;
; jdsample.asm - upsampling (64-bit AVX2)
;
; Copyright 2009 Pierre Ossman <ossman@cendio.se> for Cendio AB
; Copyright (C) 2009, 2016, D. R. Commander.
; Copyright (C) 2015, Intel Corporation.
;
; Based on the x86 SIMD extension for IJG JPEG library
; Copyright (C) 1999-2006, MIYASAKA Masaru.
; For conditions of distribution and use, see copyright notice in jsimdext.inc
;
; This file should be assembled with NASM (Netwide Assembler),
; can *not* be assembled with Microsoft's MASM or any compatible
; assembler (including Borland's Turbo Assembler).
; NASM is available from http://nasm.sourceforge.net/ or
; http://sourceforge.net/project/showfiles.php?group_id=6208
;
; [TAB8]

%include "jsimdext.inc"

; --------------------------------------------------------------------------
    SECTION     SEG_CONST

    alignz      32
    GLOBAL_DATA(jconst_fancy_upsample_avx2)

EXTN(jconst_fancy_upsample_avx2):

PW_ONE   times 16 dw 1
PW_TWO   times 16 dw 2
PW_THREE times 16 dw 3
PW_SEVEN times 16 dw 7
PW_EIGHT times 16 dw 8

    alignz      32

; --------------------------------------------------------------------------
    SECTION     SEG_TEXT
    BITS        64
;
; Fancy processing for the common case of 2:1 horizontal and 1:1 vertical.
;
; The upsampling algorithm is linear interpolation between pixel centers,
; also known as a "triangle filter".  This is a good compromise between
; speed and visual quality.  The centers of the output pixels are 1/4 and 3/4
; of the way between input pixel centers.
;
; GLOBAL(void)
; jsimd_h2v1_fancy_upsample_avx2(int max_v_samp_factor,
;                                JDIMENSION downsampled_width,
;                                JSAMPARRAY input_data,
;                                JSAMPARRAY *output_data_ptr);
;

; r10 = int max_v_samp_factor
; r11d = JDIMENSION downsampled_width
; r12 = JSAMPARRAY input_data
; r13 = JSAMPARRAY *output_data_ptr

    align       32
    GLOBAL_FUNCTION(jsimd_h2v1_fancy_upsample_avx2)

EXTN(jsimd_h2v1_fancy_upsample_avx2):
    push        rbp
    mov         rax, rsp
    mov         rbp, rsp
    push_xmm    3
    collect_args 4

    mov         eax, r11d               ; colctr
    test        rax, rax
    jz          near .return

    mov         rcx, r10                ; rowctr
    test        rcx, rcx
    jz          near .return

    mov         rsi, r12                ; input_data
    mov         rdi, r13
    mov         rdi, JSAMPARRAY [rdi]   ; output_data

    vpxor       ymm0, ymm0, ymm0                 ; ymm0=(all 0's)
    vpcmpeqb    xmm9, xmm9, xmm9
    vpsrldq     xmm10, xmm9, (SIZEOF_XMMWORD-1)  ; (ff -- -- -- ... -- --) LSB is ff

    vpslldq     xmm9, xmm9, (SIZEOF_XMMWORD-1)
    vperm2i128  ymm9, ymm9, ymm9, 1              ; (---- ---- ... ---- ---- ff) MSB is ff

.rowloop:
    push        rax                     ; colctr
    push        rdi
    push        rsi

    mov         rsi, JSAMPROW [rsi]     ; inptr
    mov         rdi, JSAMPROW [rdi]     ; outptr

    test        rax, SIZEOF_YMMWORD-1
    jz          short .skip
    mov         dl, JSAMPLE [rsi+(rax-1)*SIZEOF_JSAMPLE]
    mov         JSAMPLE [rsi+rax*SIZEOF_JSAMPLE], dl    ; insert a dummy sample
.skip:
    vpand       ymm7, ymm10, YMMWORD [rsi+0*SIZEOF_YMMWORD]

    add         rax, byte SIZEOF_YMMWORD-1
    and         rax, byte -SIZEOF_YMMWORD
    cmp         rax, byte SIZEOF_YMMWORD
    ja          short .columnloop

.columnloop_last:
    vpand       ymm6, ymm9, YMMWORD [rsi+0*SIZEOF_YMMWORD]
    jmp         short .upsample

.columnloop:
    vmovdqu     ymm6, YMMWORD [rsi+1*SIZEOF_YMMWORD]
    vperm2i128  ymm6, ymm0, ymm6, 0x20
    vpslldq     ymm6, ymm6, 15

