Annotation of gforth/float.fs, revision 1.24
1.1 anton 1: \ High level floating point 14jan94py
2:
1.23 anton 3: \ Copyright (C) 1995,1997 Free Software Foundation, Inc.
1.18 anton 4:
5: \ This file is part of Gforth.
6:
7: \ Gforth is free software; you can redistribute it and/or
8: \ modify it under the terms of the GNU General Public License
9: \ as published by the Free Software Foundation; either version 2
10: \ of the License, or (at your option) any later version.
11:
12: \ This program is distributed in the hope that it will be useful,
13: \ but WITHOUT ANY WARRANTY; without even the implied warranty of
14: \ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15: \ GNU General Public License for more details.
16:
17: \ You should have received a copy of the GNU General Public License
18: \ along with this program; if not, write to the Free Software
19: \ Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20:
1.17 anton 21: \ 1 cells 4 = [IF]
22: \ ' cells Alias sfloats
23: \ ' cell+ Alias sfloat+
24: \ ' align Alias sfalign
25: \ ' aligned Alias sfaligned
26: \ [ELSE]
27: \ : sfloats 2* 2* ;
28: \ : sfloat+ 4 + ;
29: \ : sfaligned ( addr -- addr' ) 3 + -4 and ;
30: \ : sfalign ( -- ) here dup sfaligned swap ?DO bl c, LOOP ;
31: \ [THEN]
1.6 pazsan 32:
1.17 anton 33: \ 1 floats 8 = [IF]
34: \ ' floats Alias dfloats
35: \ ' float+ Alias dfloat+
36: \ ' falign Alias dfalign
37: \ ' faligned Alias dfaligned
38: \ [ELSE]
39: \ : dfloats 2* 2* 2* ;
40: \ : dfloat+ 8 + ;
41: \ : dfaligned ( addr -- addr' ) 7 + -8 and ;
42: \ : dfalign ( -- ) here dup dfaligned swap ?DO bl c, LOOP ;
43: \ [THEN]
44:
45: : sfalign ( -- ) \ float-ext s-f-align
46: here dup sfaligned swap ?DO bl c, LOOP ;
47: : dfalign ( -- ) \ float-ext d-f-align
48: here dup dfaligned swap ?DO bl c, LOOP ;
49:
50: 1 sfloats constant sfloat+ ( sf-addr1 -- sf-addr2 ) \ float-ext s-float-plus
51: dofield: lastxt code-address! \ change the constant into a field
52:
53: 1 dfloats constant dfloat+ ( df-addr1 -- df-addr2 ) \ float-ext d-float-plus
54: dofield: lastxt code-address! \ change the constant into a field
1.6 pazsan 55:
1.1 anton 56: : f, ( f -- ) here 1 floats allot f! ;
57:
1.20 anton 58: : fconstant ( r "name" -- ) \ float
1.13 anton 59: Create f,
1.16 anton 60: DOES> ( -- r )
61: f@ ;
1.1 anton 62:
1.24 ! crook 63: : fdepth ( -- +n ) \ floating f-depth
! 64: \G +n is the current number of (floating-point) values on the
! 65: \G floating-point stack.
! 66: fp0 @ fp@ - [ 1 floats ] Literal / ;
1.1 anton 67:
1.14 pazsan 68: : FLit ( -- r ) r> dup f@ float+ >r ;
1.24 ! crook 69: : FLiteral ( compilation r -- ; run-time -- r ) \ float
! 70: \G Compile appropriate code such that, at run-time, r is placed
! 71: \G on the (floating-point) stack. Interpretation semantics are undefined.
! 72: BEGIN here cell+ dup faligned <> WHILE postpone noop REPEAT
! 73: postpone FLit f, ; immediate
! 74:
! 75: &15 Value precision ( -- u ) \ floating-ext
! 76: \G u is the number of significant digits currently used by
! 77: \G @code{F.} @code{FE.} and @code{FS.}
! 78: : set-precision ( u -- ) \ floating-ext
! 79: \G Set the number of significant digits currently used by
! 80: \G @code{F.} @code{FE.} and @code{FS.} to u.
! 81: to precision ;
1.1 anton 82:
83: : scratch ( r -- addr len )
84: pad precision - precision ;
85:
86: : zeros ( n -- ) 0 max 0 ?DO '0 emit LOOP ;
87:
88: : -zeros ( addr u -- addr' u' )
89: BEGIN dup WHILE 1- 2dup + c@ '0 <> UNTIL 1+ THEN ;
90:
1.4 pazsan 91: : f$ ( f -- n ) scratch represent 0=
92: IF 2drop scratch 3 min type rdrop EXIT THEN
93: IF '- emit THEN ;
94:
1.24 ! crook 95: : f. ( r -- ) \ floating-ext f-dot
! 96: \G Display (the floating-point number) r using fixed-point notation,
! 97: \G followed by a space.
