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asm.h
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1 /* -----------------------------------------------------------------------
2 asm.h - Copyright (c) 1998 Geoffrey Keating
3
4 PowerPC Assembly glue.
5
6 Permission is hereby granted, free of charge, to any person obtaining
7 a copy of this software and associated documentation files (the
8 ``Software''), to deal in the Software without restriction, including
9 without limitation the rights to use, copy, modify, merge, publish,
10 distribute, sublicense, and/or sell copies of the Software, and to
11 permit persons to whom the Software is furnished to do so, subject to
12 the following conditions:
13
14 The above copyright notice and this permission notice shall be included
15 in all copies or substantial portions of the Software.
16
17 THE SOFTWARE IS PROVIDED ``AS IS'', WITHOUT WARRANTY OF ANY KIND, EXPRESS
18 OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
19 MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
20 IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY CLAIM, DAMAGES OR
21 OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
22 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR
23 OTHER DEALINGS IN THE SOFTWARE.
24 ----------------------------------------------------------------------- */
25
26 #define ASM_GLOBAL_DIRECTIVE .globl
27
28
29 #define C_SYMBOL_NAME(name) name
30 /* Macro for a label. */
31 #ifdef __STDC__
32 #define C_LABEL(name) name##:
33 #else
34 #define C_LABEL(name) name:
35 #endif
36
37 /* This seems to always be the case on PPC. */
38 #define ALIGNARG(log2) log2
39 /* For ELF we need the `.type' directive to make shared libs work right. */
40 #define ASM_TYPE_DIRECTIVE(name,typearg) .type name,typearg;
41 #define ASM_SIZE_DIRECTIVE(name) .size name,.-name
42
43 /* If compiled for profiling, call `_mcount' at the start of each function. */
44 #ifdef PROF
45 /* The mcount code relies on the return address being on the stack
46 to locate our caller and so it can restore it; so store one just
47 for its benefit. */
48 #ifdef PIC
49 #define CALL_MCOUNT \
50 .pushsection; \
51 .section ".data"; \
52 .align ALIGNARG(2); \
53 0:.long 0; \
54 .previous; \
55 mflr %r0; \
56 stw %r0,4(%r1); \
57 bl _GLOBAL_OFFSET_TABLE_@local-4; \
58 mflr %r11; \
59 lwz %r0,0b@got(%r11); \
60 bl JUMPTARGET(_mcount);
61 #else /* PIC */
62 #define CALL_MCOUNT \
63 .section ".data"; \
64 .align ALIGNARG(2); \
65 0:.long 0; \
66 .previous; \
67 mflr %r0; \
68 lis %r11,0b@ha; \
69 stw %r0,4(%r1); \
70 addi %r0,%r11,0b@l; \
71 bl JUMPTARGET(_mcount);
72 #endif /* PIC */
73 #else /* PROF */
74 #define CALL_MCOUNT /* Do nothing. */
75 #endif /* PROF */
76
77 #define ENTRY(name) \
78 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \
79 ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function) \
80 .align ALIGNARG(2); \
81 C_LABEL(name) \
82 CALL_MCOUNT
83
84 #define EALIGN_W_0 /* No words to insert. */
85 #define EALIGN_W_1 nop
86 #define EALIGN_W_2 nop;nop
87 #define EALIGN_W_3 nop;nop;nop
88 #define EALIGN_W_4 EALIGN_W_3;nop
89 #define EALIGN_W_5 EALIGN_W_4;nop
90 #define EALIGN_W_6 EALIGN_W_5;nop
91 #define EALIGN_W_7 EALIGN_W_6;nop
92
93 /* EALIGN is like ENTRY, but does alignment to 'words'*4 bytes
94 past a 2^align boundary. */
95 #ifdef PROF
96 #define EALIGN(name, alignt, words) \
97 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \
98 ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function) \
99 .align ALIGNARG(2); \
100 C_LABEL(name) \
101 CALL_MCOUNT \
102 b 0f; \
103 .align ALIGNARG(alignt); \
104 EALIGN_W_##words; \
105 0:
106 #else /* PROF */
107 #define EALIGN(name, alignt, words) \
108 ASM_GLOBAL_DIRECTIVE C_SYMBOL_NAME(name); \
109 ASM_TYPE_DIRECTIVE (C_SYMBOL_NAME(name),@function) \
110 .align ALIGNARG(alignt); \
111 EALIGN_W_##words; \
112 C_LABEL(name)
113 #endif
114
115 #define END(name) \
116 ASM_SIZE_DIRECTIVE(name)
117
118 #ifdef PIC
119 #define JUMPTARGET(name) name##@plt
120 #else
121 #define JUMPTARGET(name) name
122 #endif
123
124 /* Local labels stripped out by the linker. */
125 #define L(x) .L##x