.upsample:
    vmovdqu     ymm1, YMMWORD [rsi+0*SIZEOF_YMMWORD]  ; ymm1=( 0  1  2 ... 29 30 31)

    vperm2i128  ymm2, ymm0, ymm1, 0x20
    vpalignr    ymm2, ymm1, ymm2, 15            ; ymm2=(--  0  1 ... 28 29 30)
    vperm2i128  ymm4, ymm0, ymm1, 0x03
    vpalignr    ymm3, ymm4, ymm1, 1             ; ymm3=( 1  2  3 ... 30 31 --)

    vpor        ymm2, ymm2, ymm7                ; ymm2=(-1  0  1 ... 28 29 30)
    vpor        ymm3, ymm3, ymm6                ; ymm3=( 1  2  3 ... 30 31 32)

    vpsrldq     ymm7, ymm4, (SIZEOF_XMMWORD-1)  ; ymm7=(31 -- -- ... -- -- --)

    vpunpckhbw  ymm4, ymm1, ymm0                ; ymm4=( 8  9 10 11 12 13 14 15 24 25 26 27 28 29 30 31)
    vpunpcklbw  ymm5, ymm1, ymm0                ; ymm5=( 0  1  2  3  4  5  6  7 16 17 18 19 20 21 22 23)
    vperm2i128  ymm1, ymm5, ymm4, 0x20          ; ymm1=( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vperm2i128  ymm4, ymm5, ymm4, 0x31          ; ymm4=(16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vpunpckhbw  ymm5, ymm2, ymm0                ; ymm5=( 7  8  9 10 11 12 13 14 23 24 25 26 27 28 29 30)
    vpunpcklbw  ymm6, ymm2, ymm0                ; ymm6=(-1  0  1  2  3  4  5  6 15 16 17 18 19 20 21 22)
    vperm2i128  ymm2, ymm6, ymm5, 0x20          ; ymm2=(-1  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14)
    vperm2i128  ymm5, ymm6, ymm5, 0x31          ; ymm5=(15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30)

    vpunpckhbw  ymm6, ymm3, ymm0                ; ymm6=( 1  2  3  4  5  6  7  8 17 18 19 20 21 22 23 24)
    vpunpcklbw  ymm8, ymm3, ymm0                ; ymm8=( 9 10 11 12 13 14 15 16 25 26 27 28 29 30 31 32)
    vperm2i128  ymm3, ymm8, ymm6, 0x20          ; ymm3=( 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16)
    vperm2i128  ymm6, ymm8, ymm6, 0x31          ; ymm6=(17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32)

    vpmullw     ymm1, ymm1, [rel PW_THREE]
    vpmullw     ymm4, ymm4, [rel PW_THREE]
    vpaddw      ymm2, ymm2, [rel PW_ONE]
    vpaddw      ymm5, ymm5, [rel PW_ONE]
    vpaddw      ymm3, ymm3, [rel PW_TWO]
    vpaddw      ymm6, ymm6, [rel PW_TWO]

    vpaddw      ymm2, ymm2, ymm1
    vpaddw      ymm5, ymm5, ymm4
    vpsrlw      ymm2, ymm2, 2                   ; ymm2=OutLE=( 0  2  4  6  8 10 12 14 16 18 20 22 24 26 28 30)
    vpsrlw      ymm5, ymm5, 2                   ; ymm5=OutHE=(32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62)
    vpaddw      ymm3, ymm3, ymm1
    vpaddw      ymm6, ymm6, ymm4
    vpsrlw      ymm3, ymm3, 2                   ; ymm3=OutLO=( 1  3  5  7  9 11 13 15 17 19 21 23 25 27 29 31)
    vpsrlw      ymm6, ymm6, 2                   ; ymm6=OutHO=(33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63)

    vpsllw      ymm3, ymm3, BYTE_BIT
    vpsllw      ymm6, ymm6, BYTE_BIT
    vpor        ymm2, ymm2, ymm3                ; ymm2=OutL=( 0  1  2 ... 29 30 31)
    vpor        ymm5, ymm5, ymm6                ; ymm5=OutH=(32 33 34 ... 61 62 63)

    vmovdqu     YMMWORD [rdi+0*SIZEOF_YMMWORD], ymm2
    vmovdqu     YMMWORD [rdi+1*SIZEOF_YMMWORD], ymm5

    sub         rax, byte SIZEOF_YMMWORD
    add         rsi, byte 1*SIZEOF_YMMWORD  ; inptr
    add         rdi, byte 2*SIZEOF_YMMWORD  ; outptr
    cmp         rax, byte SIZEOF_YMMWORD
    ja          near .columnloop
    test        eax, eax
    jnz         near .columnloop_last

    pop         rsi
    pop         rdi
    pop         rax

    add         rsi, byte SIZEOF_JSAMPROW  ; input_data
    add         rdi, byte SIZEOF_JSAMPROW  ; output_data
    dec         rcx                        ; rowctr
    jg          near .rowloop

