float features

About Float-Features

This is a wrapper library for IEEE floating point features not present in the Common Lisp standard.

Implementation Support

The following implementations are currently partially or entirely supported:

• abcl
• allegro
• ccl
• clasp
• cmucl
• ecl
• mezzano
• mkcl
• sbcl
• lispworks

System Information

Definition Index

• FLOAT-FEATURES

  • ORG.SHIRAKUMO.FLOAT-FEATURES

  No documentation provided.

  • EXTERNAL CONSTANT

    DOUBLE-FLOAT-NAN

    Source

    A positive quiet NaN value with zero-cleared payload for double-floats.
    This value should NOT be used for comparison with a float value for the pupose of testing NaN
    because NaN has unused bits (called payload) which are explicitly allowed to store additional information.
    Comparing this value with other NaN representations via = will fail.
    To test if a number is a NaN, use FLOAT-NAN-P.
    
    It is supported on implementations which support BITS-DOUBLE-FLOAT.
    
    Defaults to MOST-POSITIVE-DOUBLE-FLOAT on unsupported implementations.

  • EXTERNAL CONSTANT

    DOUBLE-FLOAT-NEGATIVE-INFINITY

    Source

    The negative infinity for double-floats.
    
    Supported on:
    * ABCL
    * ALLEGRO
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS
    * MEZZANO
    * MKCL
    * SBCL
    
    Defaults to MOST-NEGATIVE-DOUBLE-FLOAT on unsupported implementations.

  • EXTERNAL CONSTANT

    DOUBLE-FLOAT-POSITIVE-INFINITY

    Source

    The positive infinity for double-floats.
    
    Supported on:
    * ABCL
    * ALLEGRO
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS
    * MEZZANO
    * MKCL
    * SBCL
    
    Defaults to MOST-POSITIVE-DOUBLE-FLOAT on unsupported implementations.

  • EXTERNAL CONSTANT

    LONG-FLOAT-NEGATIVE-INFINITY

    Source

    The negative infinity for long-floats.
    
    Supported on:
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS
    * MEZZANO
    * MKCL
    * SBCL
    
    Defaults to MOST-NEGATIVE-LONG-FLOAT on unsupported implementations.

  • EXTERNAL CONSTANT

    LONG-FLOAT-POSITIVE-INFINITY

    Source

    The positive infinity for long-floats.
    
    Supported on:
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS
    * MEZZANO
    * MKCL
    * SBCL
    
    Defaults to MOST-POSITIVE-LONG-FLOAT on unsupported implementations.

  • EXTERNAL CONSTANT

    SHORT-FLOAT-NAN

    Source

    A positive quiet NaN value with zero-cleared payload for short-floats.
    This value should NOT be used for comparison with a float value for the pupose of testing NaN
    because NaN has unused bits (called payload) which are explicitly allowed to store additional information.
    Comparing this value with other NaN representations via = will fail.
    To test if a number is a NaN, use FLOAT-NAN-P.
    
    It is supported on implementations which support BITS-SHORT-FLOAT.
    
    Defaults to MOST-POSITIVE-SHORT-FLOAT on unsupported implementations.

  • EXTERNAL CONSTANT

    SHORT-FLOAT-NEGATIVE-INFINITY

    Source

    The negative infinity for short-floats.
    
    Supported on:
    * ALLEGRO
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS
    * MEZZANO
    * MKCL
    * SBCL
    
    Defaults to MOST-NEGATIVE-SHORT-FLOAT on unsupported implementations.

  • EXTERNAL CONSTANT

    SHORT-FLOAT-POSITIVE-INFINITY

    Source

    The positive infinity for short-floats.
    
    Supported on:
    * ALLEGRO
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS
    * MEZZANO
    * MKCL
    * SBCL
    
    Defaults to MOST-POSITIVE-SHORT-FLOAT on unsupported implementations.

