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jidctred-sse2.asm (21813B)


      1 ;
      2 ; jidctred.asm - reduced-size IDCT (64-bit SSE2)
      3 ;
      4 ; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
      5 ; Copyright (C) 2009, 2016, 2024, D. R. Commander.
      6 ; Copyright (C) 2018, Matthias Räncker.
      7 ; Copyright (C) 2023, Aliaksiej Kandracienka.
      8 ;
      9 ; Based on the x86 SIMD extension for IJG JPEG library
     10 ; Copyright (C) 1999-2006, MIYASAKA Masaru.
     11 ; For conditions of distribution and use, see copyright notice in jsimdext.inc
     12 ;
     13 ; This file should be assembled with NASM (Netwide Assembler) or Yasm.
     14 ;
     15 ; This file contains inverse-DCT routines that produce reduced-size
     16 ; output: either 4x4 or 2x2 pixels from an 8x8 DCT block.
     17 ; The following code is based directly on the IJG's original jidctred.c;
     18 ; see the jidctred.c for more details.
     19 
     20 %include "jsimdext.inc"
     21 %include "jdct.inc"
     22 
     23 ; --------------------------------------------------------------------------
     24 
     25 %define CONST_BITS    13
     26 %define PASS1_BITS    2
     27 
     28 %define DESCALE_P1_4  (CONST_BITS - PASS1_BITS + 1)
     29 %define DESCALE_P2_4  (CONST_BITS + PASS1_BITS + 3 + 1)
     30 %define DESCALE_P1_2  (CONST_BITS - PASS1_BITS + 2)
     31 %define DESCALE_P2_2  (CONST_BITS + PASS1_BITS + 3 + 2)
     32 
     33 %if CONST_BITS == 13
     34 F_0_211 equ  1730  ; FIX(0.211164243)
     35 F_0_509 equ  4176  ; FIX(0.509795579)
     36 F_0_601 equ  4926  ; FIX(0.601344887)
     37 F_0_720 equ  5906  ; FIX(0.720959822)
     38 F_0_765 equ  6270  ; FIX(0.765366865)
     39 F_0_850 equ  6967  ; FIX(0.850430095)
     40 F_0_899 equ  7373  ; FIX(0.899976223)
     41 F_1_061 equ  8697  ; FIX(1.061594337)
     42 F_1_272 equ 10426  ; FIX(1.272758580)
     43 F_1_451 equ 11893  ; FIX(1.451774981)
     44 F_1_847 equ 15137  ; FIX(1.847759065)
     45 F_2_172 equ 17799  ; FIX(2.172734803)
     46 F_2_562 equ 20995  ; FIX(2.562915447)
     47 F_3_624 equ 29692  ; FIX(3.624509785)
     48 %else
     49 ; NASM cannot do compile-time arithmetic on floating-point constants.
     50 %define DESCALE(x, n)  (((x) + (1 << ((n) - 1))) >> (n))
     51 F_0_211 equ DESCALE( 226735879, 30 - CONST_BITS)  ; FIX(0.211164243)
     52 F_0_509 equ DESCALE( 547388834, 30 - CONST_BITS)  ; FIX(0.509795579)
     53 F_0_601 equ DESCALE( 645689155, 30 - CONST_BITS)  ; FIX(0.601344887)
     54 F_0_720 equ DESCALE( 774124714, 30 - CONST_BITS)  ; FIX(0.720959822)
     55 F_0_765 equ DESCALE( 821806413, 30 - CONST_BITS)  ; FIX(0.765366865)
     56 F_0_850 equ DESCALE( 913142361, 30 - CONST_BITS)  ; FIX(0.850430095)
     57 F_0_899 equ DESCALE( 966342111, 30 - CONST_BITS)  ; FIX(0.899976223)
     58 F_1_061 equ DESCALE(1139878239, 30 - CONST_BITS)  ; FIX(1.061594337)
     59 F_1_272 equ DESCALE(1366614119, 30 - CONST_BITS)  ; FIX(1.272758580)
     60 F_1_451 equ DESCALE(1558831516, 30 - CONST_BITS)  ; FIX(1.451774981)
     61 F_1_847 equ DESCALE(1984016188, 30 - CONST_BITS)  ; FIX(1.847759065)
     62 F_2_172 equ DESCALE(2332956230, 30 - CONST_BITS)  ; FIX(2.172734803)
     63 F_2_562 equ DESCALE(2751909506, 30 - CONST_BITS)  ; FIX(2.562915447)
     64 F_3_624 equ DESCALE(3891787747, 30 - CONST_BITS)  ; FIX(3.624509785)
     65 %endif
     66 
     67 ; --------------------------------------------------------------------------
