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>
This commit is contained in:
Nigel Tao 2016-10-20 15:15:53 +11:00
parent 8874bef159
commit 93fad3647f
3 changed files with 68 additions and 124 deletions

View File

@ -8,8 +8,6 @@
// fl is short for floating point math. fx is short for fixed point math.
DATA flAlmost256<>+0x00(SB)/8, $0x437fffff437fffff
DATA flAlmost256<>+0x08(SB)/8, $0x437fffff437fffff
DATA flAlmost65536<>+0x00(SB)/8, $0x477fffff477fffff
DATA flAlmost65536<>+0x08(SB)/8, $0x477fffff477fffff
DATA flOne<>+0x00(SB)/8, $0x3f8000003f800000
@ -28,30 +26,26 @@ DATA flSignMask<>+0x08(SB)/8, $0x7fffffff7fffffff
DATA scatterAndMulBy0x101<>+0x00(SB)/8, $0x8080010180800000
DATA scatterAndMulBy0x101<>+0x08(SB)/8, $0x8080030380800202
// gather is a PSHUFB mask that brings the low byte of the XMM register's four
// uint32 values to the low four bytes of that register.
// 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???
// ?i???j???k???l??
// to
// ijkl000000000000
DATA gather<>+0x00(SB)/8, $0x808080800c080400
DATA gather<>+0x00(SB)/8, $0x808080800d090501
DATA gather<>+0x08(SB)/8, $0x8080808080808080
DATA fxAlmost256<>+0x00(SB)/8, $0x000000ff000000ff
DATA fxAlmost256<>+0x08(SB)/8, $0x000000ff000000ff
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 flAlmost256<>(SB), (NOPTR+RODATA), $16
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 fxAlmost256<>(SB), (NOPTR+RODATA), $16
GLOBL fxAlmost65536<>(SB), (NOPTR+RODATA), $16
GLOBL inverseFFFF<>(SB), (NOPTR+RODATA), $16
@ -196,15 +190,12 @@ fxAccOpOverLoop4:
PSRLQ $47, X0
PSRLQ $47, X11
// Merge the two registers back to one, X11.
// Merge the two registers back to one, X11, and add maskA.
PSLLQ $32, X11
XORPS X0, X11
// Add maskA, shift from 16 bit color to 8 bit color.
PADDD X11, X2
PSRLQ $8, X2
// As per opSrcStore4, shuffle and copy the low 4 bytes.
// As per opSrcStore4, shuffle and copy the 4 second-lowest bytes.
PSHUFB X6, X2
MOVL X2, (DI)
@ -292,7 +283,7 @@ fxAccOpOverEnd:
// xmm2 y, z
// xmm3 -
// xmm4 -
// xmm5 fxAlmost256
// xmm5 fxAlmost65536
// xmm6 gather
// xmm7 offset
// xmm8 -
@ -314,8 +305,8 @@ TEXT ·fixedAccumulateOpSrcSIMD(SB), NOSPLIT, $0-48
MOVQ R10, R11
ANDQ $-4, R10
// fxAlmost256 := XMM(0x000000ff repeated four times) // Maximum of an uint8.
MOVOU fxAlmost256<>(SB), X5
// 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
@ -353,24 +344,24 @@ fxAccOpSrcLoop4:
PADDD X7, X1
// y = abs(x)
// y >>= 10 // Shift by 2*ϕ - 8.
// y = min(y, fxAlmost256)
// y >>= 2 // Shift by 2*ϕ - 16.
// y = min(y, fxAlmost65536)
//
// pabsd %xmm1,%xmm2
// psrld $0xa,%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 $0x0a
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 = shuffleTheLowBytesOfEach4ByteElement(z)
// z = shuffleTheSecondLowestBytesOfEach4ByteElement(z)
// copy(dst[:4], low4BytesOf(z))
PSHUFB X6, X2
MOVL X2, (DI)
@ -397,25 +388,26 @@ fxAccOpSrcLoop1:
PADDD X7, X1
// y = abs(x)
// y >>= 10 // Shift by 2*ϕ - 8.
// y = min(y, fxAlmost256)
// y >>= 2 // Shift by 2*ϕ - 16.
// y = min(y, fxAlmost65536)
//
// pabsd %xmm1,%xmm2
// psrld $0xa,%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 $0x0a
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)
// dst[0] = uint8(z>>8)
MOVL X2, BX
SHRL $8, BX
MOVB BX, (DI)
// offset = x
@ -712,15 +704,12 @@ flAccOpOverLoop4:
PSRLQ $47, X0
PSRLQ $47, X11
// Merge the two registers back to one, X11.
// Merge the two registers back to one, X11, and add maskA.
