The DecFP package is a Julia wrapper around the Intel Decimal Floating-Point Math Library, providing a software implementation of the IEEE 754-2008 Decimal Floating-Point Arithmetic specification.
32-bit, 64-bit, and 128-bit decimal floating-point types Dec32
,
Dec64
, and Dec128
, respectively, are provided. This is very
different from packages such as
Decimals.jl, which provide
arbitrary-precision decimal types analogous to BigFloat
: arbitrary
precision types are very flexible, but fixed-precision types such
as those in DecFP are much faster (though still about 100x slower than
the hardware binary floating-point types Float32
and Float64
).
The DecFP package currently requires the Julia 0.5 release or later.
Dec64
and the other types mentioned above can be constructed from
other Julia numeric types (binary floating-point or integers) via
Dec64(3.5)
or Dec(3)
, from strings by parse(Dec64, "3.2")
or
d64"3.2"
(a Julia string macro); similarly for Dec32
and Dec128
.
The string macro d"3.2"
constructs Dec64
.
Once a decimal float is constructed, most Julia arithemetic and
special functions should work without modification. For example,
d"3.2" * d"4.5"
produces the Dec64
result +1440E-2
(14.4).
Most basic arithmetic functions are supported, and many special functions
(sqrt
, log
, trigonometric functions, etc.). Mixed operations
involving decimal and binary floating-point or integer types are supported
(the result is promoted to decimal floating-point).
In general, you should be able to use the DecFP
types in any context
where you would have used binary floating-point types: arrays, complex
arithmetic, and linear algebra should all work, for the most part.