.return:
    vzeroupper
    uncollect_args 4
    pop_xmm     3
    pop         rbp
    ret

; --------------------------------------------------------------------------
;
; Fancy processing for the common case of 2:1 horizontal and 2:1 vertical.
; Again a triangle filter; see comments for h2v1 case, above.
;
; GLOBAL(void)
; jsimd_h2v2_fancy_upsample_avx2(int max_v_samp_factor,
;                                JDIMENSION downsampled_width,
;                                JSAMPARRAY input_data,
;                                JSAMPARRAY *output_data_ptr);
;

; r10 = int max_v_samp_factor
; r11d = JDIMENSION downsampled_width
; r12 = JSAMPARRAY input_data
; r13 = JSAMPARRAY *output_data_ptr

%define wk(i)   rbp - (WK_NUM - (i)) * SIZEOF_YMMWORD  ; ymmword wk[WK_NUM]
%define WK_NUM  4

    align       32
    GLOBAL_FUNCTION(jsimd_h2v2_fancy_upsample_avx2)

EXTN(jsimd_h2v2_fancy_upsample_avx2):
    push        rbp
    mov         rax, rsp                     ; rax = original rbp
    sub         rsp, byte 4
    and         rsp, byte (-SIZEOF_YMMWORD)  ; align to 256 bits
    mov         [rsp], rax
    mov         rbp, rsp                     ; rbp = aligned rbp
    lea         rsp, [wk(0)]
    push_xmm    3
    collect_args 4
    push        rbx

    mov         eax, r11d               ; colctr
    test        rax, rax
    jz          near .return

    mov         rcx, r10                ; rowctr
    test        rcx, rcx
    jz          near .return

    mov         rsi, r12                ; input_data
    mov         rdi, r13
    mov         rdi, JSAMPARRAY [rdi]   ; output_data
.rowloop:
    push        rax                     ; colctr
    push        rcx
    push        rdi
    push        rsi

    mov         rcx, JSAMPROW [rsi-1*SIZEOF_JSAMPROW]  ; inptr1(above)
    mov         rbx, JSAMPROW [rsi+0*SIZEOF_JSAMPROW]  ; inptr0
    mov         rsi, JSAMPROW [rsi+1*SIZEOF_JSAMPROW]  ; inptr1(below)
    mov         rdx, JSAMPROW [rdi+0*SIZEOF_JSAMPROW]  ; outptr0
    mov         rdi, JSAMPROW [rdi+1*SIZEOF_JSAMPROW]  ; outptr1

    vpxor       ymm8, ymm8, ymm8                 ; ymm8=(all 0's)
    vpcmpeqb    xmm9, xmm9, xmm9
    vpsrldq     xmm10, xmm9, (SIZEOF_XMMWORD-2)  ; (ffff ---- ---- ... ---- ----) LSB is ffff
    vpslldq     xmm9, xmm9, (SIZEOF_XMMWORD-2)
    vperm2i128  ymm9, ymm9, ymm9, 1              ; (---- ---- ... ---- ---- ffff) MSB is ffff

    test        rax, SIZEOF_YMMWORD-1
    jz          short .skip
    push        rdx
    mov         dl, JSAMPLE [rcx+(rax-1)*SIZEOF_JSAMPLE]
    mov         JSAMPLE [rcx+rax*SIZEOF_JSAMPLE], dl
    mov         dl, JSAMPLE [rbx+(rax-1)*SIZEOF_JSAMPLE]
    mov         JSAMPLE [rbx+rax*SIZEOF_JSAMPLE], dl
    mov         dl, JSAMPLE [rsi+(rax-1)*SIZEOF_JSAMPLE]
    mov         JSAMPLE [rsi+rax*SIZEOF_JSAMPLE], dl    ; insert a dummy sample
    pop         rdx
.skip:
    ; -- process the first column block

    vmovdqu     ymm0, YMMWORD [rbx+0*SIZEOF_YMMWORD]  ; ymm0=row[ 0][0]
    vmovdqu     ymm1, YMMWORD [rcx+0*SIZEOF_YMMWORD]  ; ymm1=row[-1][0]
    vmovdqu     ymm2, YMMWORD [rsi+0*SIZEOF_YMMWORD]  ; ymm2=row[+1][0]