     68    SECTION     SEG_CONST
     69 
     70    ALIGNZ      32
     71    GLOBAL_DATA(jconst_idct_red_sse2)
     72 
     73 EXTN(jconst_idct_red_sse2):
     74 
     75 PW_F184_MF076   times 4  dw  F_1_847, -F_0_765
     76 PW_F256_F089    times 4  dw  F_2_562,  F_0_899
     77 PW_F106_MF217   times 4  dw  F_1_061, -F_2_172
     78 PW_MF060_MF050  times 4  dw -F_0_601, -F_0_509
     79 PW_F145_MF021   times 4  dw  F_1_451, -F_0_211
     80 PW_F362_MF127   times 4  dw  F_3_624, -F_1_272
     81 PW_F085_MF072   times 4  dw  F_0_850, -F_0_720
     82 PD_DESCALE_P1_4 times 4  dd  1 << (DESCALE_P1_4 - 1)
     83 PD_DESCALE_P2_4 times 4  dd  1 << (DESCALE_P2_4 - 1)
     84 PD_DESCALE_P1_2 times 4  dd  1 << (DESCALE_P1_2 - 1)
     85 PD_DESCALE_P2_2 times 4  dd  1 << (DESCALE_P2_2 - 1)
     86 PB_CENTERJSAMP  times 16 db  CENTERJSAMPLE
     87 
     88    ALIGNZ      32
     89 
     90 ; --------------------------------------------------------------------------
     91    SECTION     SEG_TEXT
     92    BITS        64
     93 ;
     94 ; Perform dequantization and inverse DCT on one block of coefficients,
     95 ; producing a reduced-size 4x4 output block.
     96 ;
     97 ; GLOBAL(void)
     98 ; jsimd_idct_4x4_sse2(void *dct_table, JCOEFPTR coef_block,
     99 ;                     JSAMPARRAY output_buf, JDIMENSION output_col)
    100 ;
    101 
    102 ; r10 = void *dct_table
    103 ; r11 = JCOEFPTR coef_block
    104 ; r12 = JSAMPARRAY output_buf
    105 ; r13d = JDIMENSION output_col
    106 
    107 %define wk(i)         r15 - (WK_NUM - (i)) * SIZEOF_XMMWORD
    108                                        ; xmmword wk[WK_NUM]
    109 %define WK_NUM        2
    110 
    111    align       32
    112    GLOBAL_FUNCTION(jsimd_idct_4x4_sse2)
    113 
    114 EXTN(jsimd_idct_4x4_sse2):
    115    ENDBR64
    116    push        rbp
    117    mov         rbp, rsp
    118    push        r15
    119    and         rsp, byte (-SIZEOF_XMMWORD)  ; align to 128 bits
    120    ; Allocate stack space for wk array.  r15 is used to access it.
    121    mov         r15, rsp
    122    sub         rsp, byte (SIZEOF_XMMWORD * WK_NUM)
    123    COLLECT_ARGS 4
    124 
    125    ; ---- Pass 1: process columns from input.
    126 
    127    mov         rdx, r10                ; quantptr
    128    mov         rsi, r11                ; inptr
    129 
    130 %ifndef NO_ZERO_COLUMN_TEST_4X4_SSE2
    131    mov         eax, dword [DWBLOCK(1,0,rsi,SIZEOF_JCOEF)]
    132    or          eax, dword [DWBLOCK(2,0,rsi,SIZEOF_JCOEF)]
    133    jnz         short .columnDCT
    134 
    135    movdqa      xmm0, XMMWORD [XMMBLOCK(1,0,rsi,SIZEOF_JCOEF)]
    136    movdqa      xmm1, XMMWORD [XMMBLOCK(2,0,rsi,SIZEOF_JCOEF)]
    137    por         xmm0, XMMWORD [XMMBLOCK(3,0,rsi,SIZEOF_JCOEF)]
    138    por         xmm1, XMMWORD [XMMBLOCK(5,0,rsi,SIZEOF_JCOEF)]
    139    por         xmm0, XMMWORD [XMMBLOCK(6,0,rsi,SIZEOF_JCOEF)]
    140    por         xmm1, XMMWORD [XMMBLOCK(7,0,rsi,SIZEOF_JCOEF)]
    141    por         xmm0, xmm1
    142    packsswb    xmm0, xmm0
    143    packsswb    xmm0, xmm0
    144    movd        eax, xmm0
    145    test        rax, rax
    146    jnz         short .columnDCT
    147 
    148    ; -- AC terms all zero
    149 
    150    movdqa      xmm0, XMMWORD [XMMBLOCK(0,0,rsi,SIZEOF_JCOEF)]
    151    pmullw      xmm0, XMMWORD [XMMBLOCK(0,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    152 
