golang-image/vector/acc_amd64.s
Nigel Tao 93fad3647f vector: remove a shift from the inner loop.
PSHUFB already lets us pick certain bytes out of an XMM register.
There's no need to shift by 8 bits (1 byte) beforehand.

The code generator is simpler. There's also a small win on the
benchmarks, especially for FixedAccumulateOpOverSIMD.

name                              old time/op  new time/op  delta
FixedAccumulateOpOverSIMD16-8      183ns ± 0%   174ns ± 0%  -4.92%    (p=0.000 n=8+8)
FixedAccumulateOpSrcSIMD16-8      87.0ns ± 1%  86.3ns ± 0%  -0.77%   (p=0.000 n=10+9)
FixedAccumulateMaskSIMD16-8       80.4ns ± 1%  81.2ns ± 1%  +1.01%  (p=0.000 n=10+10)
FloatingAccumulateOpOverSIMD16-8   250ns ± 1%   244ns ± 0%  -2.39%   (p=0.000 n=10+8)
FloatingAccumulateOpSrcSIMD16-8    176ns ± 1%   176ns ± 0%    ~      (p=0.142 n=10+8)
FloatingAccumulateMaskSIMD16-8     167ns ± 0%   167ns ± 0%    ~      (p=0.137 n=8+10)
FixedAccumulateOpOverSIMD64-8     2.73µs ± 1%  2.58µs ± 0%  -5.36%   (p=0.000 n=10+7)
FixedAccumulateOpSrcSIMD64-8      1.18µs ± 1%  1.17µs ± 0%  -0.33%   (p=0.003 n=10+9)
FixedAccumulateMaskSIMD64-8       1.09µs ± 0%  1.09µs ± 0%  -0.17%    (p=0.047 n=9+9)
FloatingAccumulateOpOverSIMD64-8  3.67µs ± 0%  3.61µs ± 1%  -1.47%   (p=0.000 n=7+10)
FloatingAccumulateOpSrcSIMD64-8   2.60µs ± 0%  2.61µs ± 0%  +0.19%    (p=0.003 n=8+8)
FloatingAccumulateMaskSIMD64-8    2.47µs ± 0%  2.46µs ± 0%    ~      (p=0.162 n=10+9)
GlyphAlpha16Over-8                2.99µs ± 0%  2.98µs ± 1%  -0.50%   (p=0.021 n=9+10)
GlyphAlpha16Src-8                 2.89µs ± 1%  2.89µs ± 0%    ~     (p=0.381 n=10+10)
GlyphAlpha32Over-8                4.53µs ± 0%  4.50µs ± 0%  -0.83%  (p=0.000 n=10+10)
GlyphAlpha32Src-8                 4.14µs ± 0%  4.13µs ± 0%  -0.21%   (p=0.026 n=9+10)
GlyphAlpha64Over-8                8.97µs ± 1%  8.80µs ± 0%  -1.85%   (p=0.000 n=10+9)
GlyphAlpha64Src-8                 7.42µs ± 1%  7.39µs ± 0%  -0.45%  (p=0.011 n=10+10)
GlyphAlpha128Over-8               21.8µs ± 0%  21.2µs ± 0%  -2.91%    (p=0.000 n=9+9)
GlyphAlpha128Src-8                15.6µs ± 0%  15.6µs ± 0%    ~      (p=0.982 n=10+7)
GlyphAlpha256Over-8               66.3µs ± 1%  63.7µs ± 0%  -3.84%   (p=0.000 n=10+9)
GlyphAlpha256Src-8                41.2µs ± 1%  41.2µs ± 1%    ~     (p=1.000 n=10+10)
GlyphRGBA16Over-8                 4.75µs ± 0%  4.75µs ± 1%    ~      (p=0.735 n=9+10)
GlyphRGBA16Src-8                  4.20µs ± 0%  4.20µs ± 0%    ~       (p=0.503 n=8+8)
GlyphRGBA32Over-8                 11.4µs ± 0%  11.4µs ± 0%    ~       (p=0.119 n=9+9)
GlyphRGBA32Src-8                  9.34µs ± 1%  9.32µs ± 0%    ~       (p=0.062 n=9+8)
GlyphRGBA64Over-8                 36.0µs ± 0%  36.1µs ± 0%    ~       (p=0.209 n=8+9)
GlyphRGBA64Src-8                  27.9µs ± 1%  27.8µs ± 0%    ~     (p=0.796 n=10+10)
GlyphRGBA128Over-8                 131µs ± 0%   131µs ± 0%    ~       (p=0.931 n=9+9)
GlyphRGBA128Src-8                 97.9µs ± 0%  97.7µs ± 1%    ~      (p=0.053 n=9+10)
GlyphRGBA256Over-8                 503µs ± 0%   503µs ± 1%    ~      (p=0.274 n=8+10)
GlyphRGBA256Src-8                  370µs ± 0%   369µs ± 0%    ~      (p=0.497 n=9+10)

Change-Id: I56651e70b258792b83ea2a74904756243c88bef4
Reviewed-on: https://go-review.googlesource.com/31537
Reviewed-by: David Crawshaw <crawshaw@golang.org>
2016-10-22 21:39:22 +00:00

1083 lines
25 KiB
ArmAsm

// generated by go run gen.go; DO NOT EDIT
// +build !appengine
// +build gc
// +build !noasm
#include "textflag.h"
// fl is short for floating point math. fx is short for fixed point math.
