1;
2; jchuff-sse2.asm - Huffman entropy encoding (64-bit SSE2)
3;
4; Copyright (C) 2009-2011, 2014-2016, D. R. Commander.
5; Copyright (C) 2015, Matthieu Darbois.
6;
7; Based on the x86 SIMD extension for IJG JPEG library
8; Copyright (C) 1999-2006, MIYASAKA Masaru.
9; For conditions of distribution and use, see copyright notice in jsimdext.inc
10;
11; This file should be assembled with NASM (Netwide Assembler),
12; can *not* be assembled with Microsoft's MASM or any compatible
13; assembler (including Borland's Turbo Assembler).
14; NASM is available from http://nasm.sourceforge.net/ or
15; http://sourceforge.net/project/showfiles.php?group_id=6208
16;
17; This file contains an SSE2 implementation for Huffman coding of one block.
18; The following code is based directly on jchuff.c; see jchuff.c for more
19; details.
20
21%include "jsimdext.inc"
22
23; --------------------------------------------------------------------------
24    SECTION     SEG_CONST
25
26    alignz      32
27    GLOBAL_DATA(jconst_huff_encode_one_block)
28    EXTERN      EXTN(jpeg_nbits_table)
29
30EXTN(jconst_huff_encode_one_block):
31
32    alignz      32
33
34; --------------------------------------------------------------------------
35    SECTION     SEG_TEXT
36    BITS        64
37
38; These macros perform the same task as the emit_bits() function in the
39; original libjpeg code.  In addition to reducing overhead by explicitly
40; inlining the code, additional performance is achieved by taking into
41; account the size of the bit buffer and waiting until it is almost full
42; before emptying it.  This mostly benefits 64-bit platforms, since 6
43; bytes can be stored in a 64-bit bit buffer before it has to be emptied.
44
45%macro EMIT_BYTE 0
46    sub         put_bits, 8             ; put_bits -= 8;
47    mov         rdx, put_buffer
48    mov         ecx, put_bits
49    shr         rdx, cl                 ; c = (JOCTET)GETJOCTET(put_buffer >> put_bits);
50    mov         byte [buffer], dl       ; *buffer++ = c;
51    add         buffer, 1
52    cmp         dl, 0xFF                ; need to stuff a zero byte?
53    jne         %%.EMIT_BYTE_END
54    mov         byte [buffer], 0        ; *buffer++ = 0;
55    add         buffer, 1
56%%.EMIT_BYTE_END:
57%endmacro
58
59%macro PUT_BITS 1
60    add         put_bits, ecx           ; put_bits += size;
61    shl         put_buffer, cl          ; put_buffer = (put_buffer << size);
62    or          put_buffer, %1
63%endmacro
64
65%macro CHECKBUF31 0
66    cmp         put_bits, 32            ; if (put_bits > 31) {
67    jl          %%.CHECKBUF31_END
68    EMIT_BYTE
69    EMIT_BYTE
70    EMIT_BYTE
71    EMIT_BYTE
72%%.CHECKBUF31_END:
73%endmacro
74
75%macro CHECKBUF47 0
76    cmp         put_bits, 48            ; if (put_bits > 47) {
77    jl          %%.CHECKBUF47_END
78    EMIT_BYTE
79    EMIT_BYTE
80    EMIT_BYTE
81    EMIT_BYTE
82    EMIT_BYTE
83    EMIT_BYTE
84%%.CHECKBUF47_END:
85%endmacro
86
87%macro EMIT_BITS 2
88    CHECKBUF47
89    mov         ecx, %2
90    PUT_BITS    %1
91%endmacro
92
93%macro kloop_prepare 37                 ;(ko, jno0, ..., jno31, xmm0, xmm1, xmm2, xmm3)
94    pxor        xmm8, xmm8              ; __m128i neg = _mm_setzero_si128();
95    pxor        xmm9, xmm9              ; __m128i neg = _mm_setzero_si128();
96    pxor        xmm10, xmm10            ; __m128i neg = _mm_setzero_si128();
97    pxor        xmm11, xmm11            ; __m128i neg = _mm_setzero_si128();
98    pinsrw      %34, word [r12 + %2  * SIZEOF_WORD], 0  ; xmm_shadow[0] = block[jno0];
