1 /* Assembler macros for s390.
2    Copyright (C) 2000-2021 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   lr 0,14 ; bras 14,.+12 ; .long _GLOBAL_OFFSET_TABLE_ - . ; .long 0f-. ; \
49   lr 1,14 ; al 1,4(14) ; al 14,0(14) ; l 14,_mcount@GOT(14) ; \
50   basr 14,14 ; lr 14,0 ; .data ; .align 4 ; 0: .long 0 ; .text ;
51 #else
52 #define CALL_MCOUNT \
53   lr 0,14 ; bras 14,.+12 ; .long _mcount ; .long 0f ; \
54   l 1,4(14) ; l 14,0(14) ; basr 14,14 ; lr 14,0 ; \
55   .data ; .align 4 ; 0: .long 0 ; .text ;
56 #endif
57 #else
58 #define CALL_MCOUNT		/* Do nothing.  */
59 #endif
60 
61 /* Since C identifiers are not normally prefixed with an underscore
62    on this system, the asm identifier `syscall_error' intrudes on the
63    C name space.  Make sure we use an innocuous name.  */
64 #define	syscall_error	__syscall_error
65 #define mcount		_mcount
66 
67 #undef PSEUDO
68 #define	PSEUDO(name, syscall_name, args) \
69 lose: SYSCALL_PIC_SETUP				\
70     basr %r1,0;					\
71 0:  al %r1,1f-0b(%r1);				\
72     br %r1;					\
73 1:  .long JUMPTARGET(syscall_error) - 0b;	\
74     .globl syscall_error;			\
75     ENTRY (name)				\
76     DO_CALL (syscall_name, args);		\
77     jm lose
78 
79 #undef	PSEUDO_END
80 #define	PSEUDO_END(name)						      \
81   END (name)
82 
83 #undef JUMPTARGET
84 #ifdef SHARED
85 #define JUMPTARGET(name)	name##@PLT
86 #define SYSCALL_PIC_SETUP             \
87     bras  %r12,1f;		      \
88 0:  .long _GLOBAL_OFFSET_TABLE_-0b;   \
89 1:  al    %r12,0(%r12)
90 #else
91 #define JUMPTARGET(name)	name
92 #define SYSCALL_PIC_SETUP	/* Nothing.  */
93 #endif
94 
95 /* Local label name for asm code. */
96 #ifndef L
97 #define L(name)		.L##name
98 #endif
99 
100 #endif	/* __ASSEMBLER__ */
101