xref: /llvm-project/llvm/test/CodeGen/SystemZ/frame-01.ll (revision a1710eb3cd5823c5d14899112ca3086acbdbe9cb)
1; Test the allocation of frames in cases where we do not need to save
2; registers in the prologue.
3;
4; RUN: llc < %s -mtriple=s390x-linux-gnu | FileCheck %s
5
6declare void @foo(ptr)
7
8; The CFA offset is 160 (the caller-allocated part of the frame) + 168.
9define void @f1(i64 %x) {
10; CHECK-LABEL: f1:
11; CHECK: aghi %r15, -168
12; CHECK: .cfi_def_cfa_offset 328
13; CHECK: stg %r2, 160(%r15)
14; CHECK: aghi %r15, 168
15; CHECK: br %r14
16  %y = alloca i64, align 8
17  store volatile i64 %x, ptr %y
18  ret void
19}
20
21; Check frames of size 32760, which is the largest size that can be both
22; allocated and freed using AGHI.  This size is big enough to require
23; two emergency spill slots at 160(%r15), for instructions with unsigned
24; 12-bit offsets that end up being out of range.  Fill the remaining
25; 32760 - 176 bytes by allocating (32760 - 176) / 8 = 4073 doublewords.
26define void @f2(i64 %x) {
27; CHECK-LABEL: f2:
28; CHECK: aghi %r15, -32760
29; CHECK: .cfi_def_cfa_offset 32920
30; CHECK: stg %r2, 176(%r15)
31; CHECK: aghi %r15, 32760
32; CHECK: br %r14
33  %y = alloca [4073 x i64], align 8
34  store volatile i64 %x, ptr %y
35  ret void
36}
37
38; Allocate one more doubleword.  This is the one frame size that we can
39; allocate using AGHI but must free using AGFI.
40define void @f3(i64 %x) {
41; CHECK-LABEL: f3:
42; CHECK: aghi %r15, -32768
43; CHECK: .cfi_def_cfa_offset 32928
44; CHECK: stg %r2, 176(%r15)
45; CHECK: agfi %r15, 32768
46; CHECK: br %r14
47  %y = alloca [4074 x i64], align 8
48  store volatile i64 %x, ptr %y
49  ret void
50}
51
52; Allocate another doubleword on top of that.  The allocation and free
53; must both use AGFI.
54define void @f4(i64 %x) {
55; CHECK-LABEL: f4:
56; CHECK: agfi %r15, -32776
57; CHECK: .cfi_def_cfa_offset 32936
58; CHECK: stg %r2, 176(%r15)
59; CHECK: agfi %r15, 32776
60; CHECK: br %r14
61  %y = alloca [4075 x i64], align 8
62  store volatile i64 %x, ptr %y
63  ret void
64}
65
66; The largest size that can be both allocated and freed using AGFI.
67; At this point the frame is too big to represent properly in the CFI.
68define void @f5(i64 %x) {
69; CHECK-LABEL: f5:
70; CHECK: agfi %r15, -2147483640
71; CHECK: stg %r2, 176(%r15)
72; CHECK: agfi %r15, 2147483640
73; CHECK: br %r14
74  %y = alloca [268435433 x i64], align 8
75  store volatile i64 %x, ptr %y
76  ret void
77}
78
79; The only frame size that can be allocated using a single AGFI but which
80; must be freed using two instructions.
81define void @f6(i64 %x) {
82; CHECK-LABEL: f6:
83; CHECK: agfi %r15, -2147483648
84; CHECK: stg %r2, 176(%r15)
85; CHECK: agfi %r15, 2147483640
86; CHECK: aghi %r15, 8
87; CHECK: br %r14
88  %y = alloca [268435434 x i64], align 8
89  store volatile i64 %x, ptr %y
90  ret void
91}
92
93; The smallest frame size that needs two instructions to both allocate
94; and free the frame.
95define void @f7(i64 %x) {
96; CHECK-LABEL: f7:
97; CHECK: agfi %r15, -2147483648
98; CHECK: aghi %r15, -8
99; CHECK: stg %r2, 176(%r15)
100; CHECK: agfi %r15, 2147483640
101; CHECK: aghi %r15, 16
102; CHECK: br %r14
103  %y = alloca [268435435 x i64], align 8
104  store volatile i64 %x, ptr %y
105  ret void
106}
107
108; Make sure that LA can be rematerialized.
109define void @f8() {
110; CHECK-LABEL: f8:
111; CHECK: la %r2, 164(%r15)
112; CHECK: brasl %r14, foo@PLT
113; CHECK: la %r2, 164(%r15)
114; CHECK: brasl %r14, foo@PLT
115; CHECK: br %r14
116  %ptr = alloca i32
117  call void @foo(ptr %ptr)
118  call void @foo(ptr %ptr)
119  ret void
120}
121