Diff for /gforth/float.fs between versions 1.1 and 1.44

version 1.1, 1994/02/11 16:30:46 version 1.44, 2004/12/08 11:05:08
Line 1 Line 1
 \ High level floating point                            14jan94py  \ High level floating point                            14jan94py
   
 : faligned ( addr -- f-addr )  \ Copyright (C) 1995,1997,2003 Free Software Foundation, Inc.
   [ 1 floats 1- ] Literal + [ -1 floats ] Literal and ;  
   
 : falign ( -- )  here dup aligned swap  \ This file is part of Gforth.
   ?DO  bl c,  LOOP ;  
   
 : f, ( f -- )  here 1 floats allot f! ;  \ Gforth is free software; you can redistribute it and/or
   \ modify it under the terms of the GNU General Public License
 : fconstant  ( r -- )  \ as published by the Free Software Foundation; either version 2
   Create falign f,  \ of the License, or (at your option) any later version.
   DOES>  faligned f@ ;  
   \ This program is distributed in the hope that it will be useful,
 : fvariable  \ but WITHOUT ANY WARRANTY; without even the implied warranty of
   Create falign 0 f,  \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   DOES>  faligned ;  \ GNU General Public License for more details.
   
 : fdepth  ( -- n )  f0 @ fp@ - [ 1 floats ] Literal / ;  \ You should have received a copy of the GNU General Public License
   \ along with this program; if not, write to the Free Software
 : FLit ( -- r )  r> faligned dup f@ float+ >r ;  \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
 : FLiteral ( r -- )  postpone FLit  falign f, ;  immediate  
   \ 1 cells 4 = [IF]
 &16 Value precision  \ ' cells   Alias sfloats
 : set-precision  to precision ;  \ ' cell+   Alias sfloat+
   \ ' align   Alias sfalign
   \ ' aligned Alias sfaligned
   \ [ELSE]
   \ : sfloats  2* 2* ;
   \ : sfloat+  4 + ;
   \ : sfaligned ( addr -- addr' )  3 + -4 and ;
   \ : sfalign ( -- )  here dup sfaligned swap ?DO  bl c,  LOOP ;
   \ [THEN]
   
   \ 1 floats 8 = [IF]
   \ ' floats   Alias dfloats
   \ ' float+   Alias dfloat+
   \ ' falign   Alias dfalign
   \ ' faligned Alias dfaligned
   \ [ELSE]
   \ : dfloats  2* 2* 2* ;
   \ : dfloat+  8 + ;
   \ : dfaligned ( addr -- addr' )  7 + -8 and ;
   \ : dfalign ( -- )  here dup dfaligned swap ?DO  bl c,  LOOP ;
   \ [THEN]
   
   : 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 ;
   : 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 ;
   
   1 sfloats (Field) sfloat+ , ( sf-addr1 -- sf-addr2 ) \ float-ext s-float-plus
   \G @code{1 sfloats +}.
   
   1 dfloats (Field) dfloat+ , ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus
   \G @code{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! ;
   
   : fconstant  ( r "name" -- ) \ float f-constant
       Create f,
   DOES> ( -- r )
       f@ ;
   
   : fdepth ( -- +n ) \ float f-depth
       \G @i{+n} is the current number of (floating-point) values on the
       \G floating-point stack.
       fp0 @ fp@ - [ 1 floats ] Literal / ;
   
   : FLiteral ( compilation r -- ; run-time -- r ) \ float f-literal
       \G Compile appropriate code such that, at run-time, @i{r} is placed
       \G on the (floating-point) stack. Interpretation semantics are undefined.
       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 32 Line 95
 : -zeros ( addr u -- addr' u' )  : -zeros ( addr u -- addr' u' )
   BEGIN  dup  WHILE  1- 2dup + c@ '0 <>  UNTIL  1+  THEN ;    BEGIN  dup  WHILE  1- 2dup + c@ '0 <>  UNTIL  1+  THEN ;
   
 : f.  ( r -- )  scratch represent 0=  : f$ ( f -- n )  scratch represent 0=
   IF  2drop  scratch 3 min type  EXIT  THEN    IF  2drop  scratch 3 min type  rdrop  EXIT  THEN
   IF  '- emit  THEN  dup >r 0<    IF  '- emit  THEN ;
   IF  '0 emit  
   : 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
   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
   scratch r> 0 max /string 0 max -zeros type space ;    scratch r> 0 max /string 0 max -zeros type space ;
   \ I'm afraid this does not really implement ansi semantics wrt precision.
   \ Shouldn't precision indicate the number of places shown after the point?
   