    vpunpckhbw  ymm4, ymm0, ymm8        ; ymm4=row[ 0]( 8  9 10 11 12 13 14 15 24 25 26 27 28 29 30 31)
    vpunpcklbw  ymm5, ymm0, ymm8        ; ymm5=row[ 0]( 0  1  2  3  4  5  6  7 16 17 18 19 20 21 22 23)
    vperm2i128  ymm0, ymm5, ymm4, 0x20  ; ymm0=row[ 0]( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vperm2i128  ymm4, ymm5, ymm4, 0x31  ; ymm4=row[ 0](16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vpunpckhbw  ymm5, ymm1, ymm8        ; ymm5=row[-1]( 8  9 10 11 12 13 14 15 24 25 26 27 28 29 30 31)
    vpunpcklbw  ymm6, ymm1, ymm8        ; ymm6=row[-1]( 0  1  2  3  4  5  6  7 16 17 18 19 20 21 22 23)
    vperm2i128  ymm1, ymm6, ymm5, 0x20  ; ymm1=row[-1]( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vperm2i128  ymm5, ymm6, ymm5, 0x31  ; ymm5=row[-1](16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vpunpckhbw  ymm6, ymm2, ymm8        ; ymm6=row[+1]( 8  9 10 11 12 13 14 15 24 25 26 27 28 29 30 31)
    vpunpcklbw  ymm3, ymm2, ymm8        ; ymm3=row[+1]( 0  1  2  3  4  5  6  7 16 17 18 19 20 21 22 23)
    vperm2i128  ymm2, ymm3, ymm6, 0x20  ; ymm2=row[+1]( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vperm2i128  ymm6, ymm3, ymm6, 0x31  ; ymm6=row[+1](16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vpmullw     ymm0, ymm0, [rel PW_THREE]
    vpmullw     ymm4, ymm4, [rel PW_THREE]

    vpaddw      ymm1, ymm1, ymm0        ; ymm1=Int0L=( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vpaddw      ymm5, ymm5, ymm4        ; ymm5=Int0H=(16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)
    vpaddw      ymm2, ymm2, ymm0        ; ymm2=Int1L=( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vpaddw      ymm6, ymm6, ymm4        ; ymm6=Int1H=(16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vmovdqu     YMMWORD [rdx+0*SIZEOF_YMMWORD], ymm1  ; temporarily save
    vmovdqu     YMMWORD [rdx+1*SIZEOF_YMMWORD], ymm5  ; the intermediate data
    vmovdqu     YMMWORD [rdi+0*SIZEOF_YMMWORD], ymm2
    vmovdqu     YMMWORD [rdi+1*SIZEOF_YMMWORD], ymm6

    vpand       ymm1, ymm1, ymm10       ; ymm1=( 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --)
    vpand       ymm2, ymm2, ymm10       ; ymm2=( 0 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --)

    vmovdqa     YMMWORD [wk(0)], ymm1
    vmovdqa     YMMWORD [wk(1)], ymm2

    add         rax, byte SIZEOF_YMMWORD-1
    and         rax, byte -SIZEOF_YMMWORD
    cmp         rax, byte SIZEOF_YMMWORD
    ja          short .columnloop

.columnloop_last:
    ; -- process the last column block

    vpand       ymm1, ymm9, YMMWORD [rdx+1*SIZEOF_YMMWORD]
    vpand       ymm2, ymm9, YMMWORD [rdi+1*SIZEOF_YMMWORD]

    vmovdqa     YMMWORD [wk(2)], ymm1   ; ymm1=(-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 31)
    vmovdqa     YMMWORD [wk(3)], ymm2   ; ymm2=(-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 31)

    jmp         near .upsample

.columnloop:
    ; -- process the next column block

    vmovdqu     ymm0, YMMWORD [rbx+1*SIZEOF_YMMWORD]  ; ymm0=row[ 0][1]
    vmovdqu     ymm1, YMMWORD [rcx+1*SIZEOF_YMMWORD]  ; ymm1=row[-1][1]
    vmovdqu     ymm2, YMMWORD [rsi+1*SIZEOF_YMMWORD]  ; ymm2=row[+1][1]