99    pinsrw      %35, word [r12 + %10 * SIZEOF_WORD], 0  ; xmm_shadow[8] = block[jno8];
100    pinsrw      %36, word [r12 + %18 * SIZEOF_WORD], 0  ; xmm_shadow[16] = block[jno16];
101    pinsrw      %37, word [r12 + %26 * SIZEOF_WORD], 0  ; xmm_shadow[24] = block[jno24];
102    pinsrw      %34, word [r12 + %3  * SIZEOF_WORD], 1  ; xmm_shadow[1] = block[jno1];
103    pinsrw      %35, word [r12 + %11 * SIZEOF_WORD], 1  ; xmm_shadow[9] = block[jno9];
104    pinsrw      %36, word [r12 + %19 * SIZEOF_WORD], 1  ; xmm_shadow[17] = block[jno17];
105    pinsrw      %37, word [r12 + %27 * SIZEOF_WORD], 1  ; xmm_shadow[25] = block[jno25];
106    pinsrw      %34, word [r12 + %4  * SIZEOF_WORD], 2  ; xmm_shadow[2] = block[jno2];
107    pinsrw      %35, word [r12 + %12 * SIZEOF_WORD], 2  ; xmm_shadow[10] = block[jno10];
108    pinsrw      %36, word [r12 + %20 * SIZEOF_WORD], 2  ; xmm_shadow[18] = block[jno18];
109    pinsrw      %37, word [r12 + %28 * SIZEOF_WORD], 2  ; xmm_shadow[26] = block[jno26];
110    pinsrw      %34, word [r12 + %5  * SIZEOF_WORD], 3  ; xmm_shadow[3] = block[jno3];
111    pinsrw      %35, word [r12 + %13 * SIZEOF_WORD], 3  ; xmm_shadow[11] = block[jno11];
112    pinsrw      %36, word [r12 + %21 * SIZEOF_WORD], 3  ; xmm_shadow[19] = block[jno19];
113    pinsrw      %37, word [r12 + %29 * SIZEOF_WORD], 3  ; xmm_shadow[27] = block[jno27];
114    pinsrw      %34, word [r12 + %6  * SIZEOF_WORD], 4  ; xmm_shadow[4] = block[jno4];
115    pinsrw      %35, word [r12 + %14 * SIZEOF_WORD], 4  ; xmm_shadow[12] = block[jno12];
116    pinsrw      %36, word [r12 + %22 * SIZEOF_WORD], 4  ; xmm_shadow[20] = block[jno20];
117    pinsrw      %37, word [r12 + %30 * SIZEOF_WORD], 4  ; xmm_shadow[28] = block[jno28];
118    pinsrw      %34, word [r12 + %7  * SIZEOF_WORD], 5  ; xmm_shadow[5] = block[jno5];
119    pinsrw      %35, word [r12 + %15 * SIZEOF_WORD], 5  ; xmm_shadow[13] = block[jno13];
120    pinsrw      %36, word [r12 + %23 * SIZEOF_WORD], 5  ; xmm_shadow[21] = block[jno21];
121    pinsrw      %37, word [r12 + %31 * SIZEOF_WORD], 5  ; xmm_shadow[29] = block[jno29];
122    pinsrw      %34, word [r12 + %8  * SIZEOF_WORD], 6  ; xmm_shadow[6] = block[jno6];
123    pinsrw      %35, word [r12 + %16 * SIZEOF_WORD], 6  ; xmm_shadow[14] = block[jno14];
124    pinsrw      %36, word [r12 + %24 * SIZEOF_WORD], 6  ; xmm_shadow[22] = block[jno22];
125    pinsrw      %37, word [r12 + %32 * SIZEOF_WORD], 6  ; xmm_shadow[30] = block[jno30];
126    pinsrw      %34, word [r12 + %9  * SIZEOF_WORD], 7  ; xmm_shadow[7] = block[jno7];
127    pinsrw      %35, word [r12 + %17 * SIZEOF_WORD], 7  ; xmm_shadow[15] = block[jno15];
128    pinsrw      %36, word [r12 + %25 * SIZEOF_WORD], 7  ; xmm_shadow[23] = block[jno23];
129%if %1 != 32
130    pinsrw      %37, word [r12 + %33 * SIZEOF_WORD], 7  ; xmm_shadow[31] = block[jno31];
131%else
132    pinsrw      %37, ebx, 7             ; xmm_shadow[31] = block[jno31];
133%endif
134    pcmpgtw     xmm8, %34               ; neg = _mm_cmpgt_epi16(neg, x1);
135    pcmpgtw     xmm9, %35               ; neg = _mm_cmpgt_epi16(neg, x1);
136    pcmpgtw     xmm10, %36              ; neg = _mm_cmpgt_epi16(neg, x1);
137    pcmpgtw     xmm11, %37              ; neg = _mm_cmpgt_epi16(neg, x1);
138    paddw       %34, xmm8               ; x1 = _mm_add_epi16(x1, neg);
139    paddw       %35, xmm9               ; x1 = _mm_add_epi16(x1, neg);
140    paddw       %36, xmm10              ; x1 = _mm_add_epi16(x1, neg);
141    paddw       %37, xmm11              ; x1 = _mm_add_epi16(x1, neg);
