vpx_ports/x86_abi_support.asm

   1 ;
   2 ;  Copyright (c) 2010 The WebM project authors. All Rights Reserved.
   3 ;
   4 ;  Use of this source code is governed by a BSD-style license
   5 ;  that can be found in the LICENSE file in the root of the source
   6 ;  tree. An additional intellectual property rights grant can be found
   7 ;  in the file PATENTS.  All contributing project authors may
   8 ;  be found in the AUTHORS file in the root of the source tree.
   9 ;
  10
  11
  12 %include "vpx_config.asm"
  13
  14 ; 32/64 bit compatibility macros
  15 ;
  16 ; In general, we make the source use 64 bit syntax, then twiddle with it using
  17 ; the preprocessor to get the 32 bit syntax on 32 bit platforms.
  18 ;
  19 %ifidn __OUTPUT_FORMAT__,elf32
  20 %define ABI_IS_32BIT 1
  21 %elifidn __OUTPUT_FORMAT__,macho32
  22 %define ABI_IS_32BIT 1
  23 %elifidn __OUTPUT_FORMAT__,win32
  24 %define ABI_IS_32BIT 1
  25 %else
  26 %define ABI_IS_32BIT 0
  27 %endif
  28
  29 %if ABI_IS_32BIT
  30 %define rax eax
  31 %define rbx ebx
  32 %define rcx ecx
  33 %define rdx edx
  34 %define rsi esi
  35 %define rdi edi
  36 %define rsp esp
  37 %define rbp ebp
  38 %define movsxd mov
  39 %macro movq 2
  40   %ifidn %1,eax
  41     movd %1,%2
  42   %elifidn %2,eax
  43     movd %1,%2
  44   %elifidn %1,ebx
  45     movd %1,%2
  46   %elifidn %2,ebx
  47     movd %1,%2
  48   %elifidn %1,ecx
  49     movd %1,%2
  50   %elifidn %2,ecx
  51     movd %1,%2
  52   %elifidn %1,edx
  53     movd %1,%2
  54   %elifidn %2,edx
  55     movd %1,%2
  56   %elifidn %1,esi
  57     movd %1,%2
  58   %elifidn %2,esi
  59     movd %1,%2
  60   %elifidn %1,edi
  61     movd %1,%2
  62   %elifidn %2,edi
  63     movd %1,%2
  64   %elifidn %1,esp
  65     movd %1,%2
  66   %elifidn %2,esp
  67     movd %1,%2
  68   %elifidn %1,ebp
  69     movd %1,%2
  70   %elifidn %2,ebp
  71     movd %1,%2
  72   %else
  73     movq %1,%2
  74   %endif
  75 %endmacro
  76 %endif
  77
  78
  79 ; sym()
  80 ; Return the proper symbol name for the target ABI.
  81 ;
  82 ; Certain ABIs, notably MS COFF and Darwin MACH-O, require that symbols
  83 ; with C linkage be prefixed with an underscore.
  84 ;
  85 %ifidn   __OUTPUT_FORMAT__,elf32
  86 %define sym(x) x
  87 %elifidn __OUTPUT_FORMAT__,elf64
  88 %define sym(x) x
  89 %elifidn __OUTPUT_FORMAT__,x64
  90 %define sym(x) x
  91 %else
  92 %define sym(x) _ %+ x
  93 %endif
  94
  95 ; arg()
  96 ; Return the address specification of the given argument
  97 ;
  98 %if ABI_IS_32BIT
  99   %define arg(x) [ebp+8+4*x]
 100 %else
 101   ; 64 bit ABI passes arguments in registers. This is a workaround to get up
 102   ; and running quickly. Relies on SHADOW_ARGS_TO_STACK
 103   %ifidn __OUTPUT_FORMAT__,x64
 104     %define arg(x) [rbp+16+8*x]
 105   %else
 106     %define arg(x) [rbp-8-8*x]
 107   %endif
 108 %endif
 109
 110 ; REG_SZ_BYTES, REG_SZ_BITS
 111 ; Size of a register
 112 %if ABI_IS_32BIT
 113 %define REG_SZ_BYTES 4
 114 %define REG_SZ_BITS  32
 115 %else
 116 %define REG_SZ_BYTES 8
 117 %define REG_SZ_BITS  64
 118 %endif
 119
 120
 121 ; ALIGN_STACK <alignment> <register>
 122 ; This macro aligns the stack to the given alignment (in bytes). The stack
 123 ; is left such that the previous value of the stack pointer is the first
 124 ; argument on the stack (ie, the inverse of this macro is 'pop rsp.')
