| \ High level floating point 14jan94py |
\ High level floating point 14jan94py |
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| : f, ( f -- ) here 1 floats allot f! ; |
\ Copyright (C) 1995,1997,2003,2004,2005,2006,2007,2009 Free Software Foundation, Inc. |
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| \ !! have create produce faligned pfas |
\ This file is part of Gforth. |
| : fconstant ( r -- ) |
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| falign here f, Create A, |
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| DOES> @ f@ ; |
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| : fvariable |
\ Gforth is free software; you can redistribute it and/or |
| falign here 0. d>f f, AConstant ; |
\ modify it under the terms of the GNU General Public License |
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\ as published by the Free Software Foundation, either version 3 |
| : fdepth ( -- n ) f0 @ fp@ - [ 1 floats ] Literal / ; |
\ of the License, or (at your option) any later version. |
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| : FLit ( -- r ) r> faligned dup f@ float+ >r ; |
\ This program is distributed in the hope that it will be useful, |
| : FLiteral ( r -- ) postpone FLit falign f, ; immediate |
\ but WITHOUT ANY WARRANTY; without even the implied warranty of |
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\ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| &16 Value precision |
\ GNU General Public License for more details. |
| : set-precision to precision ; |
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\ You should have received a copy of the GNU General Public License |
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\ along with this program. If not, see http://www.gnu.org/licenses/. |
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\ 1 cells 4 = [IF] |
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\ ' cells Alias sfloats |
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\ ' cell+ Alias sfloat+ |
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\ ' align Alias sfalign |
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\ ' aligned Alias sfaligned |
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\ [ELSE] |
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\ : sfloats 2* 2* ; |
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\ : sfloat+ 4 + ; |
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\ : sfaligned ( addr -- addr' ) 3 + -4 and ; |
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\ : sfalign ( -- ) here dup sfaligned swap ?DO bl c, LOOP ; |
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\ [THEN] |
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\ 1 floats 8 = [IF] |
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\ ' floats Alias dfloats |
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\ ' float+ Alias dfloat+ |
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\ ' falign Alias dfalign |
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\ ' faligned Alias dfaligned |
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\ [ELSE] |
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\ : dfloats 2* 2* 2* ; |
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\ : dfloat+ 8 + ; |
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\ : dfaligned ( addr -- addr' ) 7 + -8 and ; |
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\ : dfalign ( -- ) here dup dfaligned swap ?DO bl c, LOOP ; |
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\ [THEN] |
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: sfalign ( -- ) \ float-ext s-f-align |
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\G If the data-space pointer is not single-float-aligned, reserve |
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\G enough space to align it. |
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here dup sfaligned swap ?DO bl c, LOOP ; |
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: dfalign ( -- ) \ float-ext d-f-align |
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\G If the data-space pointer is not double-float-aligned, reserve |
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\G enough space to align it. |
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here dup dfaligned swap ?DO bl c, LOOP ; |
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(Field) sfloat+ ( sf-addr1 -- sf-addr2 ) \ float-ext s-float-plus |
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\G @code{1 sfloats +}. |
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1 sfloats , |
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(Field) dfloat+ ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus |
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\G @code{1 dfloats +}. |
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1 dfloats , |
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: f, ( f -- ) \ gforth |
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\G Reserve data space for one floating-point number and store |
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\G @i{f} in the space. |
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here 1 floats allot f! ; |
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: fconstant ( r "name" -- ) \ float f-constant |
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Create f, |
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DOES> ( -- r ) |
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f@ ; |
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: fdepth ( -- +n ) \ float f-depth |
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\G @i{+n} is the current number of (floating-point) values on the |
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\G floating-point stack. |
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fp0 @ fp@ - [ 1 floats ] Literal / ; |
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: FLiteral ( compilation r -- ; run-time -- r ) \ float f-literal |
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\G Compile appropriate code such that, at run-time, @i{r} is placed |
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\G on the (floating-point) stack. Interpretation semantics are undefined. |
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BEGIN here cell+ cell+ dup faligned <> WHILE postpone noop REPEAT |
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postpone ahead here >r f, postpone then |
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r> postpone literal postpone f@ ; immediate |
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&15 Value precision ( -- u ) \ float-ext |
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\G @i{u} is the number of significant digits currently used by |
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\G @code{F.} @code{FE.} and @code{FS.} |
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: set-precision ( u -- ) \ float-ext |
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\G Set the number of significant digits currently used by |
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\G @code{F.} @code{FE.} and @code{FS.} to @i{u}. |
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to precision ; |
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| : scratch ( r -- addr len ) |
: scratch ( r -- addr len ) |
| pad precision - precision ; |
pad precision - precision ; |
| IF 2drop scratch 3 min type rdrop EXIT THEN |
IF 2drop scratch 3 min type rdrop EXIT THEN |
| IF '- emit THEN ; |
IF '- emit THEN ; |
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| : f. ( r -- ) f$ dup >r 0< |
: f. ( r -- ) \ float-ext f-dot |
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\G Display (the floating-point number) @i{r} without exponent, |
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\G followed by a space. |
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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 |
| \ 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? |
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| : 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 |
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: fe. ( r -- ) \ float-ext f-e-dot |
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\G Display @i{r} using engineering notation (with exponent dividable |
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\G by 3), followed by a space. |
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f$ 1- s>d 3 fm/mod 3 * >r 1+ >r |
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scratch r@ tuck min tuck - >r type r> zeros |
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'. emit scratch r> /string type |
| 'E emit r> . ; |
'E emit r> . ; |