142    pxor        %34, xmm8               ; x1 = _mm_xor_si128(x1, neg);
143    pxor        %35, xmm9               ; x1 = _mm_xor_si128(x1, neg);
144    pxor        %36, xmm10              ; x1 = _mm_xor_si128(x1, neg);
145    pxor        %37, xmm11              ; x1 = _mm_xor_si128(x1, neg);
146    pxor        xmm8, %34               ; neg = _mm_xor_si128(neg, x1);
147    pxor        xmm9, %35               ; neg = _mm_xor_si128(neg, x1);
148    pxor        xmm10, %36              ; neg = _mm_xor_si128(neg, x1);
149    pxor        xmm11, %37              ; neg = _mm_xor_si128(neg, x1);
150    movdqa      XMMWORD [t1 + %1 * SIZEOF_WORD], %34           ; _mm_storeu_si128((__m128i *)(t1 + ko), x1);
151    movdqa      XMMWORD [t1 + (%1 + 8) * SIZEOF_WORD], %35     ; _mm_storeu_si128((__m128i *)(t1 + ko + 8), x1);
152    movdqa      XMMWORD [t1 + (%1 + 16) * SIZEOF_WORD], %36    ; _mm_storeu_si128((__m128i *)(t1 + ko + 16), x1);
153    movdqa      XMMWORD [t1 + (%1 + 24) * SIZEOF_WORD], %37    ; _mm_storeu_si128((__m128i *)(t1 + ko + 24), x1);
154    movdqa      XMMWORD [t2 + %1 * SIZEOF_WORD], xmm8          ; _mm_storeu_si128((__m128i *)(t2 + ko), neg);
155    movdqa      XMMWORD [t2 + (%1 + 8) * SIZEOF_WORD], xmm9    ; _mm_storeu_si128((__m128i *)(t2 + ko + 8), neg);
156    movdqa      XMMWORD [t2 + (%1 + 16) * SIZEOF_WORD], xmm10  ; _mm_storeu_si128((__m128i *)(t2 + ko + 16), neg);
157    movdqa      XMMWORD [t2 + (%1 + 24) * SIZEOF_WORD], xmm11  ; _mm_storeu_si128((__m128i *)(t2 + ko + 24), neg);
158%endmacro
159
160;
161; Encode a single block's worth of coefficients.
162;
163; GLOBAL(JOCTET *)
164; jsimd_huff_encode_one_block_sse2(working_state *state, JOCTET *buffer,
165;                                  JCOEFPTR block, int last_dc_val,
166;                                  c_derived_tbl *dctbl, c_derived_tbl *actbl)
167;
168
169; r10 = working_state *state
170; r11 = JOCTET *buffer
171; r12 = JCOEFPTR block
172; r13d = int last_dc_val
173; r14 = c_derived_tbl *dctbl
174; r15 = c_derived_tbl *actbl
175
176%define t1          rbp - (DCTSIZE2 * SIZEOF_WORD)
177%define t2          t1 - (DCTSIZE2 * SIZEOF_WORD)
178%define put_buffer  r8
179%define put_bits    r9d
180%define buffer      rax
181
182    align       32
183    GLOBAL_FUNCTION(jsimd_huff_encode_one_block_sse2)
184
185EXTN(jsimd_huff_encode_one_block_sse2):
186    push        rbp
187    mov         rax, rsp                     ; rax = original rbp
188    sub         rsp, byte 4
189    and         rsp, byte (-SIZEOF_XMMWORD)  ; align to 128 bits
190    mov         [rsp], rax
191    mov         rbp, rsp                     ; rbp = aligned rbp
192    lea         rsp, [t2]
193    push_xmm    4
194    collect_args 6
195    push        rbx
196
197    mov         buffer, r11                  ; r11 is now sratch
198
199    mov         put_buffer, MMWORD [r10+16]  ; put_buffer = state->cur.put_buffer;
200    mov         put_bits,    dword [r10+24]  ; put_bits = state->cur.put_bits;
201    push        r10                          ; r10 is now scratch
202
203    ; Encode the DC coefficient difference per section F.1.2.1
204    movsx       edi, word [r12]         ; temp = temp2 = block[0] - last_dc_val;
205    sub         edi, r13d               ; r13 is not used anymore
206    mov         ebx, edi
207
208    ; This is a well-known technique for obtaining the absolute value
209    ; without a branch.  It is derived from an assembly language technique
210    ; presented in "How to Optimize for the Pentium Processors",
211    ; Copyright (c) 1996, 1997 by Agner Fog.
