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authorKartik Agaram <vc@akkartik.com>2020-10-31 19:55:33 -0700
committerKartik Agaram <vc@akkartik.com>2020-10-31 19:55:33 -0700
commit13235878225c99275d1ae01dd3aed4aaa5b284e8 (patch)
tree2ffe16779853b6e96f9cd049f37005816c44346e /mu_instructions
parent3f30e4c6e6598eb281331626f0f021005ba608f3 (diff)
downloadmu-13235878225c99275d1ae01dd3aed4aaa5b284e8.tar.gz
7147
Diffstat (limited to 'mu_instructions')
-rw-r--r--mu_instructions11


1 files changed, 7 insertions, 4 deletions
diff --git a/mu_instructions b/mu_instructions
index 8879c878..f0e66917 100644
--- a/mu_instructions
+++ b/mu_instructions
@@ -13,6 +13,10 @@ Conversely, registers that are just read from must not be passed as inputs.
 The following chart shows all the instruction forms supported by Mu, along with
 the SubX instruction they're translated to.
 
+## Integer instructions
+
+These instructions use the general-purpose registers.
+
 var/eax <- increment              => "40/increment-eax"
 var/ecx <- increment              => "41/increment-ecx"
 var/edx <- increment              => "42/increment-edx"
@@ -126,11 +130,10 @@ compare *var/reg, n               => "81 7/subop/compare *" reg " " n "/imm32"
 var/reg <- multiply var2          => "0f af/multiply *(ebp+" var2.stack-offset ") " reg "/r32"
 var/reg <- multiply *var2/reg2    => "0f af/multiply *" reg2 " " reg "/r32"
 
-# Floating-point operations
+## Floating-point operations
 
-All the instructions so far use Intel's general-purpose integer registers.
-However, some of them translate to different SubX if their arguments are in
-floating-point registers.
+These instructions operate on either floating-point registers (xreg) or
+general-purpose registers (reg) in indirect mode.
 
 var/xreg <- add var2/xreg2        => "f3 0f 58/add %" xreg2 " " xreg1 "/x32"
 var/xreg <- add var2              => "f3 0f 58/add *(ebp+" var2.stack-offset ") " xreg "/x32"

 

generated by cgit-pink 1.4.1-2-gfad0 (git 2.36.2.497.gbbea4dcf42) at 2025-04-08 04:48:10 +0000


 


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/*
 * $LynxId: HTUU.c,v 1.11 2010/09/21 23:55:12 tom Exp $
 *
 * MODULE							HTUU.c
 *			UUENCODE AND UUDECODE
 *
 * ACKNOWLEDGEMENT:
 *	This code is taken from rpem distribution, and was originally
 *	written by Mark Riordan.
 *
 * AUTHORS:
 *	MR	Mark Riordan	riordanmr@clvax1.cl.msu.edu
 *	AL	Ari Luotonen	luotonen@dxcern.cern.ch
 *
 * HISTORY:
 *	Added as part of the WWW library and edited to conform
 *	with the WWW project coding standards by:	AL  5 Aug 1993
 *	Originally written by:				MR 12 Aug 1990
 *	Original header text:
 * -------------------------------------------------------------
 *  File containing routines to convert a buffer
 *  of bytes to/from RFC 1113 printable encoding format.
 *
 *  This technique is similar to the familiar Unix uuencode
 *  format in that it maps 6 binary bits to one ASCII
 *  character (or more aptly, 3 binary bytes to 4 ASCII
 *  characters).  However, RFC 1113 does not use the same
 *  mapping to printable characters as uuencode.
 *
 *  Mark Riordan   12 August 1990 and 17 Feb 1991.
 *  This code is hereby placed in the public domain.
 * -------------------------------------------------------------
 */

#include <HTUtils.h>
#include <HTUU.h>

#include <LYLeaks.h>

static char six2pr[64] =
{
    'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H', 'I', 'J', 'K', 'L', 'M',
    'N', 'O', 'P', 'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X', 'Y', 'Z',
    'a', 'b', 'c', 'd', 'e', 'f', 'g', 'h', 'i', 'j', 'k', 'l', 'm',
    'n', 'o', 'p', 'q', 'r', 's', 't', 'u', 'v', 'w', 'x', 'y', 'z',
    '0', '1', '2', '3', '4', '5', '6', '7', '8', '9', '+', '/'
};

static unsigned char pr2six[256];

/*--- function HTUU_encode -----------------------------------------------
 *
 * Encode a single line of binary data to a standard format that
 * uses only printing ASCII characters (but takes up 33% more bytes).
 *
 *    Entry    bufin    points to a buffer of bytes.  If nbytes is not
 *                      a multiple of three, then the byte just beyond
 *                      the last byte in the buffer must be 0.
 *             nbytes   is the number of bytes in that buffer.
 *                      This cannot be more than 48.
 *             bufcoded points to an output buffer.  Be sure that this
 *                      can hold at least 1 + (4*nbytes)/3 characters.
 *
 *    Exit     bufcoded contains the coded line.  The first 4*nbytes/3 bytes
 *                      contain printing ASCII characters representing
 *                      those binary bytes.  This may include one or
 *                      two '=' characters used as padding at the end.
 *                      The last byte is a zero byte.
 *             Returns the number of ASCII characters in "bufcoded".
 */
int HTUU_encode(unsigned char *bufin,
		size_t nbytes,
		char *bufcoded)
{
/* ENC is the basic 1 character encoding function to make a char printing */
#define ENC(c) six2pr[c]

    register char *outptr = bufcoded;
    size_t i;

