File:  [gforth] / gforth / float.fs
Wed Jan 18 18:41:35 1995 UTC (25 years ago) by anton
Branches: MAIN
worked a bit on m68k.h and power.h
moved hyperbolic functions and falog to primitives

1: \ High level floating point                            14jan94py
2:
3: 1 cells 4 = [IF]
4: ' cells   Alias sfloats
5: ' cell+   Alias sfloat+
6: ' align   Alias sfalign
7: ' aligned Alias sfaligned
8: [ELSE]
9: : sfloats  2* 2* ;
10: : sfloat+  4 + ;
11: : sfaligned ( addr -- addr' )  3 + -4 and ;
12: : sfalign ( -- )  here dup sfaligned swap ?DO  bl c,  LOOP ;
13: [THEN]
14:
15: 1 floats 8 = [IF]
16: ' floats   Alias dfloats
17: ' float+   Alias dfloat+
18: ' falign   Alias dfalign
19: ' faligned Alias dfaligned
20: [ELSE]
21: : dfloats  2* 2* 2* ;
22: : dfloat+  8 + ;
23: : dfaligned ( addr -- addr' )  7 + -8 and ;
24: : dfalign ( -- )  here dup dfaligned swap ?DO  bl c,  LOOP ;
25: [THEN]
26:
27: : f, ( f -- )  here 1 floats allot f! ;
28:
29: \ !! have create produce faligned pfas
30: : fconstant  ( r -- )
31:   falign here f,  Create A,
32:   DOES>  @ f@ ;
33:
34: : fvariable
35:   falign here 0. d>f f, AConstant ;
36:
37: : fdepth  ( -- n )  f0 @ fp@ - [ 1 floats ] Literal / ;
38:
39: : FLit ( -- r )  r> faligned dup f@ float+ >r ;
40: : FLiteral ( r -- )  postpone FLit  falign f, ;  immediate
41:
42: &16 Value precision
43: : set-precision  to precision ;
44:
45: : scratch ( r -- addr len )
46:   pad precision - precision ;
47:
48: : zeros ( n -- )   0 max 0 ?DO  '0 emit  LOOP ;
49:
51:   BEGIN  dup  WHILE  1- 2dup + c@ '0 <>  UNTIL  1+  THEN ;
52:
53: : f\$ ( f -- n )  scratch represent 0=
54:   IF  2drop  scratch 3 min type  rdrop  EXIT  THEN
55:   IF  '- emit  THEN ;
56:
57: : f.  ( r -- )  f\$ dup >r 0<
58:   IF    '0 emit
59:   ELSE  scratch r@ min type  r@ precision - zeros  THEN
60:   '. emit r@ negate zeros
61:   scratch r> 0 max /string 0 max -zeros type space ;
62: \ I'm afraid this does not really implement ansi semantics wrt precision.
63: \ Shouldn't precision indicate the number of places shown after the point?
64:
65: : fe. ( r -- )  f\$ 1- s>d 3 fm/mod 3 * >r 1+ >r
66:   scratch r@ min type '. emit  scratch r> /string type
67:   'E emit r> . ;
68:
69: : fs. ( r -- )  f\$ 1-
70:   scratch over c@ emit '. emit 1 /string type
71:   'E emit . ;
72:
73: : sfnumber ( c-addr u -- r / )
74:     2dup >float
75:     IF
76: 	2drop state @
77: 	IF
78: 	    postpone FLiteral
79: 	THEN
80:     ELSE
81: 	defers notfound
82:     THEN ;
83:
84: ' sfnumber IS notfound
85:
86: 1e0 fasin 2e0 f* fconstant pi
87:
88: : f2*  2e0 f* ;
89: : f2/  2e0 f/ ;
90: : 1/f  1e0 fswap f/ ;
91:
92:
93: \ We now have primitives for these, so we need not define them
94:
95: \ : falog ( f -- 10^f )  [ 10e0 fln ] FLiteral f* fexp ;
96:
97: \ : fsinh    fexpm1 fdup fdup 1e0 f+ f/ f+ f2/ ;
98: \ : fcosh    fexp fdup 1/f f+ f2/ ;
99: \ : ftanh    f2* fexpm1 fdup 2e0 f+ f/ ;
100:
101: \ : fatanh   fdup f0< >r fabs 1e0 fover f- f/  f2* flnp1 f2/
102: \            r> IF  fnegate  THEN ;
103: \ : facosh   fdup fdup f* 1e0 f- fsqrt f+ fln ;
104: \ : fasinh   fdup fdup f* 1e0 f+ fsqrt f/ fatanh ;
105:
106: : f.s  ." <" fdepth 0 .r ." > " fdepth 0 max maxdepth-.s @ min dup 0
107:   ?DO  dup i - 1- floats fp@ + f@ f.  LOOP  drop ;

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