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acf6404e KR |
1 | /* as.c - GAS literal pool management. |
2 | Copyright (C) 1994 Free Software Foundation, Inc. | |
19302e44 | 3 | Written by Ken Raeburn (raeburn@cygnus.com). |
acf6404e KR |
4 | |
5 | This file is part of GAS, the GNU Assembler. | |
6 | ||
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) | |
10 | any later version. | |
11 | ||
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. | |
16 | ||
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, 675 Mass Ave, Cambridge, MA 02139, USA. */ | |
20 | ||
21 | /* This isn't quite a "constant" pool. Some of the values may get | |
22 | adjusted at run time, e.g., for symbolic relocations when shared | |
23 | libraries are in use. It's more of a "literal" pool. | |
24 | ||
25 | On the Alpha, this should be used for .lita and .lit8. (Is there | |
26 | ever a .lit4?) On the MIPS, it could be used for .lit4 as well. | |
27 | ||
28 | The expressions passed here should contain either constants or symbols, | |
d5bd8e85 | 29 | not a combination of both. Typically, the constant pool is accessed |
acf6404e KR |
30 | with some sort of GP register, so the size of the pool must be kept down |
31 | if possible. The exception is section offsets -- if you're storing a | |
32 | pointer to the start of .data, for example, and your machine provides | |
33 | for 16-bit signed addends, you might want to store .data+32K, so that | |
d5bd8e85 KR |
34 | you can access all of the first 64K of .data with the one pointer. |
35 | ||
36 | This isn't a requirement, just a guideline that can help keep .o file | |
37 | size down. */ | |
acf6404e KR |
38 | |
39 | #include "as.h" | |
40 | #include "subsegs.h" | |
41 | ||
42 | #if defined (BFD_ASSEMBLER) && defined (NEED_LITERAL_POOL) | |
43 | ||
44 | valueT | |
45 | add_to_literal_pool (sym, addend, sec, size) | |
46 | symbolS *sym; | |
47 | valueT addend; | |
48 | segT sec; | |
49 | int size; | |
50 | { | |
51 | segT current_section = now_seg; | |
52 | int current_subsec = now_subseg; | |
53 | valueT offset; | |
54 | bfd_reloc_code_real_type reloc_type; | |
55 | char *p; | |
19302e44 KR |
56 | segment_info_type *seginfo = seg_info (sec); |
57 | fixS *fixp; | |
58 | ||
59 | offset = 0; | |
60 | /* @@ This assumes all entries in a given section will be of the same | |
61 | size... Probably correct, but unwise to rely on. */ | |
62 | for (fixp = seginfo->fix_root; fixp; fixp = fixp->fx_next, offset += size) | |
63 | { | |
64 | if (fixp->fx_addsy == sym && fixp->fx_offset == addend) | |
65 | return offset; | |
66 | } | |
acf6404e KR |
67 | |
68 | subseg_set (sec, 0); | |
69 | p = frag_more (size); | |
70 | memset (p, 0, size); | |
71 | ||
72 | switch (size) | |
73 | { | |
74 | case 4: | |
75 | reloc_type = BFD_RELOC_32; | |
76 | break; | |
77 | case 8: | |
78 | reloc_type = BFD_RELOC_64; | |
79 | break; | |
80 | default: | |
81 | abort (); | |
82 | } | |
83 | fix_new (frag_now, p - frag_now->fr_literal, size, sym, addend, 0, | |
84 | reloc_type); | |
85 | ||
86 | subseg_set (current_section, current_subsec); | |
87 | ||
19302e44 KR |
88 | offset = seginfo->literal_pool_size; |
89 | seginfo->literal_pool_size += size; | |
acf6404e KR |
90 | |
91 | return offset; | |
92 | } | |
93 | #endif /* BFD_ASSEMBLER */ |