rtemself.h revision 50397
150397Sobrien/* Definitions for Intel 386 running Linux-based GNU systems with ELF format. 250397Sobrien Copyright (C) 1994, 1995, 1996, 1997, 1998 Free Software Foundation, Inc. 350397Sobrien Contributed by Eric Youngdale. 450397Sobrien Modified for stabs-in-ELF by H.J. Lu. 550397Sobrien 650397SobrienThis file is part of GNU CC. 750397Sobrien 850397SobrienGNU CC is free software; you can redistribute it and/or modify 950397Sobrienit under the terms of the GNU General Public License as published by 1050397Sobrienthe Free Software Foundation; either version 2, or (at your option) 1150397Sobrienany later version. 1250397Sobrien 1350397SobrienGNU CC is distributed in the hope that it will be useful, 1450397Sobrienbut WITHOUT ANY WARRANTY; without even the implied warranty of 1550397SobrienMERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 1650397SobrienGNU General Public License for more details. 1750397Sobrien 1850397SobrienYou should have received a copy of the GNU General Public License 1950397Sobrienalong with GNU CC; see the file COPYING. If not, write to 2050397Sobrienthe Free Software Foundation, 59 Temple Place - Suite 330, 2150397SobrienBoston, MA 02111-1307, USA. */ 2250397Sobrien 2350397Sobrien#define LINUX_DEFAULT_ELF 2450397Sobrien 2550397Sobrien/* A lie, I guess, but the general idea behind linux/ELF is that we are 2650397Sobrien supposed to be outputting something that will assemble under SVr4. 2750397Sobrien This gets us pretty close. */ 2850397Sobrien#include <i386/i386.h> /* Base i386 target machine definitions */ 2950397Sobrien#include <i386/att.h> /* Use the i386 AT&T assembler syntax */ 3050397Sobrien#include <linux.h> /* some common stuff */ 3150397Sobrien 3250397Sobrien#undef TARGET_VERSION 3350397Sobrien#define TARGET_VERSION fprintf (stderr, " (i386 RTEMS with ELF)"); 3450397Sobrien 3550397Sobrien/* The svr4 ABI for the i386 says that records and unions are returned 3650397Sobrien in memory. */ 3750397Sobrien#undef DEFAULT_PCC_STRUCT_RETURN 3850397Sobrien#define DEFAULT_PCC_STRUCT_RETURN 1 3950397Sobrien 4050397Sobrien/* This is how to output an element of a case-vector that is relative. 4150397Sobrien This is only used for PIC code. See comments by the `casesi' insn in 4250397Sobrien i386.md for an explanation of the expression this outputs. */ 4350397Sobrien#undef ASM_OUTPUT_ADDR_DIFF_ELT 4450397Sobrien#define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, BODY, VALUE, REL) \ 4550397Sobrien fprintf (FILE, "\t.long _GLOBAL_OFFSET_TABLE_+[.-%s%d]\n", LPREFIX, VALUE) 4650397Sobrien 4750397Sobrien/* Indicate that jump tables go in the text section. This is 4850397Sobrien necessary when compiling PIC code. */ 4950397Sobrien#define JUMP_TABLES_IN_TEXT_SECTION (flag_pic) 5050397Sobrien 5150397Sobrien/* Copy this from the svr4 specifications... */ 5250397Sobrien/* Define the register numbers to be used in Dwarf debugging information. 5350397Sobrien The SVR4 reference port C compiler uses the following register numbers 5450397Sobrien in its Dwarf output code: 5550397Sobrien 0 for %eax (gnu regno = 0) 5650397Sobrien 1 for %ecx (gnu regno = 2) 5750397Sobrien 2 for %edx (gnu regno = 1) 5850397Sobrien 3 for %ebx (gnu regno = 3) 5950397Sobrien 4 for %esp (gnu regno = 7) 6050397Sobrien 5 for %ebp (gnu regno = 6) 6150397Sobrien 6 for %esi (gnu regno = 4) 6250397Sobrien 7 for %edi (gnu regno = 5) 6350397Sobrien The following three DWARF register numbers are never generated by 6450397Sobrien the SVR4 C compiler or by the GNU compilers, but SDB on x86/svr4 6550397Sobrien believes these numbers have these meanings. 6650397Sobrien 8 for %eip (no gnu equivalent) 6750397Sobrien 9 for %eflags (no gnu equivalent) 6850397Sobrien 10 for %trapno (no gnu equivalent) 6950397Sobrien It is not at all clear how we should number the FP stack registers 7050397Sobrien for the x86 architecture. If the version of SDB on x86/svr4 were 7150397Sobrien a bit less brain dead with respect to floating-point then we would 7250397Sobrien have a precedent to follow with respect to DWARF register numbers 7350397Sobrien for x86 FP registers, but the SDB on x86/svr4 is so completely 7450397Sobrien broken with respect to FP registers that it is hardly worth thinking 7550397Sobrien of it as something to strive for compatibility with. 7650397Sobrien The version of x86/svr4 SDB I have at the moment does (partially) 7750397Sobrien seem to believe that DWARF register number 11 is associated with 7850397Sobrien the x86 register %st(0), but that's about all. Higher DWARF 7950397Sobrien register numbers don't seem to be associated with anything in 8050397Sobrien particular, and even for DWARF regno 11, SDB only seems to under- 8150397Sobrien stand that it should say that a variable lives in %st(0) (when 8250397Sobrien asked via an `=' command) if we said it was in DWARF regno 11, 8350397Sobrien but SDB still prints garbage when asked for the value of the 8450397Sobrien variable in question (via a `/' command). 