    153    psllw       xmm0, PASS1_BITS
    154 
    155    movdqa      xmm3, xmm0        ; xmm0=in0=(00 01 02 03 04 05 06 07)
    156    punpcklwd   xmm0, xmm0        ; xmm0=(00 00 01 01 02 02 03 03)
    157    punpckhwd   xmm3, xmm3        ; xmm3=(04 04 05 05 06 06 07 07)
    158 
    159    pshufd      xmm1, xmm0, 0x50  ; xmm1=[col0 col1]=(00 00 00 00 01 01 01 01)
    160    pshufd      xmm0, xmm0, 0xFA  ; xmm0=[col2 col3]=(02 02 02 02 03 03 03 03)
    161    pshufd      xmm6, xmm3, 0x50  ; xmm6=[col4 col5]=(04 04 04 04 05 05 05 05)
    162    pshufd      xmm3, xmm3, 0xFA  ; xmm3=[col6 col7]=(06 06 06 06 07 07 07 07)
    163 
    164    jmp         near .column_end
    165 %endif
    166 .columnDCT:
    167 
    168    ; -- Odd part
    169 
    170    movdqa      xmm0, XMMWORD [XMMBLOCK(1,0,rsi,SIZEOF_JCOEF)]
    171    movdqa      xmm1, XMMWORD [XMMBLOCK(3,0,rsi,SIZEOF_JCOEF)]
    172    pmullw      xmm0, XMMWORD [XMMBLOCK(1,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    173    pmullw      xmm1, XMMWORD [XMMBLOCK(3,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    174    movdqa      xmm2, XMMWORD [XMMBLOCK(5,0,rsi,SIZEOF_JCOEF)]
    175    movdqa      xmm3, XMMWORD [XMMBLOCK(7,0,rsi,SIZEOF_JCOEF)]
    176    pmullw      xmm2, XMMWORD [XMMBLOCK(5,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    177    pmullw      xmm3, XMMWORD [XMMBLOCK(7,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    178 
    179    movdqa      xmm4, xmm0
    180    movdqa      xmm5, xmm0
    181    punpcklwd   xmm4, xmm1
    182    punpckhwd   xmm5, xmm1
    183    movdqa      xmm0, xmm4
    184    movdqa      xmm1, xmm5
    185    pmaddwd     xmm4, [rel PW_F256_F089]   ; xmm4=(tmp2L)
    186    pmaddwd     xmm5, [rel PW_F256_F089]   ; xmm5=(tmp2H)
    187    pmaddwd     xmm0, [rel PW_F106_MF217]  ; xmm0=(tmp0L)
    188    pmaddwd     xmm1, [rel PW_F106_MF217]  ; xmm1=(tmp0H)
    189 
    190    movdqa      xmm6, xmm2
    191    movdqa      xmm7, xmm2
    192    punpcklwd   xmm6, xmm3
    193    punpckhwd   xmm7, xmm3
    194    movdqa      xmm2, xmm6
    195    movdqa      xmm3, xmm7
    196    pmaddwd     xmm6, [rel PW_MF060_MF050]  ; xmm6=(tmp2L)
    197    pmaddwd     xmm7, [rel PW_MF060_MF050]  ; xmm7=(tmp2H)
    198    pmaddwd     xmm2, [rel PW_F145_MF021]   ; xmm2=(tmp0L)
    199    pmaddwd     xmm3, [rel PW_F145_MF021]   ; xmm3=(tmp0H)
    200 
    201    paddd       xmm6, xmm4              ; xmm6=tmp2L
    202    paddd       xmm7, xmm5              ; xmm7=tmp2H
    203    paddd       xmm2, xmm0              ; xmm2=tmp0L
    204    paddd       xmm3, xmm1              ; xmm3=tmp0H
    205 
    206    movdqa      XMMWORD [wk(0)], xmm2   ; wk(0)=tmp0L
    207    movdqa      XMMWORD [wk(1)], xmm3   ; wk(1)=tmp0H
    208 
    209    ; -- Even part
    210 
    211    movdqa      xmm4, XMMWORD [XMMBLOCK(0,0,rsi,SIZEOF_JCOEF)]
    212    movdqa      xmm5, XMMWORD [XMMBLOCK(2,0,rsi,SIZEOF_JCOEF)]
    213    movdqa      xmm0, XMMWORD [XMMBLOCK(6,0,rsi,SIZEOF_JCOEF)]
    214    pmullw      xmm4, XMMWORD [XMMBLOCK(0,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    215    pmullw      xmm5, XMMWORD [XMMBLOCK(2,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    216    pmullw      xmm0, XMMWORD [XMMBLOCK(6,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    217 
    218    pxor        xmm1, xmm1
    219    pxor        xmm2, xmm2
    220    punpcklwd   xmm1, xmm4               ; xmm1=tmp0L
