1; 2; jchuff-sse2.asm - Huffman entropy encoding (SSE2) 3; 4; Copyright 2009-2011, 2014-2016 D. R. Commander. 5; Copyright 2015 Matthieu Darbois 6; 7; Based on 8; x86 SIMD extension for IJG JPEG library 9; Copyright (C) 1999-2006, MIYASAKA Masaru. 10; For conditions of distribution and use, see copyright notice in jsimdext.inc 11; 12; This file should be assembled with NASM (Netwide Assembler), 13; can *not* be assembled with Microsoft's MASM or any compatible 14; assembler (including Borland's Turbo Assembler). 15; NASM is available from http://nasm.sourceforge.net/ or 16; http://sourceforge.net/project/showfiles.php?group_id=6208 17; 18; This file contains an SSE2 implementation for Huffman coding of one block. 19; The following code is based directly on jchuff.c; see jchuff.c for more 20; details. 21; 22; [TAB8] 23 24%include "jsimdext.inc" 25 26; -------------------------------------------------------------------------- 27 SECTION SEG_CONST 28 29 alignz 16 30 global EXTN(jconst_huff_encode_one_block) PRIVATE 31 32EXTN(jconst_huff_encode_one_block): 33 34%include "jpeg_nbits_table.inc" 35 36 alignz 16 37 38; -------------------------------------------------------------------------- 39 SECTION SEG_TEXT 40 BITS 32 41 42; These macros perform the same task as the emit_bits() function in the 43; original libjpeg code. In addition to reducing overhead by explicitly 44; inlining the code, additional performance is achieved by taking into 45; account the size of the bit buffer and waiting until it is almost full 46; before emptying it. This mostly benefits 64-bit platforms, since 6 47; bytes can be stored in a 64-bit bit buffer before it has to be emptied. 48 49%macro EMIT_BYTE 0 50 sub put_bits, 8 ; put_bits -= 8; 51 mov edx, put_buffer 52 mov ecx, put_bits 53 shr edx, cl ; c = (JOCTET)GETJOCTET(put_buffer >> put_bits); 54 mov byte [eax], dl ; *buffer++ = c; 55 add eax, 1 56 cmp dl, 0xFF ; need to stuff a zero byte? 57 jne %%.EMIT_BYTE_END 58 mov byte [eax], 0 ; *buffer++ = 0; 59 add eax, 1 60%%.EMIT_BYTE_END: 61%endmacro 62 63%macro PUT_BITS 1 64 add put_bits, ecx ; put_bits += size; 65 shl put_buffer, cl ; put_buffer = (put_buffer << size); 66 or put_buffer, %1 67%endmacro 68 69%macro CHECKBUF15 0 70 cmp put_bits, 16 ; if (put_bits > 31) { 71 jl %%.CHECKBUF15_END 72 mov eax, POINTER [esp+buffer] 73 EMIT_BYTE 74 EMIT_BYTE 75 mov POINTER [esp+buffer], eax 76%%.CHECKBUF15_END: 77%endmacro 78 79%macro EMIT_BITS 1 80 PUT_BITS %1 81 CHECKBUF15 82%endmacro 