    vpunpckhbw  ymm4, ymm0, ymm8        ; ymm4=row[ 0]( 8  9 10 11 12 13 14 15 24 25 26 27 28 29 30 31)
    vpunpcklbw  ymm5, ymm0, ymm8        ; ymm5=row[ 0]( 0  1  2  3  4  5  6  7 16 17 18 19 20 21 22 23)
    vperm2i128  ymm0, ymm5, ymm4, 0x20  ; ymm0=row[ 0]( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vperm2i128  ymm4, ymm5, ymm4, 0x31  ; ymm4=row[ 0](16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vpunpckhbw  ymm5, ymm1, ymm8        ; ymm5=row[-1]( 8  9 10 11 12 13 14 15 24 25 26 27 28 29 30 31)
    vpunpcklbw  ymm6, ymm1, ymm8        ; ymm6=row[-1]( 0  1  2  3  4  5  6  7 16 17 18 19 20 21 22 23)
    vperm2i128  ymm1, ymm6, ymm5, 0x20  ; ymm1=row[-1]( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vperm2i128  ymm5, ymm6, ymm5, 0x31  ; ymm5=row[-1](16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vpunpckhbw  ymm6, ymm2, ymm8        ; ymm6=row[+1]( 8  9 10 11 12 13 14 15 24 25 26 27 28 29 30 31)
    vpunpcklbw  ymm7, ymm2, ymm8        ; ymm7=row[+1]( 0  1  2  3  4  5  6  7 16 17 18 19 20 21 22 23)
    vperm2i128  ymm2, ymm7, ymm6, 0x20  ; ymm2=row[+1]( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vperm2i128  ymm6, ymm7, ymm6, 0x31  ; ymm6=row[+1](16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vpmullw     ymm0, ymm0, [rel PW_THREE]
    vpmullw     ymm4, ymm4, [rel PW_THREE]

    vpaddw      ymm1, ymm1, ymm0        ; ymm1=Int0L=( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vpaddw      ymm5, ymm5, ymm4        ; ymm5=Int0H=(16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)
    vpaddw      ymm2, ymm2, ymm0        ; ymm2=Int1L=( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vpaddw      ymm6, ymm6, ymm4        ; ymm6=Int1H=(16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vmovdqu     YMMWORD [rdx+2*SIZEOF_YMMWORD], ymm1  ; temporarily save
    vmovdqu     YMMWORD [rdx+3*SIZEOF_YMMWORD], ymm5  ; the intermediate data
    vmovdqu     YMMWORD [rdi+2*SIZEOF_YMMWORD], ymm2
    vmovdqu     YMMWORD [rdi+3*SIZEOF_YMMWORD], ymm6

    vperm2i128  ymm1, ymm8, ymm1, 0x20
    vpslldq     ymm1, ymm1, 14          ; ymm1=(-- -- -- -- -- -- -- -- -- -- -- -- -- -- --  0)
    vperm2i128  ymm2, ymm8, ymm2, 0x20
    vpslldq     ymm2, ymm2, 14          ; ymm2=(-- -- -- -- -- -- -- -- -- -- -- -- -- -- --  0)

    vmovdqa     YMMWORD [wk(2)], ymm1
    vmovdqa     YMMWORD [wk(3)], ymm2

.upsample:
    ; -- process the upper row

    vmovdqu     ymm7, YMMWORD [rdx+0*SIZEOF_YMMWORD]  ; ymm7=Int0L=( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vmovdqu     ymm3, YMMWORD [rdx+1*SIZEOF_YMMWORD]  ; ymm3=Int0H=(16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vperm2i128  ymm0, ymm8, ymm7, 0x03
    vpalignr    ymm0, ymm0, ymm7, 2     ; ymm0=( 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 --)
    vperm2i128  ymm4, ymm8, ymm3, 0x20
    vpslldq     ymm4, ymm4, 14          ; ymm4=(-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 16)

    vperm2i128  ymm5, ymm8, ymm7, 0x03
    vpsrldq     ymm5, ymm5, 14          ; ymm5=(15 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --)
    vperm2i128  ymm6, ymm8, ymm3, 0x20
    vpalignr    ymm6, ymm3, ymm6, 14    ; ymm6=(-- 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30)

    vpor        ymm0, ymm0, ymm4        ; ymm0=( 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16)
    vpor        ymm5, ymm5, ymm6        ; ymm5=(15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30)

    vperm2i128  ymm2, ymm8, ymm3, 0x03
    vpalignr    ymm2, ymm2, ymm3, 2     ; ymm2=(17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 --)
    vperm2i128  ymm4, ymm8, ymm3, 0x03
    vpsrldq     ymm4, ymm4, 14          ; ymm4=(31 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --)
    vperm2i128  ymm1, ymm8, ymm7, 0x20
    vpalignr    ymm1, ymm7, ymm1, 14    ; ymm1=(--  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14)

    vpor        ymm1, ymm1, YMMWORD [wk(0)]  ; ymm1=(-1  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14)
    vpor        ymm2, ymm2, YMMWORD [wk(2)]  ; ymm2=(17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32)

    vmovdqa     YMMWORD [wk(0)], ymm4

    vpmullw     ymm7, ymm7, [rel PW_THREE]
    vpmullw     ymm3, ymm3, [rel PW_THREE]
    vpaddw      ymm1, ymm1, [rel PW_EIGHT]
    vpaddw      ymm5, ymm5, [rel PW_EIGHT]
    vpaddw      ymm0, ymm0, [rel PW_SEVEN]
    vpaddw      ymm2, [rel PW_SEVEN]

