--- gforth/float.fs 1998/12/08 22:02:42 1.23 +++ gforth/float.fs 1999/11/08 22:01:09 1.28 @@ -43,32 +43,53 @@ \ [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 constant 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 a single-precision IEEE floating-point number, to give @i{sf-addr2}."" dofield: lastxt code-address! \ change the constant into a field 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 -- ) here 1 floats allot f! ; +: 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 Create f, DOES> ( -- r ) f@ ; -: fdepth ( -- n ) fp0 @ fp@ - [ 1 floats ] Literal / ; +: fdepth ( -- +n ) \ floating f-depth + \G @i{+n} is the current number of (floating-point) values on the + \G floating-point stack. + fp0 @ fp@ - [ 1 floats ] Literal / ; : FLit ( -- r ) r> dup f@ float+ >r ; -: FLiteral ( r -- ) - BEGIN here cell+ dup faligned <> WHILE postpone noop REPEAT - postpone FLit f, ; immediate - -&15 Value precision -: set-precision to precision ; +: FLiteral ( compilation r -- ; run-time -- r ) \ float + \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+ dup faligned <> WHILE postpone noop REPEAT + postpone FLit f, ; immediate + +&15 Value precision ( -- u ) \ floating-ext +\G @i{u} is the number of significant digits currently used by +\G @code{F.} @code{FE.} and @code{FS.} +: set-precision ( u -- ) \ floating-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 ) pad precision - precision ; @@ -82,7 +103,10 @@ DOES> ( -- r ) IF 2drop scratch 3 min type rdrop EXIT THEN IF '- emit THEN ; -: f. ( r -- ) f\$ dup >r 0< +: f. ( r -- ) \ floating-ext f-dot +\G Display (the floating-point number) @i{r} using fixed-point notation, +\G followed by a space. + f\$ dup >r 0< IF '0 emit ELSE scratch r@ min type r@ precision - zeros THEN '. emit r@ negate zeros @@ -90,11 +114,15 @@ DOES> ( -- r ) \ 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 -- ) f\$ 1- s>d 3 fm/mod 3 * >r 1+ >r +: fe. ( r -- ) \ floating-ext f-e-dot +\G Display @i{r} using engineering notation, followed by a space. + f\$ 1- s>d 3 fm/mod 3 * >r 1+ >r scratch r@ min type '. emit scratch r> /string type 'E emit r> . ; -: fs. ( r -- ) f\$ 1- +: fs. ( r -- ) \ floating-ext f-s-dot +\G Display @i{r} using scientific notation, followed by a space. + f\$ 1- scratch over c@ emit '. emit 1 /string type 'E emit . ; @@ -135,11 +163,21 @@ IS interpreter-notfound Create 0.0E0 f, ; \ does> ( -- f-addr ) -1.0e0 fasin 2.0e0 f* fconstant pi - -: f2* 2.0e0 f* ; -: f2/ 0.5e0 f* ; -: 1/f 1.0e0 fswap f/ ; +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/ ; \ We now have primitives for these, so we need not define them @@ -155,20 +193,33 @@ IS interpreter-notfound \ : facosh fdup fdup f* 1.0e0 f- fsqrt f+ fln ; \ : fasinh fdup fdup f* 1.0e0 f+ fsqrt f/ fatanh ; -\ !! factor out parts -: f~ ( f1 f2 f3 -- flag ) \ float-ext +: f~abs ( r1 r2 r3 -- flag ) \ gforth + \G Approximate equality with absolute error: |r1-r2|0: @code{f~abs}; r3=0: r1=r2; r3<0: @code{fnegate f~abs}. fdup f0= IF - fdrop f= EXIT + fdrop f= \ !! this does not work, because 0=-0 with f= on Linux-Intel + \ the standard says they should compare unequal + \ the comparison should be done with COMPARE + EXIT THEN fdup f0> IF - frot frot f- fabs fswap + f~abs ELSE - fnegate frot frot fover fabs fover fabs f+ frot frot - f- fabs frot frot f* - THEN - f< ; + fnegate f~rel + THEN ; -: f.s ." <" fdepth 0 .r ." > " fdepth 0 max maxdepth-.s @ min dup 0 - ?DO dup i - 1- floats fp@ + f@ f. LOOP drop ; +: f.s ( -- ) \ gforth f-dot-s + \G Display the number of items on the floating-point stack, + \G followed by a list of the items; TOS is the right-most item. + ." <" fdepth 0 .r ." > " fdepth 0 max maxdepth-.s @ min dup 0 + ?DO dup i - 1- floats fp@ + f@ f. LOOP drop ;