DATA flAlmost65536<>+0x00(SB)/8, $0x477fffff477fffff
DATA flAlmost65536<>+0x08(SB)/8, $0x477fffff477fffff
DATA flOne<>+0x00(SB)/8, $0x3f8000003f800000
DATA flOne<>+0x08(SB)/8, $0x3f8000003f800000
DATA flSignMask<>+0x00(SB)/8, $0x7fffffff7fffffff
DATA flSignMask<>+0x08(SB)/8, $0x7fffffff7fffffff
// scatterAndMulBy0x101 is a PSHUFB mask that brings the low four bytes of an
// XMM register to the low byte of that register's four uint32 values. It
// duplicates those bytes, effectively multiplying each uint32 by 0x101.
//
// It transforms a little-endian 16-byte XMM value from
// ijkl????????????
// to
// ii00jj00kk00ll00
DATA scatterAndMulBy0x101<>+0x00(SB)/8, $0x8080010180800000
DATA scatterAndMulBy0x101<>+0x08(SB)/8, $0x8080030380800202
// gather is a PSHUFB mask that brings the second-lowest byte of the XMM
// register's four uint32 values to the low four bytes of that register.
//
// It transforms a little-endian 16-byte XMM value from
// ?i???j???k???l??
// to
// ijkl000000000000
DATA gather<>+0x00(SB)/8, $0x808080800d090501
DATA gather<>+0x08(SB)/8, $0x8080808080808080
DATA fxAlmost65536<>+0x00(SB)/8, $0x0000ffff0000ffff
DATA fxAlmost65536<>+0x08(SB)/8, $0x0000ffff0000ffff
DATA inverseFFFF<>+0x00(SB)/8, $0x8000800180008001
DATA inverseFFFF<>+0x08(SB)/8, $0x8000800180008001
GLOBL flAlmost65536<>(SB), (NOPTR+RODATA), $16
GLOBL flOne<>(SB), (NOPTR+RODATA), $16
GLOBL flSignMask<>(SB), (NOPTR+RODATA), $16
GLOBL scatterAndMulBy0x101<>(SB), (NOPTR+RODATA), $16
GLOBL gather<>(SB), (NOPTR+RODATA), $16
GLOBL fxAlmost65536<>(SB), (NOPTR+RODATA), $16
GLOBL inverseFFFF<>(SB), (NOPTR+RODATA), $16
// func haveSSE4_1() bool
TEXT ·haveSSE4_1(SB), NOSPLIT, $0
MOVQ $1, AX
CPUID
SHRQ $19, CX
ANDQ $1, CX
MOVB CX, ret+0(FP)
RET
// ----------------------------------------------------------------------------
// func fixedAccumulateOpOverSIMD(dst []uint8, src []uint32)
//
// XMM registers. Variable names are per
// https://github.com/google/font-rs/blob/master/src/accumulate.c
//
// xmm0 scratch
// xmm1 x
// xmm2 y, z
// xmm3 -
// xmm4 -
// xmm5 fxAlmost65536
// xmm6 gather
// xmm7 offset
// xmm8 scatterAndMulBy0x101
// xmm9 fxAlmost65536
// xmm10 inverseFFFF
TEXT ·fixedAccumulateOpOverSIMD(SB), NOSPLIT, $0-48
MOVQ dst_base+0(FP), DI
MOVQ dst_len+8(FP), BX
MOVQ src_base+24(FP), SI
MOVQ src_len+32(FP), R10
// Sanity check that len(dst) >= len(src).
CMPQ BX, R10
JLT fxAccOpOverEnd
// R10 = len(src) &^ 3
// R11 = len(src)
MOVQ R10, R11
ANDQ $-4, R10
// fxAlmost65536 := XMM(0x0000ffff repeated four times) // Maximum of an uint16.
MOVOU fxAlmost65536<>(SB), X5
// gather := XMM(see above) // PSHUFB shuffle mask.
// scatterAndMulBy0x101 := XMM(see above) // PSHUFB shuffle mask.
// fxAlmost65536 := XMM(0x0000ffff repeated four times) // 0xffff.
// inverseFFFF := XMM(0x80008001 repeated four times) // Magic constant for dividing by 0xffff.
MOVOU gather<>(SB), X6
MOVOU scatterAndMulBy0x101<>(SB), X8
MOVOU fxAlmost65536<>(SB), X9
MOVOU inverseFFFF<>(SB), X10
// offset := XMM(0x00000000 repeated four times) // Cumulative sum.
XORPS X7, X7
// i := 0
MOVQ $0, R9
fxAccOpOverLoop4:
// for i < (len(src) &^ 3)
CMPQ R9, R10
JAE fxAccOpOverLoop1
// x = XMM(s0, s1, s2, s3)
//
// Where s0 is src[i+0], s1 is src[i+1], etc.
