version 1.21, 1997/05/21 20:39:25
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version 1.38, 2002/11/02 15:26:03
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\ High level floating point 14jan94py |
\ High level floating point 14jan94py |
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\ Copyright (C) 1995 Free Software Foundation, Inc. |
\ Copyright (C) 1995,1997 Free Software Foundation, Inc. |
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\ 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. |
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\ 1 cells 4 = [IF] |
\ 1 cells 4 = [IF] |
\ ' cells Alias sfloats |
\ ' cells Alias sfloats |
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\ [THEN] |
\ [THEN] |
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: sfalign ( -- ) \ float-ext s-f-align |
: 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. |
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 |
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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. |
here dup dfaligned swap ?DO bl c, LOOP ; |
here dup dfaligned swap ?DO bl c, LOOP ; |
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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 |
dofield: lastxt code-address! \ change the constant into a field |
\G @code{1 sfloats +}. |
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1 dfloats constant dfloat+ ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus |
1 dfloats (Field) dfloat+ , ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus |
dofield: lastxt code-address! \ change the constant into a field |
\G @code{1 dfloats +}. |
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: f, ( f -- ) here 1 floats allot f! ; |
: 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 |
: fconstant ( r "name" -- ) \ float f-constant |
Create f, |
Create f, |
DOES> ( -- r ) |
DOES> ( -- r ) |
f@ ; |
f@ ; |
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: fdepth ( -- n ) f0 @ fp@ - [ 1 floats ] Literal / ; |
: 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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: FLit ( -- r ) r> dup f@ float+ >r ; |
: FLit ( -- r ) r> dup f@ float+ >r ; |
: FLiteral ( r -- ) |
: FLiteral ( compilation r -- ; run-time -- r ) \ float f-literal |
BEGIN here cell+ dup faligned <> WHILE postpone noop REPEAT |
\G Compile appropriate code such that, at run-time, @i{r} is placed |
postpone FLit f, ; immediate |
\G on the (floating-point) stack. Interpretation semantics are undefined. |
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BEGIN here cell+ dup faligned <> WHILE postpone noop REPEAT |
&15 Value precision |
postpone FLit f, ; immediate |
: set-precision to precision ; |
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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 ; |
Line 82 DOES> ( -- r )
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Line 99 DOES> ( -- r )
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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 ; |
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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 |
Line 90 DOES> ( -- r )
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Line 110 DOES> ( -- r )
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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? |
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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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Line 131 IS compiler-notfound
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Line 160 IS compiler-notfound
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ENDIF ; |
ENDIF ; |
IS interpreter-notfound |
IS interpreter-notfound |
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: fvariable ( "name" -- ) \ float |
: fvariable ( "name" -- ) \ float f-variable |
Create 0.0E0 f, ; |
Create 0.0E0 f, ; |
\ does> ( -- f-addr ) |
\ does> ( -- f-addr ) |
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1.0e0 fasin 2.0e0 f* fconstant pi |
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 |
: f2* 2.0e0 f* ; |
\G to its diameter. |
: f2/ 0.5e0 f* ; |
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: 1/f 1.0e0 fswap f/ ; |
: 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 |
\ We now have primitives for these, so we need not define them |
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Line 155 IS interpreter-notfound
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Line 197 IS interpreter-notfound
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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 ; |
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\ !! 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. |
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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}. |
fdup f0= |
fdup f0= |
IF |
IF \ bitwise comparison |
fdrop f= EXIT |
fp@ float+ 1 floats over float+ -text 0= |
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fdrop fdrop fdrop |
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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 |
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f< ; |
1e 53 0 [do] f2* [loop] fconstant fround-offset \ 2^53 |
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: f.s ." <" fdepth 0 .r ." > " fdepth 0 max maxdepth-.s @ min dup 0 |
: fround ( r1 -- r2 ) \ float f-round |
?DO dup i - 1- floats fp@ + f@ f. LOOP drop ; |
\G Round to nearest integral value. Break ties with round-to-even. |
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\ assumes IEEE DP FP in round-to-even mode. |
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\ for an explanation of this code read |
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\ <2002Oct26.113823@a0.complang.tuwien.ac.at> ff. |
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fdup f0> if |
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fround-offset f- fround-offset f+ |
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else fdup f0< if \ leave 0e and -0e as is |
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fround-offset f+ fround-offset f- |
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then then ; |
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: f.s ( -- ) \ gforth f-dot-s |
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\G Display the number of items on the floating-point stack, |
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\G followed by a list of the items; TOS is the right-most item. |
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." <" fdepth 0 .r ." > " fdepth 0 max maxdepth-.s @ min dup 0 |
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?DO dup i - 1- floats fp@ + f@ f. LOOP drop ; |