1/* Assembler macros for 64 bit S/390.
2 Copyright (C) 2001-2024 Free Software Foundation, Inc.
3 This file is part of the GNU C Library.
4
5 The GNU C Library is free software; you can redistribute it and/or
6 modify it under the terms of the GNU Lesser General Public
7 License as published by the Free Software Foundation; either
8 version 2.1 of the License, or (at your option) any later version.
9
10 The GNU C Library is distributed in the hope that it will be useful,
11 but WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Lesser General Public License for more details.
14
15 You should have received a copy of the GNU Lesser General Public
16 License along with the GNU C Library; if not, see
17 <https://www.gnu.org/licenses/>. */
18
19#include <sysdeps/generic/sysdep.h>
20
21#ifdef __ASSEMBLER__
22
23/* Syntactic details of assembler. */
24
25/* ELF uses byte-counts for .align, most others use log2 of count of bytes. */
26#define ALIGNARG(log2) 1<<log2
27#define ASM_SIZE_DIRECTIVE(name) .size name,.-name;
28
29
30/* Define an entry point visible from C. */
31#define ENTRY(name) \
32 .globl C_SYMBOL_NAME(name); \
33 .type C_SYMBOL_NAME(name),@function; \
34 .align ALIGNARG(4); \
35 C_LABEL(name) \
36 cfi_startproc; \
37 CALL_MCOUNT
38
39#undef END
40#define END(name) \
41 cfi_endproc; \
42 ASM_SIZE_DIRECTIVE(name) \
43
44/* If compiled for profiling, call `mcount' at the start of each function. */
45#ifdef PROF
46#ifdef PIC
47#define CALL_MCOUNT \
48 lgr 0,14 ; larl 1,0f ; brasl 14,_mcount@PLT ; lgr 14,0 ; \
49 .data ; .align 4 ; 0: .long 0 ; .text ;
50#else
51#define CALL_MCOUNT \
52 lgr 0,14 ; larl 1,0f ; brasl 14,_mcount ; lgr 14,0 ; \
53 .data ; .align 4 ; 0: .long 0 ; .text ;
54#endif
55#else
56#define CALL_MCOUNT /* Do nothing. */
57#endif
58
59/* Since C identifiers are not normally prefixed with an underscore
60 on this system, the asm identifier `syscall_error' intrudes on the
61 C name space. Make sure we use an innocuous name. */
62#define syscall_error __syscall_error
63#define mcount _mcount
64
65#undef PSEUDO
66#define PSEUDO(name, syscall_name, args) \
67lose: SYSCALL_PIC_SETUP \
68 jg JUMPTARGET(syscall_error); \
69 .globl syscall_error; \
70 ENTRY (name) \
71 DO_CALL (syscall_name, args); \
72 jm lose
73
74#undef PSEUDO_END
75#define PSEUDO_END(name) \
76 END (name)
77
78#undef JUMPTARGET
79#ifdef SHARED
80#define JUMPTARGET(name) name##@PLT
81#define SYSCALL_PIC_SETUP \
82 larl %r12,_GLOBAL_OFFSET_TABLE_
83#else
84#define JUMPTARGET(name) name
85#define SYSCALL_PIC_SETUP /* Nothing. */
86#endif
87
88/* Local label name for asm code. */
89#ifndef L
90#define L(name) .L##name
91#endif
92
93#endif /* __ASSEMBLER__ */
94

source code of glibc/sysdeps/s390/s390-64/sysdep.h