MOVOU (SI), X1
// scratch = XMM(0, s0, s1, s2)
// x += scratch // yields x == XMM(s0, s0+s1, s1+s2, s2+s3)
MOVOU X1, X0
PSLLO $4, X0
PADDD X0, X1
// scratch = XMM(0, 0, 0, 0)
// scratch = XMM(scratch@0, scratch@0, x@0, x@1) // yields scratch == XMM(0, 0, s0, s0+s1)
// x += scratch // yields x == XMM(s0, s0+s1, s0+s1+s2, s0+s1+s2+s3)
XORPS X0, X0
SHUFPS $0x40, X1, X0
PADDD X0, X1
// x += offset
PADDD X7, X1
// y = abs(x)
// y >>= 2 // Shift by 2*ϕ - 16.
// y = min(y, fxAlmost65536)
//
// pabsd %xmm1,%xmm2
// psrld $0x2,%xmm2
// pminud %xmm5,%xmm2
//
// Hopefully we'll get these opcode mnemonics into the assembler for Go
// 1.8. https://golang.org/issue/16007 isn't exactly the same thing, but
// it's similar.
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x1e; BYTE $0xd1
BYTE $0x66; BYTE $0x0f; BYTE $0x72; BYTE $0xd2; BYTE $0x02
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x3b; BYTE $0xd5
// z = convertToInt32(y)
// No-op.
// Blend over the dst's prior value. SIMD for i in 0..3:
//
// dstA := uint32(dst[i]) * 0x101
// maskA := z@i
// outA := dstA*(0xffff-maskA)/0xffff + maskA
// dst[i] = uint8(outA >> 8)
//
// First, set X0 to dstA*(0xfff-maskA).
MOVL (DI), X0
PSHUFB X8, X0
MOVOU X9, X11
PSUBL X2, X11
PMULLD X11, X0
// We implement uint32 division by 0xffff as multiplication by a magic
// constant (0x800080001) and then a shift by a magic constant (47).
// See TestDivideByFFFF for a justification.
//
// That multiplication widens from uint32 to uint64, so we have to
// duplicate and shift our four uint32s from one XMM register (X0) to
// two XMM registers (X0 and X11).
//
// Move the second and fourth uint32s in X0 to be the first and third
// uint32s in X11.
MOVOU X0, X11
PSRLQ $32, X11
// Multiply by magic, shift by magic.
//
// pmuludq %xmm10,%xmm0
// pmuludq %xmm10,%xmm11
BYTE $0x66; BYTE $0x41; BYTE $0x0f; BYTE $0xf4; BYTE $0xc2
BYTE $0x66; BYTE $0x45; BYTE $0x0f; BYTE $0xf4; BYTE $0xda
PSRLQ $47, X0
PSRLQ $47, X11
// Merge the two registers back to one, X11, and add maskA.
PSLLQ $32, X11
XORPS X0, X11
PADDD X11, X2
// As per opSrcStore4, shuffle and copy the 4 second-lowest bytes.
PSHUFB X6, X2
MOVL X2, (DI)
// offset = XMM(x@3, x@3, x@3, x@3)
MOVOU X1, X7
SHUFPS $0xff, X1, X7
// i += 4
// dst = dst[4:]
// src = src[4:]
ADDQ $4, R9
ADDQ $4, DI
ADDQ $16, SI
JMP fxAccOpOverLoop4
fxAccOpOverLoop1:
// for i < len(src)
CMPQ R9, R11
JAE fxAccOpOverEnd
// x = src[i] + offset
MOVL (SI), X1
PADDD X7, X1
// y = abs(x)
// y >>= 2 // Shift by 2*ϕ - 16.
// y = min(y, fxAlmost65536)
//
// pabsd %xmm1,%xmm2
// psrld $0x2,%xmm2
// pminud %xmm5,%xmm2
//
// Hopefully we'll get these opcode mnemonics into the assembler for Go
// 1.8. https://golang.org/issue/16007 isn't exactly the same thing, but
// it's similar.
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x1e; BYTE $0xd1
BYTE $0x66; BYTE $0x0f; BYTE $0x72; BYTE $0xd2; BYTE $0x02
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x3b; BYTE $0xd5
// z = convertToInt32(y)
// No-op.
// Blend over the dst's prior value.
//
// dstA := uint32(dst[0]) * 0x101
// maskA := z
// outA := dstA*(0xffff-maskA)/0xffff + maskA
// dst[0] = uint8(outA >> 8)
MOVBLZX (DI), R12
IMULL $0x101, R12
MOVL X2, R13
MOVL $0xffff, AX
SUBL R13, AX
MULL R12 // MULL's implicit arg is AX, and the result is stored in DX:AX.
MOVL $0x80008001, BX // Divide by 0xffff is to first multiply by a magic constant...
MULL BX // MULL's implicit arg is AX, and the result is stored in DX:AX.
SHRL $15, DX // ...and then shift by another magic constant (47 - 32 = 15).
