Diff for /gforth/float.fs between versions 1.19 and 1.61

version 1.19, 1996/05/13 16:36:55 version 1.61, 2011/10/07 17:10:15
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 \ High level floating point                            14jan94py  \ High level floating point                            14jan94py
   
 \ Copyright (C) 1995 Free Software Foundation, Inc.  \ Copyright (C) 1995,1997,2003,2004,2005,2006,2007,2009,2010 Free Software Foundation, Inc.
   
 \ This file is part of Gforth.  \ This file is part of Gforth.
   
 \ Gforth is free software; you can redistribute it and/or  \ Gforth is free software; you can redistribute it and/or
 \ modify it under the terms of the GNU General Public License  \ modify it under the terms of the GNU General Public License
 \ as published by the Free Software Foundation; either version 2  \ as published by the Free Software Foundation, either version 3
 \ of the License, or (at your option) any later version.  \ of the License, or (at your option) any later version.
   
 \ This program is distributed in the hope that it will be useful,  \ This program is distributed in the hope that it will be useful,
Line 15 Line 15
 \ GNU General Public License for more details.  \ GNU General Public License for more details.
   
 \ You should have received a copy of the GNU General Public License  \ You should have received a copy of the GNU General Public License
 \ along with this program; if not, write to the Free Software  \ along with this program. If not, see http://www.gnu.org/licenses/.
 \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  
   
 \ 1 cells 4 = [IF]  \ 1 cells 4 = [IF]
 \ ' cells   Alias sfloats  \ ' cells   Alias sfloats
Line 43 Line 42
 \ [THEN]  \ [THEN]
   
 : sfalign ( -- ) \ float-ext s-f-align  : sfalign ( -- ) \ float-ext s-f-align
       \G If the data-space pointer is not single-float-aligned, reserve
       \G enough space to align it.
     here dup sfaligned swap ?DO  bl c,  LOOP ;      here dup sfaligned swap ?DO  bl c,  LOOP ;
 : dfalign ( -- ) \ float-ext d-f-align  : dfalign ( -- ) \ float-ext d-f-align
       \G If the data-space pointer is not double-float-aligned, reserve
       \G enough space to align it.
     here dup dfaligned swap ?DO  bl c,  LOOP ;      here dup dfaligned swap ?DO  bl c,  LOOP ;
   
 1 sfloats constant sfloat+ ( sf-addr1 -- sf-addr2 ) \ float-ext s-float-plus  (Field) sfloat+ ( sf-addr1 -- sf-addr2 ) \ float-ext s-float-plus
 dofield: lastxt code-address! \ change the constant into a field  \G @code{1 sfloats +}.
       1 sfloats ,
   
   (Field) dfloat+ ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus
   \G @code{1 dfloats +}.
       1 dfloats ,
       
   : f, ( f -- ) \ gforth
       \G Reserve data space for one floating-point number and store
       \G @i{f} in the space.
       here 1 floats allot f! ;
   
 1 dfloats constant dfloat+ ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus  : fconstant  ( r "name" -- ) \ float f-constant
 dofield: lastxt code-address! \ change the constant into a field  
   
 : f, ( f -- )  here 1 floats allot f! ;  
   
 : fconstant  ( r -- ) \ float  
     Create f,      Create f,
 DOES> ( -- r )  DOES> ( -- r )
     f@ ;      f@ ;
   
 : fdepth  ( -- n )  f0 @ fp@ - [ 1 floats ] Literal / ;  : fdepth ( -- +n ) \ float f-depth
       \G @i{+n} is the current number of (floating-point) values on the
 : FLit ( -- r )  r> dup f@ float+ >r ;      \G floating-point stack.
 : FLiteral ( r -- )      fp0 @ fp@ - [ 1 floats ] Literal / ;
   BEGIN  here cell+ dup faligned <>  WHILE  postpone noop  REPEAT  
   postpone FLit  f, ;  immediate  : FLiteral ( compilation r -- ; run-time -- r ) \ float f-literal
       \G Compile appropriate code such that, at run-time, @i{r} is placed
 &15 Value precision      \G on the (floating-point) stack. Interpretation semantics are undefined.
 : set-precision  to precision ;      BEGIN  here cell+ cell+ dup faligned <>  WHILE  postpone noop  REPEAT
       postpone ahead here >r f, postpone then
       r> postpone literal postpone f@ ;  immediate
   