83 84%macro kloop_prepare 37 ;(ko, jno0, ..., jno31, xmm0, xmm1, xmm2, xmm3) 85 pxor xmm4, xmm4 ; __m128i neg = _mm_setzero_si128(); 86 pxor xmm5, xmm5 ; __m128i neg = _mm_setzero_si128(); 87 pxor xmm6, xmm6 ; __m128i neg = _mm_setzero_si128(); 88 pxor xmm7, xmm7 ; __m128i neg = _mm_setzero_si128(); 89 pinsrw %34, word [esi + %2 * SIZEOF_WORD], 0 ; xmm_shadow[0] = block[jno0]; 90 pinsrw %35, word [esi + %10 * SIZEOF_WORD], 0 ; xmm_shadow[8] = block[jno8]; 91 pinsrw %36, word [esi + %18 * SIZEOF_WORD], 0 ; xmm_shadow[16] = block[jno16]; 92 pinsrw %37, word [esi + %26 * SIZEOF_WORD], 0 ; xmm_shadow[24] = block[jno24]; 93 pinsrw %34, word [esi + %3 * SIZEOF_WORD], 1 ; xmm_shadow[1] = block[jno1]; 94 pinsrw %35, word [esi + %11 * SIZEOF_WORD], 1 ; xmm_shadow[9] = block[jno9]; 95 pinsrw %36, word [esi + %19 * SIZEOF_WORD], 1 ; xmm_shadow[17] = block[jno17]; 96 pinsrw %37, word [esi + %27 * SIZEOF_WORD], 1 ; xmm_shadow[25] = block[jno25]; 97 pinsrw %34, word [esi + %4 * SIZEOF_WORD], 2 ; xmm_shadow[2] = block[jno2]; 98 pinsrw %35, word [esi + %12 * SIZEOF_WORD], 2 ; xmm_shadow[10] = block[jno10]; 99 pinsrw %36, word [esi + %20 * SIZEOF_WORD], 2 ; xmm_shadow[18] = block[jno18]; 100 pinsrw %37, word [esi + %28 * SIZEOF_WORD], 2 ; xmm_shadow[26] = block[jno26]; 101 pinsrw %34, word [esi + %5 * SIZEOF_WORD], 3 ; xmm_shadow[3] = block[jno3]; 102 pinsrw %35, word [esi + %13 * SIZEOF_WORD], 3 ; xmm_shadow[11] = block[jno11]; 103 pinsrw %36, word [esi + %21 * SIZEOF_WORD], 3 ; xmm_shadow[19] = block[jno19]; 104 pinsrw %37, word [esi + %29 * SIZEOF_WORD], 3 ; xmm_shadow[27] = block[jno27]; 105 pinsrw %34, word [esi + %6 * SIZEOF_WORD], 4 ; xmm_shadow[4] = block[jno4]; 106 pinsrw %35, word [esi + %14 * SIZEOF_WORD], 4 ; xmm_shadow[12] = block[jno12]; 107 pinsrw %36, word [esi + %22 * SIZEOF_WORD], 4 ; xmm_shadow[20] = block[jno20]; 108 pinsrw %37, word [esi + %30 * SIZEOF_WORD], 4 ; xmm_shadow[28] = block[jno28]; 109 pinsrw %34, word [esi + %7 * SIZEOF_WORD], 5 ; xmm_shadow[5] = block[jno5]; 110 pinsrw %35, word [esi + %15 * SIZEOF_WORD], 5 ; xmm_shadow[13] = block[jno13]; 111 pinsrw %36, word [esi + %23 * SIZEOF_WORD], 5 ; xmm_shadow[21] = block[jno21]; 112 pinsrw %37, word [esi + %31 * SIZEOF_WORD], 5 ; xmm_shadow[29] = block[jno29]; 113 pinsrw %34, word [esi + %8 * SIZEOF_WORD], 6 ; xmm_shadow[6] = block[jno6]; 114 pinsrw %35, word [esi + %16 * SIZEOF_WORD], 6 ; xmm_shadow[14] = block[jno14]; 115 pinsrw %36, word [esi + %24 * SIZEOF_WORD], 6 ; xmm_shadow[22] = block[jno22]; 116 pinsrw %37, word [esi + %32 * SIZEOF_WORD], 6 ; xmm_shadow[30] = block[jno30]; 117 pinsrw %34, word [esi + %9 * SIZEOF_WORD], 7 ; xmm_shadow[7] = block[jno7]; 118 pinsrw %35, word [esi + %17 * SIZEOF_WORD], 7 ; xmm_shadow[15] = block[jno15]; 119 pinsrw %36, word [esi + %25 * SIZEOF_WORD], 7 ; xmm_shadow[23] = block[jno23]; 120%if %1 != 32 121 pinsrw %37, word [esi + %33 * SIZEOF_WORD], 7 ; xmm_shadow[31] = block[jno31]; 122%else 123 pinsrw %37, ecx, 7 ; xmm_shadow[31] = block[jno31]; 124%endif 125 pcmpgtw xmm4, %34 ; neg = _mm_cmpgt_epi16(neg, x1); 126 pcmpgtw xmm5, %35 ; neg = _mm_cmpgt_epi16(neg, x1); 127 pcmpgtw xmm6, %36 ; neg = _mm_cmpgt_epi16(neg, x1); 128 pcmpgtw xmm7, %37 ; neg = _mm_cmpgt_epi16(neg, x1); 129 paddw %34, xmm4 ; x1 = _mm_add_epi16(x1, neg); 130 paddw %35, xmm5 ; x1 = _mm_add_epi16(x1, neg); 131 paddw %36, xmm6 ; x1 = _mm_add_epi16(x1, neg); 132 paddw %37, xmm7 ; x1 = _mm_add_epi16(x1, neg); 133 pxor %34, xmm4 ; x1 = _mm_xor_si128(x1, neg); 134 pxor %35, xmm5 ; x1 = _mm_xor_si128(x1, neg); 135 pxor %36, xmm6 ; x1 = _mm_xor_si128(x1, neg); 136 pxor %37, xmm7 ; x1 = _mm_xor_si128(x1, neg); 137 pxor xmm4, %34 ; neg = _mm_xor_si128(neg, x1); 138 pxor xmm5, %35 ; neg = _mm_xor_si128(neg, x1); 139 pxor xmm6, %36 ; neg = _mm_xor_si128(neg, x1); 140 pxor xmm7, %37 ; neg = _mm_xor_si128(neg, x1); 141 movdqa XMMWORD [esp + t1 + %1 * SIZEOF_WORD], %34 ; _mm_storeu_si128((__m128i *)(t1 + ko), x1); 142 movdqa XMMWORD [esp + t1 + (%1 + 8) * SIZEOF_WORD], %35 ; _mm_storeu_si128((__m128i *)(t1 + ko + 8), x1); 143 movdqa XMMWORD [esp + t1 + (%1 + 16) * SIZEOF_WORD], %36 ; _mm_storeu_si128((__m128i *)(t1 + ko + 16), x1); 144 movdqa XMMWORD [esp + t1 + (%1 + 24) * SIZEOF_WORD], %37 ; _mm_storeu_si128((__m128i *)(t1 + ko + 24), x1); 145 movdqa XMMWORD [esp + t2 + %1 * SIZEOF_WORD], xmm4 ; _mm_storeu_si128((__m128i *)(t2 + ko), neg); 146 movdqa XMMWORD [esp + t2 + (%1 + 8) * SIZEOF_WORD], xmm5 ; _mm_storeu_si128((__m128i *)(t2 + ko + 8), neg); 147 movdqa XMMWORD [esp + t2 + (%1 + 16) * SIZEOF_WORD], xmm6 ; _mm_storeu_si128((__m128i *)(t2 + ko + 16), neg); 148 movdqa XMMWORD [esp + t2 + (%1 + 24) * SIZEOF_WORD], xmm7 ; _mm_storeu_si128((__m128i *)(t2 + ko + 24), neg); 149%endmacro 150 151; 152; Encode a single block's worth of coefficients. 