kdb.c

这是一个同样来自贝尔实验室的和UNIX有着渊源的操作系统, 其简洁的设计和实现易于我们学习和理解

	}
	bprint(i, "%ux(R%d)", i->simm13, i->rs1);
}

static void
unimp(Instr *i, char *m)
{
	bprint(i, "%T", m);
}

static char	*bratab[16] = {	/* page 91 */
	[0X8]	"A",
	[0X0]	"N",
	[0X9]	"NE",
	[0X1]	"E",
	[0XA]	"G",
	[0X2]	"LE",
	[0XB]	"GE",
	[0X3]	"L",
	[0XC]	"GU",
	[0X4]	"LEU",
	[0XD]	"CC",
	[0X5]	"CS",
	[0XE]	"POS",
	[0X6]	"NEG",
	[0XF]	"VC",
	[0X7]	"VS",
};

static char	*fbratab[16] = {	/* page 91 */
	[0X8]	"A",
	[0X0]	"N",
	[0X7]	"U",
	[0X6]	"G",
	[0X5]	"UG",
	[0X4]	"L",
	[0X3]	"UL",
	[0X2]	"LG",
	[0X1]	"NE",
	[0X9]	"E",
	[0XA]	"UE",
	[0XB]	"GE",
	[0XC]	"UGE",
	[0XD]	"LE",
	[0XE]	"ULE",
	[0XF]	"O",
};

static char	*cbratab[16] = {	/* page 91 */
	[0X8]	"A",
	[0X0]	"N",
	[0X7]	"3",
	[0X6]	"2",
	[0X5]	"23",
	[0X4]	"1",
	[0X3]	"13",
	[0X2]	"12",
	[0X1]	"123",
	[0X9]	"0",
	[0XA]	"03",
	[0XB]	"02",
	[0XC]	"023",
	[0XD]	"01",
	[0XE]	"013",
	[0XF]	"012",
};

static void
bra1(Instr *i, char *m, char *tab[])
{
	long imm;

	imm = i->simmdisp22;
	if(i->a)
		bprint(i, "%T%T.%c\t", m, tab[i->cond], 'A'+dascase);
	else
		bprint(i, "%T%T\t", m, tab[i->cond]);
	i->curr += symoff(i->curr, i->end-i->curr, i->addr+4*imm, CTEXT);
	if (!dascase)
		bprint(i, "(SB)");
}

static void
bra(Instr *i, char *m)			/* page 91 */
{
	bra1(i, m, bratab);
}

static void
fbra(Instr *i, char *m)			/* page 93 */
{
	bra1(i, m, fbratab);
}

static void
cbra(Instr *i, char *m)			/* page 95 */
{
	bra1(i, m, cbratab);
}

static void
trap(Instr *i, char *m)			/* page 101 */
{
	if(i->i == 0)
		bprint(i, "%T%T\tR%d+R%d", m, bratab[i->cond], i->rs2, i->rs1);
	else
		bprint(i, "%T%T\t$%ux+R%d", m, bratab[i->cond], i->simm13, i->rs1);
}

static void
sethi(Instr *i, char *m)		/* page 89 */
{
	ulong imm;

	imm = i->immdisp22<<10;
	if(dascase){
		bprint(i, "%T\t%lux, R%d", m, imm, i->rd);
		return;
	}
	if(imm==0 && i->rd==0){
		bprint(i, "NOP");
		return;
	}
	if(i->target < 0){
		bprint(i, "MOVW\t$%lux, R%d", imm, i->rd);
		return;
	}
	bprint(i, "MOVW\t$%lux, R%d", i->imm32, i->target);
}

static char ldtab[] = {
	'W',
	'B',
	'H',
	'D',
};

static char*
moveinstr(int op3, char *m)
{
	char *s;
	int c;
	static char buf[8];