PSLLQ $32, X11
XORPS X0, X11
// Add maskA, shift from 16 bit color to 8 bit color.
PADDD X11, X2
PSRLQ $8, X2
// As per opSrcStore4, shuffle and copy the low 4 bytes.
// As per opSrcStore4, shuffle and copy the 4 second-lowest bytes.
PSHUFB X6, X2
MOVL X2, (DI)
@ -801,7 +790,7 @@ flAccOpOverEnd:
// xmm0 scratch
// xmm1 x
// xmm2 y, z
// xmm3 flAlmost256
// xmm3 flAlmost65536
// xmm4 flOne
// xmm5 flSignMask
// xmm6 gather
@ -832,10 +821,10 @@ TEXT ·floatingAccumulateOpSrcSIMD(SB), NOSPLIT, $8-48
ORL $0x6000, AX
MOVL AX, mxcsrNew-4(SP)
// flAlmost256 := XMM(0x437fffff repeated four times) // 255.99998 as a float32.
// 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 flAlmost256<>(SB), X3
MOVOU flAlmost65536<>(SB), X3
MOVOU flOne<>(SB), X4
MOVOU flSignMask<>(SB), X5
@ -876,7 +865,7 @@ flAccOpSrcLoop4:
// y = x & flSignMask
// y = min(y, flOne)
// y = mul(y, flAlmost256)
// y = mul(y, flAlmost65536)
MOVOU X5, X2
ANDPS X1, X2
MINPS X4, X2
@ -887,7 +876,7 @@ flAccOpSrcLoop4:
CVTPS2PL X2, X2
LDMXCSR mxcsrOrig-8(SP)
// z = shuffleTheLowBytesOfEach4ByteElement(z)
// z = shuffleTheSecondLowestBytesOfEach4ByteElement(z)
// copy(dst[:4], low4BytesOf(z))
PSHUFB X6, X2
MOVL X2, (DI)
@ -915,7 +904,7 @@ flAccOpSrcLoop1:
// y = x & flSignMask
// y = min(y, flOne)
// y = mul(y, flAlmost256)
// y = mul(y, flAlmost65536)
MOVOU X5, X2
ANDPS X1, X2
MINPS X4, X2
@ -926,8 +915,9 @@ flAccOpSrcLoop1:
CVTPS2PL X2, X2
LDMXCSR mxcsrOrig-8(SP)
// dst[0] = uint8(z)
// dst[0] = uint8(z>>8)
MOVL X2, BX
SHRL $8, BX
MOVB BX, (DI)
// offset = x

View File

@ -101,16 +101,16 @@ var instances = []struct {
DstElemSize4: 4 * sizeOfUint8,
XMM3: fxXMM3,
XMM4: fxXMM4,
XMM5: fxXMM5_65536,
XMM5: fxXMM5,
XMM6: opOverXMM6,
XMM8: opOverXMM8,
XMM9: opOverXMM9,
XMM10: opOverXMM10,
LoadArgs: twoArgLoadArgs,
Setup: fxSetup,
LoadXMMRegs: fxLoadXMMRegs65536 + "\n" + opOverLoadXMMRegs,
LoadXMMRegs: fxLoadXMMRegs + "\n" + opOverLoadXMMRegs,
Add: fxAdd,
ClampAndScale: fxClampAndScale65536,
ClampAndScale: fxClampAndScale,
ConvertToInt32: fxConvertToInt32,
Store4: opOverStore4,
Store1: opOverStore1,
@ -124,16 +124,16 @@ var instances = []struct {
DstElemSize4: 4 * sizeOfUint8,
XMM3: fxXMM3,
XMM4: fxXMM4,
XMM5: fxXMM5_256,
XMM5: fxXMM5,
XMM6: opSrcXMM6,
XMM8: opSrcXMM8,
XMM9: opSrcXMM9,
XMM10: opSrcXMM10,
LoadArgs: twoArgLoadArgs,
Setup: fxSetup,
LoadXMMRegs: fxLoadXMMRegs256 + "\n" + opSrcLoadXMMRegs,
LoadXMMRegs: fxLoadXMMRegs + "\n" + opSrcLoadXMMRegs,
Add: fxAdd,
ClampAndScale: fxClampAndScale256,
ClampAndScale: fxClampAndScale,
ConvertToInt32: fxConvertToInt32,
Store4: opSrcStore4,
Store1: opSrcStore1,
@ -147,16 +147,16 @@ var instances = []struct {
DstElemSize4: 4 * sizeOfUint32,
XMM3: fxXMM3,
XMM4: fxXMM4,
XMM5: fxXMM5_65536,
XMM5: fxXMM5,
XMM6: maskXMM6,