153; 154; GLOBAL(JOCTET*) 155; jsimd_huff_encode_one_block_sse2 (working_state *state, JOCTET *buffer, 156; JCOEFPTR block, int last_dc_val, 157; c_derived_tbl *dctbl, c_derived_tbl *actbl) 158; 159 160; eax + 8 = working_state *state 161; eax + 12 = JOCTET *buffer 162; eax + 16 = JCOEFPTR block 163; eax + 20 = int last_dc_val 164; eax + 24 = c_derived_tbl *dctbl 165; eax + 28 = c_derived_tbl *actbl 166 167%define pad 6*SIZEOF_DWORD ; Align to 16 bytes 168%define t1 pad 169%define t2 t1+(DCTSIZE2*SIZEOF_WORD) 170%define block t2+(DCTSIZE2*SIZEOF_WORD) 171%define actbl block+SIZEOF_DWORD 172%define buffer actbl+SIZEOF_DWORD 173%define temp buffer+SIZEOF_DWORD 174%define temp2 temp+SIZEOF_DWORD 175%define temp3 temp2+SIZEOF_DWORD 176%define temp4 temp3+SIZEOF_DWORD 177%define temp5 temp4+SIZEOF_DWORD 178%define gotptr temp5+SIZEOF_DWORD ; void *gotptr 179%define put_buffer ebx 180%define put_bits edi 181 182 align 16 183 global EXTN(jsimd_huff_encode_one_block_sse2) PRIVATE 184 185EXTN(jsimd_huff_encode_one_block_sse2): 186 push ebp 187 mov eax,esp ; eax = original ebp 188 sub esp, byte 4 189 and esp, byte (-SIZEOF_XMMWORD) ; align to 128 bits 190 mov [esp],eax 191 mov ebp,esp ; ebp = aligned ebp 192 sub esp, temp5+9*SIZEOF_DWORD-pad 193 push ebx 194 push ecx 195; push edx ; need not be preserved 196 push esi 197 push edi 198 push ebp 199 200 mov esi, POINTER [eax+8] ; (working_state *state) 201 mov put_buffer, DWORD [esi+8] ; put_buffer = state->cur.put_buffer; 202 mov put_bits, DWORD [esi+12] ; put_bits = state->cur.put_bits; 203 push esi ; esi is now scratch 204 205 get_GOT edx ; get GOT address 206 movpic POINTER [esp+gotptr], edx ; save GOT address 207 208 mov ecx, POINTER [eax+28] 209 mov edx, POINTER [eax+16] 210 mov esi, POINTER [eax+12] 211 mov POINTER [esp+actbl], ecx 212 mov POINTER [esp+block], edx 213 mov POINTER [esp+buffer], esi 214 215 ; Encode the DC coefficient difference per section F.1.2.1 216 mov esi, POINTER [esp+block] ; block 217 movsx ecx, word [esi] ; temp = temp2 = block[0] - last_dc_val; 218 sub ecx, DWORD [eax+20] 219 mov esi, ecx 220 221 ; This is a well-known technique for obtaining the absolute value 222 ; without a branch. It is derived from an assembly language technique 223 ; presented in "How to Optimize for the Pentium Processors", 224 ; Copyright (c) 1996, 1997 by Agner Fog. 225 mov edx, ecx 226 sar edx, 31 ; temp3 = temp >> (CHAR_BIT * sizeof(int) - 1); 227 xor ecx, edx ; temp ^= temp3; 228 sub ecx, edx ; temp -= temp3; 229 230 ; For a negative input, want temp2 = bitwise complement of abs(input) 231 ; This code assumes we are on a two's complement machine 232 add esi, edx ; temp2 += temp3; 