Function: SB-INT:SET-FLOATING-POINT-MODES

This function sets options controlling the floating-point hardware. If a keyword is not supplied, then the current value is preserved. Possible keywords:

:TRAPS A list of the exception conditions that should cause traps. Possible exceptions are :UNDERFLOW, :OVERFLOW, :INEXACT, :INVALID, :DIVIDE-BY-ZERO, and on the X86 :DENORMALIZED-OPERAND.

:ROUNDING-MODE The rounding mode to use when the result is not exact. Possible values are :NEAREST, :POSITIVE-INFINITY, :NEGATIVE-INFINITY and :ZERO. Setting this away from :NEAREST is liable to upset SBCL’s maths routines which depend on it.

:CURRENT-EXCEPTIONS :ACCRUED-EXCEPTIONS These arguments allow setting of the exception flags. The main use is setting the accrued exceptions to NIL to clear them.

:FAST-MODE Set the hardware’s “fast mode” flag, if any. When set, IEEE conformance or debuggability may be impaired. Some machines don’t have this feature, and some SBCL ports don’t implement it anyway – in such cases the value is always NIL.

:PRECISION (x86 only) :24-bit, :53-bit and :64-bit, for the internal precision of the mantissa.

GET-FLOATING-POINT-MODES may be used to find the floating point modes currently in effect. SAVE-LISP-AND-DIE preserves the floating point modes in effect.

Lambda list

(&key sb-vm::traps sb-vm::rounding-mode sb-vm::current-exceptions sb-vm::accrued-exceptions
 sb-vm::fast-mode)