/
f128_mul.go
241 lines (227 loc) · 6.44 KB
/
f128_mul.go
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package eos_math
func (a Float128) Mul(b Float128) Float128 {
var uiA64, uiA0 uint64
var signA bool
var expA int32
var sigA Uint128
var uiB64, uiB0 uint64
var signB bool
var expB int32
var sigB Uint128
var signZ bool
var magBits uint64
var normExpSig exp32_sig128
var expZ int32
var sig256Z [4]uint64
var sigZExtra uint64
var sigZ Uint128
var sig128Extra uint128Extra
var uiZ Uint128
var uZ Float128
/*------------------------------------------------------------------------
*------------------------------------------------------------------------*/
uiA64 = a.High
uiA0 = a.Low
signA = signF128UI64(uiA64)
expA = int32(expF128UI64(uiA64))
sigA.High = fracF128UI64(uiA64)
sigA.Low = uiA0
uiB64 = b.High
uiB0 = b.Low
signB = signF128UI64(uiB64)
expB = int32(expF128UI64(uiB64))
sigB.High = fracF128UI64(uiB64)
sigB.Low = uiB0
//signZ = signA ^ signB
if (signA && signB) || (signA == false && signB == false) {
signZ = false
} else {
signZ = true
}
/*------------------------------------------------------------------------
*------------------------------------------------------------------------*/
if expA == 0x7FFF {
if (sigA.High|sigA.Low) != 0 || ((expB == 0x7FFF) && (sigB.High|sigB.Low) != 0) {
goto propagateNaN
}
magBits = uint64(expB) | sigB.High | sigB.Low
goto infArg
}
if expB == 0x7FFF {
if sigB.High|sigB.Low != 0 {
goto propagateNaN
}
magBits = uint64(expA) | sigA.High | sigA.Low
goto infArg
}
/*------------------------------------------------------------------------
*------------------------------------------------------------------------*/
if expA == 0 {
if (sigA.High | sigA.Low) == 0 {
goto zero
}
normExpSig = softfloat_normSubnormalF128Sig(sigA.High, sigA.Low)
expA = normExpSig.exp
sigA = normExpSig.sig
}
if expB == 0 {
if (sigB.High | sigB.Low) == 0 {
goto zero
}
normExpSig = softfloat_normSubnormalF128Sig(sigB.High, sigB.Low)
expB = normExpSig.exp
sigB = normExpSig.sig
}
/*------------------------------------------------------------------------
*------------------------------------------------------------------------*/
expZ = expA + expB - 0x4000
sigA.High |= uint64(0x0001000000000000)
sigB = softfloat_shortShiftLeft128(sigB.High, sigB.Low, 16)
sig256Z = softfloat_mul128To256M(sigA.High, sigA.Low, sigB.High, sigB.Low, sig256Z) //TODO
//sigZExtra = sig256Z[indexWord( 4, 1 )] | (sig256Z[indexWord( 4, 0 )] != 0)
if sig256Z[indexWord(4, 0)] != 0 {
sigZExtra = sig256Z[indexWord(4, 1)] | 1
} else {
sigZExtra = sig256Z[indexWord(4, 1)] | 0
}
sigZ = softfloat_add128(sig256Z[indexWord(4, 3)], sig256Z[indexWord(4, 2)], sigA.High, sigA.Low)
if uint64(0x0002000000000000) <= sigZ.High {
expZ += 1
sig128Extra = softfloat_shortShiftRightJam128Extra(sigZ.High, sigZ.Low, sigZExtra, 1)
sigZ = sig128Extra.v
sigZExtra = sig128Extra.extra
}
return softfloat_roundPackToF128(signZ, expZ, sigZ.High, sigZ.Low, sigZExtra)
/*------------------------------------------------------------------------
*------------------------------------------------------------------------*/
propagateNaN:
uiZ = softfloat_propagateNaNF128UI(uiA64, uiA0, uiB64, uiB0)
goto uiZ
