1*a9fa9459Szrj /* literal.c - GAS literal pool management.
2*a9fa9459Szrj Copyright (C) 1994-2016 Free Software Foundation, Inc.
3*a9fa9459Szrj Written by Ken Raeburn (raeburn@cygnus.com).
4*a9fa9459Szrj
5*a9fa9459Szrj This file is part of GAS, the GNU Assembler.
6*a9fa9459Szrj
7*a9fa9459Szrj GAS is free software; you can redistribute it and/or modify
8*a9fa9459Szrj it under the terms of the GNU General Public License as published by
9*a9fa9459Szrj the Free Software Foundation; either version 3, or (at your option)
10*a9fa9459Szrj any later version.
11*a9fa9459Szrj
12*a9fa9459Szrj GAS is distributed in the hope that it will be useful,
13*a9fa9459Szrj but WITHOUT ANY WARRANTY; without even the implied warranty of
14*a9fa9459Szrj MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15*a9fa9459Szrj GNU General Public License for more details.
16*a9fa9459Szrj
17*a9fa9459Szrj You should have received a copy of the GNU General Public License
18*a9fa9459Szrj along with GAS; see the file COPYING. If not, write to
19*a9fa9459Szrj the Free Software Foundation, 51 Franklin Street - Fifth Floor,
20*a9fa9459Szrj Boston, MA 02110-1301, USA. */
21*a9fa9459Szrj
22*a9fa9459Szrj /* This isn't quite a "constant" pool. Some of the values may get
23*a9fa9459Szrj adjusted at run time, e.g., for symbolic relocations when shared
24*a9fa9459Szrj libraries are in use. It's more of a "literal" pool.
25*a9fa9459Szrj
26*a9fa9459Szrj On the Alpha, this should be used for .lita and .lit8. (Is there
27*a9fa9459Szrj ever a .lit4?) On the MIPS, it could be used for .lit4 as well.
28*a9fa9459Szrj
29*a9fa9459Szrj The expressions passed here should contain either constants or symbols,
30*a9fa9459Szrj not a combination of both. Typically, the constant pool is accessed
31*a9fa9459Szrj with some sort of GP register, so the size of the pool must be kept down
32*a9fa9459Szrj if possible. The exception is section offsets -- if you're storing a
33*a9fa9459Szrj pointer to the start of .data, for example, and your machine provides
34*a9fa9459Szrj for 16-bit signed addends, you might want to store .data+32K, so that
35*a9fa9459Szrj you can access all of the first 64K of .data with the one pointer.
36*a9fa9459Szrj
37*a9fa9459Szrj This isn't a requirement, just a guideline that can help keep .o file
38*a9fa9459Szrj size down. */
39*a9fa9459Szrj
40*a9fa9459Szrj #include "as.h"
41*a9fa9459Szrj #include "subsegs.h"
42*a9fa9459Szrj
43*a9fa9459Szrj #ifdef NEED_LITERAL_POOL
44*a9fa9459Szrj
45*a9fa9459Szrj valueT
add_to_literal_pool(symbolS * sym,valueT addend,segT sec,int size)46*a9fa9459Szrj add_to_literal_pool (symbolS *sym, valueT addend, segT sec, int size)
47*a9fa9459Szrj {
48*a9fa9459Szrj segT current_section = now_seg;
49*a9fa9459Szrj int current_subsec = now_subseg;
50*a9fa9459Szrj valueT offset;
51*a9fa9459Szrj bfd_reloc_code_real_type reloc_type;
52*a9fa9459Szrj char *p;
53*a9fa9459Szrj segment_info_type *seginfo = seg_info (sec);
54*a9fa9459Szrj fixS *fixp;
55*a9fa9459Szrj
56*a9fa9459Szrj offset = 0;
57*a9fa9459Szrj /* @@ This assumes all entries in a given section will be of the same
58*a9fa9459Szrj size... Probably correct, but unwise to rely on. */
59*a9fa9459Szrj /* This must always be called with the same subsegment. */
60*a9fa9459Szrj if (seginfo->frchainP)
61*a9fa9459Szrj for (fixp = seginfo->frchainP->fix_root;
62*a9fa9459Szrj fixp != (fixS *) NULL;
63*a9fa9459Szrj fixp = fixp->fx_next, offset += size)
64*a9fa9459Szrj {
65*a9fa9459Szrj if (fixp->fx_addsy == sym && fixp->fx_offset == addend)
66*a9fa9459Szrj return offset;
67*a9fa9459Szrj }
68*a9fa9459Szrj
69*a9fa9459Szrj subseg_set (sec, 0);
70*a9fa9459Szrj p = frag_more (size);
71*a9fa9459Szrj memset (p, 0, size);
72*a9fa9459Szrj
73*a9fa9459Szrj switch (size)
74*a9fa9459Szrj {
75*a9fa9459Szrj case 4:
76*a9fa9459Szrj reloc_type = BFD_RELOC_32;
77*a9fa9459Szrj break;
78*a9fa9459Szrj case 8:
79*a9fa9459Szrj reloc_type = BFD_RELOC_64;
80*a9fa9459Szrj break;
81*a9fa9459Szrj default:
82*a9fa9459Szrj abort ();
83*a9fa9459Szrj }
84*a9fa9459Szrj fix_new (frag_now, p - frag_now->fr_literal, size, sym, addend, 0,
85*a9fa9459Szrj reloc_type);
86*a9fa9459Szrj
87*a9fa9459Szrj subseg_set (current_section, current_subsec);
88*a9fa9459Szrj offset = seginfo->literal_pool_size;
89*a9fa9459Szrj seginfo->literal_pool_size += size;
90*a9fa9459Szrj return offset;
91*a9fa9459Szrj }
92*a9fa9459Szrj #endif
93