233 mov DWORD [esp+temp], esi ; backup temp2 in temp 234 235 ; Find the number of bits needed for the magnitude of the coefficient 236 movpic ebp, POINTER [esp+gotptr] ; load GOT address (ebp) 237 movzx edx, byte [GOTOFF(ebp, jpeg_nbits_table + ecx)] ; nbits = JPEG_NBITS(temp); 238 mov DWORD [esp+temp2], edx ; backup nbits in temp2 239 240 ; Emit the Huffman-coded symbol for the number of bits 241 mov ebp, POINTER [eax+24] ; After this point, arguments are not accessible anymore 242 mov eax, INT [ebp + edx * 4] ; code = dctbl->ehufco[nbits]; 243 movzx ecx, byte [ebp + edx + 1024] ; size = dctbl->ehufsi[nbits]; 244 EMIT_BITS eax ; EMIT_BITS(code, size) 245 246 mov ecx, DWORD [esp+temp2] ; restore nbits 247 248 ; Mask off any extra bits in code 249 mov eax, 1 250 shl eax, cl 251 dec eax 252 and eax, DWORD [esp+temp] ; temp2 &= (((JLONG) 1)<<nbits) - 1; 253 254 ; Emit that number of bits of the value, if positive, 255 ; or the complement of its magnitude, if negative. 256 EMIT_BITS eax ; EMIT_BITS(temp2, nbits) 257 258 ; Prepare data 259 xor ecx, ecx 260 mov esi, POINTER [esp+block] 261 kloop_prepare 0, 1, 8, 16, 9, 2, 3, 10, 17, 24, 32, 25, \ 262 18, 11, 4, 5, 12, 19, 26, 33, 40, 48, 41, 34, \ 263 27, 20, 13, 6, 7, 14, 21, 28, 35, \ 264 xmm0, xmm1, xmm2, xmm3 265 kloop_prepare 32, 42, 49, 56, 57, 50, 43, 36, 29, 22, 15, 23, \ 266 30, 37, 44, 51, 58, 59, 52, 45, 38, 31, 39, 46, \ 267 53, 60, 61, 54, 47, 55, 62, 63, 63, \ 268 xmm0, xmm1, xmm2, xmm3 269 270 pxor xmm7, xmm7 271 movdqa xmm0, XMMWORD [esp + t1 + 0 * SIZEOF_WORD] ; __m128i tmp0 = _mm_loadu_si128((__m128i *)(t1 + 0)); 272 movdqa xmm1, XMMWORD [esp + t1 + 8 * SIZEOF_WORD] ; __m128i tmp1 = _mm_loadu_si128((__m128i *)(t1 + 8)); 273 movdqa xmm2, XMMWORD [esp + t1 + 16 * SIZEOF_WORD] ; __m128i tmp2 = _mm_loadu_si128((__m128i *)(t1 + 16)); 274 movdqa xmm3, XMMWORD [esp + t1 + 24 * SIZEOF_WORD] ; __m128i tmp3 = _mm_loadu_si128((__m128i *)(t1 + 24)); 275 pcmpeqw xmm0, xmm7 ; tmp0 = _mm_cmpeq_epi16(tmp0, zero); 276 pcmpeqw xmm1, xmm7 ; tmp1 = _mm_cmpeq_epi16(tmp1, zero); 277 pcmpeqw xmm2, xmm7 ; tmp2 = _mm_cmpeq_epi16(tmp2, zero); 278 pcmpeqw xmm3, xmm7 ; tmp3 = _mm_cmpeq_epi16(tmp3, zero); 279 packsswb xmm0, xmm1 ; tmp0 = _mm_packs_epi16(tmp0, tmp1); 280 packsswb xmm2, xmm3 ; tmp2 = _mm_packs_epi16(tmp2, tmp3); 281 pmovmskb edx, xmm0 ; index = ((uint64_t)_mm_movemask_epi8(tmp0)) << 0; 282 pmovmskb ecx, xmm2 ; index = ((uint64_t)_mm_movemask_epi8(tmp2)) << 16; 283 shl ecx, 16 284 or edx, ecx 285 