xref: /freebsd/contrib/llvm-project/compiler-rt/lib/builtins/riscv/restore.S (revision 994297b01b98816bea1abf45ae4bac1bc69ee7a0)
1//===-- restore.S - restore up to 12 callee-save registers ----------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8//
9// Multiple entry points depending on number of registers to restore
10//
11//===----------------------------------------------------------------------===//
12
13// All of the entry points are in the same section since we rely on many of
14// them falling through into each other and don't want the linker to
15// accidentally split them up, garbage collect, or reorder them.
16//
17// The entry points are grouped up into 2s for rv64 and 4s for rv32 since this
18// is the minimum grouping which will maintain the required 16-byte stack
19// alignment.
20
21  .text
22
23#if __riscv_xlen == 32
24
25  .globl  __riscv_restore_12
26  .type   __riscv_restore_12,@function
27__riscv_restore_12:
28  lw      s11, 12(sp)
29  addi    sp, sp, 16
30  // fallthrough into __riscv_restore_11/10/9/8
31
32  .globl  __riscv_restore_11
33  .type   __riscv_restore_11,@function
34  .globl  __riscv_restore_10
35  .type   __riscv_restore_10,@function
36  .globl  __riscv_restore_9
37  .type   __riscv_restore_9,@function
38  .globl  __riscv_restore_8
39  .type   __riscv_restore_8,@function
40__riscv_restore_11:
41__riscv_restore_10:
42__riscv_restore_9:
43__riscv_restore_8:
44  lw      s10, 0(sp)
45  lw      s9,  4(sp)
46  lw      s8,  8(sp)
47  lw      s7,  12(sp)
48  addi    sp, sp, 16
49  // fallthrough into __riscv_restore_7/6/5/4
50
51  .globl  __riscv_restore_7
52  .type   __riscv_restore_7,@function
53  .globl  __riscv_restore_6
54  .type   __riscv_restore_6,@function
55  .globl  __riscv_restore_5
56  .type   __riscv_restore_5,@function
57  .globl  __riscv_restore_4
58  .type   __riscv_restore_4,@function
59__riscv_restore_7:
60__riscv_restore_6:
61__riscv_restore_5:
62__riscv_restore_4:
63  lw      s6,  0(sp)
64  lw      s5,  4(sp)
65  lw      s4,  8(sp)
66  lw      s3,  12(sp)
67  addi    sp, sp, 16
68  // fallthrough into __riscv_restore_3/2/1/0
69
70  .globl  __riscv_restore_3
71  .type   __riscv_restore_3,@function
72  .globl  __riscv_restore_2
73  .type   __riscv_restore_2,@function
74  .globl  __riscv_restore_1
75  .type   __riscv_restore_1,@function
76  .globl  __riscv_restore_0
77  .type   __riscv_restore_0,@function
78__riscv_restore_3:
79__riscv_restore_2:
80__riscv_restore_1:
81__riscv_restore_0:
82  lw      s2,  0(sp)
83  lw      s1,  4(sp)
84  lw      s0,  8(sp)
85  lw      ra,  12(sp)
86  addi    sp, sp, 16
87  ret
88
89#elif __riscv_xlen == 64
90
91  .globl  __riscv_restore_12
92  .type   __riscv_restore_12,@function
93__riscv_restore_12:
94  ld      s11, 8(sp)
95  addi    sp, sp, 16
96  // fallthrough into __riscv_restore_11/10/9/8
97
98  .globl  __riscv_restore_11
99  .type   __riscv_restore_11,@function
100  .globl  __riscv_restore_10
101  .type   __riscv_restore_10,@function
102__riscv_restore_11:
103__riscv_restore_10:
104  ld      s10, 0(sp)
105  ld      s9,  8(sp)
106  addi    sp, sp, 16
107  // fallthrough into __riscv_restore_9/8
108
109  .globl  __riscv_restore_9
110  .type   __riscv_restore_9,@function
111  .globl  __riscv_restore_8
112  .type   __riscv_restore_8,@function
113__riscv_restore_9:
114__riscv_restore_8:
115  ld      s8,  0(sp)
116  ld      s7,  8(sp)
117  addi    sp, sp, 16
118  // fallthrough into __riscv_restore_7/6
119
120  .globl  __riscv_restore_7
121  .type   __riscv_restore_7,@function
122  .globl  __riscv_restore_6
123  .type   __riscv_restore_6,@function
124__riscv_restore_7:
125__riscv_restore_6:
126  ld      s6,  0(sp)
127  ld      s5,  8(sp)
128  addi    sp, sp, 16
129  // fallthrough into __riscv_restore_5/4
130
131  .globl  __riscv_restore_5
132  .type   __riscv_restore_5,@function
133  .globl  __riscv_restore_4
134  .type   __riscv_restore_4,@function
135__riscv_restore_5:
136__riscv_restore_4:
137  ld      s4,  0(sp)
138  ld      s3,  8(sp)
139  addi    sp, sp, 16
140  // fallthrough into __riscv_restore_3/2
141
142  .globl  __riscv_restore_3
143  .type   __riscv_restore_3,@function
144  .globl  __riscv_restore_2
145  .type   __riscv_restore_2,@function
146  .globl  __riscv_restore_1
147  .type   __riscv_restore_1,@function
148  .globl  __riscv_restore_0
149  .type   __riscv_restore_0,@function
150__riscv_restore_3:
151__riscv_restore_2:
152  ld      s2,  0(sp)
153  ld      s1,  8(sp)
154  addi    sp, sp, 16
155  // fallthrough into __riscv_restore_1/0
156
157__riscv_restore_1:
158__riscv_restore_0:
159  ld      s0,  0(sp)
160  ld      ra,  8(sp)
161  addi    sp, sp, 16
162  ret
163
164#else
165# error "xlen must be 32 or 64 for save-restore implementation
166#endif
167