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/* GAS interface for targets using CGEN: Cpu tools GENerator.
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Copyright 1996, 1997, 1998, 1999, 2000, 2001, 2002, 2003
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Free Software Foundation, Inc.
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This file is part of GAS, the GNU Assembler.
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GAS is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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GAS is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with GAS; see the file COPYING. If not, write to the Free Software
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Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#include "libiberty.h"
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#include "cgen-desc.h"
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#include "dwarf2dbg.h"
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static void queue_fixup PARAMS ((int, int, expressionS *));
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/* Opcode table descriptor, must be set by md_begin. */
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CGEN_CPU_DESC gas_cgen_cpu_desc;
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/* Callback to insert a register into the symbol table.
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A target may choose to let GAS parse the registers.
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??? Not currently used. */
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cgen_asm_record_register (name, number)
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/* Use symbol_create here instead of symbol_new so we don't try to
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output registers into the object file's symbol table. */
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symbol_table_insert (symbol_create (name, reg_section,
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number, &zero_address_frag));
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/* We need to keep a list of fixups. We can't simply generate them as
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we go, because that would require us to first create the frag, and
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that would screw up references to ``.''.
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This is used by cpu's with simple operands. It keeps knowledge of what
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an `expressionS' is and what a `fixup' is out of CGEN which for the time
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OPINDEX is the index in the operand table.
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OPINFO is something the caller chooses to help in reloc determination. */
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static struct fixup fixups[GAS_CGEN_MAX_FIXUPS];
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static int num_fixups;
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/* Prepare to parse an instruction.
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??? May wish to make this static and delete calls in md_assemble. */
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gas_cgen_init_parse ()
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queue_fixup (opindex, opinfo, expP)
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/* We need to generate a fixup for this expression. */
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if (num_fixups >= GAS_CGEN_MAX_FIXUPS)
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as_fatal (_("too many fixups"));
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fixups[num_fixups].exp = *expP;
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fixups[num_fixups].opindex = opindex;
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fixups[num_fixups].opinfo = opinfo;
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/* The following functions allow fixup chains to be stored, retrieved,
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and swapped. They are a generalization of a pre-existing scheme
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for storing, restoring and swapping fixup chains that was used by
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the m32r port. The functionality is essentially the same, only
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instead of only being able to store a single fixup chain, an entire
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array of fixup chains can be stored. It is the user's responsibility
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to keep track of how many fixup chains have been stored and which
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elements of the array they are in.
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The algorithms used are the same as in the old scheme. Other than the
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"array-ness" of the whole thing, the functionality is identical to the
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gas_cgen_initialize_saved_fixups_array():
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Sets num_fixups_in_chain to 0 for each element. Call this from
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md_begin() if you plan to use these functions and you want the
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fixup count in each element to be set to 0 initially. This is
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not necessary, but it's included just in case. It performs
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the same function for each element in the array of fixup chains
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that gas_init_parse() performs for the current fixups.
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gas_cgen_save_fixups (element):
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element - element number of the array you wish to store the fixups
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to. No mechanism is built in for tracking what element
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gas_cgen_restore_fixups (element):
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element - element number of the array you wish to restore the fixups
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gas_cgen_swap_fixups(int element):
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element - swap the current fixups with those in this element number.
