• Home
  • Line#
  • Scopes#
  • Navigate#
  • Raw
  • Download
1;
2; Copyright (c) 2016, Alliance for Open Media. All rights reserved
3;
4; This source code is subject to the terms of the BSD 2 Clause License and
5; the Alliance for Open Media Patent License 1.0. If the BSD 2 Clause License
6; was not distributed with this source code in the LICENSE file, you can
7; obtain it at www.aomedia.org/license/software. If the Alliance for Open
8; Media Patent License 1.0 was not distributed with this source code in the
9; PATENTS file, you can obtain it at www.aomedia.org/license/patent.
10;
11
12;
13
14
15%include "config/aom_config.asm"
16
17; 32/64 bit compatibility macros
18;
19; In general, we make the source use 64 bit syntax, then twiddle with it using
20; the preprocessor to get the 32 bit syntax on 32 bit platforms.
21;
22%ifidn __OUTPUT_FORMAT__,elf32
23%define ABI_IS_32BIT 1
24%elifidn __OUTPUT_FORMAT__,macho32
25%define ABI_IS_32BIT 1
26%elifidn __OUTPUT_FORMAT__,win32
27%define ABI_IS_32BIT 1
28%elifidn __OUTPUT_FORMAT__,aout
29%define ABI_IS_32BIT 1
30%else
31%define ABI_IS_32BIT 0
32%endif
33
34%if ABI_IS_32BIT
35%define rax eax
36%define rbx ebx
37%define rcx ecx
38%define rdx edx
39%define rsi esi
40%define rdi edi
41%define rsp esp
42%define rbp ebp
43%define movsxd mov
44%macro movq 2
45  %ifidn %1,eax
46    movd %1,%2
47  %elifidn %2,eax
48    movd %1,%2
49  %elifidn %1,ebx
50    movd %1,%2
51  %elifidn %2,ebx
52    movd %1,%2
53  %elifidn %1,ecx
54    movd %1,%2
55  %elifidn %2,ecx
56    movd %1,%2
57  %elifidn %1,edx
58    movd %1,%2
59  %elifidn %2,edx
60    movd %1,%2
61  %elifidn %1,esi
62    movd %1,%2
63  %elifidn %2,esi
64    movd %1,%2
65  %elifidn %1,edi
66    movd %1,%2
67  %elifidn %2,edi
68    movd %1,%2
69  %elifidn %1,esp
70    movd %1,%2
71  %elifidn %2,esp
72    movd %1,%2
73  %elifidn %1,ebp
74    movd %1,%2
75  %elifidn %2,ebp
76    movd %1,%2
77  %else
78    movq %1,%2
79  %endif
80%endmacro
81%endif
82
83
84; LIBAOM_YASM_WIN64
85; Set LIBAOM_YASM_WIN64 if output is Windows 64bit so the code will work if x64
86; or win64 is defined on the Yasm command line.
87%ifidn __OUTPUT_FORMAT__,win64
88%define LIBAOM_YASM_WIN64 1
89%elifidn __OUTPUT_FORMAT__,x64
90%define LIBAOM_YASM_WIN64 1
91%else
92%define LIBAOM_YASM_WIN64 0
93%endif
94
95; Declare groups of platforms
96%ifidn   __OUTPUT_FORMAT__,elf32
97  %define LIBAOM_ELF 1
98%elifidn   __OUTPUT_FORMAT__,elfx32
99  %define LIBAOM_ELF 1
100%elifidn   __OUTPUT_FORMAT__,elf64
101  %define LIBAOM_ELF 1
102%else
103  %define LIBAOM_ELF 0
104%endif
105
106%ifidn __OUTPUT_FORMAT__,macho32
107  %define LIBAOM_MACHO 1
108%elifidn __OUTPUT_FORMAT__,macho64
109  %define LIBAOM_MACHO 1
110%else
111  %define LIBAOM_MACHO 0
112%endif
113
114; sym()
115; Return the proper symbol name for the target ABI.
116;
117; Certain ABIs, notably MS COFF and Darwin MACH-O, require that symbols
118; with C linkage be prefixed with an underscore.
119;
120%if LIBAOM_ELF || LIBAOM_YASM_WIN64
121  %define sym(x) x
122%else
123  ; Mach-O / COFF
124  %define sym(x) _ %+ x
125%endif
126
127; globalsym()
128; Return a global declaration with the proper decoration for the target ABI.
129;
130; When CHROMIUM is defined, include attributes to hide the symbol from the
131; global namespace.
132;
133; Chromium doesn't like exported global symbols due to symbol clashing with
134; plugins among other things.
