1 /* tc-openrisc.c -- Assembler for the OpenRISC family.
2 Copyright (C) 2001 Free Software Foundation.
3 Contributed by Johan Rydberg, jrydberg@opencores.org
5 This file is part of GAS, the GNU Assembler.
7 GAS 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 GAS 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 GAS; see the file COPYING. If not, write to
19 the Free Software Foundation, 59 Temple Place - Suite 330,
20 Boston, MA 02111-1307, USA. */
27 #include "opcodes/openrisc-desc.h"
28 #include "opcodes/openrisc-opc.h"
31 /* Structure to hold all of the different components describing
32 an individual instruction. */
33 typedef struct openrisc_insn openrisc_insn;
37 const CGEN_INSN * insn;
38 const CGEN_INSN * orig_insn;
41 CGEN_INSN_INT buffer [1];
42 #define INSN_VALUE(buf) (*(buf))
44 unsigned char buffer [CGEN_MAX_INSN_SIZE];
45 #define INSN_VALUE(buf) (buf)
50 fixS * fixups [GAS_CGEN_MAX_FIXUPS];
51 int indices [MAX_OPERAND_INSTANCES];
55 const char comment_chars[] = "#";
56 const char line_comment_chars[] = "#";
57 const char line_separator_chars[] = ";";
58 const char EXP_CHARS[] = "eE";
59 const char FLT_CHARS[] = "dD";
62 #define OPENRISC_SHORTOPTS "m:"
63 const char * md_shortopts = OPENRISC_SHORTOPTS;
65 struct option md_longopts[] =
67 {NULL, no_argument, NULL, 0}
69 size_t md_longopts_size = sizeof (md_longopts);
71 unsigned long openrisc_machine = 0; /* default */
74 md_parse_option (c, arg)
75 int c ATTRIBUTE_UNUSED;
76 char * arg ATTRIBUTE_UNUSED;
82 md_show_usage (stream)
83 FILE * stream ATTRIBUTE_UNUSED;
89 int val ATTRIBUTE_UNUSED;
91 discard_rest_of_line ();
94 const char openrisc_comment_chars [] = ";#";
96 /* The target specific pseudo-ops which we support. */
97 const pseudo_typeS md_pseudo_table[] =
100 { "proc", ignore_pseudo, 0 },
101 { "endproc", ignore_pseudo, 0 },
110 /* Initialize the `cgen' interface. */
112 /* Set the machine number and endian. */
113 gas_cgen_cpu_desc = openrisc_cgen_cpu_open (CGEN_CPU_OPEN_MACHS, 0,
114 CGEN_CPU_OPEN_ENDIAN,
117 openrisc_cgen_init_asm (gas_cgen_cpu_desc);
119 /* This is a callback from cgen to gas to parse operands. */
120 cgen_set_parse_operand_fn (gas_cgen_cpu_desc, gas_cgen_parse_operand);
127 static int last_insn_had_delay_slot = 0;
131 /* Initialize GAS's cgen interface for a new instruction. */
132 gas_cgen_init_parse ();
134 insn.insn = openrisc_cgen_assemble_insn
135 (gas_cgen_cpu_desc, str, & insn.fields, insn.buffer, & errmsg);
143 /* Doesn't really matter what we pass for RELAX_P here. */
144 gas_cgen_finish_insn (insn.insn, insn.buffer,
145 CGEN_FIELDS_BITSIZE (& insn.fields), 1, NULL);
147 #if 0 /* Currently disabled */
148 /* Warn about invalid insns in delay slots. */
149 if (last_insn_had_delay_slot
150 && CGEN_INSN_ATTR_VALUE (insn.insn, CGEN_INSN_NOT_IN_DELAY_SLOT))
151 as_warn (_("Instruction %s not allowed in a delay slot."),
152 CGEN_INSN_NAME (insn.insn));
155 last_insn_had_delay_slot
156 = CGEN_INSN_ATTR_VALUE (insn.insn, CGEN_INSN_DELAY_SLOT);
160 /* The syntax in the manual says constants begin with '#'.
