// absInt returns the absolute value of v as a *big.Int.
// v must be a numeric value.
func absInt(v exact.Value) *big.Int {
// compute big-endian representation of v
b := exact.Bytes(v) // little-endian
for i, j := 0, len(b)-1; i < j; i, j = i+1, j-1 {
b[i], b[j] = b[j], b[i]
}
return new(big.Int).SetBytes(b)
}
func valueToRat(x constant.Value) *big.Rat {
// Convert little-endian to big-endian.
// I can't believe this is necessary.
bytes := constant.Bytes(x)
for i := 0; i < len(bytes)/2; i++ {
bytes[i], bytes[len(bytes)-1-i] = bytes[len(bytes)-1-i], bytes[i]
}
return new(big.Rat).SetInt(new(big.Int).SetBytes(bytes))
}
// ufloat writes abs(x) in form of a binary exponent
// followed by its mantissa bytes; x must be != 0.
func (p *exporter) ufloat(x constant.Value) {
mant := constant.Bytes(x)
exp8 := -1
for i, b := range mant {
if b != 0 {
exp8 = i
break
}
}
if exp8 < 0 {
panic(fmt.Sprintf("%s has no mantissa", x))
}
p.int(exp8 * 8)
p.bytes(mant[exp8:])
}