	if(!dascase){
		/* batshit cases */
		if(op3 == 0xF || op3 == 0x1F)
			return "SWAP";
		if(op3 == 0xD || op3 == 0x1D)
			return "TAS";	/* really LDSTUB */
		c = ldtab[op3&3];
		s = "";
		if((op3&11)==1 || (op3&11)==2)
			s="U";
		sprint(buf, "MOV%c%s", c, s);
		return buf;
	}
	return m;
}

static void
load(Instr *i, char *m)			/* page 68 */
{
	m = moveinstr(i->op3, m);
	if(i->i == 0)
		bprint(i, "%s\t(R%d+R%d), R%d", m, i->rs1, i->rs2, i->rd);
	else{
		bprint(i, "%s\t", m);
		address(i);
		bprint(i, ", R%d", i->rd);
	}
}

static void
loada(Instr *i, char *m)		/* page 68 */
{
	m = moveinstr(i->op3, m);
	if(i->i == 0)
		bprint(i, "%s\t(R%d+R%d, %d), R%d", m, i->rs1, i->rs2, i->asi, i->rd);
	else
		bprint(i, "unknown ld asi %lux", i->w0);
}

static void
store(Instr *i, char *m)		/* page 74 */
{
	m = moveinstr(i->op3, m);
	if(i->i == 0)
		bprint(i, "%s\tR%d, (R%d+R%d)",
				m, i->rd, i->rs1, i->rs2);
	else{
		bprint(i, "%s\tR%d, ", m, i->rd);
		address(i);
	}
}

static void
storea(Instr *i, char *m)		/* page 74 */
{
	m = moveinstr(i->op3, m);
	if(i->i == 0)
		bprint(i, "%s\tR%d, (R%d+R%d, %d)", m, i->rd, i->rs1, i->rs2, i->asi);
	else
		bprint(i, "%s\tR%d, %d(R%d, %d), ???", m, i->rd, i->simm13, i->rs1, i->asi);
}

static void
shift(Instr *i, char *m)	/* page 88 */
{
	if(i->i == 0){
		if(i->rs1 == i->rd)
			if(dascase)
				bprint(i, "%T\tR%d, R%d", m, i->rs1, i->rs2);
			else
				bprint(i, "%T\tR%d, R%d", m, i->rs2, i->rs1);
		else
			if(dascase)
				bprint(i, "%T\tR%d, R%d, R%d", m, i->rs1, i->rs2, i->rd);
			else
				bprint(i, "%T\tR%d, R%d, R%d", m, i->rs2, i->rs1, i->rd);
	}else{
		if(i->rs1 == i->rd)
			if(dascase)
				bprint(i, "%T\t$%d,R%d", m, i->simm13&0x1F, i->rs1);
			else
				bprint(i, "%T\tR%d, $%d", m,  i->rs1, i->simm13&0x1F);
		else
			if(dascase)
				bprint(i, "%T\tR%d, $%d, R%d",m,i->rs1,i->simm13&0x1F,i->rd);
			else
				bprint(i, "%T\t$%d, R%d, R%d",m,i->simm13&0x1F,i->rs1,i->rd);
	}
}

static void
add(Instr *i, char *m)	/* page 82 */
{
	if(i->i == 0){
		if(dascase)
			bprint(i, "%T\tR%d, R%d", m, i->rs1, i->rs2);
		else
			if(i->op3==2 && i->rs1==0 && i->rd)  /* OR R2, R0, R1 */
				bprint(i, "MOVW\tR%d", i->rs2);
			else
				bprint(i, "%T\tR%d, R%d", m, i->rs2, i->rs1);
	}else{
		if(dascase)
			bprint(i, "%T\tR%d, $%ux", m, i->rs1, i->simm13);
		else
			if(i->op3==0 && i->rd && i->rs1==0)	/* ADD $x, R0, R1 */
				bprint(i, "MOVW\t$%ux", i->simm13);
			else if(i->op3==0 && i->rd && i->rs1==2){
				/* ADD $x, R2, R1 -> MOVW $x(SB), R1 */
				bprint(i, "MOVW\t$");
				address(i);
			} else
				bprint(i, "%T\t$%ux, R%d", m, i->simm13, i->rs1);
	}
	if(i->rs1 != i->rd)
		bprint(i, ", R%d", i->rd);
}

