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93 lines
3.0 KiB
C
93 lines
3.0 KiB
C
/* literal.c - GAS literal pool management.
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Copyright (C) 1994-2020 Free Software Foundation, Inc.
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Written by Ken Raeburn (raeburn@cygnus.com).
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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 3, or (at your option)
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any later version.
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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
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the Free Software Foundation, 51 Franklin Street - Fifth Floor,
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Boston, MA 02110-1301, USA. */
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/* This isn't quite a "constant" pool. Some of the values may get
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adjusted at run time, e.g., for symbolic relocations when shared
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libraries are in use. It's more of a "literal" pool.
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On the Alpha, this should be used for .lita and .lit8. (Is there
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ever a .lit4?) On the MIPS, it could be used for .lit4 as well.
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The expressions passed here should contain either constants or symbols,
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not a combination of both. Typically, the constant pool is accessed
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with some sort of GP register, so the size of the pool must be kept down
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if possible. The exception is section offsets -- if you're storing a
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pointer to the start of .data, for example, and your machine provides
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for 16-bit signed addends, you might want to store .data+32K, so that
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you can access all of the first 64K of .data with the one pointer.
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This isn't a requirement, just a guideline that can help keep .o file
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size down. */
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#include "as.h"
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#include "subsegs.h"
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#ifdef NEED_LITERAL_POOL
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valueT
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add_to_literal_pool (symbolS *sym, valueT addend, segT sec, int size)
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{
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segT current_section = now_seg;
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int current_subsec = now_subseg;
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valueT offset;
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bfd_reloc_code_real_type reloc_type;
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char *p;
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segment_info_type *seginfo = seg_info (sec);
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fixS *fixp;
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offset = 0;
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/* @@ This assumes all entries in a given section will be of the same
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size... Probably correct, but unwise to rely on. */
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/* This must always be called with the same subsegment. */
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if (seginfo->frchainP)
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for (fixp = seginfo->frchainP->fix_root;
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fixp != (fixS *) NULL;
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fixp = fixp->fx_next, offset += size)
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{
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if (fixp->fx_addsy == sym && fixp->fx_offset == addend)
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return offset;
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}
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subseg_set (sec, 0);
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p = frag_more (size);
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memset (p, 0, size);
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switch (size)
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{
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case 4:
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reloc_type = BFD_RELOC_32;
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break;
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case 8:
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reloc_type = BFD_RELOC_64;
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break;
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default:
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abort ();
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}
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fix_new (frag_now, p - frag_now->fr_literal, size, sym, addend, 0,
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reloc_type);
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subseg_set (current_section, current_subsec);
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offset = seginfo->literal_pool_size;
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seginfo->literal_pool_size += size;
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return offset;
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}
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#endif
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