  • EXTERNAL CONSTANT

    SINGLE-FLOAT-NAN

    Source

    A positive quiet NaN value with zero-cleared payload for single-floats.
    This value should NOT be used for comparison with a float value for the pupose of testing NaN
    because NaN has unused bits (called payload) which are explicitly allowed to store additional information.
    Comparing this value with other NaN representations via = will fail.
    To test if a number is a NaN, use FLOAT-NAN-P.
    
    It is supported on implementations which support BITS-SINGLE-FLOAT.
    
    Defaults to MOST-POSITIVE-SINGLE-FLOAT on unsupported implementations.

  • EXTERNAL CONSTANT

    SINGLE-FLOAT-NEGATIVE-INFINITY

    Source

    The negative infinity for single-floats.
    
    Supported on:
    * ABCL
    * ALLEGRO
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS
    * MEZZANO
    * MKCL
    * SBCL
    
    Defaults to MOST-NEGATIVE-SINGLE-FLOAT on unsupported implementations.

  • EXTERNAL CONSTANT

    SINGLE-FLOAT-POSITIVE-INFINITY

    Source

    The positive infinity for single-floats.
    
    Supported on:
    * ABCL
    * ALLEGRO
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS
    * MEZZANO
    * MKCL
    * SBCL
    
    Defaults to MOST-POSITIVE-SINGLE-FLOAT on unsupported implementations.

  • EXTERNAL SYMBOL-MACRO

    LONG-FLOAT-NAN

    Source

    A positive quiet NaN value with zero-cleared payload for long-floats.
    This value should NOT be used for comparison with a float value for the pupose of testing NaN
    because NaN has unused bits (called payload) which are explicitly allowed to store additional information.
    Comparing this value with other NaN representations via = will fail.
    To test if a number is a NaN, use FLOAT-NAN-P.
    
    It is supported on implementations which support BITS-LONG-FLOAT.
    
    Defaults to MOST-POSITIVE-LONG-FLOAT on unsupported implementations.

  • EXTERNAL FUNCTION

    BITS-DOUBLE-FLOAT

    • BITS

    Source

    Encodes the (unsigned-byte 64) bit representation into a native double-float.
    
    Supported on:
    * ABCL
    * ALLEGRO
    * CCL
    * CLASP
    * CMUCL
    * LISPWORKS
    * MEZZANO
    * SBCL
    
    Defaults to signalling an error on unsupported implementations.

  • EXTERNAL FUNCTION

    BITS-LONG-FLOAT

    • BITS

    Source

    Encodes the (unsigned-byte 128) bit representation into a native long-float.
    
    Supported on:
    
    Defaults to signalling an error on unsupported implementations.

  • EXTERNAL FUNCTION

    BITS-SHORT-FLOAT

    • BITS

    Source

    Encodes the (unsigned-byte 16) bit representation into a native short-float.
    
    Supported on:
    * MEZZANO
    
    Supported (with 32bit short-float = single-float) on:
    * ALLEGRO
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS (64-bit only. on 32-bit lw, short-float is not 16 or 32 bits)
    * SBCL
    
    Defaults to signalling an error on unsupported implementations.

  • EXTERNAL FUNCTION

    BITS-SINGLE-FLOAT

    • BITS

    Source

    Encodes the (unsigned-byte 32) bit representation into a native single-float.
    
    Supported on:
    * ABCL
    * ALLEGRO
    * CCL
    * CLASP
    * CMUCL
    * LISPWORKS
    * MEZZANO
    * SBCL
    
    Defaults to signalling an error on unsupported implementations.

  • EXTERNAL FUNCTION

    DOUBLE-FLOAT-BITS

    • FLOAT

    Source

    Returns the bit representation of the double-float as an (unsigned-byte 64).
    
    Supported on:
    * ABCL
    * ALLEGRO
    * CCL
    * CLASP
    * CMUCL
    * LISPWORKS
    * MEZZANO
    * SBCL
    
    Defaults to signalling an error on unsupported implementations.