ADDL DX, R13
SHRL $8, R13
MOVB R13, (DI)
// offset = x
MOVOU X1, X7
// i += 1
// dst = dst[1:]
// src = src[1:]
ADDQ $1, R9
ADDQ $1, DI
ADDQ $4, SI
JMP fxAccOpOverLoop1
fxAccOpOverEnd:
RET
// ----------------------------------------------------------------------------
// func fixedAccumulateOpSrcSIMD(dst []uint8, src []uint32)
//
// XMM registers. Variable names are per
// https://github.com/google/font-rs/blob/master/src/accumulate.c
//
// xmm0 scratch
// xmm1 x
// xmm2 y, z
// xmm3 -
// xmm4 -
// xmm5 fxAlmost65536
// xmm6 gather
// xmm7 offset
// xmm8 -
// xmm9 -
// xmm10 -
TEXT ·fixedAccumulateOpSrcSIMD(SB), NOSPLIT, $0-48
MOVQ dst_base+0(FP), DI
MOVQ dst_len+8(FP), BX
MOVQ src_base+24(FP), SI
MOVQ src_len+32(FP), R10
// Sanity check that len(dst) >= len(src).
CMPQ BX, R10
JLT fxAccOpSrcEnd
// R10 = len(src) &^ 3
// R11 = len(src)
MOVQ R10, R11
ANDQ $-4, R10
// fxAlmost65536 := XMM(0x0000ffff repeated four times) // Maximum of an uint16.
MOVOU fxAlmost65536<>(SB), X5
// gather := XMM(see above) // PSHUFB shuffle mask.
MOVOU gather<>(SB), X6
// offset := XMM(0x00000000 repeated four times) // Cumulative sum.
XORPS X7, X7
// i := 0
MOVQ $0, R9
fxAccOpSrcLoop4:
// for i < (len(src) &^ 3)
CMPQ R9, R10
JAE fxAccOpSrcLoop1
// x = XMM(s0, s1, s2, s3)
//
// Where s0 is src[i+0], s1 is src[i+1], etc.
MOVOU (SI), X1
// scratch = XMM(0, s0, s1, s2)
// x += scratch // yields x == XMM(s0, s0+s1, s1+s2, s2+s3)
MOVOU X1, X0
PSLLO $4, X0
PADDD X0, X1
// scratch = XMM(0, 0, 0, 0)
// scratch = XMM(scratch@0, scratch@0, x@0, x@1) // yields scratch == XMM(0, 0, s0, s0+s1)
// x += scratch // yields x == XMM(s0, s0+s1, s0+s1+s2, s0+s1+s2+s3)
XORPS X0, X0
SHUFPS $0x40, X1, X0
PADDD X0, X1
// x += offset
PADDD X7, X1
// y = abs(x)
// y >>= 2 // Shift by 2*ϕ - 16.
// y = min(y, fxAlmost65536)
//
// pabsd %xmm1,%xmm2
// psrld $0x2,%xmm2
// pminud %xmm5,%xmm2
//
// Hopefully we'll get these opcode mnemonics into the assembler for Go
// 1.8. https://golang.org/issue/16007 isn't exactly the same thing, but
// it's similar.
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x1e; BYTE $0xd1
BYTE $0x66; BYTE $0x0f; BYTE $0x72; BYTE $0xd2; BYTE $0x02
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x3b; BYTE $0xd5
// z = convertToInt32(y)
// No-op.
// z = shuffleTheSecondLowestBytesOfEach4ByteElement(z)
// copy(dst[:4], low4BytesOf(z))
PSHUFB X6, X2
MOVL X2, (DI)
// offset = XMM(x@3, x@3, x@3, x@3)
MOVOU X1, X7
SHUFPS $0xff, X1, X7
// i += 4
// dst = dst[4:]
// src = src[4:]
ADDQ $4, R9
ADDQ $4, DI
ADDQ $16, SI
JMP fxAccOpSrcLoop4
fxAccOpSrcLoop1:
// for i < len(src)
CMPQ R9, R11
JAE fxAccOpSrcEnd
// x = src[i] + offset
MOVL (SI), X1
PADDD X7, X1
// y = abs(x)
// y >>= 2 // Shift by 2*ϕ - 16.
// y = min(y, fxAlmost65536)
//
// pabsd %xmm1,%xmm2
// psrld $0x2,%xmm2
// pminud %xmm5,%xmm2
//
// Hopefully we'll get these opcode mnemonics into the assembler for Go
// 1.8. https://golang.org/issue/16007 isn't exactly the same thing, but
// it's similar.
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x1e; BYTE $0xd1
BYTE $0x66; BYTE $0x0f; BYTE $0x72; BYTE $0xd2; BYTE $0x02
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x3b; BYTE $0xd5
// z = convertToInt32(y)
// No-op.
