freebsd-dev/contrib/gcc/config/i386/linux.h
Peter Wemm a4cd5630b0 Import of unmodified (but trimmed) gcc-2.7.2. The bigger parts of the
non-i386, non-unix, and generatable files have been trimmed, but can easily
be added in later if needed.

gcc-2.7.2.1 will follow shortly, it's a very small delta to this and it's
handy to have both available for reference for such little cost.

The freebsd-specific changes will then be committed, and once the dust has
settled, the bmakefiles will be committed to use this code.
1996-09-18 05:35:50 +00:00

213 lines
7.8 KiB
C

/* Definitions for Intel 386 running Linux with ELF format
Copyright (C) 1994, 1995 Free Software Foundation, Inc.
Contributed by Eric Youngdale.
Modified for stabs-in-ELF by H.J. Lu.
This file is part of GNU CC.
GNU CC is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.
GNU CC is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with GNU CC; see the file COPYING. If not, write to
the Free Software Foundation, 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA. */
#define LINUX_DEFAULT_ELF
/* A lie, I guess, but the general idea behind linux/ELF is that we are
supposed to be outputting something that will assemble under SVr4.
This gets us pretty close. */
#include <i386/i386.h> /* Base i386 target machine definitions */
#include <i386/att.h> /* Use the i386 AT&T assembler syntax */
#include <linux.h> /* some common stuff */
#undef TARGET_VERSION
#define TARGET_VERSION fprintf (stderr, " (i386 Linux/ELF)");
/* The svr4 ABI for the i386 says that records and unions are returned
in memory. */
#undef DEFAULT_PCC_STRUCT_RETURN
#define DEFAULT_PCC_STRUCT_RETURN 1
/* This is how to output an element of a case-vector that is relative.
This is only used for PIC code. See comments by the `casesi' insn in
i386.md for an explanation of the expression this outputs. */
#undef ASM_OUTPUT_ADDR_DIFF_ELT
#define ASM_OUTPUT_ADDR_DIFF_ELT(FILE, VALUE, REL) \
fprintf (FILE, "\t.long _GLOBAL_OFFSET_TABLE_+[.-%s%d]\n", LPREFIX, VALUE)
/* Indicate that jump tables go in the text section. This is
necessary when compiling PIC code. */
#define JUMP_TABLES_IN_TEXT_SECTION
/* Copy this from the svr4 specifications... */
/* Define the register numbers to be used in Dwarf debugging information.
The SVR4 reference port C compiler uses the following register numbers
in its Dwarf output code:
0 for %eax (gnu regno = 0)
1 for %ecx (gnu regno = 2)
2 for %edx (gnu regno = 1)
3 for %ebx (gnu regno = 3)
4 for %esp (gnu regno = 7)
5 for %ebp (gnu regno = 6)
6 for %esi (gnu regno = 4)
7 for %edi (gnu regno = 5)
The following three DWARF register numbers are never generated by
the SVR4 C compiler or by the GNU compilers, but SDB on x86/svr4
believes these numbers have these meanings.
8 for %eip (no gnu equivalent)
9 for %eflags (no gnu equivalent)
10 for %trapno (no gnu equivalent)
It is not at all clear how we should number the FP stack registers
for the x86 architecture. If the version of SDB on x86/svr4 were
a bit less brain dead with respect to floating-point then we would
have a precedent to follow with respect to DWARF register numbers
for x86 FP registers, but the SDB on x86/svr4 is so completely
broken with respect to FP registers that it is hardly worth thinking
of it as something to strive for compatibility with.
The version of x86/svr4 SDB I have at the moment does (partially)
seem to believe that DWARF register number 11 is associated with
the x86 register %st(0), but that's about all. Higher DWARF
register numbers don't seem to be associated with anything in
particular, and even for DWARF regno 11, SDB only seems to under-
stand that it should say that a variable lives in %st(0) (when
asked via an `=' command) if we said it was in DWARF regno 11,
but SDB still prints garbage when asked for the value of the
variable in question (via a `/' command).
