1309 lines
28 KiB
C
1309 lines
28 KiB
C
/* Small compiler - code generation (unoptimized "assembler" code)
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*
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* Copyright (c) ITB CompuPhase, 1997-2003
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*
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* This software is provided "as-is", without any express or implied warranty.
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* In no event will the authors be held liable for any damages arising from
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* the use of this software.
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*
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* Permission is granted to anyone to use this software for any purpose,
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* including commercial applications, and to alter it and redistribute it
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* freely, subject to the following restrictions:
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*
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* 1. The origin of this software must not be misrepresented; you must not
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* claim that you wrote the original software. If you use this software in
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* a product, an acknowledgment in the product documentation would be
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* appreciated but is not required.
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* 2. Altered source versions must be plainly marked as such, and must not be
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* misrepresented as being the original software.
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* 3. This notice may not be removed or altered from any source distribution.
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*
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* Version: $Id$
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*/
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <assert.h>
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#include <ctype.h>
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#include <stdio.h>
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#include <limits.h> /* for PATH_MAX */
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#include <string.h>
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#include "embryo_cc_sc.h"
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/* When a subroutine returns to address 0, the AMX must halt. In earlier
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* releases, the RET and RETN opcodes checked for the special case 0 address.
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* Today, the compiler simply generates a HALT instruction at address 0. So
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* a subroutine can savely return to 0, and then encounter a HALT.
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*/
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void
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writeleader(void)
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{
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assert(code_idx == 0);
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stgwrite(";program exit point\n");
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stgwrite("\thalt 0\n");
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/* calculate code length */
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code_idx += opcodes(1) + opargs(1);
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}
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/* writetrailer
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* Not much left of this once important function.
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*
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* Global references: sc_stksize (referred to only)
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* sc_dataalign (referred to only)
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* code_idx (altered)
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* glb_declared (altered)
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*/
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void
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writetrailer(void)
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{
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assert(sc_dataalign % opcodes(1) == 0); /* alignment must be a multiple of
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* the opcode size */
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assert(sc_dataalign != 0);
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/* pad code to align data segment */
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if ((code_idx % sc_dataalign) != 0)
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{
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begcseg();
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while ((code_idx % sc_dataalign) != 0)
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nooperation();
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} /* if */
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/* pad data segment to align the stack and the heap */
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assert(litidx == 0); /* literal queue should have been emptied */
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assert(sc_dataalign % sizeof(cell) == 0);
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if (((glb_declared * sizeof(cell)) % sc_dataalign) != 0)
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{
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begdseg();
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defstorage();
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while (((glb_declared * sizeof(cell)) % sc_dataalign) != 0)
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{
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stgwrite("0 ");
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glb_declared++;
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} /* while */
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} /* if */
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stgwrite("\nSTKSIZE "); /* write stack size (align stack top) */
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outval(sc_stksize - (sc_stksize % sc_dataalign), TRUE);
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}
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/*
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* Start (or restart) the CODE segment.
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*
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* In fact, the code and data segment specifiers are purely informational;
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* the "DUMP" instruction itself already specifies that the following values
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* should go to the data segment. All otherinstructions go to the code
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* segment.
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*
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* Global references: curseg
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*/
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void
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begcseg(void)
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{
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if (curseg != sIN_CSEG)
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{
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stgwrite("\n");
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stgwrite("CODE\t; ");
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outval(code_idx, TRUE);
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curseg = sIN_CSEG;
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} /* endif */
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}
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/*
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* Start (or restart) the DATA segment.
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*
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* Global references: curseg
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*/
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void
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begdseg(void)
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{
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if (curseg != sIN_DSEG)
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{
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stgwrite("\n");
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stgwrite("DATA\t; ");
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outval(glb_declared - litidx, TRUE);
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curseg = sIN_DSEG;
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} /* if */
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}
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void
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setactivefile(int fnumber)
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{
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stgwrite("curfile ");
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outval(fnumber, TRUE);
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}
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cell
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nameincells(char *name)
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{
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cell clen =
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(strlen(name) + sizeof(cell)) & ~(sizeof(cell) - 1);
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return clen;
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}
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void
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setfile(char *name, int fileno)
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{
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if ((sc_debug & sSYMBOLIC) != 0)
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{
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begcseg();
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stgwrite("file ");
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outval(fileno, FALSE);
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stgwrite(" ");
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stgwrite(name);
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stgwrite("\n");
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/* calculate code length */
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code_idx += opcodes(1) + opargs(2) + nameincells(name);
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} /* if */
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}
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void
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setline(int line, int fileno)
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{
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if ((sc_debug & (sSYMBOLIC | sCHKBOUNDS)) != 0)
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{
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stgwrite("line ");
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outval(line, FALSE);
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stgwrite(" ");
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outval(fileno, FALSE);
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stgwrite("\t; ");
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outval(code_idx, TRUE);
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code_idx += opcodes(1) + opargs(2);
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} /* if */
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}
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/* setlabel
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*
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* Post a code label (specified as a number), on a new line.