// dst[0] = uint8(z>>8)
MOVL X2, BX
SHRL $8, BX
MOVB BX, (DI)
// offset = x
MOVOU X1, X7
// i += 1
// dst = dst[1:]
// src = src[1:]
ADDQ $1, R9
ADDQ $1, DI
ADDQ $4, SI
JMP fxAccOpSrcLoop1
fxAccOpSrcEnd:
RET
// ----------------------------------------------------------------------------
// func fixedAccumulateMaskSIMD(buf []uint32)
//
// XMM registers. Variable names are per
// https://github.com/google/font-rs/blob/master/src/accumulate.c
//
// xmm0 scratch
// xmm1 x
// xmm2 y, z
// xmm3 -
// xmm4 -
// xmm5 fxAlmost65536
// xmm6 -
// xmm7 offset
// xmm8 -
// xmm9 -
// xmm10 -
TEXT ·fixedAccumulateMaskSIMD(SB), NOSPLIT, $0-24
MOVQ buf_base+0(FP), DI
MOVQ buf_len+8(FP), BX
MOVQ buf_base+0(FP), SI
MOVQ buf_len+8(FP), R10
// R10 = len(src) &^ 3
// R11 = len(src)
MOVQ R10, R11
ANDQ $-4, R10
// fxAlmost65536 := XMM(0x0000ffff repeated four times) // Maximum of an uint16.
MOVOU fxAlmost65536<>(SB), X5
// offset := XMM(0x00000000 repeated four times) // Cumulative sum.
XORPS X7, X7
// i := 0
MOVQ $0, R9
fxAccMaskLoop4:
// for i < (len(src) &^ 3)
CMPQ R9, R10
JAE fxAccMaskLoop1
// x = XMM(s0, s1, s2, s3)
//
// Where s0 is src[i+0], s1 is src[i+1], etc.
MOVOU (SI), X1
// scratch = XMM(0, s0, s1, s2)
// x += scratch // yields x == XMM(s0, s0+s1, s1+s2, s2+s3)
MOVOU X1, X0
PSLLO $4, X0
PADDD X0, X1
// scratch = XMM(0, 0, 0, 0)
// scratch = XMM(scratch@0, scratch@0, x@0, x@1) // yields scratch == XMM(0, 0, s0, s0+s1)
// x += scratch // yields x == XMM(s0, s0+s1, s0+s1+s2, s0+s1+s2+s3)
XORPS X0, X0
SHUFPS $0x40, X1, X0
PADDD X0, X1
// x += offset
PADDD X7, X1
// y = abs(x)
// y >>= 2 // Shift by 2*ϕ - 16.
// y = min(y, fxAlmost65536)
//
// pabsd %xmm1,%xmm2
// psrld $0x2,%xmm2
// pminud %xmm5,%xmm2
//
// Hopefully we'll get these opcode mnemonics into the assembler for Go
// 1.8. https://golang.org/issue/16007 isn't exactly the same thing, but
// it's similar.
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x1e; BYTE $0xd1
BYTE $0x66; BYTE $0x0f; BYTE $0x72; BYTE $0xd2; BYTE $0x02
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x3b; BYTE $0xd5
// z = convertToInt32(y)
// No-op.
// copy(dst[:4], z)
MOVOU X2, (DI)
// offset = XMM(x@3, x@3, x@3, x@3)
MOVOU X1, X7
SHUFPS $0xff, X1, X7
// i += 4
// dst = dst[4:]
// src = src[4:]
ADDQ $4, R9
ADDQ $16, DI
ADDQ $16, SI
JMP fxAccMaskLoop4
fxAccMaskLoop1:
// for i < len(src)
CMPQ R9, R11
JAE fxAccMaskEnd
// x = src[i] + offset
MOVL (SI), X1
PADDD X7, X1
// y = abs(x)
// y >>= 2 // Shift by 2*ϕ - 16.
// y = min(y, fxAlmost65536)
//
// pabsd %xmm1,%xmm2
// psrld $0x2,%xmm2
// pminud %xmm5,%xmm2
//
// Hopefully we'll get these opcode mnemonics into the assembler for Go
// 1.8. https://golang.org/issue/16007 isn't exactly the same thing, but
// it's similar.
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x1e; BYTE $0xd1
BYTE $0x66; BYTE $0x0f; BYTE $0x72; BYTE $0xd2; BYTE $0x02
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x3b; BYTE $0xd5
// z = convertToInt32(y)
// No-op.
// dst[0] = uint32(z)
MOVL X2, (DI)
// offset = x
MOVOU X1, X7
// i += 1
// dst = dst[1:]
// src = src[1:]
ADDQ $1, R9
ADDQ $4, DI
ADDQ $4, SI
JMP fxAccMaskLoop1
fxAccMaskEnd:
RET
// ----------------------------------------------------------------------------
// func floatingAccumulateOpOverSIMD(dst []uint8, src []float32)
//
// XMM registers. Variable names are per
// https://github.com/google/font-rs/blob/master/src/accumulate.c
//
// xmm0 scratch
// xmm1 x
// xmm2 y, z
// xmm3 flAlmost65536
// xmm4 flOne
// xmm5 flSignMask
// xmm6 gather
// xmm7 offset
// xmm8 scatterAndMulBy0x101
// xmm9 fxAlmost65536
// xmm10 inverseFFFF
TEXT ·floatingAccumulateOpOverSIMD(SB), NOSPLIT, $8-48
MOVQ dst_base+0(FP), DI
MOVQ dst_len+8(FP), BX
MOVQ src_base+24(FP), SI
MOVQ src_len+32(FP), R10
// Sanity check that len(dst) >= len(src).