212    mov         esi, edi
213    sar         esi, 31                 ; temp3 = temp >> (CHAR_BIT * sizeof(int) - 1);
214    xor         edi, esi                ; temp ^= temp3;
215    sub         edi, esi                ; temp -= temp3;
216
217    ; For a negative input, want temp2 = bitwise complement of abs(input)
218    ; This code assumes we are on a two's complement machine
219    add         ebx, esi                ; temp2 += temp3;
220
221    ; Find the number of bits needed for the magnitude of the coefficient
222    lea         r11, [rel EXTN(jpeg_nbits_table)]
223    movzx       rdi, byte [r11 + rdi]         ; nbits = JPEG_NBITS(temp);
224    ; Emit the Huffman-coded symbol for the number of bits
225    mov         r11d,  INT [r14 + rdi * 4]    ; code = dctbl->ehufco[nbits];
226    movzx       esi, byte [r14 + rdi + 1024]  ; size = dctbl->ehufsi[nbits];
227    EMIT_BITS   r11, esi                      ; EMIT_BITS(code, size)
228
229    ; Mask off any extra bits in code
230    mov         esi, 1
231    mov         ecx, edi
232    shl         esi, cl
233    dec         esi
234    and         ebx, esi                ; temp2 &= (((JLONG)1)<<nbits) - 1;
235
236    ; Emit that number of bits of the value, if positive,
237    ; or the complement of its magnitude, if negative.
238    EMIT_BITS   rbx, edi                ; EMIT_BITS(temp2, nbits)
239
240    ; Prepare data
241    xor         ebx, ebx
242    kloop_prepare  0,  1,  8,  16, 9,  2,  3,  10, 17, 24, 32, 25, \
243                   18, 11, 4,  5,  12, 19, 26, 33, 40, 48, 41, 34, \
244                   27, 20, 13, 6,  7,  14, 21, 28, 35, \
245                   xmm0, xmm1, xmm2, xmm3
246    kloop_prepare  32, 42, 49, 56, 57, 50, 43, 36, 29, 22, 15, 23, \
247                   30, 37, 44, 51, 58, 59, 52, 45, 38, 31, 39, 46, \
248                   53, 60, 61, 54, 47, 55, 62, 63, 63, \
249                   xmm4, xmm5, xmm6, xmm7
250
251    pxor        xmm8, xmm8
252    pcmpeqw     xmm0, xmm8              ; tmp0 = _mm_cmpeq_epi16(tmp0, zero);
253    pcmpeqw     xmm1, xmm8              ; tmp1 = _mm_cmpeq_epi16(tmp1, zero);
254    pcmpeqw     xmm2, xmm8              ; tmp2 = _mm_cmpeq_epi16(tmp2, zero);
255    pcmpeqw     xmm3, xmm8              ; tmp3 = _mm_cmpeq_epi16(tmp3, zero);
256    pcmpeqw     xmm4, xmm8              ; tmp4 = _mm_cmpeq_epi16(tmp4, zero);
257    pcmpeqw     xmm5, xmm8              ; tmp5 = _mm_cmpeq_epi16(tmp5, zero);
258    pcmpeqw     xmm6, xmm8              ; tmp6 = _mm_cmpeq_epi16(tmp6, zero);
259    pcmpeqw     xmm7, xmm8              ; tmp7 = _mm_cmpeq_epi16(tmp7, zero);
260    packsswb    xmm0, xmm1              ; tmp0 = _mm_packs_epi16(tmp0, tmp1);
261    packsswb    xmm2, xmm3              ; tmp2 = _mm_packs_epi16(tmp2, tmp3);
262    packsswb    xmm4, xmm5              ; tmp4 = _mm_packs_epi16(tmp4, tmp5);
263    packsswb    xmm6, xmm7              ; tmp6 = _mm_packs_epi16(tmp6, tmp7);
264    pmovmskb    r11d, xmm0              ; index  = ((uint64_t)_mm_movemask_epi8(tmp0)) << 0;
265    pmovmskb    r12d, xmm2              ; index  = ((uint64_t)_mm_movemask_epi8(tmp2)) << 16;
266    pmovmskb    r13d, xmm4              ; index  = ((uint64_t)_mm_movemask_epi8(tmp4)) << 32;
