rtemself.h revision 50397
1/* Definitions for Intel 386 running Linux-based GNU systems with ELF format. 2 Copyright (C) 1994, 1995, 1996, 1997, 1998 Free Software Foundation, Inc. 3 Contributed by Eric Youngdale. 4 Modified for stabs-in-ELF by H.J. Lu. 5 6This file is part of GNU CC. 7 8GNU CC is free software; you can redistribute it and/or modify 9it under the terms of the GNU General Public License as published by 10the Free Software Foundation; either version 2, or (at your option) 11any later version. 12 13GNU CC is distributed in the hope that it will be useful, 14but WITHOUT ANY WARRANTY; without even the implied warranty of 15MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16GNU General Public License for more details. 17 18You should have received a copy of the GNU General Public License 19along with GNU CC; see the file COPYING. If not, write to 20the Free Software Foundation, 59 Temple Place - Suite 330, 21Boston, MA 02111-1307, USA. */ 22 23#define LINUX_DEFAULT_ELF 24 25/* A lie, I guess, but the general idea behind linux/ELF is that we are 26 supposed to be outputting something that will assemble under SVr4. 27 This gets us pretty close. */ 28#include <i386/i386.h> /* Base i386 target machine definitions */ 29#include <i386/att.h> /* Use the i386 AT&T assembler syntax */ 30#include <linux.h> /* some common stuff */ 31 32#undef TARGET_VERSION 33#define TARGET_VERSION fprintf (stderr, " (i386 RTEMS with ELF)"); 34 35/* The svr4 ABI for the i386 says that records and unions are returned 36 in memory. */ 37#undef DEFAULT_PCC_STRUCT_RETURN 38#define DEFAULT_PCC_STRUCT_RETURN 1 39 40/* This is how to output an element of a case-vector that is relative. 41 This is only used for PIC code. See comments by the `casesi' insn in 42 i386.md for an explanation of the expression this outputs. */ 43#undef ASM_OUTPUT_ADDR_DIFF_ELT 44#define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, BODY, VALUE, REL) \ 45 fprintf (FILE, "\t.long _GLOBAL_OFFSET_TABLE_+[.-%s%d]\n", LPREFIX, VALUE) 46 47/* Indicate that jump tables go in the text section. This is 48 necessary when compiling PIC code. */ 49#define JUMP_TABLES_IN_TEXT_SECTION (flag_pic) 50 51/* Copy this from the svr4 specifications... */ 52/* Define the register numbers to be used in Dwarf debugging information. 53 The SVR4 reference port C compiler uses the following register numbers 54 in its Dwarf output code: 55 0 for %eax (gnu regno = 0) 56 1 for %ecx (gnu regno = 2) 57 2 for %edx (gnu regno = 1) 58 3 for %ebx (gnu regno = 3) 59 4 for %esp (gnu regno = 7) 60 5 for %ebp (gnu regno = 6) 61 6 for %esi (gnu regno = 4) 62 7 for %edi (gnu regno = 5) 63 The following three DWARF register numbers are never generated by 64 the SVR4 C compiler or by the GNU compilers, but SDB on x86/svr4 65 believes these numbers have these meanings. 66 8 for %eip (no gnu equivalent) 67 9 for %eflags (no gnu equivalent) 68 10 for %trapno (no gnu equivalent) 69 It is not at all clear how we should number the FP stack registers 70 for the x86 architecture. If the version of SDB on x86/svr4 were 71 a bit less brain dead with respect to floating-point then we would 72 have a precedent to follow with respect to DWARF register numbers 73 for x86 FP registers, but the SDB on x86/svr4 is so completely 74 broken with respect to FP registers that it is hardly worth thinking 75 