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+
+
+libmpdec
+========
+
+libmpdec is a fast C/C++ library for correctly-rounded arbitrary precision
+decimal floating point arithmetic. It is a complete implementation of
+Mike Cowlishaw/IBM's General Decimal Arithmetic Specification.
+
+
+Files required for the Python _decimal module
+=============================================
+
+ Core files for small and medium precision arithmetic
+ ----------------------------------------------------
+
+ basearith.{c,h} -> Core arithmetic in base 10**9 or 10**19.
+ bits.h -> Portable detection of least/most significant one-bit.
+ constants.{c,h} -> Constants that are used in multiple files.
+ context.c -> Context functions.
+ io.{c,h} -> Conversions between mpd_t and ASCII strings,
+ mpd_t formatting (allows UTF-8 fill character).
+ memory.{c,h} -> Allocation handlers with overflow detection
+ and functions for switching between static
+ and dynamic mpd_t.
+ mpdecimal.{c,h} -> All (quiet) functions of the specification.
+ typearith.h -> Fast primitives for double word multiplication,
+ division etc.
+
+ Visual Studio only:
+ ~~~~~~~~~~~~~~~~~~~
+ vccompat.h -> snprintf <==> sprintf_s and similar things.
+ vcstdint.h -> stdint.h (included in VS 2010 but not in VS 2008).
+ vcdiv64.asm -> Double word division used in typearith.h. VS 2008 does
+ not allow inline asm for x64. Also, it does not provide
+ an intrinsic for double word division.
+
+ Files for bignum arithmetic:
+ ----------------------------
+
+ The following files implement the Fast Number Theoretic Transform
+ used for multiplying coefficients with more than 1024 words (see
+ mpdecimal.c: _mpd_fntmul()).
+
+ umodarith.h -> Fast low level routines for unsigned modular arithmetic.
+ numbertheory.{c,h} -> Routines for setting up the Number Theoretic Transform.
+ difradix2.{c,h} -> Decimation in frequency transform, used as the
+ "base case" by the following three files:
+
+ fnt.{c,h} -> Transform arrays up to 4096 words.
+ sixstep.{c,h} -> Transform larger arrays of length 2**n.
+ fourstep.{c,h} -> Transform larger arrays of length 3 * 2**n.
+
+ convolute.{c,h} -> Fast convolution using one of the three transform
+ functions.
+ transpose.{c,h} -> Transpositions needed for the sixstep algorithm.
+ crt.{c,h} -> Chinese Remainder Theorem: use information from three
+ transforms modulo three different primes to get the
+ final result.
+
+
+Pointers to literature, proofs and more
+========================================
+
+ literature/
+ -----------
+
+ REFERENCES.txt -> List of relevant papers.
+ bignum.txt -> Explanation of the Fast Number Theoretic Transform (FNT).
+ fnt.py -> Verify constants used in the FNT; Python demo for the
+ O(N**2) discrete transform.
+
+ matrix-transform.txt -> Proof for the Matrix Fourier Transform used in
+ fourstep.c.
+ six-step.txt -> Show that the algorithm used in sixstep.c is
+ a variant of the Matrix Fourier Transform.
+ mulmod-64.txt -> Proof for the mulmod64 algorithm from
+ umodarith.h.
+ mulmod-ppro.txt -> Proof for the x87 FPU modular multiplication
+ from umodarith.h.
+ umodarith.lisp -> ACL2 proofs for many functions from umodarith.h.
+
+
+Library Author
+==============
+
+ Stefan Krah
+
+
+