XMM8: maskXMM8,
XMM9: maskXMM9,
XMM10: maskXMM10,
LoadArgs: oneArgLoadArgs,
Setup: fxSetup,
LoadXMMRegs: fxLoadXMMRegs65536 + "\n" + maskLoadXMMRegs,
LoadXMMRegs: fxLoadXMMRegs + "\n" + maskLoadXMMRegs,
Add: fxAdd,
ClampAndScale: fxClampAndScale65536,
ClampAndScale: fxClampAndScale,
ConvertToInt32: fxConvertToInt32,
Store4: maskStore4,
Store1: maskStore1,
@ -168,7 +168,7 @@ var instances = []struct {
Args: "dst []uint8, src []float32",
DstElemSize1: 1 * sizeOfUint8,
DstElemSize4: 4 * sizeOfUint8,
XMM3: flXMM3_65536,
XMM3: flXMM3,
XMM4: flXMM4,
XMM5: flXMM5,
XMM6: opOverXMM6,
@ -177,9 +177,9 @@ var instances = []struct {
XMM10: opOverXMM10,
LoadArgs: twoArgLoadArgs,
Setup: flSetup,
LoadXMMRegs: flLoadXMMRegs65536 + "\n" + opOverLoadXMMRegs,
LoadXMMRegs: flLoadXMMRegs + "\n" + opOverLoadXMMRegs,
Add: flAdd,
ClampAndScale: flClampAndScale65536,
ClampAndScale: flClampAndScale,
ConvertToInt32: flConvertToInt32,
Store4: opOverStore4,
Store1: opOverStore1,
@ -191,7 +191,7 @@ var instances = []struct {
Args: "dst []uint8, src []float32",
DstElemSize1: 1 * sizeOfUint8,
DstElemSize4: 4 * sizeOfUint8,
XMM3: flXMM3_256,
XMM3: flXMM3,
XMM4: flXMM4,
XMM5: flXMM5,
XMM6: opSrcXMM6,
@ -200,9 +200,9 @@ var instances = []struct {
XMM10: opSrcXMM10,
LoadArgs: twoArgLoadArgs,
Setup: flSetup,
LoadXMMRegs: flLoadXMMRegs256 + "\n" + opSrcLoadXMMRegs,
LoadXMMRegs: flLoadXMMRegs + "\n" + opSrcLoadXMMRegs,
Add: flAdd,
ClampAndScale: flClampAndScale256,
ClampAndScale: flClampAndScale,
ConvertToInt32: flConvertToInt32,
Store4: opSrcStore4,
Store1: opSrcStore1,
@ -214,7 +214,7 @@ var instances = []struct {
Args: "dst []uint32, src []float32",
DstElemSize1: 1 * sizeOfUint32,
DstElemSize4: 4 * sizeOfUint32,
XMM3: flXMM3_65536,
XMM3: flXMM3,
XMM4: flXMM4,
XMM5: flXMM5,
XMM6: maskXMM6,
@ -223,9 +223,9 @@ var instances = []struct {
XMM10: maskXMM10,
LoadArgs: twoArgLoadArgs,
Setup: flSetup,
LoadXMMRegs: flLoadXMMRegs65536 + "\n" + maskLoadXMMRegs,
LoadXMMRegs: flLoadXMMRegs + "\n" + maskLoadXMMRegs,
Add: flAdd,
ClampAndScale: flClampAndScale65536,
ClampAndScale: flClampAndScale,
ConvertToInt32: flConvertToInt32,
Store4: maskStore4,
Store1: maskStore1,
@ -242,14 +242,12 @@ const (
sizeOfUint32 = 4
fxXMM3 = `-`
flXMM3_256 = `flAlmost256`
flXMM3_65536 = `flAlmost65536`
flXMM3 = `flAlmost65536`
fxXMM4 = `-`
flXMM4 = `flOne`
fxXMM5_256 = `fxAlmost256`
fxXMM5_65536 = `fxAlmost65536`
fxXMM5 = `fxAlmost65536`
flXMM5 = `flSignMask`
oneArgLoadArgs = `
@ -278,23 +276,11 @@ const (
MOVL AX, mxcsrNew-4(SP)
`
fxLoadXMMRegs256 = `
// fxAlmost256 := XMM(0x000000ff repeated four times) // Maximum of an uint8.
MOVOU fxAlmost256<>(SB), X5
`
fxLoadXMMRegs65536 = `
fxLoadXMMRegs = `
// fxAlmost65536 := XMM(0x0000ffff repeated four times) // Maximum of an uint16.
