1 /* tc-i960.h - Basic 80960 instruction formats.
2    Copyright (C) 1989-2016 Free Software Foundation, Inc.
3 
4    This file is part of GAS, the GNU Assembler.
5 
6    GAS is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as
8    published by the Free Software Foundation; either version 3,
9    or (at your option) any later version.
10 
11    GAS is distributed in the hope that it will be useful, but
12    WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See
14    the GNU General Public License for more details.
15 
16    You should have received a copy of the GNU General Public License
17    along with GAS; see the file COPYING.  If not, write to the Free
18    Software Foundation, 51 Franklin Street - Fifth Floor, Boston, MA
19    02110-1301, USA.  */
20 
21 #ifndef TC_I960
22 #define TC_I960 1
23 
24 #ifdef OBJ_ELF
25 #define TARGET_FORMAT "elf32-i960"
26 #define TARGET_ARCH bfd_arch_i960
27 #endif
28 
29 #define TARGET_BYTES_BIG_ENDIAN 0
30 
31 #define WORKING_DOT_WORD
32 
33 /*
34  * The 'COJ' instructions are actually COBR instructions with the 'b' in
35  * the mnemonic replaced by a 'j';  they are ALWAYS "de-optimized" if necessary:
36  * if the displacement will not fit in 13 bits, the assembler will replace them
37  * with the corresponding compare and branch instructions.
38  *
39  * All of the 'MEMn' instructions are the same format; the 'n' in the name
40  * indicates the default index scale factor (the size of the datum operated on).
41  *
42  * The FBRA formats are not actually an instruction format.  They are the
43  * "convenience directives" for branching on floating-point comparisons,
44  * each of which generates 2 instructions (a 'bno' and one other branch).
45  *
46  * The CALLJ format is not actually an instruction format.  It indicates that
47  * the instruction generated (a CTRL-format 'call') should have its relocation
48  * specially flagged for link-time replacement with a 'bal' or 'calls' if
49  * appropriate.
50  */
51 
52 /* tailor gas */
53 #define LOCAL_LABELS_FB 1
54 #define BITFIELD_CONS_EXPRESSIONS
55 
56 /* tailor the coff format */
57 #define COFF_MAGIC				I960ROMAGIC
58 #define OBJ_COFF_MAX_AUXENTRIES			(2)
59 
60 /* MEANING OF 'n_other' in the symbol record.
61  *
62  * If non-zero, the 'n_other' fields indicates either a leaf procedure or
63  * a system procedure, as follows:
64  *
65  *	1 <= n_other <= 32 :
66  *		The symbol is the entry point to a system procedure.
67  *		'n_value' is the address of the entry, as for any other
68  *		procedure.  The system procedure number (which can be used in
69  *		a 'calls' instruction) is (n_other-1).  These entries come from
70  *		'.sysproc' directives.
71  *
72  *	n_other == N_CALLNAME
73  *		the symbol is the 'call' entry point to a leaf procedure.
74  *		The *next* symbol in the symbol table must be the corresponding
75  *		'bal' entry point to the procedure (see following).  These
76  *		entries come from '.leafproc' directives in which two different
77  *		symbols are specified (the first one is represented here).
78  *
79  *
80  *	n_other == N_BALNAME
81  *		the symbol is the 'bal' entry point to a leaf procedure.
82  *		These entries result from '.leafproc' directives in which only
83  *		one symbol is specified, or in which the same symbol is
84  *		specified twice.
85  *
86  * Note that an N_CALLNAME entry *must* have a corresponding N_BALNAME entry,
87  * but not every N_BALNAME entry must have an N_CALLNAME entry.
88  */
89 #define	N_CALLNAME	((char)-1)
90 #define	N_BALNAME	((char)-2)
91 
92 /* i960 uses a custom relocation record.  */
93 
94 /* let obj-aout.h know */
95 #define CUSTOM_RELOC_FORMAT 1
96 /* let aout_gnu.h know */
97 #define N_RELOCATION_INFO_DECLARED 1
98 struct relocation_info
99   {
100     int r_address;		/* File address of item to be relocated	*/
101     unsigned
102       r_index:24,		/* Index of symbol on which relocation is based*/
103       r_pcrel:1,		/* 1 => relocate PC-relative; else absolute
104 				 *	On i960, pc-relative implies 24-bit
105 				 *	address, absolute implies 32-bit.
