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CPM OPERATING SYSTEMS/CPM 68K/1.0X SOURCES/v101/c/libe/iefpwr.s

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+         ttl       ieee format equivalent power function(iefpwr)
+***************************************
+* (c) copyright 1981 by motorola inc. *
+***************************************
+ 
+*************************************************
+*                  iefpwr                       *
+*   ieee format equivalent  power function      *
+*                                               *
+*  input:   d6 - ieee format exponent value     *
+*           d7 - ieee format argument value     *
+*                                               *
+*  output:  d7 - result of the value taken to   *
+*                the power specified            *
+*                                               *
+*     all registers are transparent             *
+*                                               *
+*    maximum stack used:    52 bytes            *
+*                                               *
+*  condition codes:                             *
+*        z - set if result is zero              *
+*        n - cleared                            *
+*        v - set if result is nan (not-a-number)*
+*            (input argument negative or nan)   *
+*        c - undefined                          *
+*        x - undefined                          *
+*                                               *
+*  notes:                                       *
+*    1) see the mc68344 user's guide for details*
+*       concerning limitations on normalized    *
+*       argument ranges.                        *
+*    2) a negative base value, or zero to a     *
+*       negative power is invalid and returns   *
+*       a nan with the "v" bit set.             *
+*    3) spot checks show at least six digit     *
+*       precision for 80 percent of the cases.  *
+*                                               *
+*************************************************
+         page
+iefpwr   idnt  1,1 ieee format equivalent power function
+ 
+         opt       pcs
+ 
+         section   9
+ 
+         xdef      iefpwr                        entry point
+ 
+         xref      ieflog            ieee log function
+         xref      iefmul            ieee multiply routine
+         xref      iefexp            ieee exponent function
+         xref      ffpcpyrt            copyright stub
+ 
+*****************
+* power  entry  *
+*****************
+iefpwr   bsr       ieflog              find low of base value
+         bsr       iefmul              multiply by the power
+         bra       iefexp              finish with exponent result
+