not edx ; index = ~index; 286 287 lea esi, [esp+t1] 288 mov ebp, POINTER [esp+actbl] ; ebp = actbl 289 290.BLOOP: 291 bsf ecx, edx ; r = __builtin_ctzl(index); 292 jz .ELOOP 293 lea esi, [esi+ecx*2] ; k += r; 294 shr edx, cl ; index >>= r; 295 mov DWORD [esp+temp3], edx 296.BRLOOP: 297 cmp ecx, 16 ; while (r > 15) { 298 jl .ERLOOP 299 sub ecx, 16 ; r -= 16; 300 mov DWORD [esp+temp], ecx 301 mov eax, INT [ebp + 240 * 4] ; code_0xf0 = actbl->ehufco[0xf0]; 302 movzx ecx, byte [ebp + 1024 + 240] ; size_0xf0 = actbl->ehufsi[0xf0]; 303 EMIT_BITS eax ; EMIT_BITS(code_0xf0, size_0xf0) 304 mov ecx, DWORD [esp+temp] 305 jmp .BRLOOP 306.ERLOOP: 307 movsx eax, word [esi] ; temp = t1[k]; 308 movpic edx, POINTER [esp+gotptr] ; load GOT address (edx) 309 movzx eax, byte [GOTOFF(edx, jpeg_nbits_table + eax)] ; nbits = JPEG_NBITS(temp); 310 mov DWORD [esp+temp2], eax 311 ; Emit Huffman symbol for run length / number of bits 312 shl ecx, 4 ; temp3 = (r << 4) + nbits; 313 add ecx, eax 314 mov eax, INT [ebp + ecx * 4] ; code = actbl->ehufco[temp3]; 315 movzx ecx, byte [ebp + ecx + 1024] ; size = actbl->ehufsi[temp3]; 316 EMIT_BITS eax 317 318 movsx edx, word [esi+DCTSIZE2*2] ; temp2 = t2[k]; 319 ; Mask off any extra bits in code 320 mov ecx, DWORD [esp+temp2] 321 mov eax, 1 322 shl eax, cl 323 dec eax 324 and eax, edx ; temp2 &= (((JLONG) 1)<<nbits) - 1; 325 EMIT_BITS eax ; PUT_BITS(temp2, nbits) 326 mov edx, DWORD [esp+temp3] 327 add esi, 2 ; ++k; 328 shr edx, 1 ; index >>= 1; 329 330 jmp .BLOOP 331.ELOOP: 332 movdqa xmm0, XMMWORD [esp + t1 + 32 * SIZEOF_WORD] ; __m128i tmp0 = _mm_loadu_si128((__m128i *)(t1 + 0)); 333 movdqa xmm1, XMMWORD [esp + t1 + 40 * SIZEOF_WORD] ; __m128i tmp1 = _mm_loadu_si128((__m128i *)(t1 + 8)); 334 movdqa xmm2, XMMWORD [esp + t1 + 48 * SIZEOF_WORD] ; __m128i tmp2 = _mm_loadu_si128((__m128i *)(t1 + 16)); 335 movdqa xmm3, XMMWORD [esp + t1 + 56 * SIZEOF_WORD] ; __m128i tmp3 = _mm_loadu_si128((__m128i *)(t1 + 24)); 336 pcmpeqw xmm0, xmm7 ; tmp0 = _mm_cmpeq_epi16(tmp0, zero); 337 pcmpeqw xmm1, xmm7 ; tmp1 = _mm_cmpeq_epi16(tmp1, zero); 338 pcmpeqw xmm2, xmm7 ; tmp2 = _mm_cmpeq_epi16(tmp2, zero); 339 pcmpeqw xmm3, xmm7 ; tmp3 = _mm_cmpeq_epi16(tmp3, zero); 340 packsswb xmm0, xmm1 ; tmp0 = _mm_packs_epi16(tmp0, tmp1); 341 packsswb xmm2, xmm3 ; tmp2 = _mm_packs_epi16(tmp2, tmp3); 342 pmovmskb edx, xmm0 ; index = ((uint64_t)_mm_movemask_epi8(tmp0)) << 0; 343 pmovmskb ecx, xmm2 ; index = ((uint64_t)_mm_movemask_epi8(tmp2)) << 16; 344 shl ecx, 16 