    221    punpckhwd   xmm2, xmm4               ; xmm2=tmp0H
    222    psrad       xmm1, (16-CONST_BITS-1)  ; psrad xmm1,16 & pslld xmm1,CONST_BITS+1
    223    psrad       xmm2, (16-CONST_BITS-1)  ; psrad xmm2,16 & pslld xmm2,CONST_BITS+1
    224 
    225    movdqa      xmm3, xmm5              ; xmm5=in2=z2
    226    punpcklwd   xmm5, xmm0              ; xmm0=in6=z3
    227    punpckhwd   xmm3, xmm0
    228    pmaddwd     xmm5, [rel PW_F184_MF076]  ; xmm5=tmp2L
    229    pmaddwd     xmm3, [rel PW_F184_MF076]  ; xmm3=tmp2H
    230 
    231    movdqa      xmm4, xmm1
    232    movdqa      xmm0, xmm2
    233    paddd       xmm1, xmm5              ; xmm1=tmp10L
    234    paddd       xmm2, xmm3              ; xmm2=tmp10H
    235    psubd       xmm4, xmm5              ; xmm4=tmp12L
    236    psubd       xmm0, xmm3              ; xmm0=tmp12H
    237 
    238    ; -- Final output stage
    239 
    240    movdqa      xmm5, xmm1
    241    movdqa      xmm3, xmm2
    242    paddd       xmm1, xmm6              ; xmm1=data0L
    243    paddd       xmm2, xmm7              ; xmm2=data0H
    244    psubd       xmm5, xmm6              ; xmm5=data3L
    245    psubd       xmm3, xmm7              ; xmm3=data3H
    246 
    247    movdqa      xmm6, [rel PD_DESCALE_P1_4]  ; xmm6=[rel PD_DESCALE_P1_4]
    248 
    249    paddd       xmm1, xmm6
    250    paddd       xmm2, xmm6
    251    psrad       xmm1, DESCALE_P1_4
    252    psrad       xmm2, DESCALE_P1_4
    253    paddd       xmm5, xmm6
    254    paddd       xmm3, xmm6
    255    psrad       xmm5, DESCALE_P1_4
    256    psrad       xmm3, DESCALE_P1_4
    257 
    258    packssdw    xmm1, xmm2              ; xmm1=data0=(00 01 02 03 04 05 06 07)
    259    packssdw    xmm5, xmm3              ; xmm5=data3=(30 31 32 33 34 35 36 37)
    260 
    261    movdqa      xmm7, XMMWORD [wk(0)]   ; xmm7=tmp0L
    262    movdqa      xmm6, XMMWORD [wk(1)]   ; xmm6=tmp0H
    263 
    264    movdqa      xmm2, xmm4
    265    movdqa      xmm3, xmm0
    266    paddd       xmm4, xmm7              ; xmm4=data1L
    267    paddd       xmm0, xmm6              ; xmm0=data1H
    268    psubd       xmm2, xmm7              ; xmm2=data2L
    269    psubd       xmm3, xmm6              ; xmm3=data2H
    270 
    271    movdqa      xmm7, [rel PD_DESCALE_P1_4]  ; xmm7=[rel PD_DESCALE_P1_4]
    272 
    273    paddd       xmm4, xmm7
    274    paddd       xmm0, xmm7
    275    psrad       xmm4, DESCALE_P1_4
    276    psrad       xmm0, DESCALE_P1_4
    277    paddd       xmm2, xmm7
    278    paddd       xmm3, xmm7
    279    psrad       xmm2, DESCALE_P1_4
    280    psrad       xmm3, DESCALE_P1_4
    281 
    282    packssdw    xmm4, xmm0        ; xmm4=data1=(10 11 12 13 14 15 16 17)
    283    packssdw    xmm2, xmm3        ; xmm2=data2=(20 21 22 23 24 25 26 27)
    284 
    285    movdqa      xmm6, xmm1        ; transpose coefficients(phase 1)
    286    punpcklwd   xmm1, xmm4        ; xmm1=(00 10 01 11 02 12 03 13)
    287    punpckhwd   xmm6, xmm4        ; xmm6=(04 14 05 15 06 16 07 17)
    288    movdqa      xmm7, xmm2        ; transpose coefficients(phase 1)
    289    punpcklwd   xmm2, xmm5        ; xmm2=(20 30 21 31 22 32 23 33)
    290    punpckhwd   xmm7, xmm5        ; xmm7=(24 34 25 35 26 36 27 37)
    291 
    292    movdqa      xmm0, xmm1        ; transpose coefficients(phase 2)
    293    punpckldq   xmm1, xmm2        ; xmm1=[col0 col1]=(00 10 20 30 01 11 21 31)
    294    punpckhdq   xmm0, xmm2        ; xmm0=[col2 col3]=(02 12 22 32 03 13 23 33)
