1/* tc-i960.h - Basic 80960 instruction formats.
2   Copyright 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1997, 1998, 1999,
3   2000, 2001, 2002, 2003
4   Free Software Foundation, Inc.
5
6   This file is part of GAS, the GNU Assembler.
7
8   GAS is free software; you can redistribute it and/or modify
9   it under the terms of the GNU General Public License as
10   published by the Free Software Foundation; either version 2,
11   or (at your option) any later version.
12
13   GAS is distributed in the hope that it will be useful, but
14   WITHOUT ANY WARRANTY; without even the implied warranty of
15   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
16   the GNU General Public License for more details.
17
18   You should have received a copy of the GNU General Public License
19   along with GAS; see the file COPYING.  If not, write to the Free
20   Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
21   02110-1301, USA.  */
22
23#ifndef TC_I960
24#define TC_I960 1
25
26#ifdef OBJ_ELF
27#define TARGET_FORMAT "elf32-i960"
28#define TARGET_ARCH bfd_arch_i960
29#endif
30
31#define TARGET_BYTES_BIG_ENDIAN 0
32
33#define WORKING_DOT_WORD
34
35/*
36 * The 'COJ' instructions are actually COBR instructions with the 'b' in
37 * the mnemonic replaced by a 'j';  they are ALWAYS "de-optimized" if necessary:
38 * if the displacement will not fit in 13 bits, the assembler will replace them
39 * with the corresponding compare and branch instructions.
40 *
41 * All of the 'MEMn' instructions are the same format; the 'n' in the name
42 * indicates the default index scale factor (the size of the datum operated on).
43 *
44 * The FBRA formats are not actually an instruction format.  They are the
45 * "convenience directives" for branching on floating-point comparisons,
46 * each of which generates 2 instructions (a 'bno' and one other branch).
47 *
48 * The CALLJ format is not actually an instruction format.  It indicates that
49 * the instruction generated (a CTRL-format 'call') should have its relocation
50 * specially flagged for link-time replacement with a 'bal' or 'calls' if
51 * appropriate.
52 */
53
54/* tailor gas */
55#define LOCAL_LABELS_FB 1
56#define BITFIELD_CONS_EXPRESSIONS
57
58/* tailor the coff format */
59#define COFF_MAGIC				I960ROMAGIC
60#define OBJ_COFF_MAX_AUXENTRIES			(2)
61
62/* MEANING OF 'n_other' in the symbol record.
63 *
64 * If non-zero, the 'n_other' fields indicates either a leaf procedure or
65 * a system procedure, as follows:
66 *
67 *	1 <= n_other <= 32 :
68 *		The symbol is the entry point to a system procedure.
69 *		'n_value' is the address of the entry, as for any other
70 *		procedure.  The system procedure number (which can be used in
71 *		a 'calls' instruction) is (n_other-1).  These entries come from
72 *		'.sysproc' directives.
73 *
74 *	n_other == N_CALLNAME
75 *		the symbol is the 'call' entry point to a leaf procedure.
76 *		The *next* symbol in the symbol table must be the corresponding
77 *		'bal' entry point to the procedure (see following).  These
78 *		entries come from '.leafproc' directives in which two different
79 *		symbols are specified (the first one is represented here).
80 *
81 *
82 *	n_other == N_BALNAME
83 *		the symbol is the 'bal' entry point to a leaf procedure.
84 *		These entries result from '.leafproc' directives in which only
85 *		one symbol is specified, or in which the same symbol is
86 *		specified twice.
87 *
88 * Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry,
89 * but not every N_BALNAME entry must have an N_CALLNAME entry.
90 */
91#define	N_CALLNAME	((char)-1)
92#define	N_BALNAME	((char)-2)
93
94/* i960 uses a custom relocation record.  */
95
96/* let obj-aout.h know */
97#define CUSTOM_RELOC_FORMAT 1
98/* let aout_gnu.h know */
99#define N_RELOCATION_INFO_DECLARED 1
100struct relocation_info
101  {
102    int r_address;		/* File address of item to be relocated	*/
103    unsigned
104      r_index:24,		/* Index of symbol on which relocation is based*/
105      r_pcrel:1,		/* 1 => relocate PC-relative; else absolute
106				 *	On i960, pc-relative implies 24-bit
107				 *	address, absolute implies 32-bit.