   &15 Value precision ( -- u ) \ float-ext
   \G @i{u} is the number of significant digits currently used by
   \G @code{F.} @code{FE.} and @code{FS.} 
   : set-precision ( u -- ) \ float-ext
       \G Set the number of significant digits currently used by
       \G @code{F.} @code{FE.} and @code{FS.} to @i{u}.
       to precision ;
   
 : scratch ( r -- addr len )  : scratch ( r -- addr len )
   pad precision - precision ;    pad precision - precision ;
Line 82  DOES> ( -- r ) Line 100  DOES> ( -- r )
   IF  2drop  scratch 3 min type  rdrop  EXIT  THEN    IF  2drop  scratch 3 min type  rdrop  EXIT  THEN
   IF  '- emit  THEN ;    IF  '- emit  THEN ;
   
 : f.  ( r -- )  f$ dup >r 0<  : f.  ( r -- ) \ float-ext f-dot
   \G Display (the floating-point number) @i{r} without exponent,
   \G followed by a space.
     f$ dup >r 0<=
   IF    '0 emit    IF    '0 emit
   ELSE  scratch r@ min type  r@ precision - zeros  THEN    ELSE  scratch r@ min type  r@ precision - zeros  THEN
   '. emit r@ negate zeros    '. emit r@ negate zeros
Line 90  DOES> ( -- r ) Line 111  DOES> ( -- r )
 \ I'm afraid this does not really implement ansi semantics wrt precision.  \ I'm afraid this does not really implement ansi semantics wrt precision.
 \ Shouldn't precision indicate the number of places shown after the point?  \ Shouldn't precision indicate the number of places shown after the point?
   
 : fe. ( r -- )  f$ 1- s>d 3 fm/mod 3 * >r 1+ >r  \ Why do you think so? ANS Forth appears ambiguous on this point. -anton.
   scratch r@ min type '. emit  scratch r> /string type  
   : fe. ( r -- ) \ float-ext f-e-dot
   \G Display @i{r} using engineering notation (with exponent dividable
   \G by 3), followed by a space.
     f$ 1- s>d 3 fm/mod 3 * >r 1+ >r
     scratch r@ tuck min tuck - >r type r> zeros
     '. emit scratch r> /string type
   'E emit r> . ;    'E emit r> . ;
   
 : fs. ( r -- )  f$ 1-  : fs. ( r -- ) \ float-ext f-s-dot
   \G Display @i{r} using scientific notation (with exponent), followed
   \G by a space.
     f$ 1-
   scratch over c@ emit '. emit 1 /string type    scratch over c@ emit '. emit 1 /string type
   'E emit . ;    'E emit . ;
   
 require debugging.fs  
   
 : sfnumber ( c-addr u -- r true | false )  : sfnumber ( c-addr u -- r true | false )
     2dup [CHAR] e scan ( c-addr u c-addr2 u2 )      2dup [CHAR] e scan ( c-addr u c-addr2 u2 )
     dup 0=      dup 0=
Line 113  require debugging.fs Line 141  require debugging.fs
         2drop false          2drop false
     THEN ;      THEN ;
   
 :noname ( c-addr u -- )  [ifdef] recognizer:
       ' noop
       :noname postpone Fliteral ;
       dup
       recognizer: r:fnumber
   
       : fnum-recognizer ( addr u -- float int-table | addr u r:fail )
           2dup sfnumber
           IF
               2drop r:fnumber  EXIT
           THEN
           r:fail ;
   
   ' fnum-recognizer
   forth-recognizer get-recognizers
   1+ forth-recognizer set-recognizers
   [else]
   [ifundef] compiler-notfound1
   defer compiler-notfound1
   ' no.extensions IS compiler-notfound1
   
   :noname compiler-notfound1 execute ; is compiler-notfound
   
   defer interpreter-notfound1
   ' no.extensions IS interpreter-notfound1
   
   :noname interpreter-notfound1 execute ; is interpreter-notfound
   [then]
   
   :noname ( c-addr u -- ... xt )
     2dup sfnumber      2dup sfnumber
     IF      IF
         2drop POSTPONE FLiteral          2drop [comp'] FLiteral
     ELSE      ELSE
         defers compiler-notfound          defers compiler-notfound1
     ENDIF ;      ENDIF ;
 IS compiler-notfound  IS compiler-notfound1
   
 :noname ( c-addr u -- r )  :noname ( c-addr u -- ... xt )
     2dup sfnumber      2dup sfnumber
     IF      IF
         2drop          2drop ['] noop
     ELSE      ELSE
         defers interpreter-notfound          defers interpreter-notfound1
     ENDIF ;      ENDIF ;
 IS interpreter-notfound  IS interpreter-notfound1
   [then]
   
