xref: /llvm-project/llvm/test/Transforms/InstCombine/malloc-free.ll (revision 0af5c0668a1b93c7b3b34a1885b494c4ebb0b46f)
1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
2; RUN: opt < %s -passes=instcombine -S | FileCheck %s
3; PR1201
4
5target datalayout = "p:32:32:32"
6
7define i32 @main(i32 %argc, ptr %argv) {
8; CHECK-LABEL: @main(
9; CHECK-NEXT:    ret i32 0
10;
11  %c_19 = alloca ptr
12  %malloc_206 = tail call ptr @malloc(i32 mul (i32 ptrtoint (ptr getelementptr (i8, ptr null, i32 1) to i32), i32 10))
13  store ptr %malloc_206, ptr %c_19
14  %tmp_207 = load ptr, ptr %c_19
15  tail call void @free(ptr %tmp_207)
16  ret i32 0
17}
18
19define i32 @dead_aligned_alloc(i32 %size, i32 %alignment, i8 %value) {
20; CHECK-LABEL: @dead_aligned_alloc(
21; CHECK-NEXT:    ret i32 0
22;
23  %aligned_allocation = tail call ptr @aligned_alloc(i32 %alignment, i32 %size)
24  store i8 %value, ptr %aligned_allocation
25  tail call void @free(ptr %aligned_allocation)
26  ret i32 0
27}
28
29define i1 @aligned_alloc_only_pointe(i32 %size, i32 %alignment, i8 %value) {
30; CHECK-LABEL: @aligned_alloc_only_pointe(
31; CHECK-NEXT:    [[ALIGNED_ALLOCATION:%.*]] = tail call ptr @aligned_alloc(i32 [[ALIGNMENT:%.*]], i32 [[SIZE:%.*]])
32; CHECK-NEXT:    [[CMP:%.*]] = icmp ne ptr [[ALIGNED_ALLOCATION]], null
33; CHECK-NEXT:    ret i1 [[CMP]]
34;
35  %aligned_allocation = tail call ptr @aligned_alloc(i32 %alignment, i32 %size)
36  %cmp = icmp ne ptr %aligned_allocation, null
37  ret i1 %cmp
38}
39
40define i1 @aligned_alloc_pointer_only_used_by_cmp_alignment_and_value_known_ok(i32 %size, i32 %alignment, i8 %value) {
41; CHECK-LABEL: @aligned_alloc_pointer_only_used_by_cmp_alignment_and_value_known_ok(
42; CHECK-NEXT:    ret i1 true
43;
44  %aligned_allocation = tail call ptr @aligned_alloc(i32 8, i32 32)
45  %cmp = icmp ne ptr %aligned_allocation, null
46  ret i1 %cmp
47}
48
49define i1 @aligned_alloc_pointer_only_used_by_cmp_alignment_no_power_of_2(i32 %size, i32 %alignment, i8 %value) {
50; CHECK-LABEL: @aligned_alloc_pointer_only_used_by_cmp_alignment_no_power_of_2(
51; CHECK-NEXT:    [[ALIGNED_ALLOCATION:%.*]] = tail call dereferenceable_or_null(32) ptr @aligned_alloc(i32 3, i32 32)
52; CHECK-NEXT:    [[CMP:%.*]] = icmp ne ptr [[ALIGNED_ALLOCATION]], null
53; CHECK-NEXT:    ret i1 [[CMP]]
54;
55  %aligned_allocation = tail call ptr @aligned_alloc(i32 3, i32 32)
56  %cmp = icmp ne ptr %aligned_allocation, null
57  ret i1 %cmp
58}
59
60define i1 @aligned_alloc_pointer_only_used_by_cmp_size_not_multiple_of_alignment(i32 %size, i32 %alignment, i8 %value) {
61; CHECK-LABEL: @aligned_alloc_pointer_only_used_by_cmp_size_not_multiple_of_alignment(
62; CHECK-NEXT:    [[ALIGNED_ALLOCATION:%.*]] = tail call dereferenceable_or_null(31) ptr @aligned_alloc(i32 8, i32 31)
63; CHECK-NEXT:    [[CMP:%.*]] = icmp ne ptr [[ALIGNED_ALLOCATION]], null
64; CHECK-NEXT:    ret i1 [[CMP]]
65;
66  %aligned_allocation = tail call ptr @aligned_alloc(i32 8, i32 31)
67  %cmp = icmp ne ptr %aligned_allocation, null
68  ret i1 %cmp
69}
70
71; This test uses a aligned allocation function different to @aligned_alloc,
72; and should be treated as having @aligned_alloc's constraints on alignment
73; and size operands.
