// 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 X1, X2
PSRLL $2, X2
PMINUD X5, X2
// 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.
PMULULQ X10, X0
PMULULQ X10, X11
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 X1, X2
PSRLL $2, X2
PMINUD X5, X2
// 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 X1, X2
PSRLL $2, X2
PMINUD X5, X2
// 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 X1, X2
PSRLL $2, X2
PMINUD X5, X2
// 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 X1, X2
PSRLL $2, X2
PMINUD X5, X2
// 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 X1, X2
PSRLL $2, X2
PMINUD X5, X2
// 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 flSignMask
// xmm4 flOne
// xmm5 flAlmost65536
// 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)
// flSignMask := XMM(0x7fffffff repeated four times) // All but the sign bit of a float32.
// flOne := XMM(0x3f800000 repeated four times) // 1 as a float32.
// flAlmost65536 := XMM(0x477fffff repeated four times) // 255.99998 * 256 as a float32.
MOVOU flSignMask<>(SB), X3
MOVOU flOne<>(SB), X4
MOVOU flAlmost65536<>(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 X3, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X5, 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.
PMULULQ X10, X0
PMULULQ X10, X11
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 X3, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X5, 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 flSignMask
// xmm4 flOne
// xmm5 flAlmost65536
// 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)
// flSignMask := XMM(0x7fffffff repeated four times) // All but the sign bit of a float32.
// flOne := XMM(0x3f800000 repeated four times) // 1 as a float32.
// flAlmost65536 := XMM(0x477fffff repeated four times) // 255.99998 * 256 as a float32.
MOVOU flSignMask<>(SB), X3
MOVOU flOne<>(SB), X4
MOVOU flAlmost65536<>(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 X3, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X5, 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 X3, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X5, 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 flSignMask
// xmm4 flOne
// xmm5 flAlmost65536
// 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)
// flSignMask := XMM(0x7fffffff repeated four times) // All but the sign bit of a float32.
// flOne := XMM(0x3f800000 repeated four times) // 1 as a float32.
// flAlmost65536 := XMM(0x477fffff repeated four times) // 255.99998 * 256 as a float32.
MOVOU flSignMask<>(SB), X3
MOVOU flOne<>(SB), X4
MOVOU flAlmost65536<>(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 X3, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X5, 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 X3, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X5, 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