  • EXTERNAL FUNCTION

    FLOAT-INFINITY-P

    • FLOAT

    Source

    Returns T if the given float is an infinity, NIL otherwise.
    
    Supported on:
    * ABCL
    * ALLEGRO
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS
    * MEZZANO
    * SBCL
    
    Defaults to comparing against the individual constants on unsupported
    implementations.

  • EXTERNAL FUNCTION

    FLOAT-NAN-P

    • FLOAT

    Source

    Returns T if the given float is in not-a-number state, NIL otherwise.
    
    Supported on:
    * ABCL
    * ALLEGRO
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS
    * MEZZANO
    * SBCL
    
    Defaults to returning NIL on unsupported implementations.

  • EXTERNAL FUNCTION

    LONG-FLOAT-BITS

    • FLOAT

    Source

    Returns the bit representation of the long-float as an (unsigned-byte 128).
    
    Supported on:
    
    Defaults to signalling an error on unsupported implementations.

  • EXTERNAL FUNCTION

    SHORT-FLOAT-BITS

    • FLOAT

    Source

    Returns the bit representation of the short-float as an (unsigned-byte 16).
    
    Supported on:
    * MEZZANO
    
    Supported (with 32bit short-float = single-float) on:
    * ALLEGRO
    * CCL
    * CMUCL
    * ECL
    * LISPWORKS (64-bit only. on 32-bit lw, short-float is not 16 or 32 bits)
    * SBCL
    
    On platforms with 32-bit short-float, low bits of significand are
    dropped without rounding, and out of range exponents are converted to
    infinities. All values returned by bits-short-float should convert
    back to the same bits.
    
    Defaults to signalling an error on unsupported implementations.

  • EXTERNAL FUNCTION

    SINGLE-FLOAT-BITS

    • FLOAT

    Source

    Returns the bit representation of the single-float as an (unsigned-byte 32).
    
    Supported on:
    * ABCL
    * ALLEGRO
    * CCL
    * CLASP
    * CMUCL
    * LISPWORKS
    * MEZZANO
    * SBCL
    
    Defaults to signalling an error on unsupported implementations.

  • EXTERNAL MACRO

    WITH-FLOAT-TRAPS-MASKED

    • TRAPS
    • &BODY
    • BODY

    Source

    Attempts to mask the given floating point traps.
    
    Masking a floating point trap causes the given floating point exception
    to not signal a condition in the lisp world, and instead lets the
    operation return a float that is either a NaN or an infinity.
    
    The following traps are recognised:
    
      :underflow
      :overflow
      :inexact
      :invalid 
      :divide-by-zero
      :denormalized-operand
    
    The traps argument may be either a list of the above trap identifiers,
    or T to signify all maskable traps.
    
    Note that not all implementations will signal conditions on all of the
    above floating point traps anyway, and some implementations may only
    support masking some of the above traps.
    
    Supported on:
    * ABCL (:overflow :underflow)
    * CCL (:overflow :underflow :inexact :invalid :divide-by-zero)
    * CLISP (:underflow)
    * CMUCL T
    * ECL (:underflow :overflow :inexact :invalid :divide-by-zero)
    * MEZZANO T
    * SBCL T
    
    Defaults to a progn on unsupported implementations and ignores
    unsupported traps.

  • EXTERNAL MACRO

    WITH-ROUNDING-MODE

    • MODE
    • &BODY
    • BODY

    Source

    Temporarily set rounding mode when execute body.
    
    The following modes are recognised:
    
      :nearest Round to nearest, ties to even
      :positive Round toward positive infinity
      :negative Round toward negative infinity
      :zero Round toward zero
    
    Note that many compilers would by default try to fold floating point
    expressions into constants before the rounding mode can take effect.
    It is advisory to check disassembled functions to see if that is the
    case when the result is not expected.
    
    Supported on:
    * CCL
    * CMUCL
    * MEZZANO
    * SBCL
    
    Signals an error on unsupported implementations.