 125 ; This macro uses one temporary register, which is not preserved, and thus
 126 ; must be specified as an argument.
 127 %macro ALIGN_STACK 2
 128     mov         %2, rsp
 129     and         rsp, -%1
 130     lea         rsp, [rsp - (%1 - REG_SZ_BYTES)]
 131     push        %2
 132 %endmacro
 133
 134
 135 ;
 136 ; The Microsoft assembler tries to impose a certain amount of type safety in
 137 ; its register usage. YASM doesn't recognize these directives, so we just
 138 ; %define them away to maintain as much compatibility as possible with the
 139 ; original inline assembler we're porting from.
 140 ;
 141 %idefine PTR
 142 %idefine XMMWORD
 143 %idefine MMWORD
 144
 145 ; PIC macros
 146 ;
 147 %if ABI_IS_32BIT
 148   %if CONFIG_PIC=1
 149   %ifidn __OUTPUT_FORMAT__,elf32
 150     %define WRT_PLT wrt ..plt
 151     %macro GET_GOT 1
 152       extern _GLOBAL_OFFSET_TABLE_
 153       push %1
 154       call %%get_got
 155       %%sub_offset:
 156       jmp %%exitGG
 157       %%get_got:
 158       mov %1, [esp]
 159       add %1, _GLOBAL_OFFSET_TABLE_ + $$ - %%sub_offset wrt ..gotpc
 160       ret
 161       %%exitGG:
 162       %undef GLOBAL
 163       %define GLOBAL(x) x + %1 wrt ..gotoff
 164       %undef RESTORE_GOT
 165       %define RESTORE_GOT pop %1
 166     %endmacro
 167   %elifidn __OUTPUT_FORMAT__,macho32
 168     %macro GET_GOT 1
 169       push %1
 170       call %%get_got
 171       %%get_got:
 172       pop  %1
 173       %undef GLOBAL
 174       %define GLOBAL(x) x + %1 - %%get_got
 175       %undef RESTORE_GOT
 176       %define RESTORE_GOT pop %1
 177     %endmacro
 178   %endif
 179   %endif
 180   %define HIDDEN_DATA(x) x
 181 %else
 182   %macro GET_GOT 1
 183   %endmacro
 184   %define GLOBAL(x) rel x
 185   %ifidn __OUTPUT_FORMAT__,elf64
 186     %define WRT_PLT wrt ..plt
 187     %define HIDDEN_DATA(x) x:data hidden
 188   %else
 189     %define HIDDEN_DATA(x) x
 190   %endif
 191 %endif
 192 %ifnmacro GET_GOT
 193     %macro GET_GOT 1
 194     %endmacro
 195     %define GLOBAL(x) x
 196 %endif
 197 %ifndef RESTORE_GOT
 198 %define RESTORE_GOT
 199 %endif
 200 %ifndef WRT_PLT
 201 %define WRT_PLT
 202 %endif
 203
 204 %if ABI_IS_32BIT
 205   %macro SHADOW_ARGS_TO_STACK 1
 206   %endm
 207   %define UNSHADOW_ARGS
 208 %else
 209 %ifidn __OUTPUT_FORMAT__,x64
 210   %macro SHADOW_ARGS_TO_STACK 1 ; argc
 211     %if %1 > 0
 212         mov arg(0),rcx
 213     %endif
 214     %if %1 > 1
 215         mov arg(1),rdx
 216     %endif
 217     %if %1 > 2
 218         mov arg(2),r8
 219     %endif
 220     %if %1 > 3
 221         mov arg(3),r9
 222     %endif
 223   %endm
 224 %else
 225   %macro SHADOW_ARGS_TO_STACK 1 ; argc
 226     %if %1 > 0
 227         push rdi
 228     %endif
 229     %if %1 > 1
