private SFix(Signed value, int intWidth, int fracWidth)
{
Contract.Requires(intWidth + fracWidth >= 0);
Debug.Assert(value.Size <= intWidth + fracWidth);
_value = value;
_format = new FixFormat(true, intWidth, fracWidth);
}
/// <summary>
/// Subtracts <paramref name="b"/> from <paramref name="a"/>.
/// The integer and fractional width of the result is determined according to the
/// current arithmetic sizing mode (<seealso cref="FixedPointSettings"/>).
/// </summary>
public static SFix operator -(SFix a, SFix b)
{
Signed an, bn;
FixFormat dfmt = Equalize(a, b, out an, out bn);
Signed rn = an - bn;
return(new SFix(rn, dfmt.IntWidth, dfmt.FracWidth));
}
/// <summary>
/// Multiplies <paramref name="a"/> and <paramref name="b"/>.
/// The integer and fractional width of the result is determined according to the
/// current arithmetic sizing mode (<seealso cref="FixedPointSettings"/>).
/// </summary>
public static UFix operator *(UFix a, UFix b)
{
FixFormat dfmt = new FixFormat(true,
a.Format.IntWidth + b.Format.IntWidth,
a.Format.FracWidth + b.Format.FracWidth);
return(new UFix(a._value * b._value, dfmt.IntWidth, dfmt.FracWidth));
}
/// <summary>
/// Subtracts <paramref name="b"/> from <paramref name="a"/>.
/// The integer and fractional width of the result is determined according to the
/// current arithmetic sizing mode (<seealso cref="FixedPointSettings"/>).
/// </summary>
public static UFix operator -(UFix a, UFix b)
{
Unsigned an, bn;
FixFormat dfmt = Equalize(a, b, out an, out bn);
Unsigned rn = an - bn;
return(new UFix(rn, dfmt.IntWidth, dfmt.FracWidth));
}
private static FixFormat Equalize(SFix a, SFix b, out Signed an, out Signed bn)
{
an = a._value;
bn = b._value;
FixFormat dfmt;
switch (DesignContext.Instance.FixPoint.ArithSizingMode)
{
case EArithSizingMode.Safe:
dfmt = new FixFormat(true,
Math.Max(a.Format.IntWidth, b.Format.IntWidth) + 1,
Math.Max(a.Format.FracWidth, b.Format.FracWidth));
an = an.Resize(dfmt.TotalWidth - 1);
bn = bn.Resize(dfmt.TotalWidth - 1);
if (a.Format.FracWidth > b.Format.FracWidth)
{
bn = bn << (int)(a.Format.FracWidth - b.Format.FracWidth);
}
else if (b.Format.FracWidth > a.Format.FracWidth)
{
an = an << (int)(b.Format.FracWidth - a.Format.FracWidth);
}
return(dfmt);
case EArithSizingMode.VHDLCompliant:
dfmt = new FixFormat(true,
Math.Max(a.Format.IntWidth, b.Format.IntWidth) + 1,
Math.Max(a.Format.FracWidth, b.Format.FracWidth));
an = an.Resize(dfmt.TotalWidth);
bn = bn.Resize(dfmt.TotalWidth);
if (a.Format.FracWidth > b.Format.FracWidth)
{
bn = bn << (int)(a.Format.FracWidth - b.Format.FracWidth);
}
else if (b.Format.FracWidth > a.Format.FracWidth)
{
an = an << (int)(b.Format.FracWidth - a.Format.FracWidth);
}
return(dfmt);
case EArithSizingMode.InSizeIsOutSize:
dfmt = a.Format;
bn = bn.Resize(dfmt.TotalWidth);
if (a.Format.FracWidth > b.Format.FracWidth)
{
bn = bn << (int)(a.Format.FracWidth - b.Format.FracWidth);
}
else if (b.Format.FracWidth > a.Format.FracWidth)
{
an = an << (int)(b.Format.FracWidth - a.Format.FracWidth);
}
return(dfmt);
default:
throw new NotImplementedException();
}
}
/// <summary>
/// Converts the format to a SysDOM type descriptor.
/// </summary>
public static TypeDescriptor ToType(this FixFormat fmt)
{
if (fmt.IsSigned)
{
return(TypeDescriptor.GetTypeOf(SFix.FromDouble(0.0, fmt.IntWidth, fmt.FracWidth)));
}
else
{
return(TypeDescriptor.GetTypeOf(UFix.FromDouble(0.0, fmt.IntWidth, fmt.FracWidth)));
}
}
private bool IsFix(TypeDescriptor inType, out FixFormat format)
{
if (inType.CILType.Equals(typeof(SFix)) ||
inType.CILType.Equals(typeof(UFix)))
{
format = inType.GetFixFormat();
return true;
}
format = null;
return false;
}
/// <summary>
/// Two fixed-point formats are defined to be equal iff the have the same signedness and integer/fractional widths match.
