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
100 struct 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.  */
134 extern 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 
159 extern 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 
173 extern void brtab_emit PARAMS ((void));
174 #define md_end()	brtab_emit ()
175 
176 extern void tc_set_bal_of_call PARAMS ((symbolS *, symbolS *));
177 
178 extern struct symbol *tc_get_bal_of_call PARAMS ((symbolS *));
179 
180 extern 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 
186 extern 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