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struct fixup fixup_chain[GAS_CGEN_MAX_FIXUPS];
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int num_fixups_in_chain;
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static struct saved_fixups stored_fixups[MAX_SAVED_FIXUP_CHAINS];
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gas_cgen_initialize_saved_fixups_array ()
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while (i < MAX_SAVED_FIXUP_CHAINS)
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stored_fixups[i++].num_fixups_in_chain = 0;
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gas_cgen_save_fixups (i)
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if (i < 0 || i >= MAX_SAVED_FIXUP_CHAINS)
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as_fatal ("index into stored_fixups[] out of bounds");
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stored_fixups[i].num_fixups_in_chain = num_fixups;
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memcpy (stored_fixups[i].fixup_chain, fixups,
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sizeof (fixups[0]) * num_fixups);
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gas_cgen_restore_fixups (i)
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if (i < 0 || i >= MAX_SAVED_FIXUP_CHAINS)
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as_fatal ("index into stored_fixups[] out of bounds");
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num_fixups = stored_fixups[i].num_fixups_in_chain;
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memcpy (fixups, stored_fixups[i].fixup_chain,
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(sizeof (stored_fixups[i].fixup_chain[0])) * num_fixups);
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stored_fixups[i].num_fixups_in_chain = 0;
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gas_cgen_swap_fixups (i)
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if (i < 0 || i >= MAX_SAVED_FIXUP_CHAINS)
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as_fatal ("index into stored_fixups[] out of bounds");
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gas_cgen_restore_fixups (i);
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else if (stored_fixups[i].num_fixups_in_chain == 0)
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gas_cgen_save_fixups (i);
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struct fixup tmp_fixup;
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tmp = stored_fixups[i].num_fixups_in_chain;
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stored_fixups[i].num_fixups_in_chain = num_fixups;
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for (tmp = GAS_CGEN_MAX_FIXUPS; tmp--;)
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tmp_fixup = stored_fixups[i].fixup_chain [tmp];
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stored_fixups[i].fixup_chain[tmp] = fixups [tmp];
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fixups [tmp] = tmp_fixup;
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/* Default routine to record a fixup.
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This is a cover function to fix_new.
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It exists because we record INSN with the fixup.
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FRAG and WHERE are their respective arguments to fix_new_exp.
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OPINFO is something the caller chooses to help in reloc determination.
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At this point we do not use a bfd_reloc_code_real_type for
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operands residing in the insn, but instead just use the
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operand index. This lets us easily handle fixups for any
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operand type. We pick a BFD reloc type in md_apply_fix3. */
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gas_cgen_record_fixup (frag, where, insn, length, operand, opinfo, symbol, offset)
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const CGEN_INSN * insn;
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const CGEN_OPERAND * operand;
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/* It may seem strange to use operand->attrs and not insn->attrs here,
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but it is the operand that has a pc relative relocation. */
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fixP = fix_new (frag, where, length / 8, symbol, offset,
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CGEN_OPERAND_ATTR_VALUE (operand, CGEN_OPERAND_PCREL_ADDR),
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(bfd_reloc_code_real_type)
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((int) BFD_RELOC_UNUSED
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+ (int) operand->type));
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fixP->fx_cgen.insn = insn;
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fixP->fx_cgen.opinfo = opinfo;
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/* Default routine to record a fixup given an expression.
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This is a cover function to fix_new_exp.
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It exists because we record INSN with the fixup.
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FRAG and WHERE are their respective arguments to fix_new_exp.
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OPINFO is something the caller chooses to help in reloc determination.
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At this point we do not use a bfd_reloc_code_real_type for
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operands residing in the insn, but instead just use the
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operand index. This lets us easily handle fixups for any
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operand type. We pick a BFD reloc type in md_apply_fix3. */
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gas_cgen_record_fixup_exp (frag, where, insn, length, operand, opinfo, exp)
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const CGEN_INSN * insn;
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const CGEN_OPERAND * operand;
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/* It may seem strange to use operand->attrs and not insn->attrs here,
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but it is the operand that has a pc relative relocation. */
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fixP = fix_new_exp (frag, where, length / 8, exp,
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CGEN_OPERAND_ATTR_VALUE (operand, CGEN_OPERAND_PCREL_ADDR),
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(bfd_reloc_code_real_type)
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((int) BFD_RELOC_UNUSED
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+ (int) operand->type));
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fixP->fx_cgen.insn = insn;
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fixP->fx_cgen.opinfo = opinfo;
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/* Used for communication between the next two procedures. */
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static jmp_buf expr_jmp_buf;
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static int expr_jmp_buf_p;
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/* Callback for cgen interface. Parse the expression at *STRP.
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The result is an error message or NULL for success (in which case
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*STRP is advanced past the parsed text).
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WANT is an indication of what the caller is looking for.
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If WANT == CGEN_ASM_PARSE_INIT the caller is beginning to try to match
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a table entry with the insn, reset the queued fixups counter.
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An enum cgen_parse_operand_result is stored in RESULTP.