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*/
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void
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setlabel(int number)
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{
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assert(number >= 0);
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stgwrite("l.");
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stgwrite((char *)itoh(number));
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/* To assist verification of the assembled code, put the address of the
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* label as a comment. However, labels that occur inside an expression
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* may move (through optimization or through re-ordering). So write the
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* address only if it is known to accurate.
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*/
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if (!staging)
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{
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stgwrite("\t\t; ");
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outval(code_idx, FALSE);
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} /* if */
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stgwrite("\n");
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}
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/* Write a token that signifies the end of an expression, or the end of a
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* function parameter. This allows several simple optimizations by the peephole
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* optimizer.
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*/
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void
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endexpr(int fullexpr)
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{
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if (fullexpr)
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stgwrite("\t;$exp\n");
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else
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stgwrite("\t;$par\n");
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}
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/* startfunc - declare a CODE entry point (function start)
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*
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* Global references: funcstatus (referred to only)
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*/
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void
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startfunc(char *fname __UNUSED__)
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{
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stgwrite("\tproc");
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stgwrite("\n");
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code_idx += opcodes(1);
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}
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/* endfunc
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*
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* Declare a CODE ending point (function end)
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*/
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void
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endfunc(void)
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{
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stgwrite("\n"); /* skip a line */
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}
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/* alignframe
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*
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* Aligns the frame (and the stack) of the current function to a multiple
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* of the specified byte count. Two caveats: the alignment ("numbytes") should
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* be a power of 2, and this alignment must be done right after the frame
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* is set up (before the first variable is declared)
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*/
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void
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alignframe(int numbytes)
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{
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#if !defined NDEBUG
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/* "numbytes" should be a power of 2 for this code to work */
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int i, count = 0;
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for (i = 0; i < (int)(sizeof(numbytes) * 8); i++)
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if (numbytes & (1 << i))
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count++;
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assert(count == 1);
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#endif
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stgwrite("\tlctrl 4\n"); /* get STK in PRI */
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stgwrite("\tconst.alt "); /* get ~(numbytes-1) in ALT */
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outval(~(numbytes - 1), TRUE);
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stgwrite("\tand\n"); /* PRI = STK "and" ~(numbytes-1) */
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stgwrite("\tsctrl 4\n"); /* set the new value of STK ... */
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stgwrite("\tsctrl 5\n"); /* ... and FRM */
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code_idx += opcodes(5) + opargs(4);
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}
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/* Define a variable or function
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*/
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void
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defsymbol(char *name, int ident, int vclass, cell offset, int tag)
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{
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if ((sc_debug & sSYMBOLIC) != 0)
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{
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begcseg(); /* symbol definition in code segment */
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stgwrite("symbol ");
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stgwrite(name);
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stgwrite(" ");
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outval(offset, FALSE);
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stgwrite(" ");
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outval(vclass, FALSE);
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stgwrite(" ");
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outval(ident, TRUE);
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code_idx += opcodes(1) + opargs(3) + nameincells(name); /* class and ident encoded in "flags" */
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/* also write the optional tag */
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if (tag != 0)
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{
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assert((tag & TAGMASK) != 0);
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stgwrite("symtag ");
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outval(tag & TAGMASK, TRUE);
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code_idx += opcodes(1) + opargs(1);
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} /* if */
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} /* if */
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}
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void
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symbolrange(int level, cell size)
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{
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if ((sc_debug & sSYMBOLIC) != 0)
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{
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begcseg(); /* symbol definition in code segment */
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stgwrite("srange ");
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outval(level, FALSE);
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stgwrite(" ");
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outval(size, TRUE);
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code_idx += opcodes(1) + opargs(2);
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} /* if */
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}
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/* rvalue
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*
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* Generate code to get the value of a symbol into "primary".