74define i1 @other_aligned_allocation_function(i32 %size, i32 %alignment, i8 %value) {
75; CHECK-LABEL: @other_aligned_allocation_function(
76; CHECK-NEXT:    ret i1 true
77;
78  %aligned_allocation = tail call ptr @other_aligned_alloc(i32 %alignment, i32 %size)
79  %cmp = icmp ne ptr %aligned_allocation, null
80  ret i1 %cmp
81}
82
83declare noalias ptr @calloc(i32, i32) nounwind allockind("alloc,zeroed") allocsize(0,1) "alloc-family"="malloc"
84declare noalias ptr @malloc(i32) allockind("alloc,uninitialized") allocsize(0) "alloc-family"="malloc"
85declare noalias ptr @aligned_alloc(i32, i32) allockind("alloc,uninitialized,aligned") allocsize(1) "alloc-family"="malloc"
86declare noalias ptr @other_aligned_alloc(i32, i32) allockind("alloc,uninitialized,aligned") allocsize(1) "alloc-family"="malloc"
87declare void @free(ptr) allockind("free") "alloc-family"="malloc"
88
89define i1 @foo() {
90; CHECK-LABEL: @foo(
91; CHECK-NEXT:    ret i1 false
92;
93  %m = call ptr @malloc(i32 1)
94  %z = icmp eq ptr %m, null
95  call void @free(ptr %m)
96  ret i1 %z
97}
98
99declare void @llvm.lifetime.start.p0(i64, ptr)
100declare void @llvm.lifetime.end.p0(i64, ptr)
101declare i64 @llvm.objectsize.i64(ptr, i1)
102declare void @llvm.memcpy.p0.p0.i32(ptr nocapture, ptr nocapture, i32, i1) nounwind
103declare void @llvm.memmove.p0.p0.i32(ptr nocapture, ptr nocapture, i32, i1) nounwind
104declare void @llvm.memset.p0.i32(ptr, i8, i32, i1) nounwind
105
106define void @test3(ptr %src) {
107; CHECK-LABEL: @test3(
108; CHECK-NEXT:    ret void
109;
110  %a = call noalias ptr @malloc(i32 10)
111  call void @llvm.lifetime.start.p0(i64 10, ptr %a)
112  call void @llvm.lifetime.end.p0(i64 10, ptr %a)
113  %size = call i64 @llvm.objectsize.i64(ptr %a, i1 true)
114  store i8 42, ptr %a
115  call void @llvm.memcpy.p0.p0.i32(ptr %a, ptr %src, i32 32, i1 false)
116  call void @llvm.memmove.p0.p0.i32(ptr %a, ptr %src, i32 32, i1 false)
117  call void @llvm.memset.p0.i32(ptr %a, i8 5, i32 32, i1 false)
118  %alloc2 = call noalias ptr @calloc(i32 5, i32 7) nounwind
119  %z = icmp ne ptr %alloc2, null
120  ret void
121}
122
123;; This used to crash.