/*------------------------------------------------------------------------
*------------------------------------------------------------------------*/
infArg:
if magBits == 0 {
softfloat_raiseFlags(softfloat_flag_invalid)
uiZ.High = defaultNaNF128UI64
uiZ.Low = defaultNaNF128UI0
goto uiZ
}
//uiZ.High = packToF128UI64( signZ, 0x7FFF, 0 )
if signZ {
uiZ.High = packToF128UI64(1, 0x7FFF, 0)
} else {
uiZ.High = packToF128UI64(0, 0x7FFF, 0)
}
goto uiZ0
/*------------------------------------------------------------------------
*------------------------------------------------------------------------*/
zero:
//uiZ.High = packToF128UI64( signZ, 0, 0 );
if signZ {
uiZ.High = packToF128UI64(1, 0, 0)
} else {
uiZ.High = packToF128UI64(0, 0, 0)
}
uiZ0:
uiZ.Low = 0
uiZ:
uZ.High = uiZ.High
uZ.Low = uiZ.Low
return uZ
}
//#define wordIncr 1
//#define indexWord( total, n ) (n)
//#define indexWordHi( total ) ((total) - 1)
//#define indexWordLo( total ) 0
//#define indexMultiword( total, m, n ) (n)
//#define indexMultiwordHi( total, n ) ((total) - (n))
//#define indexMultiwordLo( total, n ) 0
//#define indexMultiwordHiBut( total, n ) (n)
//#define indexMultiwordLoBut( total, n ) 0
//#define INIT_UINTM4( v3, v2, v1, v0 ) { v0, v1, v2, v3 }
func indexWord(total, n uint8) uint8 {
return n
}
func softfloat_normSubnormalF128Sig(sig64, sig0 uint64) exp32_sig128 {
var shiftDist int8
var z exp32_sig128
if sig64 == 0 {
shiftDist = int8(softfloat_countLeadingZeros64(sig0)) - 15
z.exp = int32(-63 - shiftDist)
if shiftDist < 0 {
z.sig.High = sig0 >> uint8(-shiftDist)
z.sig.Low = sig0 << uint8(shiftDist&63)
} else {
z.sig.High = sig0 << uint8(shiftDist)
z.sig.Low = 0
}
} else {
shiftDist = int8(softfloat_countLeadingZeros64(sig64)) - 15
z.exp = int32(1 - shiftDist)
z.sig = softfloat_shortShiftLeft128(sig64, sig0, uint8(shiftDist))
}
return z
}
func softfloat_mul128To256M(a64, a0, b64, b0 uint64, zPtr [4]uint64) [4]uint64 {
var p0, p64, p128 Uint128
var z64, z128, z192 uint64
p0 = softfloat_mul64To128(a0, b0)
zPtr[indexWord(4, 0)] = p0.Low
p64 = softfloat_mul64To128(a64, b0)
z64 = p64.Low + p0.High
//z128 = p64.High + (z64 < p64.Low)
if z64 < p64.Low {
z128 = p64.High + 1
} else {
z128 = p64.High
}
p128 = softfloat_mul64To128(a64, b64)
z128 += p128.Low
//z192 = p128.High + (z128 < p128.Low)
if z128 < p128.Low {
z192 = p128.High + 1
} else {
z192 = p128.High
}
p64 = softfloat_mul64To128(a0, b64)
z64 += p64.Low
zPtr[indexWord(4, 1)] = z64
//p64.High += (z64 < p64.Low);
if z64 < p64.Low {
p64.High += 1
}
z128 += p64.High
zPtr[indexWord(4, 2)] = z128
//zPtr[indexWord( 4, 3 )] = z192 + (z128 < p64.High)
if z128 < p64.High {
zPtr[indexWord(4, 3)] = z192 + 1
} else {
zPtr[indexWord(4, 3)] = z192
}
return zPtr
}
func softfloat_mul64To128(a, b uint64) Uint128 {
var a32, a0, b32, b0 uint32
var z Uint128
var mid1, mid uint64
a32 = uint32(a >> 32)
a0 = uint32(a)
b32 = uint32(b >> 32)
b0 = uint32(b)
z.Low = uint64(a0) * uint64(b0)
mid1 = uint64(a32) * uint64(b0)
mid = mid1 + uint64(a0)*uint64(b32)
z.High = uint64(a32) * uint64(b32)
if mid < mid1 {
z.High += uint64(1)<<32 | mid>>32
} else {
z.High += uint64(0)<<32 | mid>>32
}
mid <<= 32
z.Low += mid
//z.High += (z.Low < mid)
if z.Low < mid {
z.High += 1
}
return z
}