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*/
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void
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rvalue(value * lval)
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{
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symbol *sym;
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sym = lval->sym;
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if (lval->ident == iARRAYCELL)
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{
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/* indirect fetch, address already in PRI */
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stgwrite("\tload.i\n");
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code_idx += opcodes(1);
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}
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else if (lval->ident == iARRAYCHAR)
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{
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/* indirect fetch of a character from a pack, address already in PRI */
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stgwrite("\tlodb.i ");
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outval(charbits / 8, TRUE); /* read one or two bytes */
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code_idx += opcodes(1) + opargs(1);
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}
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else if (lval->ident == iREFERENCE)
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{
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/* indirect fetch, but address not yet in PRI */
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assert(sym != NULL);
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assert(sym->vclass == sLOCAL); /* global references don't exist in Small */
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if (sym->vclass == sLOCAL)
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stgwrite("\tlref.s.pri ");
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else
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stgwrite("\tlref.pri ");
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outval(sym->addr, TRUE);
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markusage(sym, uREAD);
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code_idx += opcodes(1) + opargs(1);
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}
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else
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{
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/* direct or stack relative fetch */
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assert(sym != NULL);
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if (sym->vclass == sLOCAL)
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stgwrite("\tload.s.pri ");
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else
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stgwrite("\tload.pri ");
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outval(sym->addr, TRUE);
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markusage(sym, uREAD);
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code_idx += opcodes(1) + opargs(1);
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} /* if */
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}
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/*
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* Get the address of a symbol into the primary register (used for arrays,
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* and for passing arguments by reference).
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*/
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void
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address(symbol * sym)
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{
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assert(sym != NULL);
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/* the symbol can be a local array, a global array, or an array
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* that is passed by reference.
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*/
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if (sym->ident == iREFARRAY || sym->ident == iREFERENCE)
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{
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/* reference to a variable or to an array; currently this is
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* always a local variable */
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stgwrite("\tload.s.pri ");
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}
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else
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{
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/* a local array or local variable */
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if (sym->vclass == sLOCAL)
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stgwrite("\taddr.pri ");
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else
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stgwrite("\tconst.pri ");
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} /* if */
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outval(sym->addr, TRUE);
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markusage(sym, uREAD);
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code_idx += opcodes(1) + opargs(1);
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}
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/* store
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*
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* Saves the contents of "primary" into a memory cell, either directly
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* or indirectly (at the address given in the alternate register).
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*/
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void
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store(value * lval)
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{
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symbol *sym;
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sym = lval->sym;
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if (lval->ident == iARRAYCELL)
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{
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/* store at address in ALT */
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stgwrite("\tstor.i\n");
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code_idx += opcodes(1);
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}
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else if (lval->ident == iARRAYCHAR)
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{
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/* store at address in ALT */
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stgwrite("\tstrb.i ");
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outval(charbits / 8, TRUE); /* write one or two bytes */
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code_idx += opcodes(1) + opargs(1);
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}
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else if (lval->ident == iREFERENCE)
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{
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assert(sym != NULL);
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if (sym->vclass == sLOCAL)
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stgwrite("\tsref.s.pri ");
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else
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stgwrite("\tsref.pri ");
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outval(sym->addr, TRUE);
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code_idx += opcodes(1) + opargs(1);
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}
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else
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{
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assert(sym != NULL);
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markusage(sym, uWRITTEN);
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if (sym->vclass == sLOCAL)
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stgwrite("\tstor.s.pri ");
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else
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stgwrite("\tstor.pri ");
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outval(sym->addr, TRUE);
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code_idx += opcodes(1) + opargs(1);
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} /* if */
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}
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/* source must in PRI, destination address in ALT. The "size"
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* parameter is in bytes, not cells.
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*/
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void
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memcopy(cell size)
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{
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stgwrite("\tmovs ");
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outval(size, TRUE);
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code_idx += opcodes(1) + opargs(1);
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}
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/* Address of the source must already have been loaded in PRI
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* "size" is the size in bytes (not cells).
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*/
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void
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copyarray(symbol * sym, cell size)
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{
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assert(sym != NULL);
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/* the symbol can be a local array, a global array, or an array
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* that is passed by reference.
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*/
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if (sym->ident == iREFARRAY)
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{
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/* reference to an array; currently this is always a local variable */
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assert(sym->vclass == sLOCAL); /* symbol must be stack relative */
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stgwrite("\tload.s.alt ");
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}
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else
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{
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/* a local or global array */
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if (sym->vclass == sLOCAL)
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stgwrite("\taddr.alt ");
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else
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stgwrite("\tconst.alt ");
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} /* if */
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outval(sym->addr, TRUE);
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markusage(sym, uWRITTEN);
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code_idx += opcodes(1) + opargs(1);
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memcopy(size);
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}
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void
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fillarray(symbol * sym, cell size, cell val)
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{
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const1(val); /* load val in PRI */
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assert(sym != NULL);
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/* the symbol can be a local array, a global array, or an array
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* that is passed by reference.
