Compiler Option: -fpmode

Selects faster, less accurate or slower, more precise floating-point math.

Syntax
   -fpmode < mode >

Parameters
   mode
      The floating point mode: FAST | PRECISE.

Description
   The -fpmode compiler option specifies whether speed or precision is more 
   important for floating point math. If this option is not specified, the 
   default is -fpmode PRECISE.

   -fpmode FAST will generate faster, less accurate instructions for 
   certain floating point operations.

   -fpmode PRECISE will generate standard floating point instructions that 
   operate at the default speed and accuracy of the selected floating point 
   unit.

   Currently, the only floating point operations that behave differently 
   when using -fpmode FAST are: Sin(), Cos(), reciprocal, and reciprocal 
   Square Root, all of which must operate on Single precision values.

   A number of changes were made to normalize handling of NaN's (Not a 
   Number) to get consistent results across toolchains and platforms, but 
   that costs extra code, so intention was that -fpmode FAST could allow 
   user to skip that extra code generation if they wanted (and they assume 
   responsibility how things work or do not work across platforms).

   Note:
      - for x86 and x86_64, default is -fpu x87 -fpmode PRECISE
      - -fpmode FAST|PRECISE controls code generation by fbc only
      - for optimizing with '-gen gcc' backend, use '-Wc -ffast-math'

Version
   * Before fbc-1.20.0, an error message would be displayed if -fpmode 
     FAST was with anything but -fpu SSE.

See also
   * Using the Command Line
   * Compiler Option: -fpu
   * __FB_FPMODE__