8550397Sobrien (Also note that the labels SDB prints for various FP stack regs 8650397Sobrien when doing an `x' command are all wrong.) 8750397Sobrien Note that these problems generally don't affect the native SVR4 8850397Sobrien C compiler because it doesn't allow the use of -O with -g and 8950397Sobrien because when it is *not* optimizing, it allocates a memory 9050397Sobrien location for each floating-point variable, and the memory 9150397Sobrien location is what gets described in the DWARF AT_location 9250397Sobrien attribute for the variable in question. 9350397Sobrien Regardless of the severe mental illness of the x86/svr4 SDB, we 9450397Sobrien do something sensible here and we use the following DWARF 9550397Sobrien register numbers. Note that these are all stack-top-relative 9650397Sobrien numbers. 9750397Sobrien 11 for %st(0) (gnu regno = 8) 9850397Sobrien 12 for %st(1) (gnu regno = 9) 9950397Sobrien 13 for %st(2) (gnu regno = 10) 10050397Sobrien 14 for %st(3) (gnu regno = 11) 10150397Sobrien 15 for %st(4) (gnu regno = 12) 10250397Sobrien 16 for %st(5) (gnu regno = 13) 10350397Sobrien 17 for %st(6) (gnu regno = 14) 10450397Sobrien 18 for %st(7) (gnu regno = 15) 10550397Sobrien*/ 10650397Sobrien#undef DBX_REGISTER_NUMBER 10750397Sobrien#define DBX_REGISTER_NUMBER(n) \ 10850397Sobrien((n) == 0 ? 0 \ 10950397Sobrien : (n) == 1 ? 2 \ 11050397Sobrien : (n) == 2 ? 1 \ 11150397Sobrien : (n) == 3 ? 3 \ 11250397Sobrien : (n) == 4 ? 6 \ 11350397Sobrien : (n) == 5 ? 7 \ 11450397Sobrien : (n) == 6 ? 5 \ 11550397Sobrien : (n) == 7 ? 4 \ 11650397Sobrien : ((n) >= FIRST_STACK_REG && (n) <= LAST_STACK_REG) ? (n)+3 \ 11750397Sobrien : (-1)) 11850397Sobrien 11950397Sobrien/* Output assembler code to FILE to increment profiler label # LABELNO 12050397Sobrien for profiling a function entry. */ 12150397Sobrien 12250397Sobrien#undef FUNCTION_PROFILER 12350397Sobrien#define FUNCTION_PROFILER(FILE, LABELNO) \ 12450397Sobrien{ \ 12550397Sobrien if (flag_pic) \ 12650397Sobrien { \ 12750397Sobrien fprintf (FILE, "\tleal %sP%d@GOTOFF(%%ebx),%%edx\n", \ 12850397Sobrien LPREFIX, (LABELNO)); \ 12950397Sobrien fprintf (FILE, "\tcall *mcount@GOT(%%ebx)\n"); \ 13050397Sobrien } \ 13150397Sobrien else \ 13250397Sobrien { \ 13350397Sobrien fprintf (FILE, "\tmovl $%sP%d,%%edx\n", LPREFIX, (LABELNO)); \ 13450397Sobrien fprintf (FILE, "\tcall mcount\n"); \ 13550397Sobrien } \ 13650397Sobrien} 13750397Sobrien 13850397Sobrien#undef SIZE_TYPE 13950397Sobrien#define SIZE_TYPE "unsigned int" 14050397Sobrien 14150397Sobrien#undef PTRDIFF_TYPE 14250397Sobrien#define PTRDIFF_TYPE "int" 14350397Sobrien 14450397Sobrien#undef WCHAR_TYPE 14550397Sobrien#define WCHAR_TYPE "long int" 14650397Sobrien 14750397Sobrien#undef WCHAR_TYPE_SIZE 14850397Sobrien#define WCHAR_TYPE_SIZE BITS_PER_WORD 14950397Sobrien 15050397Sobrien#undef CPP_PREDEFINES 15150397Sobrien#define CPP_PREDEFINES "-Di386 -Drtems -D__rtems__ \ 15250397Sobrien -Asystem(rtems) -Acpu(i386) -Amachine(i386)" 15350397Sobrien 15450397Sobrien/* Get perform_* macros to build libgcc.a. */ 15550397Sobrien#include "i386/perform.h" 15650397Sobrien 15750397Sobrien/* A C statement (sans semicolon) to output to the stdio stream 15850397Sobrien FILE the assembler definition of uninitialized global DECL named 15950397Sobrien NAME whose size is SIZE bytes and alignment is ALIGN bytes. 16050397Sobrien Try to use asm_output_aligned_bss to implement this macro. */ 16150397Sobrien 16250397Sobrien#define ASM_OUTPUT_ALIGNED_BSS(FILE, DECL, NAME, SIZE, ALIGN) \ 16350397Sobrien asm_output_aligned_bss (FILE, DECL, NAME, SIZE, ALIGN) 16450397Sobrien 16550397Sobrien#undef STARTFILE_SPEC 16650397Sobrien#define STARTFILE_SPEC "crt0.o%s" 16750397Sobrien 16850397Sobrien#undef ENDFILE_SPEC 16950397Sobrien 170