108				 */
109      r_length:2,		/* Number of bytes to relocate:
110				 *	0 => 1 byte
111				 *	1 => 2 bytes
112				 *	2 => 4 bytes -- only value used for i960
113				 */
114      r_extern:1, r_bsr:1,	/* Something for the GNU NS32K assembler */
115      r_disp:1,			/* Something for the GNU NS32K assembler */
116      r_callj:1,		/* 1 if relocation target is an i960 'callj' */
117      nuthin:1;			/* Unused				*/
118  };
119
120/* No shared lib support, so we don't need to ensure externally
121   visible symbols can be overridden.  */
122#define EXTERN_FORCE_RELOC 0
123
124/* Makes no sense to use the difference of 2 arbitrary symbols
125   as the target of a call instruction.  */
126#define TC_FORCE_RELOCATION_SUB_SAME(FIX, SEG)	\
127  ((FIX)->fx_tcbit				\
128   || ! SEG_NORMAL (SEG)			\
129   || TC_FORCE_RELOCATION (FIX))
130
131/* reloc_callj() may replace a 'call' with a 'calls' or a
132   'bal', in which cases it modifies *fixP as appropriate.
133   In the case of a 'calls', no further work is required.  */
134extern int reloc_callj PARAMS ((struct fix *));
135
136#define TC_FORCE_RELOCATION_ABS(FIX)		\
137  (TC_FORCE_RELOCATION (FIX)			\
138   || reloc_callj (FIX))
139
140#define TC_FORCE_RELOCATION_LOCAL(FIX)		\
141  (!(FIX)->fx_pcrel				\
142   || (FIX)->fx_plt				\
143   || TC_FORCE_RELOCATION (FIX)		\
144   || reloc_callj (FIX))
145
146#ifdef OBJ_COFF
147
148/* We store the bal information in the sy_tc field.  */
149#define TC_SYMFIELD_TYPE symbolS *
150
151#define TC_ADJUST_RELOC_COUNT(FIX,COUNT) \
152  { fixS *tcfixp = (FIX); \
153    for (;tcfixp;tcfixp=tcfixp->fx_next) \
154      if (tcfixp->fx_tcbit && tcfixp->fx_addsy != 0) \
155	++(COUNT); \
156  }
157#endif
158
159extern int i960_validate_fix PARAMS ((struct fix *, segT));
160#define TC_VALIDATE_FIX(FIX,SEGTYPE,LABEL) \
161	if (!i960_validate_fix (FIX, SEGTYPE)) goto LABEL
162
163#define tc_fix_adjustable(FIX)		((FIX)->fx_bsr == 0)
164
165#ifndef OBJ_ELF
166/* Values passed to md_apply_fix sometimes include symbol values.  */
167#define MD_APPLY_SYM_VALUE(FIX) tc_fix_adjustable (FIX)
168#else
169/* Values passed to md_apply_fix don't include the symbol value.  */
170#define MD_APPLY_SYM_VALUE(FIX) 0
171#endif
172
173extern void brtab_emit PARAMS ((void));
174#define md_end()	brtab_emit ()
175
176extern void tc_set_bal_of_call PARAMS ((symbolS *, symbolS *));
177
178extern struct symbol *tc_get_bal_of_call PARAMS ((symbolS *));
179
180extern void i960_handle_align PARAMS ((struct frag *));
181#define HANDLE_ALIGN(FRAG)	i960_handle_align (FRAG)
182#define NO_RELOC -1
183
184#define md_operand(x)
185
186extern const struct relax_type md_relax_table[];
187#define TC_GENERIC_RELAX_TABLE md_relax_table
188
189#define LINKER_RELAXING_SHRINKS_ONLY
190
191#define TC_FIX_TYPE struct { unsigned bsr : 1; }
192#define fx_bsr tc_fix_data.bsr
193#define TC_INIT_FIX_DATA(F)	((F)->tc_fix_data.bsr = 0)
194
195#endif
196