| \ 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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| \ [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 constant sfloat+ ( sf-addr1 -- sf-addr2 ) \ float-ext s-float-plus |
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\G Increment @i{sf-addr1} by the number of address units corresponding to the size of |
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\G a single-precision IEEE floating-point number, to give @i{sf-addr2}."" |
| dofield: lastxt code-address! \ change the constant into a field |
dofield: lastxt code-address! \ change the constant into a field |
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| 1 dfloats constant dfloat+ ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus |
1 dfloats constant dfloat+ ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus |
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\G Increment @i{df-addr1} by the number of address units corresponding to the size of |
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\G a double-precision IEEE floating-point number, to give @i{df-addr2}."" |
| dofield: lastxt code-address! \ change the constant into a field |
dofield: lastxt code-address! \ change the constant into a field |
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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 -- ) \ float |
: fconstant ( r "name" -- ) \ float |
| Create f, |
Create f, |
| DOES> ( -- r ) |
DOES> ( -- r ) |
| f@ ; |
f@ ; |
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| : fdepth ( -- n ) f0 @ fp@ - [ 1 floats ] Literal / ; |
: fdepth ( -- +n ) \ floating f-depth |
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\G @var{+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 |
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\G Compile appropriate code such that, at run-time, @var{r} is placed |
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\G on the (floating-point) stack. Interpretation semantics are undefined. |
| BEGIN here cell+ dup faligned <> WHILE postpone noop REPEAT |
BEGIN here cell+ dup faligned <> WHILE postpone noop REPEAT |
| postpone FLit f, ; immediate |
postpone FLit f, ; immediate |
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|
| &15 Value precision |
&15 Value precision ( -- u ) \ floating-ext |
| : set-precision to precision ; |
\G @var{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 -- ) \ floating-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 @var{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 -- ) \ floating-ext f-dot |
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\G Display (the floating-point number) @var{r} using fixed-point notation, |
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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 |
: fe. ( r -- ) \ floating-ext f-e-dot |
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\G Display @var{r} using engineering notation, followed by a space. |
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f$ 1- s>d 3 fm/mod 3 * >r 1+ >r |
| scratch r@ min type '. emit scratch r> /string type |
scratch r@ min type '. emit scratch r> /string type |
| 'E emit r> . ; |
'E emit r> . ; |
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| : fs. ( r -- ) f$ 1- |
: fs. ( r -- ) \ floating-ext f-s-dot |
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\G Display @var{r} using scientific notation, followed 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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| require debugging.fs |
require debugs.fs |
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|
| : 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 ) |
| ENDIF ; |
ENDIF ; |
| IS interpreter-notfound |
IS interpreter-notfound |
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|
| : fvariable ( -- ) |
: fvariable ( "name" -- ) \ float |
| 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 FCONSTANT: @var{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 @var{r1} by 2.0e0 |
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2.0e0 f* ; |
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|
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: f2/ ( r1 -- r2 ) \ gforth |
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\G Multiply @var{r1} by 0.5e0 |
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0.5e0 f* ; |
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|
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: 1/f ( r1 -- r2 ) \ gforth |
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\G Divide 1.0e0 by @var{r1}. |
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1.0e0 fswap f/ ; |
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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 |
| \ : 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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|
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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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|
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: f~ ( r1 r2 r3 -- flag ) \ float-ext |
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\G ANS Forth medley: r3>0: @code{f~abs}; r3=0: r1=r2; r3<0: @code{fnegate f~abs}. |
| fdup f0= |
fdup f0= |
| IF |
IF |
| fdrop f= EXIT |
fdrop f= \ !! this does not work, because 0=-0 with f= on Linux-Intel |
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\ the standard says they should compare unequal |
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\ the comparison should be done with COMPARE |
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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< ; |
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| : f.s ." <" fdepth 0 .r ." > " fdepth 0 max maxdepth-.s @ min dup 0 |
: 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 |
| ?DO dup i - 1- floats fp@ + f@ f. LOOP drop ; |
?DO dup i - 1- floats fp@ + f@ f. LOOP drop ; |