CMPQ BX, R10
JLT flAccOpOverEnd
// R10 = len(src) &^ 3
// R11 = len(src)
MOVQ R10, R11
ANDQ $-4, R10
// Prepare to set MXCSR bits 13 and 14, so that the CVTPS2PL below is
// "Round To Zero".
STMXCSR mxcsrOrig-8(SP)
MOVL mxcsrOrig-8(SP), AX
ORL $0x6000, AX
MOVL AX, mxcsrNew-4(SP)
// flAlmost65536 := XMM(0x477fffff repeated four times) // 255.99998 * 256 as a float32.
// flOne := XMM(0x3f800000 repeated four times) // 1 as a float32.
// flSignMask := XMM(0x7fffffff repeated four times) // All but the sign bit of a float32.
MOVOU flAlmost65536<>(SB), X3
MOVOU flOne<>(SB), X4
MOVOU flSignMask<>(SB), X5
// gather := XMM(see above) // PSHUFB shuffle mask.
// scatterAndMulBy0x101 := XMM(see above) // PSHUFB shuffle mask.
// fxAlmost65536 := XMM(0x0000ffff repeated four times) // 0xffff.
// inverseFFFF := XMM(0x80008001 repeated four times) // Magic constant for dividing by 0xffff.
MOVOU gather<>(SB), X6
MOVOU scatterAndMulBy0x101<>(SB), X8
MOVOU fxAlmost65536<>(SB), X9
MOVOU inverseFFFF<>(SB), X10
// offset := XMM(0x00000000 repeated four times) // Cumulative sum.
XORPS X7, X7
// i := 0
MOVQ $0, R9
flAccOpOverLoop4:
// for i < (len(src) &^ 3)
CMPQ R9, R10
JAE flAccOpOverLoop1
// x = XMM(s0, s1, s2, s3)
//
// Where s0 is src[i+0], s1 is src[i+1], etc.
MOVOU (SI), X1
// scratch = XMM(0, s0, s1, s2)
// x += scratch // yields x == XMM(s0, s0+s1, s1+s2, s2+s3)
MOVOU X1, X0
PSLLO $4, X0
ADDPS X0, X1
// scratch = XMM(0, 0, 0, 0)
// scratch = XMM(scratch@0, scratch@0, x@0, x@1) // yields scratch == XMM(0, 0, s0, s0+s1)
// x += scratch // yields x == XMM(s0, s0+s1, s0+s1+s2, s0+s1+s2+s3)
XORPS X0, X0
SHUFPS $0x40, X1, X0
ADDPS X0, X1
// x += offset
ADDPS X7, X1
// y = x & flSignMask
// y = min(y, flOne)
// y = mul(y, flAlmost65536)
MOVOU X5, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X3, X2
// z = convertToInt32(y)
LDMXCSR mxcsrNew-4(SP)
CVTPS2PL X2, X2
LDMXCSR mxcsrOrig-8(SP)
// Blend over the dst's prior value. SIMD for i in 0..3:
//
// dstA := uint32(dst[i]) * 0x101
// maskA := z@i
// outA := dstA*(0xffff-maskA)/0xffff + maskA
// dst[i] = uint8(outA >> 8)
//
// First, set X0 to dstA*(0xfff-maskA).
MOVL (DI), X0
PSHUFB X8, X0
MOVOU X9, X11
PSUBL X2, X11
PMULLD X11, X0
// We implement uint32 division by 0xffff as multiplication by a magic
// constant (0x800080001) and then a shift by a magic constant (47).
// See TestDivideByFFFF for a justification.
//
// That multiplication widens from uint32 to uint64, so we have to
// duplicate and shift our four uint32s from one XMM register (X0) to
// two XMM registers (X0 and X11).
//
// Move the second and fourth uint32s in X0 to be the first and third
// uint32s in X11.
MOVOU X0, X11
PSRLQ $32, X11
// Multiply by magic, shift by magic.
//
// pmuludq %xmm10,%xmm0
// pmuludq %xmm10,%xmm11
BYTE $0x66; BYTE $0x41; BYTE $0x0f; BYTE $0xf4; BYTE $0xc2
BYTE $0x66; BYTE $0x45; BYTE $0x0f; BYTE $0xf4; BYTE $0xda
PSRLQ $47, X0
PSRLQ $47, X11
// Merge the two registers back to one, X11, and add maskA.
PSLLQ $32, X11
XORPS X0, X11
PADDD X11, X2
// As per opSrcStore4, shuffle and copy the 4 second-lowest bytes.
PSHUFB X6, X2
MOVL X2, (DI)
// offset = XMM(x@3, x@3, x@3, x@3)
MOVOU X1, X7
SHUFPS $0xff, X1, X7
// i += 4
// dst = dst[4:]
// src = src[4:]
ADDQ $4, R9
ADDQ $4, DI
ADDQ $16, SI
JMP flAccOpOverLoop4
flAccOpOverLoop1:
// for i < len(src)
CMPQ R9, R11
JAE flAccOpOverEnd
// x = src[i] + offset
MOVL (SI), X1
ADDPS X7, X1
// y = x & flSignMask
// y = min(y, flOne)
// y = mul(y, flAlmost65536)
MOVOU X5, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X3, X2
// z = convertToInt32(y)
LDMXCSR mxcsrNew-4(SP)
CVTPS2PL X2, X2
LDMXCSR mxcsrOrig-8(SP)
// Blend over the dst's prior value.
