version 1.38, 2002/11/02 15:26:03
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version 1.46, 2004/12/31 13:23:57
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\ High level floating point 14jan94py |
\ High level floating point 14jan94py |
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\ Copyright (C) 1995,1997 Free Software Foundation, Inc. |
\ Copyright (C) 1995,1997,2003,2004 Free Software Foundation, Inc. |
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\ This file is part of Gforth. |
\ This file is part of Gforth. |
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Line 72 DOES> ( -- r )
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Line 72 DOES> ( -- r )
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\G floating-point stack. |
\G floating-point stack. |
fp0 @ fp@ - [ 1 floats ] Literal / ; |
fp0 @ fp@ - [ 1 floats ] Literal / ; |
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: FLit ( -- r ) r> dup f@ float+ >r ; |
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: FLiteral ( compilation r -- ; run-time -- r ) \ float f-literal |
: FLiteral ( compilation r -- ; run-time -- r ) \ float f-literal |
\G Compile appropriate code such that, at run-time, @i{r} is placed |
\G Compile appropriate code such that, at run-time, @i{r} is placed |
\G on the (floating-point) stack. Interpretation semantics are undefined. |
\G on the (floating-point) stack. Interpretation semantics are undefined. |
BEGIN here cell+ dup faligned <> WHILE postpone noop REPEAT |
BEGIN here cell+ cell+ dup faligned <> WHILE postpone noop REPEAT |
postpone FLit f, ; immediate |
postpone ahead here >r f, postpone then |
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r> postpone literal postpone f@ ; immediate |
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&15 Value precision ( -- u ) \ float-ext |
&15 Value precision ( -- u ) \ float-ext |
\G @i{u} is the number of significant digits currently used by |
\G @i{u} is the number of significant digits currently used by |
Line 211 set-current
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Line 211 set-current
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\G @code{f~abs}; r3=0: bitwise comparison; r3<0: @code{fnegate f~rel}. |
\G @code{f~abs}; r3=0: bitwise comparison; r3<0: @code{fnegate f~rel}. |
fdup f0= |
fdup f0= |
IF \ bitwise comparison |
IF \ bitwise comparison |
fp@ float+ 1 floats over float+ -text 0= |
fp@ float+ 1 floats over float+ over str= |
fdrop fdrop fdrop |
fdrop fdrop fdrop |
EXIT |
EXIT |
THEN |
THEN |
Line 222 set-current
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Line 222 set-current
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fnegate f~rel |
fnegate f~rel |
THEN ; |
THEN ; |
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1e 53 0 [do] f2* [loop] fconstant fround-offset \ 2^53 |
\ proposals from Krishna Myeni in <cjsp2d$47l$1@ngspool-d02.news.aol.com> |
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\ not sure if they are a good idea |
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: fround ( r1 -- r2 ) \ float f-round |
: FTRUNC ( r1 -- r2 ) |
\G Round to nearest integral value. Break ties with round-to-even. |
\ round towards 0 |
\ assumes IEEE DP FP in round-to-even mode. |
\ !! should be implemented properly |
\ for an explanation of this code read |
F>D D>F ; |
\ <2002Oct26.113823@a0.complang.tuwien.ac.at> ff. |
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fdup f0> if |
: FMOD ( r1 r2 -- r ) |
fround-offset f- fround-offset f+ |
\ remainder of r1/r2 |
else fdup f0< if \ leave 0e and -0e as is |
FOVER FOVER F/ ftrunc F* F- ; |
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 ; |
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