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OPINDEX is the operand's table entry index.
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OPINFO is something the caller chooses to help in reloc determination.
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The resulting value is stored in VALUEP. */
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gas_cgen_parse_operand (cd, want, strP, opindex, opinfo, resultP, valueP)
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CGEN_CPU_DESC cd ATTRIBUTE_UNUSED;
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enum cgen_parse_operand_type want;
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enum cgen_parse_operand_result *resultP;
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/* These are volatile to survive the setjmp. */
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char * volatile hold;
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enum cgen_parse_operand_result * volatile resultP_1;
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static enum cgen_parse_operand_result *resultP_1;
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if (want == CGEN_PARSE_OPERAND_INIT)
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gas_cgen_init_parse ();
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hold = input_line_pointer;
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input_line_pointer = (char *) *strP;
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/* We rely on md_operand to longjmp back to us.
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This is done via gas_cgen_md_operand. */
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if (setjmp (expr_jmp_buf) != 0)
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input_line_pointer = (char *) hold;
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*resultP_1 = CGEN_PARSE_OPERAND_RESULT_ERROR;
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return _("illegal operand");
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*strP = input_line_pointer;
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input_line_pointer = hold;
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/* FIXME: Need to check `want'. */
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errmsg = _("illegal operand");
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*resultP = CGEN_PARSE_OPERAND_RESULT_ERROR;
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errmsg = _("missing operand");
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*resultP = CGEN_PARSE_OPERAND_RESULT_ERROR;
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*valueP = exp.X_add_number;
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*resultP = CGEN_PARSE_OPERAND_RESULT_NUMBER;
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*valueP = exp.X_add_number;
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*resultP = CGEN_PARSE_OPERAND_RESULT_REGISTER;
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queue_fixup (opindex, opinfo, &exp);
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*resultP = CGEN_PARSE_OPERAND_RESULT_QUEUED;
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/* md_operand handler to catch unrecognized expressions and halt the
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parsing process so the next entry can be tried.
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??? This could be done differently by adding code to `expression'. */
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gas_cgen_md_operand (expressionP)
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expressionS *expressionP ATTRIBUTE_UNUSED;
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/* Don't longjmp if we're not called from within cgen_parse_operand(). */
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longjmp (expr_jmp_buf, 1);
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/* Finish assembling instruction INSN.
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BUF contains what we've built up so far.
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LENGTH is the size of the insn in bits.
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RELAX_P is non-zero if relaxable insns should be emitted as such.
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Otherwise they're emitted in non-relaxable forms.
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The "result" is stored in RESULT if non-NULL. */
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gas_cgen_finish_insn (insn, buf, length, relax_p, result)
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const CGEN_INSN *insn;
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CGEN_INSN_BYTES_PTR buf;
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finished_insnS *result;
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unsigned int byte_len = length / 8;
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/* ??? Target foo issues various warnings here, so one might want to provide
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a hook here. However, our caller is defined in tc-foo.c so there
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shouldn't be a need for a hook. */
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/* Write out the instruction.
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It is important to fetch enough space in one call to `frag_more'.
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We use (f - frag_now->fr_literal) to compute where we are and we
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don't want frag_now to change between calls.
