1 /* tc-i960.h - Basic 80960 instruction formats.
2    Copyright 1989, 1990, 1991, 1992, 1993, 1994, 1995, 1997, 1998, 1999,
3    2000, 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, 59 Temple Place - Suite 330, Boston, MA
21    02111-1307, 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 SYMBOLS_NEED_BACKPOINTERS
56 #define LOCAL_LABELS_FB 1
57 #define BITFIELD_CONS_EXPRESSIONS
58 
59 /* tailor the coff format */
60 #define BFD_ARCH				bfd_arch_i960
61 #define COFF_FLAGS				F_AR32WR
62 #define COFF_MAGIC				I960ROMAGIC
63 #define OBJ_COFF_SECTION_HEADER_HAS_ALIGNMENT
64 #define OBJ_COFF_MAX_AUXENTRIES			(2)
65 #define TC_COUNT_RELOC(FIX)			(!(FIX)->fx_done)
66 #define TC_COFF_FIX2RTYPE(FIX)			tc_coff_fix2rtype (FIX)
67 #define TC_COFF_SIZEMACHDEP(FRAGP)		tc_coff_sizemachdep (FRAGP)
68 #define TC_COFF_SET_MACHINE(HDRS)		tc_headers_hook (HDRS)
69 extern int tc_coff_sizemachdep PARAMS ((struct frag *));
70 
71 /* MEANING OF 'n_other' in the symbol record.
72  *
73  * If non-zero, the 'n_other' fields indicates either a leaf procedure or
74  * a system procedure, as follows:
75  *
76  *	1 <= n_other <= 32 :
77  *		The symbol is the entry point to a system procedure.
78  *		'n_value' is the address of the entry, as for any other
79  *		procedure.  The system procedure number (which can be used in
80  *		a 'calls' instruction) is (n_other-1).  These entries come from
81  *		'.sysproc' directives.
82  *
83  *	n_other == N_CALLNAME
84  *		the symbol is the 'call' entry point to a leaf procedure.
85  *		The *next* symbol in the symbol table must be the corresponding
86  *		'bal' entry point to the procedure (see following).  These
87  *		entries come from '.leafproc' directives in which two different
88  *		symbols are specified (the first one is represented here).
89  *
90  *
91  *	n_other == N_BALNAME
92  *		the symbol is the 'bal' entry point to a leaf procedure.
93  *		These entries result from '.leafproc' directives in which only
94  *		one symbol is specified, or in which the same symbol is
95  *		specified twice.
96  *
97  * Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry,
98  * but not every N_BALNAME entry must have an N_CALLNAME entry.
99  */
100 #define	N_CALLNAME	((char)-1)
101 #define	N_BALNAME	((char)-2)
102 
103 /* i960 uses a custom relocation record.  */
104 
105 /* let obj-aout.h know */
106 #define CUSTOM_RELOC_FORMAT 1
107 /* let aout_gnu.h know */
108 #define N_RELOCATION_INFO_DECLARED 1
109 struct relocation_info
110   {
111     int r_address;		/* File address of item to be relocated	*/
112     unsigned
113       r_index:24,		/* Index of symbol on which relocation is based*/
114       r_pcrel:1,		/* 1 => relocate PC-relative; else absolute
115 				 *	On i960, pc-relative implies 24-bit
116 				 *	address, absolute implies 32-bit.
117 				 */
118       r_length:2,		/* Number of bytes to relocate:
119 				 *	0 => 1 byte
120 				 *	1 => 2 bytes
121 				 *	2 => 4 bytes -- only value used for i960
122 				 */
123       r_extern:1, r_bsr:1,	/* Something for the GNU NS32K assembler */
124       r_disp:1,			/* Something for the GNU NS32K assembler */
125       r_callj:1,		/* 1 if relocation target is an i960 'callj' */
126       nuthin:1;			/* Unused				*/
127   };
128 
129 /* No shared lib support, so we don't need to ensure externally
130    visible symbols can be overridden.  */
131 #define EXTERN_FORCE_RELOC 0
132 
133 /* Makes no sense to use the difference of 2 arbitrary symbols
134    as the target of a call instruction.  */
135 #define TC_FORCE_RELOCATION_SUB_SAME(FIX, SEG)	\
136   ((FIX)->fx_tcbit				\
137    || ! SEG_NORMAL (SEG)			\
138    || TC_FORCE_RELOCATION (FIX))
139 
140 /* reloc_callj() may replace a 'call' with a 'calls' or a
141    'bal', in which cases it modifies *fixP as appropriate.
142    In the case of a 'calls', no further work is required.  */
143 extern int reloc_callj PARAMS ((struct fix *));
144 
145 #define TC_FORCE_RELOCATION_ABS(FIX)		\
146   (TC_FORCE_RELOCATION (FIX)			\
147    || reloc_callj (FIX))
148 
149 #define TC_FORCE_RELOCATION_LOCAL(FIX)		\
150   (!(FIX)->fx_pcrel				\
151    || (FIX)->fx_plt				\
152    || TC_FORCE_RELOCATION (FIX)		\
153    || reloc_callj (FIX))
154 
155 #ifdef OBJ_COFF
156 
157 /* We store the bal information in the sy_tc field.  */
158 #define TC_SYMFIELD_TYPE symbolS *
159 
160 #define TC_ADJUST_RELOC_COUNT(FIX,COUNT) \
161   { fixS *tcfixp = (FIX); \
162     for (;tcfixp;tcfixp=tcfixp->fx_next) \
163       if (tcfixp->fx_tcbit && tcfixp->fx_addsy != 0) \
164 	++(COUNT); \
165   }
166 #endif
167 
168 extern int i960_validate_fix PARAMS ((struct fix *, segT));
169 #define TC_VALIDATE_FIX(FIX,SEGTYPE,LABEL) \
170 	if (!i960_validate_fix (FIX, SEGTYPE)) goto LABEL
171 
172 #define tc_fix_adjustable(FIX)		((FIX)->fx_bsr == 0)
173 
174 #ifndef OBJ_ELF
175 /* Values passed to md_apply_fix3 sometimes include symbol values.  */
176 #define MD_APPLY_SYM_VALUE(FIX) tc_fix_adjustable (FIX)
177 #else
178 /* Values passed to md_apply_fix3 don't include the symbol value.  */
179 #define MD_APPLY_SYM_VALUE(FIX) 0
180 #endif
181 
182 extern void brtab_emit PARAMS ((void));
183 #define md_end()	brtab_emit ()
184 
185 extern void tc_set_bal_of_call PARAMS ((symbolS *, symbolS *));
186 
187 extern struct symbol *tc_get_bal_of_call PARAMS ((symbolS *));
188 
189 extern void i960_handle_align PARAMS ((struct frag *));
190 #define HANDLE_ALIGN(FRAG)	i960_handle_align (FRAG)
191 #define NEED_FX_R_TYPE
192 #define NO_RELOC -1
193 
194 #define md_operand(x)
195 
196 extern const struct relax_type md_relax_table[];
197 #define TC_GENERIC_RELAX_TABLE md_relax_table
198 
199 #define LINKER_RELAXING_SHRINKS_ONLY
200 
201 #define TC_FIX_TYPE struct { unsigned bsr : 1; }
202 #define fx_bsr tc_fix_data.bsr
203 #define TC_INIT_FIX_DATA(F)	((F)->tc_fix_data.bsr = 0)
204 
205 #endif
206