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176 lines
5.9 KiB
C
176 lines
5.9 KiB
C
/* Definitions of target machine for GNU compiler, NetBSD/arm ELF version.
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Copyright (C) 2002-2013 Free Software Foundation, Inc.
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Contributed by Wasabi Systems, Inc.
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This file is part of GCC.
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GCC is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published
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by the Free Software Foundation; either version 3, or (at your
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option) any later version.
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GCC is distributed in the hope that it will be useful, but WITHOUT
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ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public
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License for more details.
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You should have received a copy of the GNU General Public License
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along with GCC; see the file COPYING3. If not see
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<http://www.gnu.org/licenses/>. */
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/* Run-time Target Specification. */
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/* arm.h defaults to ARM6 CPU. */
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/* Default EABI to armv5t so that thumb shared libraries work.
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The ARM926EH-S core is the default for armv5te, so set
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SUBTARGET_CPU_DEFAULT to achieve this. */
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#define SUBTARGET_CPU_DEFAULT \
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(ARM_DEFAULT_ABI != ARM_ABI_APCS && ARM_DEFAULT_ABI != ARM_ABI_ATPCS \
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? TARGET_CPU_arm926ejs : TARGET_CPU_arm6)
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/* TARGET_BIG_ENDIAN_DEFAULT is set in
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config.gcc for big endian configurations. */
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#if TARGET_BIG_ENDIAN_DEFAULT
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#define TARGET_ENDIAN_DEFAULT MASK_BIG_END
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#else
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#define TARGET_ENDIAN_DEFAULT 0
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#endif
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#undef MULTILIB_DEFAULTS
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/* Default it to use ATPCS with soft-VFP. */
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#undef TARGET_DEFAULT
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#define TARGET_DEFAULT \
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(MASK_APCS_FRAME \
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| TARGET_ENDIAN_DEFAULT)
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#undef ARM_DEFAULT_ABI
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#define ARM_DEFAULT_ABI ARM_ABI_ATPCS
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#undef TARGET_OS_CPP_BUILTINS
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#define TARGET_OS_CPP_BUILTINS() \
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do \
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{ \
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NETBSD_OS_CPP_BUILTINS_ELF(); \
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} \
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while (0)
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#undef SUBTARGET_CPP_SPEC
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#define SUBTARGET_CPP_SPEC NETBSD_CPP_SPEC
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#undef SUBTARGET_EXTRA_ASM_SPEC
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#define SUBTARGET_EXTRA_ASM_SPEC \
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"-matpcs %{mabi=aapcs*:-meabi=5} %{fpic|fpie:-k} %{fPIC|fPIE:-k}"
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/* Default to full VFP if -mfloat-abi=hard is specified. */
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#undef SUBTARGET_ASM_FLOAT_SPEC
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#define SUBTARGET_ASM_FLOAT_SPEC \
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"%{mhard-float:%{!mfpu=*:-mfpu=vfp}} \
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%{mfloat-abi=hard:%{!mfpu=*:-mfpu=vfp}}"
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#undef SUBTARGET_EXTRA_SPECS
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#define SUBTARGET_EXTRA_SPECS \
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{ "subtarget_extra_asm_spec", SUBTARGET_EXTRA_ASM_SPEC }, \
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{ "subtarget_asm_float_spec", SUBTARGET_ASM_FLOAT_SPEC }, \
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{ "netbsd_link_spec", NETBSD_LINK_SPEC_ELF }, \
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{ "netbsd_entry_point", NETBSD_ENTRY_POINT },
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#define NETBSD_ENTRY_POINT "__start"
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#undef LINK_SPEC
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#define LINK_SPEC \
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"-X \
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%{mbig-endian:-EB %{-mabi=aapcs*:-m armelfb_nbsd_eabi}} \
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%{mlittle-endian:-EL %{-mabi=aapcs*:-m armelf_nbsd_eabi}} \
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%(netbsd_link_spec)"
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/* Make GCC agree with <machine/ansi.h>. */
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#undef SIZE_TYPE
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#define SIZE_TYPE "long unsigned int"
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#undef PTRDIFF_TYPE
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#define PTRDIFF_TYPE "long int"
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#undef INTPTR_TYPE
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#define INTPTR_TYPE PTRDIFF_TYPE
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#undef UINTPTR_TYPE
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#define UINTPTR_TYPE SIZE_TYPE
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/* We don't have any limit on the length as out debugger is GDB. */
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#undef DBX_CONTIN_LENGTH
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/* NetBSD does its profiling differently to the Acorn compiler. We
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don't need a word following the mcount call; and to skip it
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requires either an assembly stub or use of fomit-frame-pointer when
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compiling the profiling functions. Since we break Acorn CC
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compatibility below a little more won't hurt. */
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#undef ARM_FUNCTION_PROFILER
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#define ARM_FUNCTION_PROFILER(STREAM,LABELNO) \
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{ \
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asm_fprintf (STREAM, "\tmov\t%Rip, %Rlr\n"); \
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asm_fprintf (STREAM, "\tbl\t__mcount%s\n", \
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(TARGET_ARM && NEED_PLT_RELOC) \
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? "(PLT)" : ""); \
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}
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/* VERY BIG NOTE: Change of structure alignment for NetBSD/arm.
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There are consequences you should be aware of...
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Normally GCC/arm uses a structure alignment of 32 for compatibility
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with armcc. This means that structures are padded to a word
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boundary. However this causes problems with bugged NetBSD kernel
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code (possibly userland code as well - I have not checked every
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binary). The nature of this bugged code is to rely on sizeof()
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returning the correct size of various structures rounded to the
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nearest byte (SCSI and ether code are two examples, the vm system
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is another). This code breaks when the structure alignment is 32
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as sizeof() will report a word=rounded size. By changing the
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structure alignment to 8. GCC will conform to what is expected by
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NetBSD.
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This has several side effects that should be considered.
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1. Structures will only be aligned to the size of the largest member.
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i.e. structures containing only bytes will be byte aligned.
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structures containing shorts will be half word aligned.
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structures containing ints will be word aligned.
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This means structures should be padded to a word boundary if
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alignment of 32 is required for byte structures etc.
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2. A potential performance penalty may exist if strings are no longer
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word aligned. GCC will not be able to use word load/stores to copy
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short strings.
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This modification is not encouraged but with the present state of the
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NetBSD source tree it is currently the only solution that meets the
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requirements. */
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#undef DEFAULT_STRUCTURE_SIZE_BOUNDARY
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#define DEFAULT_STRUCTURE_SIZE_BOUNDARY 8
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/* Clear the instruction cache from `BEG' to `END'. This makes a
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call to the ARM_SYNC_ICACHE architecture specific syscall. */
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#define CLEAR_INSN_CACHE(BEG, END) \
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do \
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{ \
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extern int sysarch(int number, void *args); \
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struct \
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{ \
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unsigned int addr; \
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int len; \
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} s; \
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s.addr = (unsigned int)(BEG); \
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s.len = (END) - (BEG); \
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(void) sysarch (0, &s); \
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} \
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while (0)
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#undef FPUTYPE_DEFAULT
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#define FPUTYPE_DEFAULT "vfp"
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