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| : fs. ( r -- ) f$ 1- |
: fs. ( r -- ) \ float-ext f-s-dot |
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\G Display @i{r} using scientific notation (with exponent), followed |
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\G by a space. |
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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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| : fnumber ( string -- r / ) |
: sfnumber ( c-addr u -- r true | false ) |
| ?dup IF dup count >float 0= |
2dup [CHAR] e scan ( c-addr u c-addr2 u2 ) |
| IF defers notfound |
dup 0= |
| ELSE drop state @ |
IF |
| IF postpone FLiteral THEN THEN THEN ; |
2drop 2dup [CHAR] E scan ( c-addr u c-addr3 u3 ) |
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THEN |
| ' fnumber IS notfound |
nip |
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IF |
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>float |
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ELSE |
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2drop false |
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THEN ; |
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[ifundef] compiler-notfound1 |
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defer compiler-notfound1 |
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' no.extensions IS compiler-notfound1 |
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:noname compiler-notfound1 execute ; is compiler-notfound |
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defer interpreter-notfound1 |
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' no.extensions IS interpreter-notfound1 |
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:noname interpreter-notfound1 execute ; is interpreter-notfound |
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[then] |
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:noname ( c-addr u -- ... xt ) |
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2dup sfnumber |
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IF |
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2drop [comp'] FLiteral |
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ELSE |
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defers compiler-notfound1 |
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ENDIF ; |
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IS compiler-notfound1 |
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:noname ( c-addr u -- ... xt ) |
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2dup sfnumber |
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IF |
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2drop ['] noop |
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ELSE |
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defers interpreter-notfound1 |
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ENDIF ; |
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IS interpreter-notfound1 |
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: fvariable ( "name" -- ) \ float f-variable |
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Create 0.0E0 f, ; |
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\ does> ( -- f-addr ) |
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1.0e0 fasin 2.0e0 f* fconstant pi ( -- r ) \ gforth |
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\G @code{Fconstant} -- @i{r} is the value pi; the ratio of a circle's area |
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\G to its diameter. |
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: f2* ( r1 -- r2 ) \ gforth |
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\G Multiply @i{r1} by 2.0e0 |
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2.0e0 f* ; |
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: f2/ ( r1 -- r2 ) \ gforth |
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\G Multiply @i{r1} by 0.5e0 |
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0.5e0 f* ; |
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: 1/f ( r1 -- r2 ) \ gforth |
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\G Divide 1.0e0 by @i{r1}. |
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1.0e0 fswap f/ ; |
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get-current environment-wordlist set-current |
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1.7976931348623157e308 FConstant max-float |
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set-current |
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\ We now have primitives for these, so we need not define them |
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\ : falog ( f -- 10^f ) [ 10.0e0 fln ] FLiteral f* fexp ; |
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\ : fsinh fexpm1 fdup fdup 1.0e0 f+ f/ f+ f2/ ; |
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\ : fcosh fexp fdup 1/f f+ f2/ ; |
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\ : ftanh f2* fexpm1 fdup 2.0e0 f+ f/ ; |
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\ : fatanh fdup f0< >r fabs 1.0e0 fover f- f/ f2* flnp1 f2/ |
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\ r> IF fnegate THEN ; |
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\ : facosh fdup fdup f* 1.0e0 f- fsqrt f+ fln ; |
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\ : fasinh fdup fdup f* 1.0e0 f+ fsqrt f/ fatanh ; |
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: f~abs ( r1 r2 r3 -- flag ) \ gforth |
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\G Approximate equality with absolute error: |r1-r2|<r3. |
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frot frot f- fabs fswap f< ; |
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: f~rel ( r1 r2 r3 -- flag ) \ gforth |
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\G Approximate equality with relative error: |r1-r2|<r3*|r1+r2|. |
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frot frot fover fabs fover fabs f+ frot frot |
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f- fabs frot frot f* f< ; |
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: f~ ( r1 r2 r3 -- flag ) \ float-ext f-proximate |
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\G ANS Forth medley for comparing r1 and r2 for equality: r3>0: |
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\G @code{f~abs}; r3=0: bitwise comparison; r3<0: @code{fnegate f~rel}. |
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fdup f0= |
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IF \ bitwise comparison |
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fp@ float+ 1 floats over float+ over str= |
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fdrop fdrop fdrop |
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EXIT |
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THEN |
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fdup f0> |
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IF |
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f~abs |
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ELSE |
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fnegate f~rel |
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THEN ; |
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-0e fp@ c@ $80 = [if] 0 [else] 7 [endif] constant fsign-offset |
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: fcopysign ( r1 r2 -- r3 ) \ gforth |
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\G r3 takes its absolute value from r1 and its sign from r2 |
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\ !! implementation relies on IEEE DP format |
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fp@ fsign-offset + dup c@ $80 and >r ( r1 r2 addr-r1sign ) |
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float+ dup c@ $7f and r> or swap c! |
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fdrop ; |
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\ proposals from Krishna Myeni in <cjsp2d$47l$1@ngspool-d02.news.aol.com> |
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\ not sure if they are a good idea |
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: ftrunc ( r1 -- r2 ) \ X:ftrunc |
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\ round towards 0 |
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fdup fabs floor fswap fcopysign ; |
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: FMOD ( r1 r2 -- r ) |
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\ remainder of r1/r2 |
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FOVER FOVER F/ ftrunc F* F- ; |
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| 1e0 fasin 2e0 f* fconstant pi |
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