135;
136; Requires Chromium's patched copy of yasm:
137;   http://src.chromium.org/viewvc/chrome?view=rev&revision=73761
138;   http://www.tortall.net/projects/yasm/ticket/236
139; or nasm > 2.14.
140;
141%ifdef CHROMIUM
142  %ifdef __NASM_VER__
143    %if __NASM_VERSION_ID__ < 0x020e0000 ; 2.14
144      ; nasm < 2.14 does not support :private_extern directive
145      %fatal Must use nasm 2.14 or newer
146    %endif
147  %endif
148
149  %if LIBAOM_ELF
150    %define globalsym(x) global sym(x) %+ :function hidden
151  %elif LIBAOM_MACHO
152    %define globalsym(x) global sym(x) %+ :private_extern
153  %else
154    ; COFF / PE32+
155    %define globalsym(x) global sym(x)
156  %endif
157%else
158  %define globalsym(x) global sym(x)
159%endif
160
161; arg()
162; Return the address specification of the given argument
163;
164%if ABI_IS_32BIT
165  %define arg(x) [ebp+8+4*x]
166%else
167  ; 64 bit ABI passes arguments in registers. This is a workaround to get up
168  ; and running quickly. Relies on SHADOW_ARGS_TO_STACK
169  %if LIBAOM_YASM_WIN64
170    %define arg(x) [rbp+16+8*x]
171  %else
172    %define arg(x) [rbp-8-8*x]
173  %endif
174%endif
175
176; REG_SZ_BYTES, REG_SZ_BITS
177; Size of a register
178%if ABI_IS_32BIT
179%define REG_SZ_BYTES 4
180%define REG_SZ_BITS  32
181%else
182%define REG_SZ_BYTES 8
183%define REG_SZ_BITS  64
184%endif
185
186
187; ALIGN_STACK <alignment> <register>
188; This macro aligns the stack to the given alignment (in bytes). The stack
189; is left such that the previous value of the stack pointer is the first
190; argument on the stack (ie, the inverse of this macro is 'pop rsp.')
191; This macro uses one temporary register, which is not preserved, and thus
192; must be specified as an argument.
193%macro ALIGN_STACK 2
194    mov         %2, rsp
195    and         rsp, -%1
196    lea         rsp, [rsp - (%1 - REG_SZ_BYTES)]
197    push        %2
198%endmacro
199
200
201;
202; The Microsoft assembler tries to impose a certain amount of type safety in
203; its register usage. YASM doesn't recognize these directives, so we just
204; %define them away to maintain as much compatibility as possible with the
205; original inline assembler we're porting from.
206;
207%idefine PTR
208%idefine XMMWORD
209%idefine MMWORD
210
211; PIC macros
212;
213%if ABI_IS_32BIT
214  %if CONFIG_PIC=1
215  %ifidn __OUTPUT_FORMAT__,elf32
216    %define WRT_PLT wrt ..plt
217    %macro GET_GOT 1
218      extern _GLOBAL_OFFSET_TABLE_
219      push %1
220      call %%get_got
221      %%sub_offset:
222      jmp %%exitGG
223      %%get_got:
224      mov %1, [esp]
225      add %1, _GLOBAL_OFFSET_TABLE_ + $$ - %%sub_offset wrt ..gotpc
226      ret
227      %%exitGG:
228      %undef GLOBAL
229      %define GLOBAL(x) x + %1 wrt ..gotoff
230      %undef RESTORE_GOT
231      %define RESTORE_GOT pop %1
232    %endmacro
233  %elifidn __OUTPUT_FORMAT__,macho32
234    %macro GET_GOT 1
235      push %1
236      call %%get_got
237      %%get_got:
238      pop  %1
239      %undef GLOBAL
240      %define GLOBAL(x) x + %1 - %%get_got
241      %undef RESTORE_GOT
242      %define RESTORE_GOT pop %1
243    %endmacro
244  %endif
245  %endif
246
247  %ifdef CHROMIUM
248    %ifidn __OUTPUT_FORMAT__,macho32
249      %define HIDDEN_DATA(x) x:private_extern
250    %else
251      %define HIDDEN_DATA(x) x
252    %endif
253  %else
254    %define HIDDEN_DATA(x) x
255  %endif
256%else
257  %macro GET_GOT 1
258  %endmacro
259  %define GLOBAL(x) rel x
260  %ifidn __OUTPUT_FORMAT__,elf64
261    %define WRT_PLT wrt ..plt
262    %define HIDDEN_DATA(x) x:data hidden
263  %elifidn __OUTPUT_FORMAT__,elfx32
264    %define WRT_PLT wrt ..plt
265    %define HIDDEN_DATA(x) x:data hidden