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*/
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if (sym->ident == iREFARRAY)
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{
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/* reference to an array; currently this is always a local variable */
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assert(sym->vclass == sLOCAL); /* symbol must be stack relative */
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stgwrite("\tload.s.alt ");
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}
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else
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{
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/* a local or global array */
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if (sym->vclass == sLOCAL)
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stgwrite("\taddr.alt ");
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else
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stgwrite("\tconst.alt ");
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} /* if */
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outval(sym->addr, TRUE);
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markusage(sym, uWRITTEN);
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stgwrite("\tfill ");
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outval(size, TRUE);
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code_idx += opcodes(2) + opargs(2);
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}
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/*
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* Instruction to get an immediate value into the primary register
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*/
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void
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const1(cell val)
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{
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if (val == 0)
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{
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stgwrite("\tzero.pri\n");
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code_idx += opcodes(1);
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}
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else
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{
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stgwrite("\tconst.pri ");
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outval(val, TRUE);
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code_idx += opcodes(1) + opargs(1);
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} /* if */
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}
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/*
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* Instruction to get an immediate value into the secondary register
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*/
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void
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const2(cell val)
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{
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if (val == 0)
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{
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stgwrite("\tzero.alt\n");
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code_idx += opcodes(1);
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}
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else
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{
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stgwrite("\tconst.alt ");
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outval(val, TRUE);
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code_idx += opcodes(1) + opargs(1);
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} /* if */
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}
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/* Copy value in secondary register to the primary register */
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void
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moveto1(void)
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{
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stgwrite("\tmove.pri\n");
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code_idx += opcodes(1) + opargs(0);
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}
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/*
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* Push primary register onto the stack
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*/
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void
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push1(void)
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{
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stgwrite("\tpush.pri\n");
|
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code_idx += opcodes(1);
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}
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|
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/*
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* Push alternate register onto the stack
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|
*/
|
|
void
|
|
push2(void)
|
|
{
|
|
stgwrite("\tpush.alt\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* Push a constant value onto the stack
|
|
*/
|
|
void
|
|
pushval(cell val)
|
|
{
|
|
stgwrite("\tpush.c ");
|
|
outval(val, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
}
|
|
|
|
/*
|
|
* pop stack to the primary register
|
|
*/
|
|
void
|
|
pop1(void)
|
|
{
|
|
stgwrite("\tpop.pri\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* pop stack to the secondary register
|
|
*/
|
|
void
|
|
pop2(void)
|
|
{
|
|
stgwrite("\tpop.alt\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* swap the top-of-stack with the value in primary register
|
|
*/
|
|
void
|
|
swap1(void)
|
|
{
|
|
stgwrite("\tswap.pri\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/* Switch statements
|
|
* The "switch" statement generates a "case" table using the "CASE" opcode.
|
|
* The case table contains a list of records, each record holds a comparison
|
|
* value and a label to branch to on a match. The very first record is an
|
|
* exception: it holds the size of the table (excluding the first record) and
|
|
* the label to branch to when none of the values in the case table match.
|
|
* The case table is sorted on the comparison value. This allows more advanced
|
|
* abstract machines to sift the case table with a binary search.
|
|
*/
|
|
void
|
|
ffswitch(int label)
|
|
{
|
|
stgwrite("\tswitch ");
|
|
outval(label, TRUE); /* the label is the address of the case table */
|
|
code_idx += opcodes(1) + opargs(1);
|
|
}
|
|
|
|
void
|
|
ffcase(cell val, char *labelname, int newtable)
|
|
{
|
|
if (newtable)
|
|
{
|
|
stgwrite("\tcasetbl\n");
|
|
code_idx += opcodes(1);
|
|
} /* if */
|
|
stgwrite("\tcase ");
|
|
outval(val, FALSE);
|
|
stgwrite(" ");
|
|
stgwrite(labelname);
|
|
stgwrite("\n");
|
|
code_idx += opcodes(0) + opargs(2);
|
|
}
|
|
|
|
/*
|
|
* Call specified function
|
|
*/
|
|
void
|
|
ffcall(symbol * sym, int numargs)
|
|
{
|
|
assert(sym != NULL);
|
|
assert(sym->ident == iFUNCTN);
|
|
if ((sym->usage & uNATIVE) != 0)
|
|
{
|
|
/* reserve a SYSREQ id if called for the first time */
|
|
if (sc_status == statWRITE && (sym->usage & uREAD) == 0
|
|
&& sym->addr >= 0)
|
|
sym->addr = ntv_funcid++;
|
|
stgwrite("\tsysreq.c ");
|
|
outval(sym->addr, FALSE);
|
|
stgwrite("\n\tstack ");
|
|
outval((numargs + 1) * sizeof(cell), TRUE);
|
|
code_idx += opcodes(2) + opargs(2);
|
|
}
|
|
else
|
|
{
|
|
/* normal function */
|
|
stgwrite("\tcall ");
|
|
stgwrite(sym->name);
|
|
stgwrite("\n");
|
|
code_idx += opcodes(1) + opargs(1);
|
|
} /* if */
|
|
}
|
|
|
|
/* Return from function
|
|
*
|
|
* Global references: funcstatus (referred to only)
|
|
*/
|
|
void
|
|
ffret(void)
|
|
{
|
|
stgwrite("\tretn\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
void
|
|
ffabort(int reason)
|
|
{
|
|
stgwrite("\thalt ");
|
|
outval(reason, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
}
|
|
|
|
void
|
|
ffbounds(cell size)
|
|
{
|
|
if ((sc_debug & sCHKBOUNDS) != 0)
|
|
{
|
|
stgwrite("\tbounds ");
|
|
outval(size, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
} /* if */
|
|
}
|
|
|
|
/*
|
|
* Jump to local label number (the number is converted to a name)
|
|
*/
|
|
void
|
|
jumplabel(int number)
|
|
{
|
|
stgwrite("\tjump ");
|
|
outval(number, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
}
|
|
|
|
/*
|
|
* Define storage (global and static variables)
|
|
*/
|
|
void
|
|
defstorage(void)
|
|
{
|
|
stgwrite("dump ");
|
|
}
|
|
|
|
/*
|
|
* Inclrement/decrement stack pointer. Note that this routine does
|
|
* nothing if the delta is zero.