(Also note that the labels SDB prints for various FP stack regs
when doing an `x' command are all wrong.)
Note that these problems generally don't affect the native SVR4
C compiler because it doesn't allow the use of -O with -g and
because when it is *not* optimizing, it allocates a memory
location for each floating-point variable, and the memory
location is what gets described in the DWARF AT_location
attribute for the variable in question.
Regardless of the severe mental illness of the x86/svr4 SDB, we
do something sensible here and we use the following DWARF
register numbers. Note that these are all stack-top-relative
numbers.
11 for %st(0) (gnu regno = 8)
12 for %st(1) (gnu regno = 9)
13 for %st(2) (gnu regno = 10)
14 for %st(3) (gnu regno = 11)
15 for %st(4) (gnu regno = 12)
16 for %st(5) (gnu regno = 13)
17 for %st(6) (gnu regno = 14)
18 for %st(7) (gnu regno = 15)
*/
#undef DBX_REGISTER_NUMBER
#define DBX_REGISTER_NUMBER(n) \
((n) == 0 ? 0 \
: (n) == 1 ? 2 \
: (n) == 2 ? 1 \
: (n) == 3 ? 3 \
: (n) == 4 ? 6 \
: (n) == 5 ? 7 \
: (n) == 6 ? 5 \
: (n) == 7 ? 4 \
: ((n) >= FIRST_STACK_REG && (n) <= LAST_STACK_REG) ? (n)+3 \
: (-1))
/* Output assembler code to FILE to increment profiler label # LABELNO
for profiling a function entry. */
#undef FUNCTION_PROFILER
#define FUNCTION_PROFILER(FILE, LABELNO) \
{ \
if (flag_pic) \
{ \
fprintf (FILE, "\tleal %sP%d@GOTOFF(%%ebx),%%edx\n", \
LPREFIX, (LABELNO)); \
fprintf (FILE, "\tcall *mcount@GOT(%%ebx)\n"); \
} \
else \
{ \
fprintf (FILE, "\tmovl $%sP%d,%%edx\n", LPREFIX, (LABELNO)); \
fprintf (FILE, "\tcall mcount\n"); \
} \
}
#undef SIZE_TYPE
#define SIZE_TYPE "unsigned int"
#undef PTRDIFF_TYPE
#define PTRDIFF_TYPE "int"
#undef WCHAR_TYPE
#define WCHAR_TYPE "long int"
#undef WCHAR_TYPE_SIZE
#define WCHAR_TYPE_SIZE BITS_PER_WORD
#undef CPP_PREDEFINES
#define CPP_PREDEFINES "-D__ELF__ -Dunix -Di386 -Dlinux -Asystem(unix) -Asystem(posix) -Acpu(i386) -Amachine(i386)"
#undef CPP_SPEC
#if TARGET_CPU_DEFAULT == 2
#define CPP_SPEC "%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{!m386:-D__i486__} %{posix:-D_POSIX_SOURCE}"
#else
#define CPP_SPEC "%{fPIC:-D__PIC__ -D__pic__} %{fpic:-D__PIC__ -D__pic__} %{m486:-D__i486__} %{posix:-D_POSIX_SOURCE}"
#endif
#undef LIB_SPEC
#if 1
/* We no longer link with libc_p.a or libg.a by default. If you
* want to profile or debug the Linux C library, please add
* -lc_p or -ggdb to LDFLAGS at the link time, respectively.
*/
#define LIB_SPEC \
"%{!shared: %{mieee-fp:-lieee} %{p:-lgmon} %{pg:-lgmon} \
%{!ggdb:-lc} %{ggdb:-lg}}"
#else
#define LIB_SPEC \
"%{!shared: \
%{mieee-fp:-lieee} %{p:-lgmon -lc_p} %{pg:-lgmon -lc_p} \
%{!p:%{!pg:%{!g*:-lc} %{g*:-lg}}}}"
#endif
/* Provide a LINK_SPEC appropriate for Linux. Here we provide support
for the special GCC options -static and -shared, which allow us to
link things in one of these three modes by applying the appropriate
combinations of options at link-time. We like to support here for
as many of the other GNU linker options as possible. But I don't
have the time to search for those flags. I am sure how to add
support for -soname shared_object_name. H.J.
I took out %{v:%{!V:-V}}. It is too much :-(. They can use
-Wl,-V.
When the -shared link option is used a final link is not being
done. */
/* If ELF is the default format, we should not use /lib/elf. */
#undef LINK_SPEC
#ifndef LINUX_DEFAULT_ELF
#define LINK_SPEC "-m elf_i386 %{shared:-shared} \
%{!shared: \
%{!ibcs: \
%{!static: \
%{rdynamic:-export-dynamic} \
%{!dynamic-linker:-dynamic-linker /lib/elf/ld-linux.so.1} \
%{!rpath:-rpath /lib/elf/}} %{static:-static}}}"
#else
#define LINK_SPEC "-m elf_i386 %{shared:-shared} \
%{!shared: \
%{!ibcs: \
%{!static: \
%{rdynamic:-export-dynamic} \
%{!dynamic-linker:-dynamic-linker /lib/ld-linux.so.1}} \
%{static:-static}}}"
#endif
/* Get perform_* macros to build libgcc.a. */
#include "i386/perform.h"