124define void @test4() {
125; CHECK-LABEL: @test4(
126; CHECK-NEXT:    ret void
127;
128  %A = call ptr @malloc(i32 16000)
129  call void @free(ptr %A)
130  ret void
131}
132
133define void @test5(ptr %ptr, ptr %esc) {
134; CHECK-LABEL: @test5(
135; CHECK-NEXT:    [[A:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
136; CHECK-NEXT:    [[B:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
137; CHECK-NEXT:    [[C:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
138; CHECK-NEXT:    [[D:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
139; CHECK-NEXT:    [[E:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
140; CHECK-NEXT:    [[F:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
141; CHECK-NEXT:    [[G:%.*]] = call dereferenceable_or_null(700) ptr @malloc(i32 700)
142; CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i32(ptr noundef nonnull align 1 dereferenceable(32) [[PTR:%.*]], ptr noundef nonnull align 1 dereferenceable(32) [[A]], i32 32, i1 false)
143; CHECK-NEXT:    call void @llvm.memmove.p0.p0.i32(ptr noundef nonnull align 1 dereferenceable(32) [[PTR]], ptr noundef nonnull align 1 dereferenceable(32) [[B]], i32 32, i1 false)
144; CHECK-NEXT:    store ptr [[C]], ptr [[ESC:%.*]], align 4
145; CHECK-NEXT:    call void @llvm.memcpy.p0.p0.i32(ptr [[D]], ptr [[PTR]], i32 32, i1 true)
146; CHECK-NEXT:    call void @llvm.memmove.p0.p0.i32(ptr [[E]], ptr [[PTR]], i32 32, i1 true)
147; CHECK-NEXT:    call void @llvm.memset.p0.i32(ptr [[F]], i8 5, i32 32, i1 true)
148; CHECK-NEXT:    store volatile i8 4, ptr [[G]], align 1
149; CHECK-NEXT:    ret void
150;
151  %a = call ptr @malloc(i32 700)
152  %b = call ptr @malloc(i32 700)
153  %c = call ptr @malloc(i32 700)
154  %d = call ptr @malloc(i32 700)
155  %e = call ptr @malloc(i32 700)
156  %f = call ptr @malloc(i32 700)
157  %g = call ptr @malloc(i32 700)
158  call void @llvm.memcpy.p0.p0.i32(ptr %ptr, ptr %a, i32 32, i1 false)
159  call void @llvm.memmove.p0.p0.i32(ptr %ptr, ptr %b, i32 32, i1 false)
160  store ptr %c, ptr %esc
161  call void @llvm.memcpy.p0.p0.i32(ptr %d, ptr %ptr, i32 32, i1 true)
162  call void @llvm.memmove.p0.p0.i32(ptr %e, ptr %ptr, i32 32, i1 true)
163  call void @llvm.memset.p0.i32(ptr %f, i8 5, i32 32, i1 true)
164  store volatile i8 4, ptr %g
165  ret void
166}
167
168;; When a basic block contains only a call to free and this block is accessed
169;; through a test of the argument of free against null, move the call in the
170;; predecessor block.
171;; Using simplifycfg will remove the empty basic block and the branch operation
172;; Then, performing a dead elimination will remove the comparison.
173;; This is what happens with -O1 and upper.
174define void @test6(ptr %foo) minsize {
175; CHECK-LABEL: @test6(
176; CHECK-NEXT:  entry:
177; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq ptr [[FOO:%.*]], null
178; CHECK-NEXT:    tail call void @free(ptr [[FOO]])
179; CHECK-NEXT:    br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]]
180; CHECK:       if.then:
181; CHECK-NEXT:    br label [[IF_END]]
182; CHECK:       if.end:
183; CHECK-NEXT:    ret void
184;
185;; Call to free moved
186;; Block is now empty and may be simplified by simplifycfg
187entry:
188  %tobool = icmp eq ptr %foo, null
189  br i1 %tobool, label %if.end, label %if.then
190
191if.then:                                          ; preds = %entry
192  tail call void @free(ptr %foo)
193  br label %if.end
194
195if.end:                                           ; preds = %entry, %if.then
196  ret void
197}
198
199;; Check that the optimization that moves a call to free in its predecessor
200;; block (see test6) also happens when noop casts are involved.
201define void @test12(ptr %foo) minsize {
202; CHECK-LABEL: @test12(
203; CHECK-NEXT:  entry:
204; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq ptr [[FOO:%.*]], null
205; CHECK-NEXT:    tail call void @free(ptr [[FOO]])
206; CHECK-NEXT:    br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]]
207; CHECK:       if.then:
208; CHECK-NEXT:    br label [[IF_END]]
209; CHECK:       if.end:
210; CHECK-NEXT:    ret void
211;
212;; Everything before the call to free should have been moved as well.
213;; Call to free moved
214;; Block is now empty and may be simplified by simplifycfg
215entry:
216  %tobool = icmp eq ptr %foo, null
217  br i1 %tobool, label %if.end, label %if.then
218
219if.then:                                          ; preds = %entry
220  tail call void @free(ptr %foo)
221  br label %if.end
222
223if.end:                                           ; preds = %entry, %if.then
224  ret void
225}
226
227;; Test that nonnull-implying attributes on the parameter are adjusted when the
228;; call is moved, since they may no longer be valid and result in miscompiles if
229;; kept unchanged.
