[gforth] / gforth / float.fs  

gforth: gforth/float.fs

Diff for /gforth/float.fs between version 1.26 and 1.42

version 1.26, Thu May 6 21:33:32 1999 UTC version 1.42, Sun Mar 9 15:16:49 2003 UTC
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 \ High level floating point                            14jan94py  \ High level floating point                            14jan94py
   
 \ Copyright (C) 1995,1997 Free Software Foundation, Inc.  \ Copyright (C) 1995,1997,2003 Free Software Foundation, Inc.
   
 \ This file is part of Gforth.  \ This file is part of Gforth.
   
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 \ 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, write to the Free Software
 \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.  \ Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111, USA.
   
 \ 1 cells 4 = [IF]  \ 1 cells 4 = [IF]
 \ ' cells   Alias sfloats  \ ' cells   Alias sfloats
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     \G enough space to align it.      \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  1 sfloats (Field) sfloat+ , ( sf-addr1 -- sf-addr2 ) \ float-ext s-float-plus
 \G Increment @i{sf-addr1} by the number of address units corresponding to the size of  \G @code{1 sfloats +}.
 \G a single-precision IEEE floating-point number, to give @i{sf-addr2}.""  
 dofield: lastxt code-address! \ change the constant into a field  1 dfloats (Field) dfloat+ , ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus
   \G @code{1 dfloats +}.
 1 dfloats constant dfloat+ ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus  
 \G Increment @i{df-addr1} by the number of address units corresponding to the size of  
 \G a double-precision IEEE floating-point number, to give @i{df-addr2}.""  
 dofield: lastxt code-address! \ change the constant into a field  
   
 : f, ( f -- ) \ gforth  : f, ( f -- ) \ gforth
     \G Reserve data space for one floating-point number and store      \G Reserve data space for one floating-point number and store
     \G @i{f} in the space.      \G @i{f} in the space.
     here 1 floats allot f! ;      here 1 floats allot f! ;
   
 : fconstant  ( r "name" -- ) \ float  : fconstant  ( r "name" -- ) \ float f-constant
     Create f,      Create f,
 DOES> ( -- r )  DOES> ( -- r )
     f@ ;      f@ ;
   
 : fdepth ( -- +n ) \ floating f-depth  : fdepth ( -- +n ) \ float f-depth
     \G @var{+n} is the current number of (floating-point) values on the      \G @i{+n} is the current number of (floating-point) values on the
     \G floating-point stack.      \G floating-point stack.
     fp0 @ fp@ - [ 1 floats ] Literal / ;      fp0 @ fp@ - [ 1 floats ] Literal / ;
   
 : FLit ( -- r )  r> dup f@ float+ >r ;  : FLiteral ( compilation r -- ; run-time -- r ) \ float f-literal
 : FLiteral ( compilation r -- ; run-time -- r ) \ float      \G Compile appropriate code such that, at run-time, @i{r} is placed
     \G Compile appropriate code such that, at run-time, @var{r} is placed  
     \G on the (floating-point) stack. Interpretation semantics are undefined.      \G on the (floating-point) stack. Interpretation semantics are undefined.
     BEGIN  here cell+ dup faligned <>  WHILE  postpone noop  REPEAT      BEGIN  here cell+ cell+ dup faligned <>  WHILE  postpone noop  REPEAT
     postpone FLit  f, ;  immediate      postpone ahead here >r f, postpone then
       r> postpone literal postpone f@ ;  immediate
   
 &15 Value precision ( -- u ) \ floating-ext  &15 Value precision ( -- u ) \ float-ext
 \G @var{u} is the number of significant digits currently used by  \G @i{u} is the number of significant digits currently used by
 \G @code{F.} @code{FE.} and @code{FS.}  \G @code{F.} @code{FE.} and @code{FS.}
 : set-precision ( u -- ) \ floating-ext  : set-precision ( u -- ) \ float-ext
     \G Set the number of significant digits currently used by      \G Set the number of significant digits currently used by
     \G @code{F.} @code{FE.} and @code{FS.} to @var{u}.      \G @code{F.} @code{FE.} and @code{FS.} to @i{u}.
     to precision ;      to precision ;
   
 : scratch ( r -- addr len )  : scratch ( r -- addr len )
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   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 -- ) \ floating-ext f-dot  : f.  ( r -- ) \ float-ext f-dot
 \G Display (the floating-point number) @var{r} using fixed-point notation,  \G Display (the floating-point number) @i{r} without exponent,
 \G followed by a space.  \G followed by a space.
   f$ dup >r 0<    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
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 \ 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 -- ) \ floating-ext f-e-dot  \ Why do you think so? ANS Forth appears ambiguous on this point. -anton.
 \G Display @var{r} using engineering notation, followed by a space.  
   : 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    f$ 1- s>d 3 fm/mod 3 * >r 1+ >r
   scratch r@ min type '. emit  scratch r> /string type    scratch r@ tuck min tuck - >r type r> zeros
     '. emit scratch r> /string type
   'E emit r> . ;    'E emit r> . ;
   
 : fs. ( r -- ) \ floating-ext f-s-dot  : fs. ( r -- ) \ float-ext f-s-dot
 \G Display @var{r} using scientific notation, followed by a space.  \G Display @i{r} using scientific notation (with exponent), followed
   \G by a space.
   f$ 1-    f$ 1-
   scratch over c@ emit '. emit 1 /string type    scratch over c@ emit '. emit 1 /string type
   'E emit . ;    'E emit . ;
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     ENDIF ;      ENDIF ;
 IS interpreter-notfound  IS interpreter-notfound
   
 : fvariable ( "name" -- ) \ float  : 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 ( -- r ) \ gforth  1.0e0 fasin 2.0e0 f* fconstant pi ( -- r ) \ gforth
 \G FCONSTANT: @var{r} is the value pi; the ratio of a circle's area  \G @code{Fconstant} -- @i{r} is the value pi; the ratio of a circle's area
 \G to its diameter.  \G to its diameter.
   
 : f2* ( r1 -- r2 ) \ gforth  : f2* ( r1 -- r2 ) \ gforth
     \G Multiply @var{r1} by 2.0e0      \G Multiply @i{r1} by 2.0e0
     2.0e0 f* ;      2.0e0 f* ;
   
 : f2/ ( r1 -- r2 ) \ gforth  : f2/ ( r1 -- r2 ) \ gforth
     \G Multiply @var{r1} by 0.5e0      \G Multiply @i{r1} by 0.5e0
     0.5e0 f* ;      0.5e0 f* ;
   
 : 1/f ( r1 -- r2 ) \ gforth  : 1/f ( r1 -- r2 ) \ gforth
     \G Divide 1.0e0 by @var{r1}.      \G Divide 1.0e0 by @i{r1}.
     1.0e0 fswap f/ ;      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
   
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 \ : 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< ;  
   
 : f.s ( -- ) \ gforth f-dot-s  : f.s ( -- ) \ gforth f-dot-s
     \G Display the number of items on the floating-point stack,      \G Display the number of items on the floating-point stack,

Generate output suitable for use with a patch program
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