|
|
*/
|
|
void
|
|
modstk(int delta)
|
|
{
|
|
if (delta)
|
|
{
|
|
stgwrite("\tstack ");
|
|
outval(delta, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
} /* if */
|
|
}
|
|
|
|
/* set the stack to a hard offset from the frame */
|
|
void
|
|
setstk(cell val)
|
|
{
|
|
stgwrite("\tlctrl 5\n"); /* get FRM */
|
|
assert(val <= 0); /* STK should always become <= FRM */
|
|
if (val < 0)
|
|
{
|
|
stgwrite("\tadd.c ");
|
|
outval(val, TRUE); /* add (negative) offset */
|
|
code_idx += opcodes(1) + opargs(1);
|
|
// ??? write zeros in the space between STK and the val in PRI (the new stk)
|
|
// get val of STK in ALT
|
|
// zero PRI
|
|
// need new FILL opcode that takes a variable size
|
|
} /* if */
|
|
stgwrite("\tsctrl 4\n"); /* store in STK */
|
|
code_idx += opcodes(2) + opargs(2);
|
|
}
|
|
|
|
void
|
|
modheap(int delta)
|
|
{
|
|
if (delta)
|
|
{
|
|
stgwrite("\theap ");
|
|
outval(delta, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
} /* if */
|
|
}
|
|
|
|
void
|
|
setheap_pri(void)
|
|
{
|
|
stgwrite("\theap "); /* ALT = HEA++ */
|
|
outval(sizeof(cell), TRUE);
|
|
stgwrite("\tstor.i\n"); /* store PRI (default value) at address ALT */
|
|
stgwrite("\tmove.pri\n"); /* move ALT to PRI: PRI contains the address */
|
|
code_idx += opcodes(3) + opargs(1);
|
|
}
|
|
|
|
void
|
|
setheap(cell val)
|
|
{
|
|
stgwrite("\tconst.pri "); /* load default val in PRI */
|
|
outval(val, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
setheap_pri();
|
|
}
|
|
|
|
/*
|
|
* Convert a cell number to a "byte" address; i.e. double or quadruple
|
|
* the primary register.
|
|
*/
|
|
void
|
|
cell2addr(void)
|
|
{
|
|
#if defined(BIT16)
|
|
stgwrite("\tshl.c.pri 1\n");
|
|
#else
|
|
stgwrite("\tshl.c.pri 2\n");
|
|
#endif
|
|
code_idx += opcodes(1) + opargs(1);
|
|
}
|
|
|
|
/*
|
|
* Double or quadruple the alternate register.
|
|
*/
|
|
void
|
|
cell2addr_alt(void)
|
|
{
|
|
#if defined(BIT16)
|
|
stgwrite("\tshl.c.alt 1\n");
|
|
#else
|
|
stgwrite("\tshl.c.alt 2\n");
|
|
#endif
|
|
code_idx += opcodes(1) + opargs(1);
|
|
}
|
|
|
|
/*
|
|
* Convert "distance of addresses" to "number of cells" in between.
|
|
* Or convert a number of packed characters to the number of cells (with
|
|
* truncation).
|
|
*/
|
|
void
|
|
addr2cell(void)
|
|
{
|
|
#if defined(BIT16)
|
|
stgwrite("\tshr.c.pri 1\n");
|
|
#else
|
|
stgwrite("\tshr.c.pri 2\n");
|
|
#endif
|
|
code_idx += opcodes(1) + opargs(1);
|
|
}
|
|
|
|
/* Convert from character index to byte address. This routine does
|
|
* nothing if a character has the size of a byte.