230define void @test_nonnull_free_move(ptr %foo) minsize {
231; CHECK-LABEL: @test_nonnull_free_move(
232; CHECK-NEXT:  entry:
233; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq ptr [[FOO:%.*]], null
234; CHECK-NEXT:    tail call void @free(ptr [[FOO]])
235; CHECK-NEXT:    br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]]
236; CHECK:       if.then:
237; CHECK-NEXT:    br label [[IF_END]]
238; CHECK:       if.end:
239; CHECK-NEXT:    ret void
240;
241entry:
242  %tobool = icmp eq ptr %foo, null
243  br i1 %tobool, label %if.end, label %if.then
244
245if.then:                                          ; preds = %entry
246  tail call void @free(ptr nonnull %foo)
247  br label %if.end
248
249if.end:                                           ; preds = %entry, %if.then
250  ret void
251}
252
253define void @test_dereferenceable_free_move(ptr %foo) minsize {
254; CHECK-LABEL: @test_dereferenceable_free_move(
255; CHECK-NEXT:  entry:
256; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq ptr [[FOO:%.*]], null
257; CHECK-NEXT:    tail call void @free(ptr dereferenceable_or_null(4) [[FOO]])
258; CHECK-NEXT:    br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]]
259; CHECK:       if.then:
260; CHECK-NEXT:    br label [[IF_END]]
261; CHECK:       if.end:
262; CHECK-NEXT:    ret void
263;
264entry:
265  %tobool = icmp eq ptr %foo, null
266  br i1 %tobool, label %if.end, label %if.then
267
268if.then:                                          ; preds = %entry
269  tail call void @free(ptr dereferenceable(4) %foo)
270  br label %if.end
271
272if.end:                                           ; preds = %entry, %if.then
273  ret void
274}
275
276define void @test_nonnull_dereferenceable_free_move(ptr %foo) minsize {
277; CHECK-LABEL: @test_nonnull_dereferenceable_free_move(
278; CHECK-NEXT:  entry:
279; CHECK-NEXT:    [[TOBOOL:%.*]] = icmp eq ptr [[FOO:%.*]], null
280; CHECK-NEXT:    tail call void @free(ptr dereferenceable_or_null(16) [[FOO]])
281; CHECK-NEXT:    br i1 [[TOBOOL]], label [[IF_END:%.*]], label [[IF_THEN:%.*]]
282; CHECK:       if.then:
283; CHECK-NEXT:    br label [[IF_END]]
284; CHECK:       if.end:
285; CHECK-NEXT:    ret void
286;
287entry:
288  %tobool = icmp eq ptr %foo, null
289  br i1 %tobool, label %if.end, label %if.then
290
291if.then:                                          ; preds = %entry
292  tail call void @free(ptr nonnull dereferenceable(16) %foo)
293  br label %if.end
294
295if.end:                                           ; preds = %entry, %if.then
296  ret void
297}
298
299; The next four tests cover the semantics of the nofree attributes.  These
300; are thought to be legal transforms, but an implementation thereof has
301; been reverted once due to difficult to isolate fallout.
302
303; TODO: Freeing a no-free pointer -> %foo must be null
304define void @test13(ptr nofree %foo) {
305; CHECK-LABEL: @test13(
306; CHECK-NEXT:    call void @free(ptr [[FOO:%.*]])
307; CHECK-NEXT:    ret void
308;
309  call void @free(ptr %foo)
310  ret void
311}
312
313; TODO: Freeing a no-free pointer -> %foo must be null
314define void @test14(ptr %foo) nofree {
315; CHECK-LABEL: @test14(
316; CHECK-NEXT:    call void @free(ptr [[FOO:%.*]])
317; CHECK-NEXT:    ret void
318;
319  call void @free(ptr %foo)
320  ret void
321}
322
323; TODO: free call marked no-free ->  %foo must be null
324define void @test15(ptr %foo) {
325; CHECK-LABEL: @test15(
326; CHECK-NEXT:    call void @free(ptr [[FOO:%.*]]) #[[ATTR8:[0-9]+]]
327; CHECK-NEXT:    ret void
328;
329  call void @free(ptr %foo) nofree
330  ret void
331}
332
333; TODO: freeing a nonnull nofree pointer -> full UB
334define void @test16(ptr nonnull nofree %foo) {
335; CHECK-LABEL: @test16(
336; CHECK-NEXT:    call void @free(ptr [[FOO:%.*]])
337; CHECK-NEXT:    ret void
338;
339  call void @free(ptr %foo)
340  ret void
341}
342