267    pmovmskb    r14d, xmm6              ; index  = ((uint64_t)_mm_movemask_epi8(tmp6)) << 48;
268    shl         r12, 16
269    shl         r14, 16
270    or          r11, r12
271    or          r13, r14
272    shl         r13, 32
273    or          r11, r13
274    not         r11                     ; index = ~index;
275
276    ;mov MMWORD [ t1 + DCTSIZE2 * SIZEOF_WORD ], r11
277    ;jmp .EFN
278
279    mov         r13d,  INT [r15 + 240 * 4]     ; code_0xf0 = actbl->ehufco[0xf0];
280    movzx       r14d, byte [r15 + 1024 + 240]  ; size_0xf0 = actbl->ehufsi[0xf0];
281    lea         rsi, [t1]
282.BLOOP:
283    bsf         r12, r11                     ; r = __builtin_ctzl(index);
284    jz          .ELOOP
285    mov         rcx, r12
286    lea         rsi, [rsi+r12*2]             ; k += r;
287    shr         r11, cl                      ; index >>= r;
288    movzx       rdi, word [rsi]              ; temp = t1[k];
289    lea         rbx, [rel EXTN(jpeg_nbits_table)]
290    movzx       rdi, byte [rbx + rdi]        ; nbits = JPEG_NBITS(temp);
291.BRLOOP:
292    cmp         r12, 16                 ; while (r > 15) {
293    jl          .ERLOOP
294    EMIT_BITS   r13, r14d               ; EMIT_BITS(code_0xf0, size_0xf0)
295    sub         r12, 16                 ; r -= 16;
296    jmp         .BRLOOP
297.ERLOOP:
298    ; Emit Huffman symbol for run length / number of bits
299    CHECKBUF31  ; uses rcx, rdx
300
301    shl         r12, 4                        ; temp3 = (r << 4) + nbits;
302    add         r12, rdi
303    mov         ebx,  INT [r15 + r12 * 4]     ; code = actbl->ehufco[temp3];
304    movzx       ecx, byte [r15 + r12 + 1024]  ; size = actbl->ehufsi[temp3];
305    PUT_BITS    rbx
306
307    ;EMIT_CODE(code, size)
308
309    movsx       ebx, word [rsi-DCTSIZE2*2]    ; temp2 = t2[k];
310    ; Mask off any extra bits in code
311    mov         rcx, rdi
312    mov         rdx, 1
313    shl         rdx, cl
314    dec         rdx
315    and         rbx, rdx                ; temp2 &= (((JLONG)1)<<nbits) - 1;
316    PUT_BITS    rbx                     ; PUT_BITS(temp2, nbits)
317
318    shr         r11, 1                  ; index >>= 1;
319    add         rsi, 2                  ; ++k;
320    jmp         .BLOOP
321.ELOOP:
322    ; If the last coef(s) were zero, emit an end-of-block code
323    lea         rdi, [t1 + (DCTSIZE2-1) * 2]  ; r = DCTSIZE2-1-k;
324    cmp         rdi, rsi                      ; if (r > 0) {
325    je          .EFN
326    mov         ebx,  INT [r15]               ; code = actbl->ehufco[0];
327    movzx       r12d, byte [r15 + 1024]       ; size = actbl->ehufsi[0];
328    EMIT_BITS   rbx, r12d
329.EFN:
330    pop         r10
331    ; Save put_buffer & put_bits
332    mov         MMWORD [r10+16], put_buffer  ; state->cur.put_buffer = put_buffer;
333    mov         dword  [r10+24], put_bits    ; state->cur.put_bits = put_bits;
334
335    pop         rbx
336    uncollect_args 6
337    pop_xmm     4
338    mov         rsp, rbp                ; rsp <- aligned rbp
339    pop         rsp                     ; rsp <- original rbp
340    pop         rbp
341    ret
342
343; For some reason, the OS X linker does not honor the request to align the
344; segment unless we do this.
345    align       32
346