/// </summary>
public override bool Equals(object obj)
{
FixFormat other = (FixFormat)obj;
if (other == null)
{
return(false);
}
return(IsSigned == other.IsSigned &&
IntWidth == other.IntWidth &&
FracWidth == other.FracWidth);
}
/// <summary>
/// Multiplies <paramref name="a"/> and <paramref name="b"/>.
/// The integer and fractional width of the result is determined according to the
/// current arithmetic sizing mode (<seealso cref="FixedPointSettings"/>).
/// </summary>
public static UFix operator *(UFix a, UFix b)
{
FixFormat dfmt = new FixFormat(true,
a.Format.IntWidth + b.Format.IntWidth,
a.Format.FracWidth + b.Format.FracWidth);
return new UFix(a._value * b._value, dfmt.IntWidth, dfmt.FracWidth);
}
private static FixFormat Equalize(UFix a, UFix b, out Unsigned an, out Unsigned bn)
{
an = a._value;
bn = b._value;
FixFormat dfmt;
switch (DesignContext.Instance.FixPoint.ArithSizingMode)
{
case EArithSizingMode.Safe:
dfmt = new FixFormat(false,
Math.Max(a.Format.IntWidth, b.Format.IntWidth) + 1,
Math.Max(a.Format.FracWidth, b.Format.FracWidth));
an = an.Resize(dfmt.TotalWidth - 1);
bn = bn.Resize(dfmt.TotalWidth - 1);
if (a.Format.FracWidth > b.Format.FracWidth)
bn = bn << (int)(a.Format.FracWidth - b.Format.FracWidth);
else if (b.Format.FracWidth > a.Format.FracWidth)
an = an << (int)(b.Format.FracWidth - a.Format.FracWidth);
return dfmt;
case EArithSizingMode.VHDLCompliant:
dfmt = new FixFormat(false,
Math.Max(a.Format.IntWidth, b.Format.IntWidth) + 1,
Math.Max(a.Format.FracWidth, b.Format.FracWidth));
an = an.Resize(dfmt.TotalWidth);
bn = bn.Resize(dfmt.TotalWidth);
if (a.Format.FracWidth > b.Format.FracWidth)
bn = bn << (int)(a.Format.FracWidth - b.Format.FracWidth);
else if (b.Format.FracWidth > a.Format.FracWidth)
an = an << (int)(b.Format.FracWidth - a.Format.FracWidth);
return dfmt;
case EArithSizingMode.InSizeIsOutSize:
dfmt = a.Format;
bn = bn.Resize(dfmt.TotalWidth);
if (a.Format.FracWidth > b.Format.FracWidth)
bn = bn << (int)(a.Format.FracWidth - b.Format.FracWidth);
else if (b.Format.FracWidth > a.Format.FracWidth)
an = an << (int)(b.Format.FracWidth - a.Format.FracWidth);
return dfmt;
default:
throw new NotImplementedException();
}
}
private UFix(Unsigned value, int intWidth, int fracWidth)
{
Contract.Requires(intWidth + fracWidth >= 0);
Debug.Assert(value.Size <= intWidth + fracWidth);
_value = value;
_format = new FixFormat(false, intWidth, fracWidth);
}
/// <summary>
/// Constructs a new instance.
/// </summary>
/// <param name="floatWidth">total bit-width of input floating-point number
/// (actual partitioning between exponent and mantissa bits does not matter)</param>
/// <param name="outFormat">desired fixed-point output format</param>
public FloatSignAsSigned(int floatWidth, FixFormat outFormat)
{
FloatWidth = floatWidth;
OutFormat = outFormat;
_outM1 = SFix.FromDouble(-1.0, outFormat.IntWidth, outFormat.FracWidth).SLVValue;
_out0 = SFix.FromDouble(0.0, outFormat.IntWidth, outFormat.FracWidth).SLVValue;
_out1 = SFix.FromDouble(1.0, outFormat.IntWidth, outFormat.FracWidth).SLVValue;
_zeros = StdLogicVector._0s(floatWidth - 1);
TASite = new TransactionSite(this);
}
public override TypeDescriptor MakeWireType(TypeDescriptor ctype)
{
FixFormat fmt = (FixFormat)ctype.TypeParams[0];
return(TypeDescriptor.GetTypeOf(StdLogicVector._0s(fmt.TotalWidth)));
}
/// <summary>
/// Converts <paramref name="fmt"/> to a range repesentation in the way it is typically used in VHDL designs.
/// </summary>
public static Range ConvertToRange(FixFormat fmt)
{
return(new Range(fmt.IntWidth - 1, -fmt.FracWidth, EDimDirection.Downto));
}
/// <summary>
/// Converts <paramref name="fmt"/> to a range repesentation in the way it is typically used in VHDL designs.
/// </summary>
public static Range ConvertToRange(FixFormat fmt)
{
return new Range(fmt.IntWidth - 1, -fmt.FracWidth, EDimDirection.Downto);
}