    vpaddw      ymm1, ymm1, ymm7
    vpaddw      ymm5, ymm5, ymm3
    vpsrlw      ymm1, ymm1, 4           ; ymm1=Out0LE=( 0  2  4  6  8 10 12 14 16 18 20 22 24 26 28 30)
    vpsrlw      ymm5, ymm5, 4           ; ymm5=Out0HE=(32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62)
    vpaddw      ymm0, ymm0, ymm7
    vpaddw      ymm2, ymm2, ymm3
    vpsrlw      ymm0, ymm0, 4           ; ymm0=Out0LO=( 1  3  5  7  9 11 13 15 17 19 21 23 25 27 29 31)
    vpsrlw      ymm2, ymm2, 4           ; ymm2=Out0HO=(33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63)

    vpsllw      ymm0, ymm0, BYTE_BIT
    vpsllw      ymm2, ymm2, BYTE_BIT
    vpor        ymm1, ymm1, ymm0        ; ymm1=Out0L=( 0  1  2 ... 29 30 31)
    vpor        ymm5, ymm5, ymm2        ; ymm5=Out0H=(32 33 34 ... 61 62 63)

    vmovdqu     YMMWORD [rdx+0*SIZEOF_YMMWORD], ymm1
    vmovdqu     YMMWORD [rdx+1*SIZEOF_YMMWORD], ymm5

    ; -- process the lower row

    vmovdqu     ymm6, YMMWORD [rdi+0*SIZEOF_YMMWORD]  ; ymm6=Int1L=( 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15)
    vmovdqu     ymm4, YMMWORD [rdi+1*SIZEOF_YMMWORD]  ; ymm4=Int1H=(16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31)

    vperm2i128  ymm7, ymm8, ymm6, 0x03
    vpalignr    ymm7, ymm7, ymm6, 2     ; ymm7=( 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 --)
    vperm2i128  ymm3, ymm8, ymm4, 0x20
    vpslldq     ymm3, ymm3, 14          ; ymm3=(-- -- -- -- -- -- -- -- -- -- -- -- -- -- -- 16)

    vperm2i128  ymm0, ymm8, ymm6, 0x03
    vpsrldq     ymm0, ymm0, 14          ; ymm0=(15 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --)
    vperm2i128  ymm2, ymm8, ymm4, 0x20
    vpalignr    ymm2, ymm4, ymm2, 14    ; ymm2=(-- 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30)

    vpor        ymm7, ymm7, ymm3        ; ymm7=( 1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 16)
    vpor        ymm0, ymm0, ymm2        ; ymm0=(15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30)

    vperm2i128  ymm5, ymm8, ymm4, 0x03
    vpalignr    ymm5, ymm5, ymm4, 2     ; ymm5=(17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 --)
    vperm2i128  ymm3, ymm8, ymm4, 0x03
    vpsrldq     ymm3, ymm3, 14          ; ymm3=(31 -- -- -- -- -- -- -- -- -- -- -- -- -- -- --)
    vperm2i128  ymm1, ymm8, ymm6, 0x20
    vpalignr    ymm1, ymm6, ymm1, 14    ; ymm1=(--  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14)

    vpor        ymm1, ymm1, YMMWORD [wk(1)]  ; ymm1=(-1  0  1  2  3  4  5  6  7  8  9 10 11 12 13 14)
    vpor        ymm5, ymm5, YMMWORD [wk(3)]  ; ymm5=(17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32)

    vmovdqa     YMMWORD [wk(1)], ymm3

    vpmullw     ymm6, ymm6, [rel PW_THREE]
    vpmullw     ymm4, ymm4, [rel PW_THREE]
    vpaddw      ymm1, ymm1, [rel PW_EIGHT]
    vpaddw      ymm0, ymm0, [rel PW_EIGHT]
    vpaddw      ymm7, ymm7, [rel PW_SEVEN]
    vpaddw      ymm5, ymm5, [rel PW_SEVEN]

    vpaddw      ymm1, ymm1, ymm6
    vpaddw      ymm0, ymm0, ymm4
    vpsrlw      ymm1, ymm1, 4           ; ymm1=Out1LE=( 0  2  4  6  8 10 12 14 16 18 20 22 24 26 28 30)
    vpsrlw      ymm0, ymm0, 4           ; ymm0=Out1HE=(32 34 36 38 40 42 44 46 48 50 52 54 56 58 60 62)
    vpaddw      ymm7, ymm7, ymm6
    vpaddw      ymm5, ymm5, ymm4
    vpsrlw      ymm7, ymm7, 4           ; ymm7=Out1LO=( 1  3  5  7  9 11 13 15 17 19 21 23 25 27 29 31)
    vpsrlw      ymm5, ymm5, 4           ; ymm5=Out1HO=(33 35 37 39 41 43 45 47 49 51 53 55 57 59 61 63)