    295    movdqa      xmm3, xmm6        ; transpose coefficients(phase 2)
    296    punpckldq   xmm6, xmm7        ; xmm6=[col4 col5]=(04 14 24 34 05 15 25 35)
    297    punpckhdq   xmm3, xmm7        ; xmm3=[col6 col7]=(06 16 26 36 07 17 27 37)
    298 .column_end:
    299 
    300    ; -- Prefetch the next coefficient block
    301 
    302    prefetchnta [rsi + DCTSIZE2*SIZEOF_JCOEF + 0*32]
    303    prefetchnta [rsi + DCTSIZE2*SIZEOF_JCOEF + 1*32]
    304    prefetchnta [rsi + DCTSIZE2*SIZEOF_JCOEF + 2*32]
    305    prefetchnta [rsi + DCTSIZE2*SIZEOF_JCOEF + 3*32]
    306 
    307    ; ---- Pass 2: process rows, store into output array.
    308 
    309    mov         rdi, r12                ; (JSAMPROW *)
    310    mov         eax, r13d
    311 
    312    ; -- Even part
    313 
    314    pxor        xmm4, xmm4
    315    punpcklwd   xmm4, xmm1               ; xmm4=tmp0
    316    psrad       xmm4, (16-CONST_BITS-1)  ; psrad xmm4,16 & pslld xmm4,CONST_BITS+1
    317 
    318    ; -- Odd part
    319 
    320    punpckhwd   xmm1, xmm0
    321    punpckhwd   xmm6, xmm3
    322    movdqa      xmm5, xmm1
    323    movdqa      xmm2, xmm6
    324    pmaddwd     xmm1, [rel PW_F256_F089]    ; xmm1=(tmp2)
    325    pmaddwd     xmm6, [rel PW_MF060_MF050]  ; xmm6=(tmp2)
    326    pmaddwd     xmm5, [rel PW_F106_MF217]   ; xmm5=(tmp0)
    327    pmaddwd     xmm2, [rel PW_F145_MF021]   ; xmm2=(tmp0)
    328 
    329    paddd       xmm6, xmm1              ; xmm6=tmp2
    330    paddd       xmm2, xmm5              ; xmm2=tmp0
    331 
    332    ; -- Even part
    333 
    334    punpcklwd   xmm0, xmm3
    335    pmaddwd     xmm0, [rel PW_F184_MF076]  ; xmm0=tmp2
    336 
    337    movdqa      xmm7, xmm4
    338    paddd       xmm4, xmm0              ; xmm4=tmp10
    339    psubd       xmm7, xmm0              ; xmm7=tmp12
    340 
    341    ; -- Final output stage
    342 
    343    movdqa      xmm1, [rel PD_DESCALE_P2_4]  ; xmm1=[rel PD_DESCALE_P2_4]
    344 
    345    movdqa      xmm5, xmm4
    346    movdqa      xmm3, xmm7
    347    paddd       xmm4, xmm6              ; xmm4=data0=(00 10 20 30)
    348    paddd       xmm7, xmm2              ; xmm7=data1=(01 11 21 31)
    349    psubd       xmm5, xmm6              ; xmm5=data3=(03 13 23 33)
    350    psubd       xmm3, xmm2              ; xmm3=data2=(02 12 22 32)
    351 
    352    paddd       xmm4, xmm1
    353    paddd       xmm7, xmm1
    354    psrad       xmm4, DESCALE_P2_4
    355    psrad       xmm7, DESCALE_P2_4
    356    paddd       xmm5, xmm1
    357    paddd       xmm3, xmm1
    358    psrad       xmm5, DESCALE_P2_4
    359    psrad       xmm3, DESCALE_P2_4
    360 
    361    packssdw    xmm4, xmm3              ; xmm4=(00 10 20 30 02 12 22 32)
    362    packssdw    xmm7, xmm5              ; xmm7=(01 11 21 31 03 13 23 33)
    363 
    364    movdqa      xmm0, xmm4              ; transpose coefficients(phase 1)
    365    punpcklwd   xmm4, xmm7              ; xmm4=(00 01 10 11 20 21 30 31)
    366    punpckhwd   xmm0, xmm7              ; xmm0=(02 03 12 13 22 23 32 33)
    367 
    368    movdqa      xmm6, xmm4              ; transpose coefficients(phase 2)
    369    punpckldq   xmm4, xmm0              ; xmm4=(00 01 02 03 10 11 12 13)
    370    punpckhdq   xmm6, xmm0              ; xmm6=(20 21 22 23 30 31 32 33)
    371 
    372    packsswb    xmm4, xmm6              ; xmm4=(00 01 02 03 10 11 12 13 20 ..)