|
|
*/
|
|
void
|
|
char2addr(void)
|
|
{
|
|
if (charbits == 16)
|
|
{
|
|
stgwrite("\tshl.c.pri 1\n");
|
|
code_idx += opcodes(1) + opargs(1);
|
|
} /* if */
|
|
}
|
|
|
|
/* Align PRI (which should hold a character index) to an address.
|
|
* The first character in a "pack" occupies the highest bits of
|
|
* the cell. This is at the lower memory address on Big Endian
|
|
* computers and on the higher address on Little Endian computers.
|
|
* The ALIGN.pri/alt instructions must solve this machine dependence;
|
|
* that is, on Big Endian computers, ALIGN.pri/alt shuold do nothing
|
|
* and on Little Endian computers they should toggle the address.
|
|
*/
|
|
void
|
|
charalign(void)
|
|
{
|
|
stgwrite("\talign.pri ");
|
|
outval(charbits / 8, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
}
|
|
|
|
/*
|
|
* Add a constant to the primary register.
|
|
*/
|
|
void
|
|
addconst(cell val)
|
|
{
|
|
if (val != 0)
|
|
{
|
|
stgwrite("\tadd.c ");
|
|
outval(val, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
} /* if */
|
|
}
|
|
|
|
/*
|
|
* signed multiply of primary and secundairy registers (result in primary)
|
|
*/
|
|
void
|
|
os_mult(void)
|
|
{
|
|
stgwrite("\tsmul\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* signed divide of alternate register by primary register (quotient in
|
|
* primary; remainder in alternate)
|
|
*/
|
|
void
|
|
os_div(void)
|
|
{
|
|
stgwrite("\tsdiv.alt\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* modulus of (alternate % primary), result in primary (signed)
|
|
*/
|
|
void
|
|
os_mod(void)
|
|
{
|
|
stgwrite("\tsdiv.alt\n");
|
|
stgwrite("\tmove.pri\n"); /* move ALT to PRI */
|
|
code_idx += opcodes(2);
|
|
}
|
|
|
|
/*
|
|
* Add primary and alternate registers (result in primary).
|
|
*/
|
|
void
|
|
ob_add(void)
|
|
{
|
|
stgwrite("\tadd\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* subtract primary register from alternate register (result in primary)
|
|
*/
|
|
void
|
|
ob_sub(void)
|
|
{
|
|
stgwrite("\tsub.alt\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* arithmic shift left alternate register the number of bits
|
|
* given in the primary register (result in primary).
|
|
* There is no need for a "logical shift left" routine, since
|
|
* logical shift left is identical to arithmic shift left.
|
|
*/
|
|
void
|
|
ob_sal(void)
|
|
{
|
|
stgwrite("\txchg\n");
|
|
stgwrite("\tshl\n");
|
|
code_idx += opcodes(2);
|
|
}
|
|
|
|
/*
|
|
* arithmic shift right alternate register the number of bits
|
|
* given in the primary register (result in primary).
|
|
*/
|
|
void
|
|
os_sar(void)
|
|
{
|
|
stgwrite("\txchg\n");
|
|
stgwrite("\tsshr\n");
|
|
code_idx += opcodes(2);
|
|
}
|
|
|
|
/*
|
|
* logical (unsigned) shift right of the alternate register by the
|
|
* number of bits given in the primary register (result in primary).
|
|
*/
|
|
void
|
|
ou_sar(void)
|
|
{
|
|
stgwrite("\txchg\n");
|
|
stgwrite("\tshr\n");
|
|
code_idx += opcodes(2);
|
|
}
|
|
|
|
/*
|
|
* inclusive "or" of primary and secondary registers (result in primary)
|
|
*/
|
|
void
|
|
ob_or(void)
|
|
{
|
|
stgwrite("\tor\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* "exclusive or" of primary and alternate registers (result in primary)
|
|
*/
|
|
void
|
|
ob_xor(void)
|
|
{
|
|
stgwrite("\txor\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* "and" of primary and secundairy registers (result in primary)
|
|
*/
|
|
void
|
|
ob_and(void)
|
|
{
|
|
stgwrite("\tand\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* test ALT==PRI; result in primary register (1 or 0).
|
|
*/
|
|
void
|
|
ob_eq(void)
|
|
{
|
|
stgwrite("\teq\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* test ALT!=PRI
|
|
*/
|
|
void
|
|
ob_ne(void)
|
|
{
|
|
stgwrite("\tneq\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/* The abstract machine defines the relational instructions so that PRI is
|
|
* on the left side and ALT on the right side of the operator. For example,
|
|
* SLESS sets PRI to either 1 or 0 depending on whether the expression
|
|
* "PRI < ALT" is true.