    vpsllw      ymm7, ymm7, BYTE_BIT
    vpsllw      ymm5, ymm5, BYTE_BIT
    vpor        ymm1, ymm1, ymm7        ; ymm1=Out1L=( 0  1  2 ... 29 30 31)
    vpor        ymm0, ymm0, ymm5        ; ymm0=Out1H=(32 33 34 ... 61 62 63)

    vmovdqu     YMMWORD [rdi+0*SIZEOF_YMMWORD], ymm1
    vmovdqu     YMMWORD [rdi+1*SIZEOF_YMMWORD], ymm0

    sub         rax, byte SIZEOF_YMMWORD
    add         rcx, byte 1*SIZEOF_YMMWORD  ; inptr1(above)
    add         rbx, byte 1*SIZEOF_YMMWORD  ; inptr0
    add         rsi, byte 1*SIZEOF_YMMWORD  ; inptr1(below)
    add         rdx, byte 2*SIZEOF_YMMWORD  ; outptr0
    add         rdi, byte 2*SIZEOF_YMMWORD  ; outptr1
    cmp         rax, byte SIZEOF_YMMWORD
    ja          near .columnloop
    test        rax, rax
    jnz         near .columnloop_last

    pop         rsi
    pop         rdi
    pop         rcx
    pop         rax

    add         rsi, byte 1*SIZEOF_JSAMPROW  ; input_data
    add         rdi, byte 2*SIZEOF_JSAMPROW  ; output_data
    sub         rcx, byte 2                  ; rowctr
    jg          near .rowloop

.return:
    pop         rbx
    vzeroupper
    uncollect_args 4
    pop_xmm     3
    mov         rsp, rbp                ; rsp <- aligned rbp
    pop         rsp                     ; rsp <- original rbp
    pop         rbp
    ret

; --------------------------------------------------------------------------
;
; Fast processing for the common case of 2:1 horizontal and 1:1 vertical.
; It's still a box filter.
;
; GLOBAL(void)
; jsimd_h2v1_upsample_avx2(int max_v_samp_factor, JDIMENSION output_width,
;                          JSAMPARRAY input_data, JSAMPARRAY *output_data_ptr);
;

; r10 = int max_v_samp_factor
; r11d = JDIMENSION output_width
; r12 = JSAMPARRAY input_data
; r13 = JSAMPARRAY *output_data_ptr

    align       32
    GLOBAL_FUNCTION(jsimd_h2v1_upsample_avx2)

EXTN(jsimd_h2v1_upsample_avx2):
    push        rbp
    mov         rax, rsp
    mov         rbp, rsp
    collect_args 4

    mov         edx, r11d
    add         rdx, byte (SIZEOF_YMMWORD-1)
    and         rdx, -SIZEOF_YMMWORD
    jz          near .return

    mov         rcx, r10                ; rowctr
    test        rcx, rcx
    jz          short .return

    mov         rsi, r12                ; input_data
    mov         rdi, r13
    mov         rdi, JSAMPARRAY [rdi]   ; output_data
.rowloop:
    push        rdi
    push        rsi

    mov         rsi, JSAMPROW [rsi]     ; inptr
    mov         rdi, JSAMPROW [rdi]     ; outptr
    mov         rax, rdx                ; colctr
.columnloop:

    cmp         rax, byte SIZEOF_YMMWORD
    ja          near .above_16

    vmovdqu     xmm0, XMMWORD [rsi+0*SIZEOF_YMMWORD]
    vpunpckhbw  xmm1, xmm0, xmm0
    vpunpcklbw  xmm0, xmm0, xmm0

    vmovdqu     XMMWORD [rdi+0*SIZEOF_XMMWORD], xmm0
    vmovdqu     XMMWORD [rdi+1*SIZEOF_XMMWORD], xmm1

    jmp         short .nextrow

.above_16:
    vmovdqu     ymm0, YMMWORD [rsi+0*SIZEOF_YMMWORD]

    vpermq      ymm0, ymm0, 0xd8
    vpunpckhbw  ymm1, ymm0, ymm0
    vpunpcklbw  ymm0, ymm0, ymm0

    vmovdqu     YMMWORD [rdi+0*SIZEOF_YMMWORD], ymm0
    vmovdqu     YMMWORD [rdi+1*SIZEOF_YMMWORD], ymm1

    sub         rax, byte 2*SIZEOF_YMMWORD
    jz          short .nextrow

    add         rsi, byte SIZEOF_YMMWORD    ; inptr
    add         rdi, byte 2*SIZEOF_YMMWORD  ; outptr
    jmp         short .columnloop