 : fe. ( r -- )  scratch represent 0=  \ Why do you think so? ANS Forth appears ambiguous on this point. -anton.
   IF  2drop  scratch 3 min type  EXIT  THEN  
   IF  '- emit  THEN  1- s>d 3 fm/mod 3 * >r 1+ >r  
   scratch r@ min type '. emit  scratch r> /string type  
   'E emit r> . ;  
   
 : fs. ( r -- )  scratch represent 0=  : fe. ( r -- ) \ float-ext f-e-dot
   IF  2drop  scratch 3 min type  EXIT  THEN  \G Display @i{r} using engineering notation (with exponent dividable
   IF  '- emit  THEN  1- >r  \G by 3), followed by a space.
   scratch 1 min type '. emit  scratch 1 /string type    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> . ;
   
 : fnumber ( string -- r / )  dup count >float 0=  : fs. ( r -- ) \ float-ext f-s-dot
   IF  defers notfound  ELSE  drop  THEN ;  \G Display @i{r} using scientific notation (with exponent), followed
   \G by a space.
 ' fnumber IS notfound    f$ 1-
     scratch over c@ emit '. emit 1 /string type
 1e0 fasin 2e0 f* fconstant pi    'E emit . ;
   
   require debugs.fs
   
   : sfnumber ( c-addr u -- r true | false )
       2dup [CHAR] e scan ( c-addr u c-addr2 u2 )
       dup 0=
       IF
           2drop 2dup [CHAR] E scan ( c-addr u c-addr3 u3 )
       THEN
       nip
       IF
           >float
       ELSE
           2drop false
       THEN ;
   
   :noname ( c-addr u -- )
       2dup sfnumber
       IF
           2drop POSTPONE FLiteral
       ELSE
           defers compiler-notfound
       ENDIF ;
   IS compiler-notfound
   
   :noname ( c-addr u -- r )
       2dup sfnumber
       IF
           2drop
       ELSE
           defers interpreter-notfound
       ENDIF ;
   IS interpreter-notfound
   
   : fvariable ( "name" -- ) \ float f-variable
       Create 0.0E0 f, ;
       \ does> ( -- f-addr )
   
   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
   \G to its diameter.
   
   : 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
   
   \ : falog ( f -- 10^f )  [ 10.0e0 fln ] FLiteral f* fexp ;
   
   \ : fsinh    fexpm1 fdup fdup 1.0e0 f+ f/ f+ f2/ ;
   \ : fcosh    fexp fdup 1/f f+ f2/ ;
   \ : ftanh    f2* fexpm1 fdup 2.0e0 f+ f/ ;
   
   \ : fatanh   fdup f0< >r fabs 1.0e0 fover f- f/  f2* flnp1 f2/
   \            r> IF  fnegate  THEN ;
   \ : facosh   fdup fdup f* 1.0e0 f- fsqrt f+ fln ;
   \ : fasinh   fdup fdup f* 1.0e0 f+ fsqrt f/ fatanh ;
   
   : f~abs ( r1 r2 r3 -- flag ) \ gforth
       \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=
       IF \ bitwise comparison
           fp@ float+ 1 floats over float+ over str=
           fdrop fdrop fdrop
           EXIT
       THEN
       fdup f0>
       IF
           f~abs
       ELSE
           fnegate f~rel
       THEN ;
   
   \ proposals from Krishna Myeni in <cjsp2d$47l$1@ngspool-d02.news.aol.com>
   \ not sure if they are a good idea
   
   : FTRUNC ( r1 -- r2 )
       \ round towards 0
       \ !! should be implemented properly
       F>D D>F ;
   
   : FMOD ( r1 r2 -- r )
       \ remainder of r1/r2
       \ !! should be implemented properly
       FOVER FOVER F/ ftrunc F* F- ;

Removed from v.1.1  
changed lines
  Added in v.1.44


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