    373    paddb       xmm4, [rel PB_CENTERJSAMP]
    374 
    375    pshufd      xmm2, xmm4, 0x39        ; xmm2=(10 11 12 13 20 21 22 23 30 ..)
    376    pshufd      xmm1, xmm4, 0x4E        ; xmm1=(20 21 22 23 30 31 32 33 00 ..)
    377    pshufd      xmm3, xmm4, 0x93        ; xmm3=(30 31 32 33 00 01 02 03 10 ..)
    378 
    379    mov         rdxp, JSAMPROW [rdi+0*SIZEOF_JSAMPROW]
    380    mov         rsip, JSAMPROW [rdi+1*SIZEOF_JSAMPROW]
    381    movd        XMM_DWORD [rdx+rax*SIZEOF_JSAMPLE], xmm4
    382    movd        XMM_DWORD [rsi+rax*SIZEOF_JSAMPLE], xmm2
    383    mov         rdxp, JSAMPROW [rdi+2*SIZEOF_JSAMPROW]
    384    mov         rsip, JSAMPROW [rdi+3*SIZEOF_JSAMPROW]
    385    movd        XMM_DWORD [rdx+rax*SIZEOF_JSAMPLE], xmm1
    386    movd        XMM_DWORD [rsi+rax*SIZEOF_JSAMPLE], xmm3
    387 
    388    UNCOLLECT_ARGS 4
    389    lea         rsp, [rbp-8]
    390    pop         r15
    391    pop         rbp
    392    ret
    393 
    394 ; --------------------------------------------------------------------------
    395 ;
    396 ; Perform dequantization and inverse DCT on one block of coefficients,
    397 ; producing a reduced-size 2x2 output block.
    398 ;
    399 ; GLOBAL(void)
    400 ; jsimd_idct_2x2_sse2(void *dct_table, JCOEFPTR coef_block,
    401 ;                     JSAMPARRAY output_buf, JDIMENSION output_col)
    402 ;
    403 
    404 ; r10 = void *dct_table
    405 ; r11 = JCOEFPTR coef_block
    406 ; r12 = JSAMPARRAY output_buf
    407 ; r13d = JDIMENSION output_col
    408 
    409    align       32
    410    GLOBAL_FUNCTION(jsimd_idct_2x2_sse2)
    411 
    412 EXTN(jsimd_idct_2x2_sse2):
    413    ENDBR64
    414    push        rbp
    415    mov         rbp, rsp
    416    COLLECT_ARGS 4
    417    push        rbx
    418 
    419    ; ---- Pass 1: process columns from input.