static void
cmp(Instr *i, char *m)
{
	if(dascase || i->rd){
		add(i, m);
		return;
	}
	if(i->i == 0)
		bprint(i, "CMP\tR%d, R%d", i->rs1, i->rs2);
	else
		bprint(i, "CMP\tR%d, $%ux", i->rs1, i->simm13);
}

static char *regtab[4] = {
	"Y",
	"PSR",
	"WIM",
	"TBR",
};

static void
wr(Instr *i, char *m)		/* page 82 */
{
	if(dascase){
		if(i->i == 0)
			bprint(i, "%s\tR%d, R%d", m, i->rs1, i->rs2);
		else
			bprint(i, "%s\tR%d, $%ux", m, i->rs1, i->simm13);
	}else{
		if(i->i && i->simm13==0)
			bprint(i, "MOVW\tR%d", i->rs1);
		else if(i->i == 0)
			bprint(i, "wr\tR%d, R%d", i->rs2, i->rs1);
		else
			bprint(i, "wr\t$%ux, R%d", i->simm13, i->rs1);
	}
	bprint(i, ", %s", regtab[i->op3&3]);
}

static void
rd(Instr *i, char *m)		/* page 103 */
{
	if(i->rs1==15 && i->rd==0){
		m = "stbar";
		if(!dascase)
			m = "STBAR";
		bprint(i, "%s", m);
	}else{
		if(!dascase)
			m = "MOVW";
		bprint(i, "%s\t%s, R%d", m, regtab[i->op3&3], i->rd);
	}
}

static void
jmpl(Instr *i, char *m)		/* page 82 */
{
	if(i->i == 0){
		if(i->rd == 15)
			bprint(i, "%T\t(R%d+R%d)", "CALL", i->rs2, i->rs1);
		else
			bprint(i, "%T\t(R%d+R%d), R%d", m, i->rs2, i->rs1, i->rd);
	}else{
		if(!dascase && i->simm13==8 && i->rs1==15 && i->rd==0)
			bprint(i, "RETURN");
		else{
			bprint(i, "%T\t", m);
			address(i);
			bprint(i, ", R%d", i->rd);
		}
	}
}

static void
loadf(Instr *i, char *m)		/* page 70 */
{
	if(!dascase){
		m = "FMOVD";
		if(i->op3 == 0x20)
			m = "FMOVF";
		else if(i->op3 == 0x21)
			m = "MOVW";
	}
	if(i->i == 0)
		bprint(i, "%s\t(R%d+R%d)", m, i->rs1, i->rs2);
	else{
		bprint(i, "%s\t", m);
		address(i);
	}
	if(i->op3 == 0x21)
		bprint(i, ", FSR");
	else
		bprint(i, ", R%d", i->rd);
}

static void
storef(Instr *i, char *m)		/* page 70 */
{
	if(!dascase){
		m = "FMOVD";
		if(i->op3 == 0x25 || i->op3 == 0x26)
			m = "MOVW";
		else if(i->op3 == 0x20)
			m = "FMOVF";
	}
	bprint(i, "%s\t", m);
	if(i->op3 == 0x25)
		bprint(i, "FSR, ");
	else if(i->op3 == 0x26)
		bprint(i, "FQ, ");
	else
		bprint(i, "R%d, ", i->rd);
	if(i->i == 0)
		bprint(i, "(R%d+R%d)", i->rs1, i->rs2);
	else
		address(i);
}

static void
loadc(Instr *i, char *m)			/* page 72 */
{
	if(i->i == 0)
		bprint(i, "%s\t(R%d+R%d), C%d", m, i->rs1, i->rs2, i->rd);
	else{
		bprint(i, "%s\t", m);
		address(i);
		bprint(i, ", C%d", i->rd);
	}
}

static void
loadcsr(Instr *i, char *m)			/* page 72 */
{
	if(i->i == 0)
		bprint(i, "%s\t(R%d+R%d), CSR", m, i->rs1, i->rs2);
	else{
		bprint(i, "%s\t", m);
		address(i);
		bprint(i, ", CSR");
	}
}

static struct{
	int	opf;
	char	*name;
} fptab1[] = {			/* ignores rs1 */
	0xC4,	"FITOS",	/* page 109 */
	0xC8,	"FITOD",
	0xCC,	"FITOX",

