Flattened packed-word exact-dyadic posit arithmetic #
Addition, subtraction, multiplication, and fused multiply-add decode finite posits to exact
dyadic fields before one direct rounding step. The logical definitions use Option Dyadic;
these kernels pass the decoded fields through continuations instead.
The kernels in this module pass signs, significands, and exponents directly to the
format-independent exact field operations, avoiding intermediate input options and dyadic
records. Their semantic and compiler-refinement proofs live in
FloatLib.Floats.Formats.Posit.Arithmetic.Word.Packed.Dyadic.Proof.
Addition #
Add packed posit words after eliminating decoded input records.
Instances For
Add two words whose packed carrier has already proved both encodings valid.
Instances For
Subtraction #
Subtract packed posit words after eliminating decoded input records.
Instances For
Subtract two words whose packed carrier has already proved both encodings valid.
Instances For
Multiplication #
Multiply packed posit words after scalar-field elimination.
The product is computed with natural-number significands. The fixed-carrier multiplier in
Packed.Product is proved equal to this definition.
Instances For
Multiply two words whose packed carrier has already proved both encodings valid.
Instances For
Fused multiply-add #
Fuse a packed-word product and addend through scalar exact fields.
Dyadic.fmaFields forms the exact product and sum before the sole call to the posit rounder.
Instances For
FMA for three words whose packed carrier has proved every encoding valid.