of it as something to strive for compatibility with. 76 The version of x86/svr4 SDB I have at the moment does (partially) 77 seem to believe that DWARF register number 11 is associated with 78 the x86 register %st(0), but that's about all. Higher DWARF 79 register numbers don't seem to be associated with anything in 80 particular, and even for DWARF regno 11, SDB only seems to under- 81 stand that it should say that a variable lives in %st(0) (when 82 asked via an `=' command) if we said it was in DWARF regno 11, 83 but SDB still prints garbage when asked for the value of the 84 variable in question (via a `/' command). 85 (Also note that the labels SDB prints for various FP stack regs 86 when doing an `x' command are all wrong.) 87 Note that these problems generally don't affect the native SVR4 88 C compiler because it doesn't allow the use of -O with -g and 89 because when it is *not* optimizing, it allocates a memory 90 location for each floating-point variable, and the memory 91 location is what gets described in the DWARF AT_location 92 attribute for the variable in question. 93 Regardless of the severe mental illness of the x86/svr4 SDB, we 94 do something sensible here and we use the following DWARF 95 register numbers. Note that these are all stack-top-relative 96 numbers. 97 11 for %st(0) (gnu regno = 8) 98 12 for %st(1) (gnu regno = 9) 99 13 for %st(2) (gnu regno = 10) 100 14 for %st(3) (gnu regno = 11) 101 15 for %st(4) (gnu regno = 12) 102 16 for %st(5) (gnu regno = 13) 103 17 for %st(6) (gnu regno = 14) 104 18 for %st(7) (gnu regno = 15) 105*/ 106#undef DBX_REGISTER_NUMBER 107#define DBX_REGISTER_NUMBER(n) \ 108((n) == 0 ? 0 \ 109 : (n) == 1 ? 2 \ 110 : (n) == 2 ? 1 \ 111 : (n) == 3 ? 3 \ 112 : (n) == 4 ? 6 \ 113 : (n) == 5 ? 7 \ 114 : (n) == 6 ? 5 \ 115 : (n) == 7 ? 4 \ 116 : ((n) >= FIRST_STACK_REG && (n) <= LAST_STACK_REG) ? (n)+3 \ 117 : (-1)) 118 119/* Output assembler code to FILE to increment profiler label # LABELNO 120 for profiling a function entry. */ 121 122#undef FUNCTION_PROFILER 123#define FUNCTION_PROFILER(FILE, LABELNO) \ 124{ \ 125 if (flag_pic) \ 126 { \ 127 fprintf (FILE, "\tleal %sP%d@GOTOFF(%%ebx),%%edx\n", \ 128 LPREFIX, (LABELNO)); \ 129 fprintf (FILE, "\tcall *mcount@GOT(%%ebx)\n"); \ 130 } \ 131 else \ 132 { \ 133 fprintf (FILE, "\tmovl $%sP%d,%%edx\n", LPREFIX, (LABELNO)); \ 134 fprintf (FILE, "\tcall mcount\n"); \ 135 } \ 136} 137 138#undef SIZE_TYPE 139#define SIZE_TYPE "unsigned int" 140 141#undef PTRDIFF_TYPE 142#define PTRDIFF_TYPE "int" 143 144#undef WCHAR_TYPE 145#define WCHAR_TYPE "long int" 146 147#undef WCHAR_TYPE_SIZE 148#define WCHAR_TYPE_SIZE BITS_PER_WORD 149 150#undef CPP_PREDEFINES 151#define CPP_PREDEFINES "-Di386 -Drtems -D__rtems__ \ 152 -Asystem(rtems) -Acpu(i386) -Amachine(i386)" 153 154/* Get perform_* macros to build libgcc.a. */ 155#include "i386/perform.h" 156 157/* A C statement (sans semicolon) to output to the stdio stream 158 FILE the assembler definition of uninitialized global DECL named 159 NAME whose size is SIZE bytes and alignment is ALIGN bytes. 160 Try to use asm_output_aligned_bss to implement this macro. */ 161 162#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \ 163 asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN) 164 165#undef STARTFILE_SPEC 166#define STARTFILE_SPEC "crt0.o%s" 167 168#undef ENDFILE_SPEC 169 170