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Relaxable instructions: We need to ensure we allocate enough
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space for the largest insn. */
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if (CGEN_INSN_ATTR_VALUE (insn, CGEN_INSN_RELAXED))
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/* These currently shouldn't get here. */
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/* Is there a relaxable insn with the relaxable operand needing a fixup? */
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if (relax_p && CGEN_INSN_ATTR_VALUE (insn, CGEN_INSN_RELAXABLE))
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/* Scan the fixups for the operand affected by relaxing
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(i.e. the branch address). */
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for (i = 0; i < num_fixups; ++i)
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if (CGEN_OPERAND_ATTR_VALUE (cgen_operand_lookup_by_num (gas_cgen_cpu_desc, fixups[i].opindex),
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if (relax_operand != -1)
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#ifdef TC_CGEN_MAX_RELAX
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max_len = TC_CGEN_MAX_RELAX (insn, byte_len);
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max_len = CGEN_MAX_INSN_SIZE;
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/* Ensure variable part and fixed part are in same fragment. */
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/* FIXME: Having to do this seems like a hack. */
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/* Allocate space for the fixed part. */
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f = frag_more (byte_len);
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/* Create a relaxable fragment for this instruction. */
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exp = &fixups[relax_operand].exp;
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sym = exp->X_add_symbol;
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off = exp->X_add_number;
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if (exp->X_op != O_constant && exp->X_op != O_symbol)
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/* Handle complex expressions. */
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sym = make_expr_symbol (exp);
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frag_var (rs_machine_dependent,
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max_len - byte_len /* max chars */,
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0 /* variable part already allocated */,
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/* FIXME: When we machine generate the relax table,
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machine generate a macro to compute subtype. */
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/* Record the operand number with the fragment so md_convert_frag
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can use gas_cgen_md_record_fixup to record the appropriate reloc. */
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old_frag->fr_cgen.insn = insn;
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old_frag->fr_cgen.opindex = fixups[relax_operand].opindex;
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old_frag->fr_cgen.opinfo = fixups[relax_operand].opinfo;
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result->frag = old_frag;
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f = frag_more (byte_len);
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result->frag = frag_now;
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/* If we're recording insns as numbers (rather than a string of bytes),
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target byte order handling is deferred until now. */
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cgen_put_insn_value (gas_cgen_cpu_desc, f, length, *buf);
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memcpy (f, buf, byte_len);
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/* Emit DWARF2 debugging information. */
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dwarf2_emit_insn (byte_len);
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/* Create any fixups. */
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for (i = 0; i < num_fixups; ++i)
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const CGEN_OPERAND *operand =
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cgen_operand_lookup_by_num (gas_cgen_cpu_desc, fixups[i].opindex);
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/* Don't create fixups for these. That's done during relaxation.
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We don't need to test for CGEN_INSN_RELAXED as they can't get here
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&& CGEN_INSN_ATTR_VALUE (insn, CGEN_INSN_RELAXABLE)
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&& CGEN_OPERAND_ATTR_VALUE (operand, CGEN_OPERAND_RELAX))
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#ifndef md_cgen_record_fixup_exp
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#define md_cgen_record_fixup_exp gas_cgen_record_fixup_exp
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fixP = md_cgen_record_fixup_exp (frag_now, f - frag_now->fr_literal,
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insn, length, operand,
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result->fixups[i] = fixP;
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result->num_fixups = num_fixups;
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/* Apply a fixup to the object code. This is called for all the
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fixups we generated by the call to fix_new_exp, above. In the call
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above we used a reloc code which was the largest legal reloc code
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plus the operand index. Here we undo that to recover the operand
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index. At this point all symbol values should be fully resolved,
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and we attempt to completely resolve the reloc. If we can not do
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that, we determine the correct reloc code and put it back in the fixup. */
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/* FIXME: This function handles some of the fixups and bfd_install_relocation
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handles the rest. bfd_install_relocation (or some other bfd function)
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should handle them all. */
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gas_cgen_md_apply_fix3 (fixP, valP, seg)
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segT seg ATTRIBUTE_UNUSED;
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char *where = fixP->fx_frag->fr_literal + fixP->fx_where;
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valueT value = * valP;
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/* Canonical name, since used a lot. */
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CGEN_CPU_DESC cd = gas_cgen_cpu_desc;