|
|
*
|
|
* The compiler generates comparisons with ALT on the left side of the
|
|
* relational operator and PRI on the right side. The XCHG instruction
|
|
* prefixing the relational operators resets this. We leave it to the
|
|
* peephole optimizer to choose more compact instructions where possible.
|
|
*/
|
|
|
|
/* Relational operator prefix for chained relational expressions. The
|
|
* "suffix" code restores the stack.
|
|
* For chained relational operators, the goal is to keep the comparison
|
|
* result "so far" in PRI and the value of the most recent operand in
|
|
* ALT, ready for a next comparison.
|
|
* The "prefix" instruction pushed the comparison result (PRI) onto the
|
|
* stack and moves the value of ALT into PRI. If there is a next comparison,
|
|
* PRI can now serve as the "left" operand of the relational operator.
|
|
*/
|
|
void
|
|
relop_prefix(void)
|
|
{
|
|
stgwrite("\tpush.pri\n");
|
|
stgwrite("\tmove.pri\n");
|
|
code_idx += opcodes(2);
|
|
}
|
|
|
|
void
|
|
relop_suffix(void)
|
|
{
|
|
stgwrite("\tswap.alt\n");
|
|
stgwrite("\tand\n");
|
|
stgwrite("\tpop.alt\n");
|
|
code_idx += opcodes(3);
|
|
}
|
|
|
|
/*
|
|
* test ALT<PRI (signed)
|
|
*/
|
|
void
|
|
os_lt(void)
|
|
{
|
|
stgwrite("\txchg\n");
|
|
stgwrite("\tsless\n");
|
|
code_idx += opcodes(2);
|
|
}
|
|
|
|
/*
|
|
* test ALT<=PRI (signed)
|
|
*/
|
|
void
|
|
os_le(void)
|
|
{
|
|
stgwrite("\txchg\n");
|
|
stgwrite("\tsleq\n");
|
|
code_idx += opcodes(2);
|
|
}
|
|
|
|
/*
|
|
* test ALT>PRI (signed)
|
|
*/
|
|
void
|
|
os_gt(void)
|
|
{
|
|
stgwrite("\txchg\n");
|
|
stgwrite("\tsgrtr\n");
|
|
code_idx += opcodes(2);
|
|
}
|
|
|
|
/*
|
|
* test ALT>=PRI (signed)
|
|
*/
|
|
void
|
|
os_ge(void)
|
|
{
|
|
stgwrite("\txchg\n");
|
|
stgwrite("\tsgeq\n");
|
|
code_idx += opcodes(2);
|
|
}
|
|
|
|
/*
|
|
* logical negation of primary register
|
|
*/
|
|
void
|
|
lneg(void)
|
|
{
|
|
stgwrite("\tnot\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* two's complement primary register
|
|
*/
|
|
void
|
|
neg(void)
|
|
{
|
|
stgwrite("\tneg\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* one's complement of primary register
|
|
*/
|
|
void
|
|
invert(void)
|
|
{
|
|
stgwrite("\tinvert\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/*
|
|
* nop
|
|
*/
|
|
void
|
|
nooperation(void)
|
|
{
|
|
stgwrite("\tnop\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
|
|
/* increment symbol
|
|
*/
|
|
void
|
|
inc(value * lval)
|
|
{
|
|
symbol *sym;
|
|
|
|
sym = lval->sym;
|
|
if (lval->ident == iARRAYCELL)
|
|
{
|
|
/* indirect increment, address already in PRI */
|
|
stgwrite("\tinc.i\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
else if (lval->ident == iARRAYCHAR)
|
|
{
|
|
/* indirect increment of single character, address already in PRI */
|
|
stgwrite("\tpush.pri\n");
|
|
stgwrite("\tpush.alt\n");
|
|
stgwrite("\tmove.alt\n"); /* copy address */
|
|
stgwrite("\tlodb.i "); /* read from PRI into PRI */
|
|
outval(charbits / 8, TRUE); /* read one or two bytes */
|
|
stgwrite("\tinc.pri\n");
|
|
stgwrite("\tstrb.i "); /* write PRI to ALT */
|
|
outval(charbits / 8, TRUE); /* write one or two bytes */
|
|
stgwrite("\tpop.alt\n");
|
|
stgwrite("\tpop.pri\n");
|
|
code_idx += opcodes(8) + opargs(2);
|
|
}
|
|
else if (lval->ident == iREFERENCE)
|
|
{
|
|
assert(sym != NULL);
|
|
stgwrite("\tpush.pri\n");
|
|
/* load dereferenced value */
|
|
assert(sym->vclass == sLOCAL); /* global references don't exist in Small */
|
|
if (sym->vclass == sLOCAL)
|
|
stgwrite("\tlref.s.pri ");
|
|
else
|
|
stgwrite("\tlref.pri ");
|
|
outval(sym->addr, TRUE);
|
|
/* increment */
|
|
stgwrite("\tinc.pri\n");
|
|
/* store dereferenced value */
|
|
if (sym->vclass == sLOCAL)
|
|
stgwrite("\tsref.s.pri ");
|
|
else
|
|
stgwrite("\tsref.pri ");
|
|
outval(sym->addr, TRUE);
|
|
stgwrite("\tpop.pri\n");
|
|
code_idx += opcodes(5) + opargs(2);
|
|
}
|
|
else
|
|
{
|
|
/* local or global variable */
|
|
assert(sym != NULL);
|
|
if (sym->vclass == sLOCAL)
|
|
stgwrite("\tinc.s ");
|
|
else
|
|
stgwrite("\tinc ");
|
|
outval(sym->addr, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
} /* if */
|
|
}
|
|
|
|
/* decrement symbol
|
|
*
|
|
* in case of an integer pointer, the symbol must be incremented by 2.