161 We just ignore it. */
164 md_operand (expressionP)
165 expressionS * expressionP;
167 if (* input_line_pointer == '#')
169 input_line_pointer ++;
170 expression (expressionP);
175 md_section_align (segment, size)
179 int align = bfd_get_section_alignment (stdoutput, segment);
180 return ((size + (1 << align) - 1) & (-1 << align));
184 md_undefined_symbol (name)
185 char * name ATTRIBUTE_UNUSED;
191 /* Interface to relax_segment. */
193 /* FIXME: Look through this. */
195 const relax_typeS md_relax_table[] =
198 1) most positive reach of this state,
199 2) most negative reach of this state,
200 3) how many bytes this mode will add to the size of the current frag
201 4) which index into the table to try if we can't fit into this one. */
203 /* The first entry must be unused because an `rlx_more' value of zero ends
207 /* The displacement used by GAS is from the end of the 2 byte insn,
208 so we subtract 2 from the following. */
209 /* 16 bit insn, 8 bit disp -> 10 bit range.
210 This doesn't handle a branch in the right slot at the border:
211 the "& -4" isn't taken into account. It's not important enough to
212 complicate things over it, so we subtract an extra 2 (or + 2 in -ve
214 {511 - 2 - 2, -512 - 2 + 2, 0, 2 },
215 /* 32 bit insn, 24 bit disp -> 26 bit range. */
216 {0x2000000 - 1 - 2, -0x2000000 - 2, 2, 0 },
217 /* Same thing, but with leading nop for alignment. */
218 {0x2000000 - 1 - 2, -0x2000000 - 2, 4, 0 }
222 openrisc_relax_frag (segment, fragP, stretch)
227 /* Address of branch insn. */
228 long address = fragP->fr_address + fragP->fr_fix - 2;
231 /* Keep 32 bit insns aligned on 32 bit boundaries. */
232 if (fragP->fr_subtype == 2)
234 if ((address & 3) != 0)
236 fragP->fr_subtype = 3;
240 else if (fragP->fr_subtype == 3)
242 if ((address & 3) == 0)
244 fragP->fr_subtype = 2;
250 growth = relax_frag (segment, fragP, stretch);
252 /* Long jump on odd halfword boundary? */
253 if (fragP->fr_subtype == 2 && (address & 3) != 0)
255 fragP->fr_subtype = 3;
264 /* Return an initial guess of the length by which a fragment must grow to
265 hold a branch to reach its destination.
266 Also updates fr_type/fr_subtype as necessary.
268 Called just before doing relaxation.
269 Any symbol that is now undefined will not become defined.
270 The guess for fr_var is ACTUALLY the growth beyond fr_fix.
271 Whatever we do to grow fr_fix or fr_var contributes to our returned value.
272 Although it may not be explicit in the frag, pretend fr_var starts with a
276 md_estimate_size_before_relax (fragP, segment)
280 int old_fr_fix = fragP->fr_fix;
282 /* The only thing we have to handle here are symbols outside of the
283 current segment. They may be undefined or in a different segment in
284 which case linker scripts may place them anywhere.
285 However, we can't finish the fragment here and emit the reloc as insn
286 alignment requirements may move the insn about. */
288 if (S_GET_SEGMENT (fragP->fr_symbol) != segment)
290 /* The symbol is undefined in this segment.
291 Change the relaxation subtype to the max allowable and leave
292 all further handling to md_convert_frag. */
293 fragP->fr_subtype = 2;
296 const CGEN_INSN * insn;
299 /* Update the recorded insn.
300 Fortunately we don't have to look very far.
301 FIXME: Change this to record in the instruction the next higher
302 relaxable insn to use. */
303 for (i = 0, insn = fragP->fr_cgen.insn; i < 4; i++, insn++)
305 if ((strcmp (CGEN_INSN_MNEMONIC (insn),
306 CGEN_INSN_MNEMONIC (fragP->fr_cgen.insn))
308 && CGEN_INSN_ATTR_VALUE (insn, CGEN_INSN_RELAX))
314 fragP->fr_cgen.insn = insn;
319 return (fragP->fr_var + fragP->fr_fix - old_fr_fix);
322 /* *fragP has been relaxed to its final size, and now needs to have
323 the bytes inside it modified to conform to the new size.
