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CPM OPERATING SYSTEMS/CPM 68K/1.2 SOURCE/8/IEFFPI.S

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+        ttl       ieee format equivalent float to integer (ieffpi)
+**************************************
+* (c) copyright 1981 by motorla inc. *
+**************************************
+ 
+***********************************************************
+*    ieffpi - ieee format equivalent float to integer     *
+*                                                         *
+*      input:  d7 = ieee format number                    *
+*      output: d7 = fixed point longword integer          *
+*                            (2's complement)             *
+*                                                         *
+*  condition codes:                                       *
+*             n - set if result is negative               *
+*             z - set if result is zero                   *
+*             v - set if result overflowed integer        *
+*                 representation or input was a nan       *
+*                 (not-a-number)                          *
+*             c - undefined                               *
+*             x - undefined                               *
+*                                                         *
+*     registers are transparent over this routine         *
+*                                                         *
+*              stack used:    54 bytes                    *
+*                                                         *
+*  the range provided with 2's complement longword binary *
+*  is:   -2,147,483,649 < value < +2,147,483,648          *
+*                                                         *
+*  notes:                                                 *
+*   1) since ieee single precision format holds 24 bits   *
+*      of precision which is less than the 31 bits of     *
+*      longword binary integer arithmetic, results of     *
+*      over 24 bit integer magnitude will be imprecise    *
+*      and have low-end zeroes.                           *
+*   2) if the input argument is too large to be contained *
+*      in the longword fixed point binary format, the     *
+*      largest possible magnitude value is returned with  *
+*      the "v" bit set in the condition code register.    *
+*   3) if a nan (not-a-number) is the input argument,     *
+*      it will be returned as is with the "v" bit set.    *
+*   4) since the "v" bit is set for two possible          *
+*      conditions (overflow or nan) they can be separated *
+*      by testing the significand (bits 0 thru 22).  if   *
+*      these bits are all ones, then the value probably   *
+*      was an overflow.  any other pattern indicates the  *
+*      input argument was nan.                            *
+*                                                         *
+***********************************************************
+         page
+         xdef      ieffpi    entry point
+ 
+        xref      ffpfpi    fast floating point float to integer
+        xref      ffpfieee  ffp conversion of ieee to ffp format
+        xref      iefsop    ieee single operand convert internal routine
+        xref      ffpcpyrt  copyright notice
+ 
+ieffpi  idnt      1,1  ieee format equivalent float to integer
+ 
+        section    9
+ 
+*************************
+* ieee float to integer *
+*************************
+ieffpi   bsr       iefsop    convert to fast floating point or reject nan
+         bra.s     iefnrm    +0 normalized value, denormalized value or zero
+*                                       +2 argument infinity
+ 
+* infinity - convert to ffp format's largest magnitude
+         bsr       ffpfieee  ffp's conversion will force to highest possible
+ 
+* normalized value, denormalized or zero
+iefnrm   bsr       ffpfpi    convert from fast floating point to integer
+         movem.l   (sp)+,d3-d6 reload callers registers
+         add.l     #4,sp     skip original argument
+         rts                 return to caller with integer in d7 and ccr set
+ 
+         end
+,sp     skip original argument
+         rts                 return to caller with integer in d7 and ccr set
+ 
+        end
+,sp     skip original argument
+         rts                 return to caller with integer in d7 and ccr set
+ 
+        end
+,sp     skip original argument
+         rts                 return to caller with integer in d7 and ccr set
+ 
+        end
+,sp     skip original argument
+         rts                 return to caller with integer in d7 and ccr set
+ 
+