    420 
    421    mov         rdx, r10                ; quantptr
    422    mov         rsi, r11                ; inptr
    423 
    424    ; | input:                  | result:        |
    425    ; | 00 01 ** 03 ** 05 ** 07 |                |
    426    ; | 10 11 ** 13 ** 15 ** 17 |                |
    427    ; | ** ** ** ** ** ** ** ** |                |
    428    ; | 30 31 ** 33 ** 35 ** 37 | A0 A1 A3 A5 A7 |
    429    ; | ** ** ** ** ** ** ** ** | B0 B1 B3 B5 B7 |
    430    ; | 50 51 ** 53 ** 55 ** 57 |                |
    431    ; | ** ** ** ** ** ** ** ** |                |
    432    ; | 70 71 ** 73 ** 75 ** 77 |                |
    433 
    434    ; -- Odd part
    435 
    436    movdqa      xmm0, XMMWORD [XMMBLOCK(1,0,rsi,SIZEOF_JCOEF)]
    437    movdqa      xmm1, XMMWORD [XMMBLOCK(3,0,rsi,SIZEOF_JCOEF)]
    438    pmullw      xmm0, XMMWORD [XMMBLOCK(1,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    439    pmullw      xmm1, XMMWORD [XMMBLOCK(3,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    440    movdqa      xmm2, XMMWORD [XMMBLOCK(5,0,rsi,SIZEOF_JCOEF)]
    441    movdqa      xmm3, XMMWORD [XMMBLOCK(7,0,rsi,SIZEOF_JCOEF)]
    442    pmullw      xmm2, XMMWORD [XMMBLOCK(5,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    443    pmullw      xmm3, XMMWORD [XMMBLOCK(7,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    444 
    445    ; xmm0=(10 11 ** 13 ** 15 ** 17), xmm1=(30 31 ** 33 ** 35 ** 37)
    446    ; xmm2=(50 51 ** 53 ** 55 ** 57), xmm3=(70 71 ** 73 ** 75 ** 77)
    447 
    448    pcmpeqd     xmm7, xmm7
    449    pslld       xmm7, WORD_BIT          ; xmm7={0x0000 0xFFFF 0x0000 0xFFFF ..}
    450 
    451    movdqa      xmm4, xmm0              ; xmm4=(10 11 ** 13 ** 15 ** 17)
    452    movdqa      xmm5, xmm2              ; xmm5=(50 51 ** 53 ** 55 ** 57)
    453    punpcklwd   xmm4, xmm1              ; xmm4=(10 30 11 31 ** ** 13 33)
    454    punpcklwd   xmm5, xmm3              ; xmm5=(50 70 51 71 ** ** 53 73)
    455    pmaddwd     xmm4, [rel PW_F362_MF127]
    456    pmaddwd     xmm5, [rel PW_F085_MF072]
    457 
    458    psrld       xmm0, WORD_BIT          ; xmm0=(11 -- 13 -- 15 -- 17 --)
    459    pand        xmm1, xmm7              ; xmm1=(-- 31 -- 33 -- 35 -- 37)
    460    psrld       xmm2, WORD_BIT          ; xmm2=(51 -- 53 -- 55 -- 57 --)
    461    pand        xmm3, xmm7              ; xmm3=(-- 71 -- 73 -- 75 -- 77)
    462    por         xmm0, xmm1              ; xmm0=(11 31 13 33 15 35 17 37)
    463    por         xmm2, xmm3              ; xmm2=(51 71 53 73 55 75 57 77)
    464    pmaddwd     xmm0, [rel PW_F362_MF127]
    465    pmaddwd     xmm2, [rel PW_F085_MF072]
    466 
    467    paddd       xmm4, xmm5              ; xmm4=tmp0[col0 col1 **** col3]
    468    paddd       xmm0, xmm2              ; xmm0=tmp0[col1 col3 col5 col7]
    469 
    470    ; -- Even part
    471 
    472    movdqa      xmm6, XMMWORD [XMMBLOCK(0,0,rsi,SIZEOF_JCOEF)]
    473    pmullw      xmm6, XMMWORD [XMMBLOCK(0,0,rdx,SIZEOF_ISLOW_MULT_TYPE)]
    474 
    475    ; xmm6=(00 01 ** 03 ** 05 ** 07)
    476 
    477    movdqa      xmm1, xmm6              ; xmm1=(00 01 ** 03 ** 05 ** 07)
    478    pslld       xmm6, WORD_BIT          ; xmm6=(-- 00 -- ** -- ** -- **)
    479    pand        xmm1, xmm7              ; xmm1=(-- 01 -- 03 -- 05 -- 07)
    480    psrad       xmm6, (WORD_BIT-CONST_BITS-2)  ; xmm6=tmp10[col0 **** **** ****]
    481    psrad       xmm1, (WORD_BIT-CONST_BITS-2)  ; xmm1=tmp10[col1 col3 col5 col7]
    482 
