P2Pool/go-randomx
P2Pool/go-randomx
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Speedup randomx_reciprocal

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This commit is contained in:
DataHoarder 2024-04-11 08:47:24 +02:00
parent b207b994b3
commit 0167b005eb
Signed by: DataHoarder
SSH key fingerprint: SHA256:OLTRf6Fl87G52SiR7sWLGNzlJt4WOX+tfI2yxo0z7xk
1 changed files with 5 additions and 17 deletions
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22
superscalar.go
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@ -961,12 +961,11 @@ func (p *SuperScalarProgram) executeSuperscalar_nocache(r []uint64) {
r[ins.Dst_Reg] ^= r[ins.Src_Reg]
case S_IADD_RS:
mod_shift := (ins.Mod >> 2) % 4 // bits 2-3
r[ins.Dst_Reg] += (r[ins.Src_Reg] << mod_shift)
r[ins.Dst_Reg] += r[ins.Src_Reg] << mod_shift
case S_IMUL_R:
r[ins.Dst_Reg] *= r[ins.Src_Reg]
case S_IROR_C:
r[ins.Dst_Reg] = bits.RotateLeft64(r[ins.Dst_Reg], 0-int(ins.Imm32))
// panic("check rotate right is working fine")
case S_IADD_C7, S_IADD_C8, S_IADD_C9:
r[ins.Dst_Reg] += signExtend2sCompl(ins.Imm32)
case S_IXOR_C7, S_IXOR_C8, S_IXOR_C9:
@ -974,7 +973,7 @@ func (p *SuperScalarProgram) executeSuperscalar_nocache(r []uint64) {
case S_IMULH_R:
r[ins.Dst_Reg], _ = bits.Mul64(r[ins.Dst_Reg], r[ins.Src_Reg])
case S_ISMULH_R:
r[ins.Dst_Reg] = uint64(smulh(int64(r[ins.Dst_Reg]), int64(r[ins.Src_Reg])))
r[ins.Dst_Reg] = smulh(int64(r[ins.Dst_Reg]), int64(r[ins.Src_Reg]))
case S_IMUL_RCP:
r[ins.Dst_Reg] *= randomx_reciprocal(uint64(ins.Imm32))
@ -1004,20 +1003,9 @@ func randomx_reciprocal(divisor uint64) uint64 {
quotient := p2exp63 / divisor
remainder := p2exp63 % divisor
bsr := uint32(0)
for bit := divisor; bit > 0; bit >>= 1 {
bsr++
}
for shift := uint32(0); shift < bsr; shift++ {
if remainder >= divisor-remainder {
quotient = quotient*2 + 1
remainder = remainder*2 - divisor
} else {
quotient = quotient * 2
remainder = remainder * 2
}
}
return quotient
shift := uint32(64 - bits.LeadingZeros64(divisor))
return (quotient << shift) + ((remainder << shift) / divisor)
}
func signExtend2sCompl(x uint32) uint64 {