	0xD1,	"FSTOI",	/* page 110 */
	0xD2,	"FDTOI",
	0xD3,	"FXTOI",

	0xC9,	"FSTOD",	/* page 111 */
	0xCD,	"FSTOX",
	0xC6,	"FDTOS",
	0xCE,	"FDTOX",
	0xC7,	"FXTOS",
	0xCB,	"FXTOD",

	0x01,	"FMOVS",	/* page 112 */
	0x05,	"FNEGS",
	0x09,	"FABSS",

	0x29,	"FSQRTS", 	/* page 113 */
	0x2A,	"FSQRTD",
	0x2B,	"FSQRTX",

	0,	0,
};

static struct{
	int	opf;
	char	*name;
} fptab2[] = {			/* uses rs1 */

	0x41,	"FADDS",	/* page 114 */
	0x42,	"FADDD",
	0x43,	"FADDX",
	0x45,	"FSUBS",
	0x46,	"FSUBD",
	0x47,	"FSUBX",

	0x49,	"FMULS",	/* page 115 */
	0x4A,	"FMULD",
	0x4B,	"FMULX",
	0x4D,	"FDIVS",
	0x4E,	"FDIVD",
	0x4F,	"FDIVX",

	0x51,	"FCMPS",	/* page 116 */
	0x52,	"FCMPD",
	0x53,	"FCMPX",
	0x55,	"FCMPES",
	0x56,	"FCMPED",
	0x57,	"FCMPEX",

	0, 0
};

static void
fpop(Instr *i, char *m)	/* page 108-116 */
{
	int j;

	if(dascase==0 && i->size==2){
		bprint(i, "FMOVD\tF%d, F%d", i->rs2, i->rd);
		return;
	}
	for(j=0; fptab1[j].name; j++)
		if(fptab1[j].opf == i->opf){
			bprint(i, "%T\tF%d, F%d", fptab1[j].name, i->rs2, i->rd);
			return;
		}
	for(j=0; fptab2[j].name; j++)
		if(fptab2[j].opf == i->opf){
			bprint(i, "%T\tF%d, F%d, F%d", fptab2[j].name, i->rs1, i->rs2, i->rd);
			return;
		}
	bprint(i, "%T%ux\tF%d, F%d, F%d", m, i->opf, i->rs1, i->rs2, i->rd);
}

static int
sparcfoll(Map *map, uvlong pc, Rgetter rget, uvlong *foll)
{
	ulong w, r1, r2;
	char buf[8];
	Instr i;

	mymap = map;
	if (mkinstr(pc, &i) < 0)
		return -1;
	w = i.w0;
	switch(w & 0xC1C00000){
	case 0x00800000:		/* branch on int cond */
	case 0x01800000:		/* branch on fp cond */
	case 0x01C00000:		/* branch on copr cond */
		foll[0] = pc+8;
		foll[1] = pc + (i.simmdisp22<<2);
		return 2;
	}

	if((w&0xC0000000) == 0x40000000){	/* CALL */
		foll[0] = pc + (i.disp30<<2);
		return 1;
	}

	if((w&0xC1F80000) == 0x81C00000){	/* JMPL */
		sprint(buf, "R%ld", (w>>14)&0xF);
		r1 = (*rget)(map, buf);
		if(w & 0x2000)			/* JMPL R1+simm13 */
			r2 = i.simm13;
		else{				/* JMPL R1+R2 */
			sprint(buf, "R%ld", w&0xF);
			r2 = (*rget)(map, buf);
		}
		foll[0] = r1 + r2;
		return 1;
	}
	foll[0] = pc+i.size*4;
	return 1;
}