    483    ; -- Final output stage
    484 
    485    movdqa      xmm3, xmm6
    486    movdqa      xmm5, xmm1
    487    paddd       xmm6, xmm4      ; xmm6=data0[col0 **** **** ****]=(A0 ** ** **)
    488    paddd       xmm1, xmm0      ; xmm1=data0[col1 col3 col5 col7]=(A1 A3 A5 A7)
    489    psubd       xmm3, xmm4      ; xmm3=data1[col0 **** **** ****]=(B0 ** ** **)
    490    psubd       xmm5, xmm0      ; xmm5=data1[col1 col3 col5 col7]=(B1 B3 B5 B7)
    491 
    492    movdqa      xmm2, [rel PD_DESCALE_P1_2]  ; xmm2=[rel PD_DESCALE_P1_2]
    493 
    494    punpckldq   xmm6, xmm3              ; xmm6=(A0 B0 ** **)
    495 
    496    movdqa      xmm7, xmm1
    497    punpcklqdq  xmm1, xmm5              ; xmm1=(A1 A3 B1 B3)
    498    punpckhqdq  xmm7, xmm5              ; xmm7=(A5 A7 B5 B7)
    499 
    500    paddd       xmm6, xmm2
    501    psrad       xmm6, DESCALE_P1_2
    502 
    503    paddd       xmm1, xmm2
    504    paddd       xmm7, xmm2
    505    psrad       xmm1, DESCALE_P1_2
    506    psrad       xmm7, DESCALE_P1_2
    507 
    508    ; -- Prefetch the next coefficient block
    509 
    510    prefetchnta [rsi + DCTSIZE2*SIZEOF_JCOEF + 0*32]
    511    prefetchnta [rsi + DCTSIZE2*SIZEOF_JCOEF + 1*32]
    512    prefetchnta [rsi + DCTSIZE2*SIZEOF_JCOEF + 2*32]
    513    prefetchnta [rsi + DCTSIZE2*SIZEOF_JCOEF + 3*32]
    514 
    515    ; ---- Pass 2: process rows, store into output array.
    516 
    517    mov         rdi, r12                ; (JSAMPROW *)
    518    mov         eax, r13d
    519 
    520    ; | input:| result:|
    521    ; | A0 B0 |        |
    522    ; | A1 B1 | C0 C1  |
    523    ; | A3 B3 | D0 D1  |
    524    ; | A5 B5 |        |
    525    ; | A7 B7 |        |
    526 
    527    ; -- Odd part
    528 
    529    packssdw    xmm1, xmm1              ; xmm1=(A1 A3 B1 B3 A1 A3 B1 B3)
    530    packssdw    xmm7, xmm7              ; xmm7=(A5 A7 B5 B7 A5 A7 B5 B7)
    531    pmaddwd     xmm1, [rel PW_F362_MF127]
    532    pmaddwd     xmm7, [rel PW_F085_MF072]
    533 
    534    paddd       xmm1, xmm7              ; xmm1=tmp0[row0 row1 row0 row1]
    535 
    536    ; -- Even part
    537 
    538    pslld       xmm6, (CONST_BITS+2)    ; xmm6=tmp10[row0 row1 **** ****]
    539 
    540    ; -- Final output stage
    541 
    542    movdqa      xmm4, xmm6
    543    paddd       xmm6, xmm1     ; xmm6=data0[row0 row1 **** ****]=(C0 C1 ** **)
    544    psubd       xmm4, xmm1     ; xmm4=data1[row0 row1 **** ****]=(D0 D1 ** **)
    545 
    546    punpckldq   xmm6, xmm4     ; xmm6=(C0 D0 C1 D1)
    547 
    548    paddd       xmm6, [rel PD_DESCALE_P2_2]
    549    psrad       xmm6, DESCALE_P2_2
    550 
    551    packssdw    xmm6, xmm6              ; xmm6=(C0 D0 C1 D1 C0 D0 C1 D1)
    552    packsswb    xmm6, xmm6              ; xmm6=(C0 D0 C1 D1 C0 D0 C1 D1 ..)
    553    paddb       xmm6, [rel PB_CENTERJSAMP]
    554 
    555    pextrw      ebx, xmm6, 0x00         ; ebx=(C0 D0 -- --)
    556    pextrw      ecx, xmm6, 0x01         ; ecx=(C1 D1 -- --)
    557 
    558    mov         rdxp, JSAMPROW [rdi+0*SIZEOF_JSAMPROW]
    559    mov         rsip, JSAMPROW [rdi+1*SIZEOF_JSAMPROW]
    560    mov         word [rdx+rax*SIZEOF_JSAMPLE], bx
    561    mov         word [rsi+rax*SIZEOF_JSAMPLE], cx
    562 
    563    pop         rbx
    564    UNCOLLECT_ARGS 4
    565    pop         rbp
    566    ret
    567 
    568 ; For some reason, the OS X linker does not honor the request to align the
    569 ; segment unless we do this.
    570    align       32