tile38/vendor/github.com/mmcloughlin/geohash/asm_x86.s

// +build amd64,go1.6

#include "textflag.h"

// func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)
TEXT ·cpuid(SB), NOSPLIT, $0-24
	MOVL eaxArg+0(FP), AX
	MOVL ecxArg+4(FP), CX
	CPUID
	MOVL AX, eax+8(FP)
	MOVL BX, ebx+12(FP)
	MOVL CX, ecx+16(FP)
	MOVL DX, edx+20(FP)
	RET

// func EncodeInt(lat, lng float64) uint64
TEXT ·EncodeInt(SB), NOSPLIT, $0
	CMPB ·useAsm(SB), $1
	JNE  fallback

#define LATF	X0
#define LATI	R8
#define LNGF	X1
#define LNGI	R9
#define TEMP	R10
#define GHSH	R11
#define MASK	BX

	MOVSD lat+0(FP), LATF
	MOVSD lng+8(FP), LNGF

	MOVQ $0x5555555555555555, MASK

	MULSD $(0.005555555555555556), LATF
	ADDSD $(1.5), LATF

	MULSD $(0.002777777777777778), LNGF
	ADDSD $(1.5), LNGF

	MOVQ LNGF, LNGI
	SHRQ $20, LNGI

	MOVQ  LATF, LATI
	SHRQ  $20, LATI
	PDEPQ MASK, LATI, GHSH

	PDEPQ MASK, LNGI, TEMP

	SHLQ $1, TEMP
	XORQ TEMP, GHSH

	MOVQ GHSH, ret+16(FP)
	RET

fallback:
	JMP ·encodeInt(SB)
Faster point in polygon / GeoJSON updates The big change is that the GeoJSON package has been completely rewritten to fix a few of geometry calculation bugs, increase performance, and to better follow the GeoJSON spec RFC 7946. GeoJSON updates - A LineString now requires at least two points. - All json members, even foreign, now persist with the object. - The bbox member persists too but is no longer used for geometry calculations. This is change in behavior. Previously Tile38 would treat the bbox as the object's physical rectangle. - Corrections to geometry intersects and within calculations. Faster spatial queries - The performance of Point-in-polygon and object intersect operations are greatly improved for complex polygons and line strings. It went from O(n) to roughly O(log n). - The same for all collection types with many children, including FeatureCollection, GeometryCollection, MultiPoint, MultiLineString, and MultiPolygon. Codebase changes - The pkg directory has been renamed to internal - The GeoJSON internal package has been moved to a seperate repo at https://github.com/tidwall/geojson. It's now vendored. Please look out for higher memory usage for datasets using complex shapes. A complex shape is one that has 64 or more points. For these shapes it's expected that there will be increase of least 54 bytes per point. 2018-10-11 00:25:40 +03:00			`// +build amd64,go1.6`

			`#include "textflag.h"`

			`// func cpuid(eaxArg, ecxArg uint32) (eax, ebx, ecx, edx uint32)`
			`TEXT ·cpuid(SB), NOSPLIT, $0-24`
			`MOVL eaxArg+0(FP), AX`
			`MOVL ecxArg+4(FP), CX`
			`CPUID`
			`MOVL AX, eax+8(FP)`
			`MOVL BX, ebx+12(FP)`
			`MOVL CX, ecx+16(FP)`
			`MOVL DX, edx+20(FP)`
			`RET`

			`// func EncodeInt(lat, lng float64) uint64`
			`TEXT ·EncodeInt(SB), NOSPLIT, $0`
			`CMPB ·useAsm(SB), $1`
			`JNE fallback`

			`#define LATF X0`
			`#define LATI R8`
			`#define LNGF X1`
			`#define LNGI R9`
			`#define TEMP R10`
			`#define GHSH R11`
			`#define MASK BX`

			`MOVSD lat+0(FP), LATF`
			`MOVSD lng+8(FP), LNGF`

			`MOVQ $0x5555555555555555, MASK`

			`MULSD $(0.005555555555555556), LATF`
			`ADDSD $(1.5), LATF`

			`MULSD $(0.002777777777777778), LNGF`
			`ADDSD $(1.5), LNGF`

			`MOVQ LNGF, LNGI`
			`SHRQ $20, LNGI`

			`MOVQ LATF, LATI`
			`SHRQ $20, LATI`
			`PDEPQ MASK, LATI, GHSH`

			`PDEPQ MASK, LNGI, TEMP`

			`SHLQ $1, TEMP`
			`XORQ TEMP, GHSH`

			`MOVQ GHSH, ret+16(FP)`
			`RET`

			`fallback:`
			`JMP ·encodeInt(SB)`