 : fvariable ( -- )  : fvariable ( "name" -- ) \ float f-variable
     Create 0.0E0 f, ;      Create 0.0E0 f, ;
     \ does> ( -- f-addr )      \ does> ( -- f-addr )
   
 1.0e0 fasin 2.0e0 f* fconstant pi  1.0e0 fasin 2.0e0 f* fconstant pi ( -- r ) \ gforth
   \G @code{Fconstant} -- @i{r} is the value pi; the ratio of a circle's area
 : f2*  2.0e0 f* ;  \G to its diameter.
 : f2/  0.5e0 f* ;  
 : 1/f  1.0e0 fswap f/ ;  : f2* ( r1 -- r2 ) \ gforth
       \G Multiply @i{r1} by 2.0e0
       2.0e0 f* ;
   
   : f2/ ( r1 -- r2 ) \ gforth
       \G Multiply @i{r1} by 0.5e0
       0.5e0 f* ;
   
   : 1/f ( r1 -- r2 ) \ gforth
       \G Divide 1.0e0 by @i{r1}.
       1.0e0 fswap f/ ;
   
   get-current environment-wordlist set-current
   1.7976931348623157e308 FConstant max-float
   set-current
   
 \ We now have primitives for these, so we need not define them  \ We now have primitives for these, so we need not define them
   
Line 155  IS interpreter-notfound Line 226  IS interpreter-notfound
 \ : facosh   fdup fdup f* 1.0e0 f- fsqrt f+ fln ;  \ : facosh   fdup fdup f* 1.0e0 f- fsqrt f+ fln ;
 \ : fasinh   fdup fdup f* 1.0e0 f+ fsqrt f/ fatanh ;  \ : fasinh   fdup fdup f* 1.0e0 f+ fsqrt f/ fatanh ;
   
 \ !! factor out parts  : f~abs ( r1 r2 r3 -- flag ) \ gforth
 : f~ ( f1 f2 f3 -- flag ) \ float-ext      \G Approximate equality with absolute error: |r1-r2|<r3.
       frot frot f- fabs fswap f< ;
   
   : f~rel ( r1 r2 r3 -- flag ) \ gforth
       \G Approximate equality with relative error: |r1-r2|<r3*|r1+r2|.
           frot frot fover fabs fover fabs f+ frot frot
           f- fabs frot frot f* f< ;
   
   : f~ ( r1 r2 r3 -- flag ) \ float-ext f-proximate
       \G ANS Forth medley for comparing r1 and r2 for equality: r3>0:
       \G @code{f~abs}; r3=0: bitwise comparison; r3<0: @code{fnegate f~rel}.
     fdup f0=      fdup f0=
     IF      IF \ bitwise comparison
         fdrop f= EXIT          fp@ float+ 1 floats over float+ over str=
           fdrop fdrop fdrop
           EXIT
     THEN      THEN
     fdup f0>      fdup f0>
     IF      IF
         frot frot f- fabs fswap          f~abs
     ELSE      ELSE
         fnegate frot frot fover fabs fover fabs f+ frot frot          fnegate f~rel
         f- fabs frot frot f*      THEN ;
     THEN  
     f< ;  -0e 8 0 [do] fp@ [i] + c@ $80 = [if] [i] constant fsign-offset [then] [loop]
   
   : fcopysign ( r1 r2 -- r3 ) \ gforth
   \G r3 takes its absolute value from r1 and its sign from r2
       \ !! implementation relies on IEEE DP format
       fp@ fsign-offset + dup c@ $80 and >r ( r1 r2 addr-r1sign )
       float+ dup c@ $7f and r> or swap c!
       fdrop ;
   
   \ proposals from Krishna Myeni in <cjsp2d$47l$1@ngspool-d02.news.aol.com>
   \ not sure if they are a good idea
   
   : ftrunc ( r1 -- r2 ) \ X:ftrunc
       \ round towards 0
       fdup fabs floor fswap fcopysign ;
   
   : FMOD ( r1 r2 -- r )
       \ remainder of r1/r2
       FOVER FOVER F/ ftrunc F* F- ;
   
 : f.s  ." <" fdepth 0 .r ." > " fdepth 0 max maxdepth-.s @ min dup 0   
   ?DO  dup i - 1- floats fp@ + f@ f.  LOOP  drop ;   

Removed from v.1.19  
changed lines
  Added in v.1.61


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