|
|
*/
|
|
void
|
|
dec(value * lval)
|
|
{
|
|
symbol *sym;
|
|
|
|
sym = lval->sym;
|
|
if (lval->ident == iARRAYCELL)
|
|
{
|
|
/* indirect decrement, address already in PRI */
|
|
stgwrite("\tdec.i\n");
|
|
code_idx += opcodes(1);
|
|
}
|
|
else if (lval->ident == iARRAYCHAR)
|
|
{
|
|
/* indirect decrement of single character, address already in PRI */
|
|
stgwrite("\tpush.pri\n");
|
|
stgwrite("\tpush.alt\n");
|
|
stgwrite("\tmove.alt\n"); /* copy address */
|
|
stgwrite("\tlodb.i "); /* read from PRI into PRI */
|
|
outval(charbits / 8, TRUE); /* read one or two bytes */
|
|
stgwrite("\tdec.pri\n");
|
|
stgwrite("\tstrb.i "); /* write PRI to ALT */
|
|
outval(charbits / 8, TRUE); /* write one or two bytes */
|
|
stgwrite("\tpop.alt\n");
|
|
stgwrite("\tpop.pri\n");
|
|
code_idx += opcodes(8) + opargs(2);
|
|
}
|
|
else if (lval->ident == iREFERENCE)
|
|
{
|
|
assert(sym != NULL);
|
|
stgwrite("\tpush.pri\n");
|
|
/* load dereferenced value */
|
|
assert(sym->vclass == sLOCAL); /* global references don't exist in Small */
|
|
if (sym->vclass == sLOCAL)
|
|
stgwrite("\tlref.s.pri ");
|
|
else
|
|
stgwrite("\tlref.pri ");
|
|
outval(sym->addr, TRUE);
|
|
/* decrement */
|
|
stgwrite("\tdec.pri\n");
|
|
/* store dereferenced value */
|
|
if (sym->vclass == sLOCAL)
|
|
stgwrite("\tsref.s.pri ");
|
|
else
|
|
stgwrite("\tsref.pri ");
|
|
outval(sym->addr, TRUE);
|
|
stgwrite("\tpop.pri\n");
|
|
code_idx += opcodes(5) + opargs(2);
|
|
}
|
|
else
|
|
{
|
|
/* local or global variable */
|
|
assert(sym != NULL);
|
|
if (sym->vclass == sLOCAL)
|
|
stgwrite("\tdec.s ");
|
|
else
|
|
stgwrite("\tdec ");
|
|
outval(sym->addr, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
} /* if */
|
|
}
|
|
|
|
/*
|
|
* Jumps to "label" if PRI != 0
|
|
*/
|
|
void
|
|
jmp_ne0(int number)
|
|
{
|
|
stgwrite("\tjnz ");
|
|
outval(number, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
}
|
|
|
|
/*
|
|
* Jumps to "label" if PRI == 0
|
|
*/
|
|
void
|
|
jmp_eq0(int number)
|
|
{
|
|
stgwrite("\tjzer ");
|
|
outval(number, TRUE);
|
|
code_idx += opcodes(1) + opargs(1);
|
|
}
|
|
|
|
/* write a value in hexadecimal; optionally adds a newline */
|
|
void
|
|
outval(cell val, int newline)
|
|
{
|
|
stgwrite(itoh(val));
|
|
if (newline)
|
|
stgwrite("\n");
|
|
}
|