475a241446
Intended to address an asmdecl error. [amd64] Butterfly: use of unnamed argument 0(FP); offset 0 is x0+0(FP) Updates #24
geohash
Integer geohash encoding.
Refer to "Geohash in Golang Assembly" for implementation details.
func main() {
TEXT("EncodeInt", NOSPLIT, "func(lat, lng float64) uint64")
Doc("EncodeInt computes the 64-bit integer geohash of (lat, lng).")
lat := Load(Param("lat"), XMM())
lng := Load(Param("lng"), XMM())
MULSD(ConstData("reciprocal180", F64(1/180.0)), lat)
onepointfive := ConstData("onepointfive", F64(1.5))
ADDSD(onepointfive, lat)
MULSD(ConstData("reciprocal360", F64(1/360.0)), lng)
ADDSD(onepointfive, lng)
lngi, lati := GP64(), GP64()
MOVQ(lat, lati)
SHRQ(U8(20), lati)
MOVQ(lng, lngi)
SHRQ(U8(20), lngi)
mask := ConstData("mask", U64(0x5555555555555555))
ghsh := GP64()
PDEPQ(mask, lati, ghsh)
temp := GP64()
PDEPQ(mask, lngi, temp)
SHLQ(U8(1), temp)
XORQ(temp, ghsh)
Store(ghsh, ReturnIndex(0))
RET()
Generate()
}