//
// dstA := uint32(dst[0]) * 0x101
// maskA := z
// outA := dstA*(0xffff-maskA)/0xffff + maskA
// dst[0] = uint8(outA >> 8)
MOVBLZX (DI), R12
IMULL $0x101, R12
MOVL X2, R13
MOVL $0xffff, AX
SUBL R13, AX
MULL R12 // MULL's implicit arg is AX, and the result is stored in DX:AX.
MOVL $0x80008001, BX // Divide by 0xffff is to first multiply by a magic constant...
MULL BX // MULL's implicit arg is AX, and the result is stored in DX:AX.
SHRL $15, DX // ...and then shift by another magic constant (47 - 32 = 15).
ADDL DX, R13
SHRL $8, R13
MOVB R13, (DI)
// offset = x
MOVOU X1, X7
// i += 1
// dst = dst[1:]
// src = src[1:]
ADDQ $1, R9
ADDQ $1, DI
ADDQ $4, SI
JMP flAccOpOverLoop1
flAccOpOverEnd:
RET
// ----------------------------------------------------------------------------
// func floatingAccumulateOpSrcSIMD(dst []uint8, src []float32)
//
// XMM registers. Variable names are per
// https://github.com/google/font-rs/blob/master/src/accumulate.c
//
// xmm0 scratch
// xmm1 x
// xmm2 y, z
// xmm3 flAlmost65536
// xmm4 flOne
// xmm5 flSignMask
// xmm6 gather
// xmm7 offset
// xmm8 -
// xmm9 -
// xmm10 -
TEXT ·floatingAccumulateOpSrcSIMD(SB), NOSPLIT, $8-48
MOVQ dst_base+0(FP), DI
MOVQ dst_len+8(FP), BX
MOVQ src_base+24(FP), SI
MOVQ src_len+32(FP), R10
// Sanity check that len(dst) >= len(src).
CMPQ BX, R10
JLT flAccOpSrcEnd
// R10 = len(src) &^ 3
// R11 = len(src)
MOVQ R10, R11
ANDQ $-4, R10
// Prepare to set MXCSR bits 13 and 14, so that the CVTPS2PL below is
// "Round To Zero".
STMXCSR mxcsrOrig-8(SP)
MOVL mxcsrOrig-8(SP), AX
ORL $0x6000, AX
MOVL AX, mxcsrNew-4(SP)
// flAlmost65536 := XMM(0x477fffff repeated four times) // 255.99998 * 256 as a float32.
// flOne := XMM(0x3f800000 repeated four times) // 1 as a float32.
// flSignMask := XMM(0x7fffffff repeated four times) // All but the sign bit of a float32.
MOVOU flAlmost65536<>(SB), X3
MOVOU flOne<>(SB), X4
MOVOU flSignMask<>(SB), X5
// gather := XMM(see above) // PSHUFB shuffle mask.
MOVOU gather<>(SB), X6
// offset := XMM(0x00000000 repeated four times) // Cumulative sum.
XORPS X7, X7
// i := 0
MOVQ $0, R9
flAccOpSrcLoop4:
// for i < (len(src) &^ 3)
CMPQ R9, R10
JAE flAccOpSrcLoop1
// x = XMM(s0, s1, s2, s3)
//
// Where s0 is src[i+0], s1 is src[i+1], etc.
MOVOU (SI), X1
// scratch = XMM(0, s0, s1, s2)
// x += scratch // yields x == XMM(s0, s0+s1, s1+s2, s2+s3)
MOVOU X1, X0
PSLLO $4, X0
ADDPS X0, X1
// scratch = XMM(0, 0, 0, 0)
// scratch = XMM(scratch@0, scratch@0, x@0, x@1) // yields scratch == XMM(0, 0, s0, s0+s1)
// x += scratch // yields x == XMM(s0, s0+s1, s0+s1+s2, s0+s1+s2+s3)
XORPS X0, X0
SHUFPS $0x40, X1, X0
ADDPS X0, X1
// x += offset
ADDPS X7, X1
// y = x & flSignMask
// y = min(y, flOne)
// y = mul(y, flAlmost65536)
MOVOU X5, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X3, X2
// z = convertToInt32(y)
LDMXCSR mxcsrNew-4(SP)
CVTPS2PL X2, X2
LDMXCSR mxcsrOrig-8(SP)
// z = shuffleTheSecondLowestBytesOfEach4ByteElement(z)
// copy(dst[:4], low4BytesOf(z))
PSHUFB X6, X2
MOVL X2, (DI)
// offset = XMM(x@3, x@3, x@3, x@3)
MOVOU X1, X7
SHUFPS $0xff, X1, X7
// i += 4
// dst = dst[4:]
// src = src[4:]
ADDQ $4, R9
ADDQ $4, DI
ADDQ $16, SI
JMP flAccOpSrcLoop4
flAccOpSrcLoop1:
// for i < len(src)
CMPQ R9, R11
JAE flAccOpSrcEnd
// x = src[i] + offset
MOVL (SI), X1
