Author: wmb Date: 2007-07-05 19:28:08 +0200 (Thu, 05 Jul 2007) New Revision: 464
Added: dev/diaguart.fth forth/kernel/dmuldiv.fth Log: Added some common files needed by the PowerPC version.
Added: dev/diaguart.fth =================================================================== --- dev/diaguart.fth (rev 0) +++ dev/diaguart.fth 2007-07-05 17:28:08 UTC (rev 464) @@ -0,0 +1,38 @@ +purpose: Diagnostic (before console installation) access to serial port +copyright: Copyright 1994 Firmworks All Rights Reserved + +headerless +d# 1843200 constant uart-clock-frequency + +[ifndef] uart@ +h# 3f8 value uart-base \ Virtual address of UART; set later + +: uart@ ( reg# -- byte ) uart-base + pc@ ; \ Read from a UART register +: uart! ( byte reg# -- ) uart-base + pc! ; \ Write to a UART register +[then] + +: baud ( baud-rate -- ) + uart-clock-frequency d# 16 / swap rounded-/ ( baud-rate-divisor ) + + begin 5 uart@ h# 40 and until \ Wait until transmit done + + 3 uart@ dup >r h# 80 or 3 uart! \ divisor latch access bit on + dup h# ff and 0 uart! 8 >> 1 uart! \ Write lsb and msb + r> 3 uart! \ Restore old state +; + +: inituarts ( -- ) + 3 3 uart! \ 8 bits, no parity + 7 2 uart! \ Clear and enable FIFOs +\ d# 38400 baud + d# 9600 baud +; + +: ukey? ( -- flag ) 5 uart@ 1 and 0<> ; \ Test for rcv character +: uemit? ( -- flag ) 5 uart@ h# 20 and 0<> ; \ Test for xmit ready +: ubreak? ( -- flag ) 5 uart@ h# 10 and 0<> ; \ Test for received break +: clear-break ( -- ) 5 uart@ drop ; \ Clear break indication + +: ukey ( -- char ) begin ukey? until 0 uart@ ; \ Receive a character +: uemit ( char -- ) begin uemit? until 0 uart! ; \ Transmit a character +headers
Added: forth/kernel/dmuldiv.fth =================================================================== --- forth/kernel/dmuldiv.fth (rev 0) +++ forth/kernel/dmuldiv.fth 2007-07-05 17:28:08 UTC (rev 464) @@ -0,0 +1,172 @@ +purpose: Extended precision multiplication and division +\ See license at end of file + +\ alias um* u*x ( u1 u2 -- ud ) + +headerless +/n-t 4 * constant bits/half-cell + +: scale-up ( -- ) bits/half-cell << ; +: scale-down ( -- ) bits/half-cell >> ; +: split-halves ( n -- low-half high-half ) + dup 1 scale-up 1- and swap scale-down +; + +headers +\ This is the elementary school long-division algorithm, base 2^^16 (on a +\ 32-bit system) or 2^32 (on a 64-bit system). +\ It depends on the assumption that "/" can accurately divide a single-cell +\ (i.e. 32 or 64 bit) number by a half-cell (i.e. 16 or 32 bit) number. +\ Each "digit" is a half-cell number; thus the dividend is a 4-digit +\ number "ABCD" and the divisor is a 2-digit number "EF". + +\ It would be interesting to compare the performance of this to a +\ "bit-banging" non-restoring division loop. +: um/mod ( ud u -- urem uquot ) + 2dup u>= if \ Overflow; return max-uint for quotient + 0= if 0 / then \ Force divide by zero trap + 2drop 0 -1 exit ( 0 max-u ) + then ( ud u ) + + \ Split the divisor into two 16-bit "digits" + dup split-halves ( ud u ulow uhigh ) + + \ If the high "digit" of the divisor is zero, we can skip a lot + \ of the steps. In this case, we only have to worry about the + \ middle two digits of the dividend in developing the quotient. + ?dup 0= if ( ud u ulow ) + + \ Approximate the high digit of the quotient by dividing the "BC" + \ digits by the "F" digit. The answer could by low by one, but if + \ so it will be fixed in the next step. + 2over swap scale-down swap scale-up + over / scale-up + ( ud u ulow guess<< ) + + \ Multiply the trial quotient by the divisor + rot over um* ( ud ulow guess<< udtemp ) + + \ Subtract the trial product from the dividend, giving the remainder + 2swap >r >r d- drop ( error ) ( r: guess<< ulow ) + + \ Divide the remainder by the divisor, giving the rest of the + \ quotient. + dup r@ u/mod nip ( error guess1 ) + r> r> ( error guess1 ulow guess<< ) + + \ Merge the two halves of the quotient + 2 pick + >r ( error guess1 ulow ) ( r: uquot ) + + \ Calculate the remainder + * - r> ( urem uquot ) + exit + then ( ud u ulow uhigh ) + + \ The high divisor digit is non-zero, so we have to deal with + \ both digits, dividing "ABCD" by "EF". + + \ Approximate the high digit of the quotient. + 3 pick over u/mod nip ( ud u ulow uhigh guess ) + + \ Reduce guess by one if "E" = "A" + dup 1 scale-up = if 1- then ( ud u ulow uhigh guess' ) + + \ Multiply the trial quotient by the divisor + 3 pick over scale-up um* ( ud u ulow uhigh guess' ud.temp ) + + \ Subtract the trial product from the dividend, giving the remainder + >r >r 2rot r> r> d- ( u ulow uhigh guess' d.resid ) + + \ If the remainder is negative, add the divisor and reduce the trial + \ quotient by one. The following loop executes at most twice. + begin dup 0< while ( u ulow uhigh guess' d.resid ) + rot 1- -rot ( u ulow uhigh guess+ d.resid ) + 4 pick scale-up 4 pick d+ ( u ulow uhigh guess+ d.resid' ) + repeat ( u ulow uhigh guess+ +d.resid ) + + \ Now we have the correct high quotient digit; save it for later + rot scale-up >r ( u ulow uhigh +d.resid ) ( r: q.high ) + + \ Repeat the above process, using the partial remainder as the + \ dividend. Ulow is no longer needed + 3 roll drop ( u uhigh +d.resid ) + + \ Trial quotient digit... + 2dup scale-up swap scale-down + 3 roll u/mod nip + ( u +d.resid guess1 ) ( r: q.high ) + dup 1 scale-up = if 1- then ( u +d.resid guess1' ) + + \ Trial product + 3 pick over um* ( u +d.resid guess1' d.err ) + + \ New partial remainder + rot >r d- ( u d.resid' ) ( r: q.high guess1' ) + + \ Adjust quotient digit until partial remainder is positive + begin dup 0< while ( u d.resid' ) ( r: q.high guess1' ) + r> 1- >r ( u d.resid' ) ( r: q.high guess1' ) + 2 pick m+ ( u d.resid'' ) ( r: q.high guess1' ) + repeat ( u +d.resid ) ( r: q.high guess1' ) + + \ Discard divisior and high cell of quotient (which must be zero) + rot 2drop ( u.rem ) + + \ Merge quotient digits + r> r> + ( u.rem u.quot ) +; +: sm/rem ( d n -- rem quot ) + 0 ( d n sign ) + 2 pick 0< if ( d n sign ) + 1+ 2swap dnegate 2swap ( +d n sign ) + then ( +d n sign ) + over 0< if ( +d n sign ) + 2+ swap negate swap ( +d +n sign ) + then ( +d +n sign ) + >r um/mod r> ( u.rem u.quot sign ) + case + 1 of swap negate swap negate endof \ -dividend, +divisor + 2 of negate endof \ +dividend, -divisor + 3 of swap negate swap endof \ -dividend, -divisor + endcase +; +: fm/mod ( d.dividend n.divisor -- n.rem n.quot ) + 2dup xor 0< if \ Fixup only if operands have opposite signs + dup >r sm/rem ( rem' quot' r: divisor ) + over if 1- swap r> + swap else r> drop then + exit + then + \ In the usual case of similar signs (i.e. positive quotient), + \ sm/rem gives the correct answer + sm/rem ( n.rem' n.quot' ) +; + +" m*" $sfind [if] drop [else] 2drop +: m* ( n1 n2 -- d ) + 2dup xor >r abs swap abs um* r> 0< if dnegate then +; +[then] +: */mod ( n1 n2 n3 -- n.mod n.quot ) >r m* r> fm/mod ; +: */ ( n1 n2 n3 -- n4 ) */mod nip ; + +\ LICENSE_BEGIN +\ Copyright (c) 1994 FirmWorks +\ +\ Permission is hereby granted, free of charge, to any person obtaining +\ a copy of this software and associated documentation files (the +\ "Software"), to deal in the Software without restriction, including +\ without limitation the rights to use, copy, modify, merge, publish, +\ distribute, sublicense, and/or sell copies of the Software, and to +\ permit persons to whom the Software is furnished to do so, subject to +\ the following conditions: +\ +\ The above copyright notice and this permission notice shall be +\ included in all copies or substantial portions of the Software. +\ +\ THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +\ EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +\ MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND +\ NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE +\ LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION +\ OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION +\ WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +\ +\ LICENSE_END
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