MOVOU fxAlmost65536<>(SB), X5
`
flLoadXMMRegs256 = `
// flAlmost256 := XMM(0x437fffff repeated four times) // 255.99998 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 flAlmost256<>(SB), X3
MOVOU flOne<>(SB), X4
MOVOU flSignMask<>(SB), X5
`
flLoadXMMRegs65536 = `
flLoadXMMRegs = `
// 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.
@ -306,23 +292,7 @@ const (
fxAdd = `PADDD`
flAdd = `ADDPS`
fxClampAndScale256 = `
// y = abs(x)
// y >>= 10 // Shift by 2*ϕ - 8.
// y = min(y, fxAlmost256)
//
// pabsd %xmm1,%xmm2
// psrld $0xa,%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 $0x0a
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x3b; BYTE $0xd5
`
fxClampAndScale65536 = `
fxClampAndScale = `
// y = abs(x)
// y >>= 2 // Shift by 2*ϕ - 16.
// y = min(y, fxAlmost65536)
@ -338,16 +308,7 @@ const (
BYTE $0x66; BYTE $0x0f; BYTE $0x72; BYTE $0xd2; BYTE $0x02
BYTE $0x66; BYTE $0x0f; BYTE $0x38; BYTE $0x3b; BYTE $0xd5
`
flClampAndScale256 = `
// y = x & flSignMask
// y = min(y, flOne)
// y = mul(y, flAlmost256)
MOVOU X5, X2
ANDPS X1, X2
MINPS X4, X2
MULPS X3, X2
`
flClampAndScale65536 = `
flClampAndScale = `
// y = x & flSignMask
// y = min(y, flOne)
// y = mul(y, flAlmost65536)
@ -402,18 +363,16 @@ const (
BYTE $0x66; BYTE $0x45; BYTE $0x0f; BYTE $0xf4; BYTE $0xda
PSRLQ $47, X0
PSRLQ $47, X11
// Merge the two registers back to one, X11.
// Merge the two registers back to one, X11, and add maskA.
PSLLQ $32, X11
XORPS X0, X11
// Add maskA, shift from 16 bit color to 8 bit color.
PADDD X11, X2
PSRLQ $8, X2
// As per opSrcStore4, shuffle and copy the low 4 bytes.
// As per opSrcStore4, shuffle and copy the 4 second-lowest bytes.
PSHUFB X6, X2
MOVL X2, (DI)
`
opSrcStore4 = `
// z = shuffleTheLowBytesOfEach4ByteElement(z)
// z = shuffleTheSecondLowestBytesOfEach4ByteElement(z)
// copy(dst[:4], low4BytesOf(z))
PSHUFB X6, X2
MOVL X2, (DI)
@ -444,8 +403,9 @@ const (
MOVB R13, (DI)
`
opSrcStore1 = `
// dst[0] = uint8(z)
// dst[0] = uint8(z>>8)
MOVL X2, BX
SHRL $8, BX
MOVB BX, (DI)
`
maskStore1 = `

View File

@ -10,8 +10,6 @@
// fl is short for floating point math. fx is short for fixed point math.
DATA flAlmost256<>+0x00(SB)/8, $0x437fffff437fffff
DATA flAlmost256<>+0x08(SB)/8, $0x437fffff437fffff
DATA flAlmost65536<>+0x00(SB)/8, $0x477fffff477fffff
DATA flAlmost65536<>+0x08(SB)/8, $0x477fffff477fffff
DATA flOne<>+0x00(SB)/8, $0x3f8000003f800000
@ -30,30 +28,26 @@ DATA flSignMask<>+0x08(SB)/8, $0x7fffffff7fffffff
DATA scatterAndMulBy0x101<>+0x00(SB)/8, $0x8080010180800000
DATA scatterAndMulBy0x101<>+0x08(SB)/8, $0x8080030380800202
// gather is a PSHUFB mask that brings the low byte of the XMM register's four
// uint32 values to the low four bytes of that register.
// 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???
// ?i???j???k???l??
// to
// ijkl000000000000
DATA gather<>+0x00(SB)/8, $0x808080800c080400
DATA gather<>+0x00(SB)/8, $0x808080800d090501
DATA gather<>+0x08(SB)/8, $0x8080808080808080
DATA fxAlmost256<>+0x00(SB)/8, $0x000000ff000000ff
DATA fxAlmost256<>+0x08(SB)/8, $0x000000ff000000ff
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 flAlmost256<>(SB), (NOPTR+RODATA), $16
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 fxAlmost256<>(SB), (NOPTR+RODATA), $16
GLOBL fxAlmost65536<>(SB), (NOPTR+RODATA), $16
GLOBL inverseFFFF<>(SB), (NOPTR+RODATA), $16