.nextrow:
    pop         rsi
    pop         rdi

    add         rsi, byte SIZEOF_JSAMPROW  ; input_data
    add         rdi, byte SIZEOF_JSAMPROW  ; output_data
    dec         rcx                        ; rowctr
    jg          short .rowloop

.return:
    vzeroupper
    uncollect_args 4
    pop         rbp
    ret

; --------------------------------------------------------------------------
;
; Fast processing for the common case of 2:1 horizontal and 2:1 vertical.
; It's still a box filter.
;
; GLOBAL(void)
; jsimd_h2v2_upsample_avx2(int max_v_samp_factor, JDIMENSION output_width,
;                          JSAMPARRAY input_data, JSAMPARRAY *output_data_ptr);
;

; r10 = int max_v_samp_factor
; r11d = JDIMENSION output_width
; r12 = JSAMPARRAY input_data
; r13 = JSAMPARRAY *output_data_ptr

    align       32
    GLOBAL_FUNCTION(jsimd_h2v2_upsample_avx2)

EXTN(jsimd_h2v2_upsample_avx2):
    push        rbp
    mov         rax, rsp
    mov         rbp, rsp
    collect_args 4
    push        rbx

    mov         edx, r11d
    add         rdx, byte (SIZEOF_YMMWORD-1)
    and         rdx, -SIZEOF_YMMWORD
    jz          near .return

    mov         rcx, r10                ; rowctr
    test        rcx, rcx
    jz          near .return

    mov         rsi, r12                ; input_data
    mov         rdi, r13
    mov         rdi, JSAMPARRAY [rdi]   ; output_data
.rowloop:
    push        rdi
    push        rsi

    mov         rsi, JSAMPROW [rsi]                    ; inptr
    mov         rbx, JSAMPROW [rdi+0*SIZEOF_JSAMPROW]  ; outptr0
    mov         rdi, JSAMPROW [rdi+1*SIZEOF_JSAMPROW]  ; outptr1
    mov         rax, rdx                               ; colctr
.columnloop:

    cmp         rax, byte SIZEOF_YMMWORD
    ja          short .above_16

    vmovdqu     xmm0, XMMWORD [rsi+0*SIZEOF_XMMWORD]
    vpunpckhbw  xmm1, xmm0, xmm0
    vpunpcklbw  xmm0, xmm0, xmm0

    vmovdqu     XMMWORD [rbx+0*SIZEOF_XMMWORD], xmm0
    vmovdqu     XMMWORD [rbx+1*SIZEOF_XMMWORD], xmm1
    vmovdqu     XMMWORD [rdi+0*SIZEOF_XMMWORD], xmm0
    vmovdqu     XMMWORD [rdi+1*SIZEOF_XMMWORD], xmm1

    jmp         near .nextrow

.above_16:
    vmovdqu     ymm0, YMMWORD [rsi+0*SIZEOF_YMMWORD]

    vpermq      ymm0, ymm0, 0xd8
    vpunpckhbw  ymm1, ymm0, ymm0
    vpunpcklbw  ymm0, ymm0, ymm0

    vmovdqu     YMMWORD [rbx+0*SIZEOF_YMMWORD], ymm0
    vmovdqu     YMMWORD [rbx+1*SIZEOF_YMMWORD], ymm1
    vmovdqu     YMMWORD [rdi+0*SIZEOF_YMMWORD], ymm0
    vmovdqu     YMMWORD [rdi+1*SIZEOF_YMMWORD], ymm1

    sub         rax, byte 2*SIZEOF_YMMWORD
    jz          short .nextrow

    add         rsi, byte SIZEOF_YMMWORD  ; inptr
    add         rbx, 2*SIZEOF_YMMWORD     ; outptr0
    add         rdi, 2*SIZEOF_YMMWORD     ; outptr1
    jmp         short .columnloop

.nextrow:
    pop         rsi
    pop         rdi

    add         rsi, byte 1*SIZEOF_JSAMPROW  ; input_data
    add         rdi, byte 2*SIZEOF_JSAMPROW  ; output_data
    sub         rcx, byte 2                  ; rowctr
    jg          near .rowloop

.return:
    pop         rbx
    vzeroupper
    uncollect_args 4
    pop         rbp
    ret

; For some reason, the OS X linker does not honor the request to align the
; segment unless we do this.
    align       32