! 98: f$ dup >r 0<
1.4 pazsan 99: IF '0 emit
1.1 anton 100: ELSE scratch r@ min type r@ precision - zeros THEN
101: '. emit r@ negate zeros
102: scratch r> 0 max /string 0 max -zeros type space ;
1.3 benschop 103: \ I'm afraid this does not really implement ansi semantics wrt precision.
104: \ Shouldn't precision indicate the number of places shown after the point?
1.1 anton 105:
1.24 ! crook 106: : fe. ( r -- ) \ floating-ext f-e-dot
! 107: \G Display r using engineering notation, followed by a space.
! 108: f$ 1- s>d 3 fm/mod 3 * >r 1+ >r
1.1 anton 109: scratch r@ min type '. emit scratch r> /string type
110: 'E emit r> . ;
111:
1.24 ! crook 112: : fs. ( r -- ) \ floating-ext f-s-dot
! 113: \G Display r using scientific notation, followed by a space.
! 114: f$ 1-
1.4 pazsan 115: scratch over c@ emit '. emit 1 /string type
116: 'E emit . ;
117:
1.21 anton 118: require debugs.fs
1.16 anton 119:
1.19 anton 120: : sfnumber ( c-addr u -- r true | false )
121: 2dup [CHAR] e scan ( c-addr u c-addr2 u2 )
1.16 anton 122: dup 0=
123: IF
1.19 anton 124: 2drop 2dup [CHAR] E scan ( c-addr u c-addr3 u3 )
1.16 anton 125: THEN
126: nip
1.7 anton 127: IF
1.19 anton 128: >float
129: ELSE
130: 2drop false
131: THEN ;
132:
133: :noname ( c-addr u -- )
134: 2dup sfnumber
135: IF
136: 2drop POSTPONE FLiteral
137: ELSE
138: defers compiler-notfound
139: ENDIF ;
140: IS compiler-notfound
1.1 anton 141:
1.19 anton 142: :noname ( c-addr u -- r )
143: 2dup sfnumber
144: IF
145: 2drop
146: ELSE
147: defers interpreter-notfound
148: ENDIF ;
149: IS interpreter-notfound
1.13 anton 150:
1.20 anton 151: : fvariable ( "name" -- ) \ float
1.15 pazsan 152: Create 0.0E0 f, ;
1.13 anton 153: \ does> ( -- f-addr )
1.1 anton 154:
1.24 ! crook 155: 1.0e0 fasin 2.0e0 f* fconstant pi ( -- r ) \ gforth
! 156: \G FCONSTANT: r is the value pi; the ratio of a circle's area
! 157: \G to its diameter.
! 158:
! 159: : f2* ( r1 -- r2 ) \ gforth
! 160: \G Multiply r1 by 2.0e0
! 161: 2.0e0 f* ;
! 162:
! 163: : f2/ ( r1 -- r2 ) \ gforth
! 164: \G Multiply r1 by 0.5e0
! 165: 0.5e0 f* ;
! 166:
! 167: : 1/f ( r1 -- r2 ) \ gforth
! 168: \G Divide 1.0e0 by r1
! 169: 1.0e0 fswap f/ ;
1.6 pazsan 170:
171:
1.10 anton 172: \ We now have primitives for these, so we need not define them
1.6 pazsan 173:
1.15 pazsan 174: \ : falog ( f -- 10^f ) [ 10.0e0 fln ] FLiteral f* fexp ;
1.10 anton 175:
1.15 pazsan 176: \ : fsinh fexpm1 fdup fdup 1.0e0 f+ f/ f+ f2/ ;
1.10 anton 177: \ : fcosh fexp fdup 1/f f+ f2/ ;
1.15 pazsan 178: \ : ftanh f2* fexpm1 fdup 2.0e0 f+ f/ ;
1.10 anton 179:
1.15 pazsan 180: \ : fatanh fdup f0< >r fabs 1.0e0 fover f- f/ f2* flnp1 f2/
1.10 anton 181: \ r> IF fnegate THEN ;
1.15 pazsan 182: \ : facosh fdup fdup f* 1.0e0 f- fsqrt f+ fln ;
183: \ : fasinh fdup fdup f* 1.0e0 f+ fsqrt f/ fatanh ;
1.9 pazsan 184:
1.16 anton 185: \ !! factor out parts
186: : f~ ( f1 f2 f3 -- flag ) \ float-ext
187: fdup f0=
188: IF
189: fdrop f= EXIT
190: THEN
191: fdup f0>
192: IF
193: frot frot f- fabs fswap
194: ELSE
195: fnegate frot frot fover fabs fover fabs f+ frot frot
196: f- fabs frot frot f*
197: THEN
198: f< ;
1.11 pazsan 199:
1.24 ! crook 200: : f.s ( -- ) \ gforth f-dot-s
! 201: \G Display the number of items on the floating-point stack,
! 202: \G followed by a list of the items; TOS is the right-most item.
! 203: ." <" fdepth 0 .r ." > " fdepth 0 max maxdepth-.s @ min dup 0
! 204: ?DO dup i - 1- floats fp@ + f@ f. LOOP drop ;
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