 230         push rsi
 231     %endif
 232     %if %1 > 2
 233         push rdx
 234     %endif
 235     %if %1 > 3
 236         push rcx
 237     %endif
 238     %if %1 > 4
 239         push r8
 240     %endif
 241     %if %1 > 5
 242         push r9
 243     %endif
 244     %if %1 > 6
 245       %assign i %1-6
 246       %assign off 16
 247       %rep i
 248         mov rax,[rbp+off]
 249         push rax
 250         %assign off off+8
 251       %endrep
 252     %endif
 253   %endm
 254 %endif
 255   %define UNSHADOW_ARGS mov rsp, rbp
 256 %endif
 257
 258 ; Win64 ABI requires that XMM6:XMM15 are callee saved
 259 ; SAVE_XMM n, [u]
 260 ; store registers 6-n on the stack
 261 ; if u is specified, use unaligned movs.
 262 ; Win64 ABI requires 16 byte stack alignment, but then pushes an 8 byte return
 263 ; value. Typically we follow this up with 'push rbp' - re-aligning the stack -
 264 ; but in some cases this is not done and unaligned movs must be used.
 265 %ifidn __OUTPUT_FORMAT__,x64
 266 %macro SAVE_XMM 1-2 a
 267   %if %1 < 6
 268     %error Only xmm registers 6-15 must be preserved
 269   %else
 270     %assign last_xmm %1
 271     %define movxmm movdq %+ %2
 272     %assign xmm_stack_space ((last_xmm - 5) * 16)
 273     sub rsp, xmm_stack_space
 274     %assign i 6
 275     %rep (last_xmm - 5)
 276       movxmm [rsp + ((i - 6) * 16)], xmm %+ i
 277       %assign i i+1
 278     %endrep
 279   %endif
 280 %endmacro
 281 %macro RESTORE_XMM 0
 282   %ifndef last_xmm
 283     %error RESTORE_XMM must be paired with SAVE_XMM n
 284   %else
 285     %assign i last_xmm
 286     %rep (last_xmm - 5)
 287       movxmm xmm %+ i, [rsp +((i - 6) * 16)]
 288       %assign i i-1
 289     %endrep
 290     add rsp, xmm_stack_space
 291     ; there are a couple functions which return from multiple places.
 292     ; otherwise, we could uncomment these:
 293     ; %undef last_xmm
 294     ; %undef xmm_stack_space
 295     ; %undef movxmm
 296   %endif
 297 %endmacro
 298 %else
 299 %macro SAVE_XMM 1-2
 300 %endmacro
 301 %macro RESTORE_XMM 0
 302 %endmacro
 303 %endif
 304
 305 ; Name of the rodata section
 306 ;
 307 ; .rodata seems to be an elf-ism, as it doesn't work on OSX.
 308 ;
 309 %ifidn __OUTPUT_FORMAT__,macho64
 310 %define SECTION_RODATA section .text
 311 %elifidn __OUTPUT_FORMAT__,macho32
 312 %macro SECTION_RODATA 0
 313 section .text
 314 %endmacro
 315 %else
 316 %define SECTION_RODATA section .rodata
 317 %endif
 318
 319
 320 ; Tell GNU ld that we don't require an executable stack.
 321 %ifidn __OUTPUT_FORMAT__,elf32
 322 section .note.GNU-stack noalloc noexec nowrite progbits
 323 section .text
 324 %elifidn __OUTPUT_FORMAT__,elf64
 325 section .note.GNU-stack noalloc noexec nowrite progbits
 326 section .text
 327 %endif
 328