xref: /llvm-project/llvm/test/Transforms/Inline/cgscc-invalidate.ll (revision 151602c7a9935558ca671b35359989b261045db0)
1; This test tries to ensure that the inliner successfully invalidates function
2; analyses after inlining into the function body.
3;
4; The strategy for these tests is to compute domtree over all the functions,
5; then run the inliner, and then verify the domtree. Then we can arrange the
6; inline to disturb the domtree (easy) and detect any stale cached entries in
7; the verifier. We do the initial computation both *inside* the CGSCC walk and
8; in a pre-step to make sure both work.
9;
10; RUN: opt < %s -passes='function(require<domtree>),cgscc(inline,function(verify<domtree>))' -S | FileCheck %s
11; RUN: opt < %s -passes='cgscc(function(require<domtree>),inline,function(verify<domtree>))' -S | FileCheck %s
12
13; An external function used to control branches.
14declare i1 @flag()
15; CHECK-LABEL: declare i1 @flag()
16
17; The utility function with interesting control flow that gets inlined below to
18; perturb the dominator tree.
19define internal void @callee() {
20; CHECK-LABEL: @callee
21entry:
22  %ptr = alloca i8
23  %flag = call i1 @flag()
24  br i1 %flag, label %then, label %else
25
26then:
27  store volatile i8 42, ptr %ptr
28  br label %return
29
30else:
31  store volatile i8 -42, ptr %ptr
32  br label %return
33
34return:
35  ret void
36}
37
38
39; The 'test1_' prefixed functions test the basic scenario of inlining
40; destroying dominator tree.
41
42define void @test1_caller() {
43; CHECK-LABEL: define void @test1_caller()
44entry:
45  call void @callee()
46; CHECK-NOT: @callee
47  ret void
48; CHECK: ret void
49}
50
51
52; The 'test2_' prefixed functions test the scenario of not inlining preserving
53; dominators.
54
55define void @test2_caller() {
56; CHECK-LABEL: define void @test2_caller()
57entry:
58  call void @callee() noinline
59; CHECK: call void @callee
60  ret void
61; CHECK: ret void
62}
63
64
65; The 'test3_' prefixed functions test the scenario of not inlining preserving
66; dominators after splitting an SCC into two smaller SCCs.
67
68; This function gets visited first and we end up inlining everything we
69; can into this routine. That splits test3_g into a separate SCC that is enqued
70; for later processing.
71define void @test3_f() {
72; CHECK-LABEL: define void @test3_f()
73entry:
74  ; Create the first edge in the SCC cycle.
75  call void @test3_g()
76; CHECK-NOT: @test3_g()
77; CHECK: call void @test3_f()
78
79  ; Pull interesting CFG into this function.
80  call void @callee()
81; CHECK-NOT: call void @callee()
82
83  ret void
84; CHECK: ret void
85}
86
87; This function ends up split into a separate SCC, which can cause its analyses
88; to become stale if the splitting doesn't properly invalidate things. Also, as
89; a consequence of being split out, test3_f is too large to inline by the time
90; we get here.
91define void @test3_g() {
92; CHECK-LABEL: define void @test3_g()
93entry:
94  ; Create the second edge in the SCC cycle.
95  call void @test3_f()
96; CHECK: call void @test3_f()
97
98  ; Pull interesting CFG into this function.
99  call void @callee()
100; CHECK-NOT: call void @callee()
101
102  ret void
103; CHECK: ret void
104}
105