ADDPS X7, X1
// y = x & flSignMask
// y = min(y, flOne)
// y = mul(y, flAlmost65536)
MOVOU X5, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X3, X2
// z = convertToInt32(y)
LDMXCSR mxcsrNew-4(SP)
CVTPS2PL X2, X2
LDMXCSR mxcsrOrig-8(SP)
// dst[0] = uint8(z>>8)
MOVL X2, BX
SHRL $8, BX
MOVB BX, (DI)
// offset = x
MOVOU X1, X7
// i += 1
// dst = dst[1:]
// src = src[1:]
ADDQ $1, R9
ADDQ $1, DI
ADDQ $4, SI
JMP flAccOpSrcLoop1
flAccOpSrcEnd:
RET
// ----------------------------------------------------------------------------
// func floatingAccumulateMaskSIMD(dst []uint32, src []float32)
//
// XMM registers. Variable names are per
// https://github.com/google/font-rs/blob/master/src/accumulate.c
//
// xmm0 scratch
// xmm1 x
// xmm2 y, z
// xmm3 flAlmost65536
// xmm4 flOne
// xmm5 flSignMask
// xmm6 -
// xmm7 offset
// xmm8 -
// xmm9 -
// xmm10 -
TEXT ·floatingAccumulateMaskSIMD(SB), NOSPLIT, $8-48
MOVQ dst_base+0(FP), DI
MOVQ dst_len+8(FP), BX
MOVQ src_base+24(FP), SI
MOVQ src_len+32(FP), R10
// Sanity check that len(dst) >= len(src).
CMPQ BX, R10
JLT flAccMaskEnd
// R10 = len(src) &^ 3
// R11 = len(src)
MOVQ R10, R11
ANDQ $-4, R10
// Prepare to set MXCSR bits 13 and 14, so that the CVTPS2PL below is
// "Round To Zero".
STMXCSR mxcsrOrig-8(SP)
MOVL mxcsrOrig-8(SP), AX
ORL $0x6000, AX
MOVL AX, mxcsrNew-4(SP)
// flAlmost65536 := XMM(0x477fffff repeated four times) // 255.99998 * 256 as a float32.
// flOne := XMM(0x3f800000 repeated four times) // 1 as a float32.
// flSignMask := XMM(0x7fffffff repeated four times) // All but the sign bit of a float32.
MOVOU flAlmost65536<>(SB), X3
MOVOU flOne<>(SB), X4
MOVOU flSignMask<>(SB), X5
// offset := XMM(0x00000000 repeated four times) // Cumulative sum.
XORPS X7, X7
// i := 0
MOVQ $0, R9
flAccMaskLoop4:
// for i < (len(src) &^ 3)
CMPQ R9, R10
JAE flAccMaskLoop1
// x = XMM(s0, s1, s2, s3)
//
// Where s0 is src[i+0], s1 is src[i+1], etc.
MOVOU (SI), X1
// scratch = XMM(0, s0, s1, s2)
// x += scratch // yields x == XMM(s0, s0+s1, s1+s2, s2+s3)
MOVOU X1, X0
PSLLO $4, X0
ADDPS X0, X1
// scratch = XMM(0, 0, 0, 0)
// scratch = XMM(scratch@0, scratch@0, x@0, x@1) // yields scratch == XMM(0, 0, s0, s0+s1)
// x += scratch // yields x == XMM(s0, s0+s1, s0+s1+s2, s0+s1+s2+s3)
XORPS X0, X0
SHUFPS $0x40, X1, X0
ADDPS X0, X1
// x += offset
ADDPS X7, X1
// y = x & flSignMask
// y = min(y, flOne)
// y = mul(y, flAlmost65536)
MOVOU X5, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X3, X2
// z = convertToInt32(y)
LDMXCSR mxcsrNew-4(SP)
CVTPS2PL X2, X2
LDMXCSR mxcsrOrig-8(SP)
// copy(dst[:4], z)
MOVOU X2, (DI)
// offset = XMM(x@3, x@3, x@3, x@3)
MOVOU X1, X7
SHUFPS $0xff, X1, X7
// i += 4
// dst = dst[4:]
// src = src[4:]
ADDQ $4, R9
ADDQ $16, DI
ADDQ $16, SI
JMP flAccMaskLoop4
flAccMaskLoop1:
// for i < len(src)
CMPQ R9, R11
JAE flAccMaskEnd
// x = src[i] + offset
MOVL (SI), X1
ADDPS X7, X1
// y = x & flSignMask
// y = min(y, flOne)
// y = mul(y, flAlmost65536)
MOVOU X5, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X3, X2
// z = convertToInt32(y)
LDMXCSR mxcsrNew-4(SP)
CVTPS2PL X2, X2
LDMXCSR mxcsrOrig-8(SP)
// dst[0] = uint32(z)
MOVL X2, (DI)
// offset = x
MOVOU X1, X7
// i += 1
// dst = dst[1:]
// src = src[1:]
ADDQ $1, R9
ADDQ $4, DI
ADDQ $4, SI
JMP flAccMaskLoop1
flAccMaskEnd:
RET