345 or edx, ecx 346 not edx ; index = ~index; 347 348 lea eax, [esp + t1 + (DCTSIZE2/2) * 2] 349 sub eax, esi 350 shr eax, 1 351 bsf ecx, edx ; r = __builtin_ctzl(index); 352 jz .ELOOP2 353 shr edx, cl ; index >>= r; 354 add ecx, eax 355 lea esi, [esi+ecx*2] ; k += r; 356 mov DWORD [esp+temp3], edx 357 jmp .BRLOOP2 358.BLOOP2: 359 bsf ecx, edx ; r = __builtin_ctzl(index); 360 jz .ELOOP2 361 lea esi, [esi+ecx*2] ; k += r; 362 shr edx, cl ; index >>= r; 363 mov DWORD [esp+temp3], edx 364.BRLOOP2: 365 cmp ecx, 16 ; while (r > 15) { 366 jl .ERLOOP2 367 sub ecx, 16 ; r -= 16; 368 mov DWORD [esp+temp], ecx 369 mov eax, INT [ebp + 240 * 4] ; code_0xf0 = actbl->ehufco[0xf0]; 370 movzx ecx, byte [ebp + 1024 + 240] ; size_0xf0 = actbl->ehufsi[0xf0]; 371 EMIT_BITS eax ; EMIT_BITS(code_0xf0, size_0xf0) 372 mov ecx, DWORD [esp+temp] 373 jmp .BRLOOP2 374.ERLOOP2: 375 movsx eax, word [esi] ; temp = t1[k]; 376 bsr eax, eax ; nbits = 32 - __builtin_clz(temp); 377 inc eax 378 mov DWORD [esp+temp2], eax 379 ; Emit Huffman symbol for run length / number of bits 380 shl ecx, 4 ; temp3 = (r << 4) + nbits; 381 add ecx, eax 382 mov eax, INT [ebp + ecx * 4] ; code = actbl->ehufco[temp3]; 383 movzx ecx, byte [ebp + ecx + 1024] ; size = actbl->ehufsi[temp3]; 384 EMIT_BITS eax 385 386 movsx edx, word [esi+DCTSIZE2*2] ; temp2 = t2[k]; 387 ; Mask off any extra bits in code 388 mov ecx, DWORD [esp+temp2] 389 mov eax, 1 390 shl eax, cl 391 dec eax 392 and eax, edx ; temp2 &= (((JLONG) 1)<<nbits) - 1; 393 EMIT_BITS eax ; PUT_BITS(temp2, nbits) 394 mov edx, DWORD [esp+temp3] 395 add esi, 2 ; ++k; 396 shr edx, 1 ; index >>= 1; 397 398 jmp .BLOOP2 399.ELOOP2: 400 ; If the last coef(s) were zero, emit an end-of-block code 401 lea edx, [esp + t1 + (DCTSIZE2-1) * 2] ; r = DCTSIZE2-1-k; 402 cmp edx, esi ; if (r > 0) { 403 je .EFN 404 mov eax, INT [ebp] ; code = actbl->ehufco[0]; 405 movzx ecx, byte [ebp + 1024] ; size = actbl->ehufsi[0]; 406 EMIT_BITS eax 407.EFN: 408 mov eax, [esp+buffer] 409 pop esi 410 ; Save put_buffer & put_bits 411 mov DWORD [esi+8], put_buffer ; state->cur.put_buffer = put_buffer; 412 mov DWORD [esi+12], put_bits ; state->cur.put_bits = put_bits; 413 414 pop ebp 415 pop edi 416 pop esi 417; pop edx ; need not be preserved 418 pop ecx 419 pop ebx 420 mov esp,ebp ; esp <- aligned ebp 421 pop esp ; esp <- original ebp 422 pop ebp 423 ret 424 425; For some reason, the OS X linker does not honor the request to align the 426; segment unless we do this. 427 align 16 428