266  %elifidn __OUTPUT_FORMAT__,macho64
267    %ifdef CHROMIUM
268      %define HIDDEN_DATA(x) x:private_extern
269    %else
270      %define HIDDEN_DATA(x) x
271    %endif
272  %else
273    %define HIDDEN_DATA(x) x
274  %endif
275%endif
276%ifnmacro GET_GOT
277    %macro GET_GOT 1
278    %endmacro
279    %define GLOBAL(x) x
280%endif
281%ifndef RESTORE_GOT
282%define RESTORE_GOT
283%endif
284%ifndef WRT_PLT
285%define WRT_PLT
286%endif
287
288%if ABI_IS_32BIT
289  %macro SHADOW_ARGS_TO_STACK 1
290  %endm
291  %define UNSHADOW_ARGS
292%else
293%if LIBAOM_YASM_WIN64
294  %macro SHADOW_ARGS_TO_STACK 1 ; argc
295    %if %1 > 0
296        mov arg(0),rcx
297    %endif
298    %if %1 > 1
299        mov arg(1),rdx
300    %endif
301    %if %1 > 2
302        mov arg(2),r8
303    %endif
304    %if %1 > 3
305        mov arg(3),r9
306    %endif
307  %endm
308%else
309  %macro SHADOW_ARGS_TO_STACK 1 ; argc
310    %if %1 > 0
311        push rdi
312    %endif
313    %if %1 > 1
314        push rsi
315    %endif
316    %if %1 > 2
317        push rdx
318    %endif
319    %if %1 > 3
320        push rcx
321    %endif
322    %if %1 > 4
323        push r8
324    %endif
325    %if %1 > 5
326        push r9
327    %endif
328    %if %1 > 6
329      %assign i %1-6
330      %assign off 16
331      %rep i
332        mov rax,[rbp+off]
333        push rax
334        %assign off off+8
335      %endrep
336    %endif
337  %endm
338%endif
339  %define UNSHADOW_ARGS mov rsp, rbp
340%endif
341
342; Win64 ABI requires that XMM6:XMM15 are callee saved
343; SAVE_XMM n, [u]
344; store registers 6-n on the stack
345; if u is specified, use unaligned movs.
346; Win64 ABI requires 16 byte stack alignment, but then pushes an 8 byte return
347; value. Typically we follow this up with 'push rbp' - re-aligning the stack -
348; but in some cases this is not done and unaligned movs must be used.
349%if LIBAOM_YASM_WIN64
350%macro SAVE_XMM 1-2 a
351  %if %1 < 6
352    %error Only xmm registers 6-15 must be preserved
353  %else
354    %assign last_xmm %1
355    %define movxmm movdq %+ %2
356    %assign xmm_stack_space ((last_xmm - 5) * 16)
357    sub rsp, xmm_stack_space
358    %assign i 6
359    %rep (last_xmm - 5)
360      movxmm [rsp + ((i - 6) * 16)], xmm %+ i
361      %assign i i+1
362    %endrep
363  %endif
364%endmacro
365%macro RESTORE_XMM 0
366  %ifndef last_xmm
367    %error RESTORE_XMM must be paired with SAVE_XMM n
368  %else
369    %assign i last_xmm
370    %rep (last_xmm - 5)
371      movxmm xmm %+ i, [rsp +((i - 6) * 16)]
372      %assign i i-1
373    %endrep
374    add rsp, xmm_stack_space
375    ; there are a couple functions which return from multiple places.
376    ; otherwise, we could uncomment these:
377    ; %undef last_xmm
378    ; %undef xmm_stack_space
379    ; %undef movxmm
380  %endif
381%endmacro
382%else
383%macro SAVE_XMM 1-2
384%endmacro
385%macro RESTORE_XMM 0
386%endmacro
387%endif
388
389; Name of the rodata section
390;
391; .rodata seems to be an elf-ism, as it doesn't work on OSX.
392;
393%ifidn __OUTPUT_FORMAT__,macho64
394%define SECTION_RODATA section .text
395%elifidn __OUTPUT_FORMAT__,macho32
396%macro SECTION_RODATA 0
397section .text
398%endmacro
399%elifidn __OUTPUT_FORMAT__,aout
400%define SECTION_RODATA section .data
401%else
402%define SECTION_RODATA section .rodata
403%endif
404
405
406; Tell GNU ld that we don't require an executable stack.
407%ifidn __OUTPUT_FORMAT__,elf32
408section .note.GNU-stack noalloc noexec nowrite progbits
409section .text
410%elifidn __OUTPUT_FORMAT__,elf64
411section .note.GNU-stack noalloc noexec nowrite progbits
412section .text
413%elifidn __OUTPUT_FORMAT__,elfx32
414section .note.GNU-stack noalloc noexec nowrite progbits
415section .text
416%endif
417