106 				 */
107       r_length:2,		/* Number of bytes to relocate:
108 				 *	0 => 1 byte
109 				 *	1 => 2 bytes
110 				 *	2 => 4 bytes -- only value used for i960
111 				 */
112       r_extern:1, r_bsr:1,	/* Something for the GNU NS32K assembler */
113       r_disp:1,			/* Something for the GNU NS32K assembler */
114       r_callj:1,		/* 1 if relocation target is an i960 'callj' */
115       nuthin:1;			/* Unused				*/
116   };
117 
118 /* No shared lib support, so we don't need to ensure externally
119    visible symbols can be overridden.  */
120 #define EXTERN_FORCE_RELOC 0
121 
122 /* Makes no sense to use the difference of 2 arbitrary symbols
123    as the target of a call instruction.  */
124 #define TC_FORCE_RELOCATION_SUB_SAME(FIX, SEG)	\
125   ((FIX)->fx_tcbit				\
126    || ! SEG_NORMAL (SEG)			\
127    || TC_FORCE_RELOCATION (FIX))
128 
129 /* reloc_callj() may replace a 'call' with a 'calls' or a
130    'bal', in which cases it modifies *fixP as appropriate.
131    In the case of a 'calls', no further work is required.  */
132 extern int reloc_callj (struct fix *);
133 
134 #define TC_FORCE_RELOCATION_ABS(FIX)		\
135   (TC_FORCE_RELOCATION (FIX)			\
136    || reloc_callj (FIX))
137 
138 #define TC_FORCE_RELOCATION_LOCAL(FIX)		\
139   (!(FIX)->fx_pcrel				\
140    || TC_FORCE_RELOCATION (FIX)		\
141    || reloc_callj (FIX))
142 
143 #ifdef OBJ_COFF
144 
145 /* We store the bal information in the sy_tc field.  */
146 #define TC_SYMFIELD_TYPE symbolS *
147 
148 #endif
149 
150 extern int i960_validate_fix (struct fix *, segT);
151 #define TC_VALIDATE_FIX(FIX,SEGTYPE,LABEL) \
152 	if (!i960_validate_fix (FIX, SEGTYPE)) goto LABEL
153 
154 #define tc_fix_adjustable(FIX)		((FIX)->fx_bsr == 0)
155 
156 #ifndef OBJ_ELF
157 /* Values passed to md_apply_fix sometimes include symbol values.  */
158 #define MD_APPLY_SYM_VALUE(FIX) tc_fix_adjustable (FIX)
159 #else
160 /* Values passed to md_apply_fix don't include the symbol value.  */
161 #define MD_APPLY_SYM_VALUE(FIX) 0
162 #endif
163 
164 extern void brtab_emit (void);
165 #define md_end()	brtab_emit ()
166 
167 extern void tc_set_bal_of_call (symbolS *, symbolS *);
168 
169 extern struct symbol *tc_get_bal_of_call (symbolS *);
170 
171 extern void i960_handle_align (struct frag *);
172 #define HANDLE_ALIGN(FRAG)	i960_handle_align (FRAG)
173 #define NO_RELOC -1
174 
175 #define md_operand(x)
176 
177 extern const struct relax_type md_relax_table[];
178 #define TC_GENERIC_RELAX_TABLE md_relax_table
179 
180 #define LINKER_RELAXING_SHRINKS_ONLY
181 
182 #define TC_FIX_TYPE struct { unsigned bsr : 1; }
183 #define fx_bsr tc_fix_data.bsr
184 #define TC_INIT_FIX_DATA(F)	((F)->tc_fix_data.bsr = 0)
185 
186 #endif
187