325 Called after relaxation is finished.
326 fragP->fr_type == rs_machine_dependent.
327 fragP->fr_subtype is the subtype of what the address relaxed to. */
330 md_convert_frag (abfd, sec, fragP)
331 bfd * abfd ATTRIBUTE_UNUSED;
332 segT sec ATTRIBUTE_UNUSED;
333 fragS * fragP ATTRIBUTE_UNUSED;
339 /* Functions concerning relocs. */
341 /* The location from which a PC relative jump should be calculated,
342 given a PC relative reloc. */
345 md_pcrel_from_section (fixP, sec)
349 if (fixP->fx_addsy != (symbolS *) NULL
350 && (! S_IS_DEFINED (fixP->fx_addsy)
351 || S_GET_SEGMENT (fixP->fx_addsy) != sec))
353 /* The symbol is undefined (or is defined but not in this section).
354 Let the linker figure it out. */
358 return (fixP->fx_frag->fr_address + fixP->fx_where) & ~1;
362 /* Return the bfd reloc type for OPERAND of INSN at fixup FIXP.
363 Returns BFD_RELOC_NONE if no reloc type can be found.
364 *FIXP may be modified if desired. */
366 bfd_reloc_code_real_type
367 md_cgen_lookup_reloc (insn, operand, fixP)
368 const CGEN_INSN * insn ATTRIBUTE_UNUSED;
369 const CGEN_OPERAND * operand;
372 bfd_reloc_code_real_type type;
374 switch (operand->type)
376 case OPENRISC_OPERAND_ABS_26:
378 type = BFD_RELOC_OPENRISC_ABS_26;
380 case OPENRISC_OPERAND_DISP_26:
382 type = BFD_RELOC_OPENRISC_REL_26;
385 case OPENRISC_OPERAND_HI16:
386 type = BFD_RELOC_HI16;
389 case OPENRISC_OPERAND_LO16:
390 type = BFD_RELOC_LO16;
396 default : /* avoid -Wall warning */
400 return BFD_RELOC_NONE;
403 /* See whether we need to force a relocation into the output file.
404 This is used to force out switch and PC relative relocations when
408 openrisc_force_relocation (fix)
409 fixS * fix ATTRIBUTE_UNUSED;
411 if (fix->fx_r_type == BFD_RELOC_VTABLE_INHERIT
412 || fix->fx_r_type == BFD_RELOC_VTABLE_ENTRY)
420 /* Write a value out to the object file, using the appropriate endianness. */
423 md_number_to_chars (buf, val, n)
428 number_to_chars_bigendian (buf, val, n);
431 /* Turn a string in input_line_pointer into a floating point constant of type
432 type, and store the appropriate bytes in *litP. The number of LITTLENUMS
433 emitted is stored in *sizeP . An error message is returned, or NULL on OK.
436 /* Equal to MAX_PRECISION in atof-ieee.c */
437 #define MAX_LITTLENUMS 6
440 md_atof (type, litP, sizeP)
447 LITTLENUM_TYPE words [MAX_LITTLENUMS];
467 /* FIXME: Some targets allow other format chars for bigger sizes here. */
471 return _("Bad call to md_atof()");
474 t = atof_ieee (input_line_pointer, type, words);
476 input_line_pointer = t;
477 * sizeP = prec * sizeof (LITTLENUM_TYPE);
479 for (i = 0; i < prec; i++)
481 md_number_to_chars (litP, (valueT) words[i],
482 sizeof (LITTLENUM_TYPE));
483 litP += sizeof (LITTLENUM_TYPE);
490 openrisc_fix_adjustable (fixP)
493 if (fixP->fx_addsy == NULL)
496 /* We need the symbol name for the VTABLE entries */
497 if (fixP->fx_r_type == BFD_RELOC_VTABLE_INHERIT
498 || fixP->fx_r_type == BFD_RELOC_VTABLE_ENTRY)