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if (fixP->fx_addsy == (symbolS *) NULL)
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/* We don't actually support subtracting a symbol. */
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if (fixP->fx_subsy != (symbolS *) NULL)
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as_bad_where (fixP->fx_file, fixP->fx_line, _("expression too complex"));
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if ((int) fixP->fx_r_type >= (int) BFD_RELOC_UNUSED)
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int opindex = (int) fixP->fx_r_type - (int) BFD_RELOC_UNUSED;
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const CGEN_OPERAND *operand = cgen_operand_lookup_by_num (cd, opindex);
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bfd_reloc_code_real_type reloc_type;
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CGEN_FIELDS *fields = alloca (CGEN_CPU_SIZEOF_FIELDS (cd));
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const CGEN_INSN *insn = fixP->fx_cgen.insn;
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/* If the reloc has been fully resolved finish the operand here. */
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/* FIXME: This duplicates the capabilities of code in BFD. */
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/* FIXME: If partial_inplace isn't set bfd_install_relocation won't
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finish the job. Testing for pcrel is a temporary hack. */
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CGEN_CPU_SET_FIELDS_BITSIZE (cd) (fields, CGEN_INSN_BITSIZE (insn));
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CGEN_CPU_SET_VMA_OPERAND (cd) (cd, opindex, fields, (bfd_vma) value);
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CGEN_INSN_INT insn_value =
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cgen_get_insn_value (cd, where, CGEN_INSN_BITSIZE (insn));
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/* ??? 0 is passed for `pc'. */
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errmsg = CGEN_CPU_INSERT_OPERAND (cd) (cd, opindex, fields,
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&insn_value, (bfd_vma) 0);
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cgen_put_insn_value (cd, where, CGEN_INSN_BITSIZE (insn),
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/* ??? 0 is passed for `pc'. */
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errmsg = CGEN_CPU_INSERT_OPERAND (cd) (cd, opindex, fields, where,
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as_bad_where (fixP->fx_file, fixP->fx_line, "%s", errmsg);
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/* The operand isn't fully resolved. Determine a BFD reloc value
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based on the operand information and leave it to
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bfd_install_relocation. Note that this doesn't work when
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partial_inplace == false. */
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reloc_type = md_cgen_lookup_reloc (insn, operand, fixP);
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if (reloc_type != BFD_RELOC_NONE)
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fixP->fx_r_type = reloc_type;
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as_bad_where (fixP->fx_file, fixP->fx_line,
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_("unresolved expression that must be resolved"));
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else if (fixP->fx_done)
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/* We're finished with this fixup. Install it because
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bfd_install_relocation won't be called to do it. */
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switch (fixP->fx_r_type)
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md_number_to_chars (where, value, 1);
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md_number_to_chars (where, value, 2);
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md_number_to_chars (where, value, 4);
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md_number_to_chars (where, value, 8);
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as_bad_where (fixP->fx_file, fixP->fx_line,
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_("internal error: can't install fix for reloc type %d (`%s')"),
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fixP->fx_r_type, bfd_get_reloc_code_name (fixP->fx_r_type));
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bfd_install_relocation will be called to finish things up. */
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/* Tuck `value' away for use by tc_gen_reloc.
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See the comment describing fx_addnumber in write.h.
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This field is misnamed (or misused :-). */
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fixP->fx_addnumber = value;
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/* Translate internal representation of relocation info to BFD target format.
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FIXME: To what extent can we get all relevant targets to use this? */
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gas_cgen_tc_gen_reloc (section, fixP)
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asection * section ATTRIBUTE_UNUSED;
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reloc = (arelent *) xmalloc (sizeof (arelent));
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reloc->howto = bfd_reloc_type_lookup (stdoutput, fixP->fx_r_type);
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if (reloc->howto == (reloc_howto_type *) NULL)
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as_bad_where (fixP->fx_file, fixP->fx_line,
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_("relocation is not supported"));
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assert (!fixP->fx_pcrel == !reloc->howto->pc_relative);
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reloc->sym_ptr_ptr = (asymbol **) xmalloc (sizeof (asymbol *));
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*reloc->sym_ptr_ptr = symbol_get_bfdsym (fixP->fx_addsy);
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/* Use fx_offset for these cases. */
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if (fixP->fx_r_type == BFD_RELOC_VTABLE_ENTRY
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|| fixP->fx_r_type == BFD_RELOC_VTABLE_INHERIT)
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reloc->addend = fixP->fx_offset;
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reloc->addend = fixP->fx_addnumber;
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reloc->address = fixP->fx_frag->fr_address + fixP->fx_where;
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/* Perform any cgen specific initialisation.
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Called after gas_cgen_cpu_desc has been created. */
726
if (flag_signed_overflow_ok)
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cgen_set_signed_overflow_ok (gas_cgen_cpu_desc);
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cgen_clear_signed_overflow_ok (gas_cgen_cpu_desc);