [[INCDEC_PTR]] = getelementptr inbounds i8, ptr [[APTR]], i32 1
247; CHECK-NEXT:    store i8 3, ptr [[APTR]], align 1
248; CHECK-NEXT:    [[INC]] = add nuw i32 [[I]], 1
249; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne i32 [[INC]], [[LIM]]
250; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT_LOOPEXIT:%.*]]
251; CHECK:       exit.loopexit:
252; CHECK-NEXT:    br label [[EXIT]]
253; CHECK:       exit:
254; CHECK-NEXT:    ret void
255;
256entry:
257  %x.ext = sext i32 %x to i64
258  %add.ptr = getelementptr inbounds i8, ptr %base, i64 %x.ext
259  %y.ext = sext i32 %y to i64
260  %add.ptr10 = getelementptr inbounds i8, ptr %add.ptr, i64 %y.ext
261  %lim = add i32 %x, %n
262  %cmp.ph = icmp ult i32 %x, %lim
263  br i1 %cmp.ph, label %loop, label %exit
264loop:
265  %i = phi i32 [ %x, %entry ], [ %inc, %loop ]
266  %aptr = phi ptr [ %add.ptr10, %entry ], [ %incdec.ptr, %loop ]
267  %incdec.ptr = getelementptr inbounds i8, ptr %aptr, i32 1
268  store i8 3, ptr %aptr
269  %inc = add i32 %i, 1
270  %cmp = icmp ult i32 %inc, %lim
271  br i1 %cmp, label %loop, label %exit
272
273exit:
274  ret void
275}
276
277; Exercise backedge taken count verification with a never-taken loop.
278define void @nevertaken() nounwind uwtable ssp {
279; CHECK-LABEL: @nevertaken(
280; CHECK-NEXT:  entry:
281; CHECK-NEXT:    br label [[LOOP:%.*]]
282; CHECK:       loop:
283; CHECK-NEXT:    br i1 false, label [[LOOP]], label [[EXIT:%.*]]
284; CHECK:       exit:
285; CHECK-NEXT:    ret void
286;
287entry:
288  br label %loop
289loop:
290  %i = phi i32 [ 0, %entry ], [ %inc, %loop ]
291  %inc = add nsw i32 %i, 1
292  %cmp = icmp sle i32 %inc, 0
293  br i1 %cmp, label %loop, label %exit
294
295exit:
296  ret void
297}
298
299; Test LFTR on an IV whose recurrence start is a non-unit pointer type.
300define void @aryptriv(ptr %base, i32 %n) nounwind {
301; CHECK-LABEL: @aryptriv(
302; CHECK-NEXT:  entry:
303; CHECK-NEXT:    [[IVEND:%.*]] = getelementptr inbounds [256 x i8], ptr [[BASE:%.*]], i32 0, i32 [[N:%.*]]
304; CHECK-NEXT:    [[CMP_PH:%.*]] = icmp ult ptr [[BASE]], [[IVEND]]
305; CHECK-NEXT:    br i1 [[CMP_PH]], label [[LOOP_PREHEADER:%.*]], label [[EXIT:%.*]]
306; CHECK:       loop.preheader:
307; CHECK-NEXT:    br label [[LOOP:%.*]]
308; CHECK:       loop:
309; CHECK-NEXT:    [[APTR:%.*]] = phi ptr [ [[INCDEC_PTR:%.*]], [[LOOP]] ], [ [[BASE]], [[LOOP_PREHEADER]] ]
310; CHECK-NEXT:    [[INCDEC_PTR]] = getelementptr inbounds i8, ptr [[APTR]], i32 1
311; CHECK-NEXT:    store i8 3, ptr [[APTR]], align 1
312; CHECK-NEXT:    [[EXITCOND:%.*]] = icmp ne ptr [[INCDEC_PTR]], [[IVEND]]
313; CHECK-NEXT:    br i1 [[EXITCOND]], label [[LOOP]], label [[EXIT_LOOPEXIT:%.*]]
314; CHECK:       exit.loopexit:
315; CHECK-NEXT:    br label [[EXIT]]
316; CHECK:       exit:
317; CHECK-NEXT:    ret void
318;
319entry:
320  %ivend = getelementptr inbounds [256 x i8], ptr %base, i32 0, i32 %n
321  %cmp.ph = icmp ult ptr %base, %ivend
322  br i1 %cmp.ph, label %loop, label %exit
323
324loop:
325  %aptr = phi ptr [ %base, %entry ], [ %incdec.ptr, %loop ]
326  %incdec.ptr = getelementptr inbounds i8, ptr %aptr, i32 1
327  store i8 3, ptr %aptr
328  %cmp = icmp ult ptr %incdec.ptr, %ivend
329  br i1 %cmp, label %loop, label %exit
330
331exit:
332  ret void
333}
334