1 /* Assembler macros for i386. 2 Copyright (C) 1991, 92, 93, 95, 96, 98 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, write to the Free 17 Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 18 02111-1307 USA. */ 19 20 #include_next <sysdep.h> 21 22 #ifdef __ASSEMBLER__ 23 24 /* Syntactic details of assembler. */ 25 26 #ifdef HAVE_ELF 27 28 /* ELF uses byte-counts for .align, most others use log2 of count of bytes. */ 29 #define ALIGNARG(log2) 1<<log2 30 /* For ELF we need the `.type' directive to make shared libs work right. */ 31 #define ASM_TYPE_DIRECTIVE(name,typearg) .type name,typearg; 32 #define ASM_SIZE_DIRECTIVE(name) .size name,.-name; 33 34 /* In ELF C symbols are asm symbols. */ 35 #undef NO_UNDERSCORES 36 #define NO_UNDERSCORES 37 38 #else 39 40 #define ALIGNARG(log2) log2 41 #define ASM_TYPE_DIRECTIVE(name,type) /* Nothing is specified. */ 42 #define ASM_SIZE_DIRECTIVE(name) /* Nothing is specified. */ 43 44 #endif 45 46 47 /* Define an entry point visible from C. 48 49 There is currently a bug in gdb which prevents us from specifying 50 incomplete stabs information. Fake some entries here which specify 51 the current source file. */ 52 #define ENTRY(name) \ 53 STABS_CURRENT_FILE1("") \ 54 STABS_CURRENT_FILE(name) \ 55 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \ 56 ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function) \ 57 .align ALIGNARG(4); \ 58 STABS_FUN(name) \ 59 C_LABEL(name) \ 60 CALL_MCOUNT 61 62 #undef END 63 #define END(name) \ 64 ASM_SIZE_DIRECTIVE(name) \ 65 STABS_FUN_END(name) 66 67 /* Remove the following two lines once the gdb bug is fixed. */ 68 #define STABS_CURRENT_FILE(name) \ 69 STABS_CURRENT_FILE1 (#name) 70 #define STABS_CURRENT_FILE1(name) \ 71 1: .stabs name,100,0,0,1b; 72 /* Emit stabs definition lines. We use F(0,1) and define t(0,1) as `int', 73 the same way gcc does it. */ 74 #define STABS_FUN(name) STABS_FUN2(name, name##:F(0,1)) 75 #define STABS_FUN2(name, namestr) \ 76 .stabs "int:t(0,1)=r(0,1);-2147483648;2147483647;",128,0,0,0; \ 77 .stabs #namestr,36,0,0,name; 78 #define STABS_FUN_END(name) \ 79 1: .stabs "",36,0,0,1b-name; 80 81 /* If compiled for profiling, call `mcount' at the start of each function. */ 82 #ifdef PROF 83 /* The mcount code relies on a normal frame pointer being on the stack 84 to locate our caller, so push one just for its benefit. */ 85 #define CALL_MCOUNT \ 86 pushl %ebp; movl %esp, %ebp; call JUMPTARGET(mcount); popl %ebp; 87 #else 88 #define CALL_MCOUNT /* Do nothing. */ 89 #endif 90 91 #ifdef NO_UNDERSCORES 92 /* Since C identifiers are not normally prefixed with an underscore 93 on this system, the asm identifier `syscall_error' intrudes on the 94 C name space. Make sure we use an innocuous name. */ 95 #define syscall_error __syscall_error 96 #define mcount _mcount 97 #endif 98 99 #define PSEUDO(name, syscall_name, args) \ 100 lose: SYSCALL_PIC_SETUP \ 101 jmp JUMPTARGET(syscall_error) \ 102 .globl syscall_error; \ 103 ENTRY (name) \ 104 DO_CALL (syscall_name, args); \ 105 jb lose 106 107 #undef PSEUDO_END 108 #define PSEUDO_END(name) \ 109 END (name) 110 111 #ifdef PIC 112 #define JUMPTARGET(name) name##@PLT 113 #define SYSCALL_PIC_SETUP \ 114 pushl %ebx; \ 115 call 0f; \ 116 0: popl %ebx; \ 117 addl $_GLOBAL_OFFSET_TABLE+[.-0b], %ebx; 118 #else 119 #define JUMPTARGET(name) name 120 #define SYSCALL_PIC_SETUP /* Nothing. */ 121 #endif 122 123 /* Local label name for asm code. */ 124 #ifndef L 125 #define L(name) name 126 #endif 127 128 #endif /* __ASSEMBLER__ */ 129