    /* This doesn't seem to be needed (AL):   register unsigned char *inptr  = bufin; */

    for (i = 0; i < nbytes; i += 3) {
	*(outptr++) = ENC(*bufin >> 2);		/* c1 */
	*(outptr++) = ENC(((*bufin << 4) & 060) | ((bufin[1] >> 4) & 017));	/*c2 */
	*(outptr++) = ENC(((bufin[1] << 2) & 074) | ((bufin[2] >> 6) & 03));	/*c3 */
	*(outptr++) = ENC(bufin[2] & 077);	/* c4 */

	bufin += 3;
    }

    /* If nbytes was not a multiple of 3, then we have encoded too
     * many characters.  Adjust appropriately.
     */
    if (i == nbytes + 1) {
	/* There were only 2 bytes in that last group */
	outptr[-1] = '=';
    } else if (i == nbytes + 2) {
	/* There was only 1 byte in that last group */
	outptr[-1] = '=';
	outptr[-2] = '=';
    }
    *outptr = '\0';
    return (int) (outptr - bufcoded);
}

/*--- function HTUU_decode ------------------------------------------------
 *
 * Decode an ASCII-encoded buffer back to its original binary form.
 *
 *    Entry    bufcoded    points to a uuencoded string.  It is
 *                         terminated by any character not in
 *                         the printable character table six2pr, but
 *                         leading whitespace is stripped.
 *             bufplain    points to the output buffer; must be big
 *                         enough to hold the decoded string (generally
 *                         shorter than the encoded string) plus
 *                         as many as two extra bytes used during
 *                         the decoding process.
 *             outbufsize  is the maximum number of bytes that
 *                         can fit in bufplain.
 *
 *    Exit     Returns the number of binary bytes decoded.
 *             bufplain    contains these bytes.
 */
int HTUU_decode(char *bufcoded,
		unsigned char *bufplain,
		int outbufsize)
{
/* single character decode */
#define DEC(c) pr2six[(int)c]
#define MAXVAL 63

    static int first = 1;

    int nbytesdecoded, j;
    register char *bufin;
    register unsigned char *bufout = bufplain;
    register int nprbytes;

    /* If this is the first call, initialize the mapping table.
     * This code should work even on non-ASCII machines.
     */
    if (first) {
	first = 0;
	for (j = 0; j < 256; j++)
	    pr2six[j] = MAXVAL + 1;

	for (j = 0; j < 64; j++)
	    pr2six[UCH(six2pr[j])] = UCH(j);
#if 0
      /* *INDENT-OFF* */
      pr2six['A']= 0; pr2six['B']= 1; pr2six['C']= 2; pr2six['D']= 3;
      pr2six['E']= 4; pr2six['F']= 5; pr2six['G']= 6; pr2six['H']= 7;
      pr2six['I']= 8; pr2six['J']= 9; pr2six['K']=10; pr2six['L']=11;
      pr2six['M']=12; pr2six['N']=13; pr2six['O']=14; pr2six['P']=15;
      pr2six['Q']=16; pr2six['R']=17; pr2six['S']=18; pr2six['T']=19;
      pr2six['U']=20; pr2six['V']=21; pr2six['W']=22; pr2six['X']=23;
      pr2six['Y']=24; pr2six['Z']=25; pr2six['a']=26; pr2six['b']=27;
      pr2six['c']=28; pr2six['d']=29; pr2six['e']=30; pr2six['f']=31;
      pr2six['g']=32; pr2six['h']=33; pr2six['i']=34; pr2six['j']=35;
      pr2six['k']=36; pr2six['l']=37; pr2six['m']=38; pr2six['n']=39;
      pr2six['o']=40; pr2six['p']=41; pr2six['q']=42; pr2six['r']=43;
      pr2six['s']=44; pr2six['t']=45; pr2six['u']=46; pr2six['v']=47;
      pr2six['w']=48; pr2six['x']=49; pr2six['y']=50; pr2six['z']=51;
      pr2six['0']=52; pr2six['1']=53; pr2six['2']=54; pr2six['3']=55;
      pr2six['4']=56; pr2six['5']=57; pr2six['6']=58; pr2six['7']=59;
      pr2six['8']=60; pr2six['9']=61; pr2six['+']=62; pr2six['/']=63;
      /* *INDENT-ON* */

#endif
    }

    /* Strip leading whitespace. */

    while (*bufcoded == ' ' || *bufcoded == '\t')
	bufcoded++;

    /* Figure out how many characters are in the input buffer.
     * If this would decode into more bytes than would fit into
     * the output buffer, adjust the number of input bytes downwards.
     */
    bufin = bufcoded;
    while (pr2six[UCH(*(bufin++))] <= MAXVAL) ;
    nprbytes = (int) (bufin - bufcoded - 1);
    nbytesdecoded = ((nprbytes + 3) / 4) * 3;
    if (nbytesdecoded > outbufsize) {
	nprbytes = (outbufsize * 4) / 3;
    }

    bufin = bufcoded;

    while (nprbytes > 0) {
	*(bufout++) = UCH((DEC(bufin[0]) << 2) | (DEC(bufin[1]) >> 4));
	*(bufout++) = UCH((DEC(bufin[1]) << 4) | (DEC(bufin[2]) >> 2));
	*(bufout++) = UCH((DEC(bufin[2]) << 6) | (DEC(bufin[3])));
	bufin += 4;
	nprbytes -= 4;
    }

    if (nprbytes & 03) {
	if (pr2six[(int) bufin[-2]] > MAXVAL) {
	    nbytesdecoded -= 2;
	} else {
	    nbytesdecoded -= 1;
	}
    }

    return (nbytesdecoded);
}