01811101b198c1e3deb6f906ede2c0250cf6fabd
1 /* NetBSD/arm (RiscBSD) version.
2 Copyright (C) 1993, 1994, 1997 Free Software Foundation, Inc.
3 Contributed by Mark Brinicombe (amb@physig.ph.kcl.ac.uk)
5 This file is part of GNU CC.
7 GNU CC is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2, or (at your option)
12 GNU CC is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
17 You should have received a copy of the GNU General Public License
18 along with GNU CC; see the file COPYING. If not, write to
19 the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. */
21 /* Run-time Target Specification. */
22 #define TARGET_VERSION fputs (" (ARM/NetBSD)", stderr);
24 /* This is used in ASM_FILE_START. */
25 #define ARM_OS_NAME "NetBSD"
27 /* Unsigned chars produces much better code than signed. */
28 #define DEFAULT_SIGNED_CHAR 0
30 /* Since we always use GAS as our assembler we support stabs. */
31 #define DBX_DEBUGGING_INFO 1
33 /*#undef ASM_DECLARE_FUNCTION_NAME*/
35 /* ARM6 family default cpu. */
36 #define SUBTARGET_CPU_DEFAULT TARGET_CPU_arm6
38 /* Default is to use APCS-32 mode. */
39 #define TARGET_DEFAULT ARM_FLAG_APCS_32
43 /* This gets redefined in config/netbsd.h. */
44 #undef TARGET_MEM_FUNCTIONS
48 /* Some defines for CPP.
49 arm32 is the NetBSD port name, so we always define arm32 and __arm32__. */
51 #define CPP_PREDEFINES "\
52 -Dunix -Driscbsd -Darm32 -D__arm32__ -D__arm__ -D__NetBSD__ \
53 -Asystem(unix) -Asystem(NetBSD) -Acpu(arm) -Amachine(arm)"
55 /* Define _POSIX_SOURCE if necessary. */
58 %(cpp_cpu_arch) %(cpp_apcs_pc) %(cpp_float) %(cpp_endian) \
59 %{posix:-D_POSIX_SOURCE} \
62 /* Because TARGET_DEFAULT sets ARM_FLAG_APCS_32 */
63 #undef CPP_APCS_PC_DEFAULT_SPEC
64 #define CPP_APCS_PC_DEFAULT_SPEC "-D__APCS_32__"
66 /* Pass -X to the linker so that it will strip symbols starting with 'L' */
69 -X %{!nostdlib:%{!r*:%{!e*:-e start}}} -dc -dp %{R*} \
70 %{static:-Bstatic} %{assert*} \
74 #define SIZE_TYPE "unsigned int"
77 #define PTRDIFF_TYPE "int"
80 #define WCHAR_TYPE "int"
83 #define WCHAR_UNSIGNED 0
85 #undef WCHAR_TYPE_SIZE
86 #define WCHAR_TYPE_SIZE 32
88 #define HANDLE_SYSV_PRAGMA
90 /* We don't have any limit on the length as out debugger is GDB. */
91 #undef DBX_CONTIN_LENGTH
93 /* NetBSD does its profiling differently to the Acorn compiler. We
94 don't need a word following the mcount call; and to skip it
95 requires either an assembly stub or use of fomit-frame-pointer when
96 compiling the profiling functions. Since we break Acorn CC
97 compatibility below a little more won't hurt. */
99 #undef FUNCTION_PROFILER
100 #define FUNCTION_PROFILER(STREAM,LABELNO) \
102 fprintf(STREAM, "\tmov\t%sip, %slr\n", REGISTER_PREFIX, REGISTER_PREFIX); \
103 fprintf(STREAM, "\tbl\tmcount\n"); \
106 /* On the ARM `@' introduces a comment, so we must use something else
107 for .type directives. */
108 #undef TYPE_OPERAND_FMT
109 #define TYPE_OPERAND_FMT "%%%s"
111 /* VERY BIG NOTE : Change of structure alignment for RiscBSD.
112 There are consequences you should be aware of...
114 Normally GCC/arm uses a structure alignment of 32 for compatibility
115 with armcc. This means that structures are padded to a word
116 boundary. However this causes problems with bugged NetBSD kernel
117 code (possibly userland code as well - I have not checked every
118 binary). The nature of this bugged code is to rely on sizeof()
119 returning the correct size of various structures rounded to the
120 nearest byte (SCSI and ether code are two examples, the vm system
121 is another). This code breaks when the structure alignment is 32
122 as sizeof() will report a word=rounded size. By changing the
123 structure alignment to 8. GCC will conform to what is expected by
126 This has several side effects that should be considered.
127 1. Structures will only be aligned to the size of the largest member.
128 i.e. structures containing only bytes will be byte aligned.
129 structures containing shorts will be half word alinged.
130 structures containing ints will be word aligned.
132 This means structures should be padded to a word boundary if
133 alignment of 32 is required for byte structures etc.
135 2. A potential performance penalty may exist if strings are no longer
136 word aligned. GCC will not be able to use word load/stores to copy
139 This modification is not encouraged but with the present state of the
140 NetBSD source tree it is currently the only solution that meets the
142 #undef STRUCTURE_SIZE_BOUNDARY
143 #define STRUCTURE_SIZE_BOUNDARY 8
145 /* Until they use ELF or something that handles dwarf2 unwinds
146 and initialization stuff better. */
147 #define DWARF2_UNWIND_INFO 0