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- static char *sccsid =
- "@(#) disfp.c, Ver. 2.1 created 00:00:00 87/09/01";
- /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- * *
- * Copyright (C) 1987 G. M. Harding, all rights reserved *
- * *
- * Permission to copy and redistribute is hereby granted, *
- * provided full source code, with all copyright notices, *
- * accompanies any redistribution. *
- * *
- * This file contains handler routines for the numeric op- *
- * codes of the 8087 co-processor, as well as a few other *
- * opcodes which are related to 8087 emulation. *
- * *
- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
- #include "dis.h" /* Disassembler declarations */
- #define FPINT0 0xd8 /* Floating-point interrupts */
- #define FPINT1 0xd9
- #define FPINT2 0xda
- #define FPINT3 0xdb
- #define FPINT4 0xdc
- #define FPINT5 0xdd
- #define FPINT6 0xde
- #define FPINT7 0xdf
- /* Test for floating opcodes */
- #define ISFLOP(x) \
- (((x) >= FPINT0) && ((x) <= FPINT7))
- /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- * *
- * This is the handler for the escape family of opcodes. *
- * These opcodes place the contents of a specified memory *
- * location on the system bus, for access by a peripheral *
- * or by a co-processor such as the 8087. (The 8087 NDP is *
- * accessed only via bus escapes.) Due to a bug in the *
- * PC/IX assembler, the "esc" mnemonic is not recognized; *
- * consequently, escape opcodes are disassembled as .byte *
- * directives, with the appropriate mnemonic and operand *
- * included as a comment. FOR NOW, those escape sequences *
- * corresponding to 8087 opcodes are treated as simple *
- * escapes. *
- * *
- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
- void
- eshand(j)
- register int j; /* Pointer to optab[] entry */
- {/* * * * * * * * * * START OF eshand() * * * * * * * * * */
- register char *a;
- register int k;
- objini(j);
- FETCH(k);
- a = mtrans((j & 0xfd),(k & 0xc7),TR_STD);
- mtrunc(a);
- printf("\t.byte\t0x%02.2x\t\t| esc\t%s\n",j,a);
- for (k = 1; k < objptr; ++k)
- printf("\t.byte\t0x%02.2x\n",objbuf[k]);
- }/* * * * * * * * * * * END OF eshand() * * * * * * * * * * */
- /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- * *
- * This is the handler routine for floating-point opcodes. *
- * Since PC/IX must accommodate systems with and without *
- * 8087 co-processors, it allows floating-point operations *
- * to be initiated in either of two ways: by a software *
- * interrput whose type is in the range 0xd8 through 0xdf, *
- * or by a CPU escape sequence, which is invoked by an op- *
- * code in the same range. In either case, the subsequent *
- * byte determines the actual numeric operation to be per- *
- * formed. However, depending on the method of access, *
- * either one or two code bytes will precede that byte, *
- * and the fphand() routine has no way of knowing whether *
- * it was invoked by interrupt or by an escape sequence. *
- * Therefore, unlike all of the other handler routines ex- *
- * cept dfhand(), fphand() does not initialize the object *
- * buffer, leaving that chore to the caller. *
- * *
- * FOR NOW, fphand() does not disassemble floating-point *
- * opcodes to floating mnemonics, but simply outputs the *
- * object code as .byte directives. *
- * *
- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
- void
- fphand(j)
- register int j; /* Pointer to optab[] entry */
- {/* * * * * * * * * * START OF fphand() * * * * * * * * * */
- register int k;
- segflg = 0;
- FETCH(k);
- printf("\t.byte\t0x%02.2x\t\t| 8087 code sequence\n",
- objbuf[0]);
- for (k = 1; k < objptr; ++k)
- printf("\t.byte\t0x%02.2x\n",objbuf[k]);
- /* objout(); FOR NOW */
- }/* * * * * * * * * * * END OF fphand() * * * * * * * * * * */
- /* * * * * * * * * * * * * * * * * * * * * * * * * * * * * *
- * *
- * This is the handler for variable software interrupt *
- * opcodes. It is included in this file because PC/IX im- *
- * plements its software floating-point emulation by means *
- * of interrupts. Any interrupt in the range 0xd8 through *
- * 0xdf is an NDP-emulation interrupt, and is specially *
- * handled by the assembler. *
- * *
- * * * * * * * * * * * * * * * * * * * * * * * * * * * * * */
- void
- inhand(j)
- register int j; /* Pointer to optab[] entry */
- {/* * * * * * * * * * START OF inhand() * * * * * * * * * */
- register int k;
- objini(j);
- FETCH(k);
- if (ISFLOP(k))
- {
- fphand(k);
- return;
- }
- printf("%s\t$%02x\n",optab[j].text,k);
- objout();
- }/* * * * * * * * * * * END OF inhand() * * * * * * * * * * */
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