10 files changed, 1037 insertions(+), 14 deletions(-)

M bitsy/dat.h
M bitsy/fns.h
A bitsy/fpi.c
A bitsy/fpi.h
A bitsy/fpiarm.c
A bitsy/fpimem.c
M bitsy/main.c
M bitsy/screen.c
M bitsy/trap.c
M port/proc.c

@@ 1,4 1,6 @@
 typedef struct Conf	Conf;
+typedef struct FPU	FPU;
+typedef struct FPenv	FPenv;
 typedef struct FPsave	FPsave;
 typedef struct Label	Label;
 typedef struct Lock	Lock;


@@ 34,20 36,19 @@ struct Label
 };
 
 /*
- *  no floating point, hence nothing to save
- */
-
-/*
  * FPsave.status
  */
 enum
 {
-	FPinit,
-	FPinactive,
+	FPINIT,
+	FPACTIVE,
+	FPINACTIVE,
 };
 struct	FPsave
 {
-	int	dummy;
+	ulong	status;
+	ulong	control;
+	ulong	regs[8][3];	/* emulated fp */	
 };
 
 struct Conf

@@ 12,6 12,7 @@ void	clockinit(void);
 void	delay(int);
 void	evenaddr(ulong);
 void	flushmmu(void);
+int		fpiarm(Ureg *ur);
 char*	getconf(char*);
 ulong	getfar(void);
 ulong	getfsr(void);

@@ 0,0 1,300 @@
+/*
+ * Floating Point Interpreter.
+ * shamelessly stolen from an original by ark.
+ */
+#include "fpi.h"
+
+void
+fpiround(Internal *i)
+{
+	unsigned long guard;
+
+	guard = i->l & GuardMask;
+	i->l &= ~GuardMask;
+	if(guard > (LsBit>>1) || (guard == (LsBit>>1) && (i->l & LsBit))){
+		i->l += LsBit;
+		if(i->l & CarryBit){
+			i->l &= ~CarryBit;
+			i->h++;
+			if(i->h & CarryBit){
+				if (i->h & 0x01)
+					i->l |= CarryBit;
+				i->l >>= 1;
+				i->h >>= 1;
+				i->e++;
+			}
+		}
+	}
+}
+
+static void
+matchexponents(Internal *x, Internal *y)
+{
+	int count;
+
+	count = y->e - x->e;
+	x->e = y->e;
+	if(count >= 2*FractBits){
+		x->l = x->l || x->h;
+		x->h = 0;
+		return;
+	}
+	if(count >= FractBits){
+		count -= FractBits;
+		x->l = x->h|(x->l != 0);
+		x->h = 0;
+	}
+	while(count > 0){
+		count--;
+		if(x->h & 0x01)
+			x->l |= CarryBit;
+		if(x->l & 0x01)
+			x->l |= 2;
+		x->l >>= 1;
+		x->h >>= 1;
+	}
+}
+
+static void
+shift(Internal *i)
+{
+	i->e--;
+	i->h <<= 1;
+	i->l <<= 1;
+	if(i->l & CarryBit){
+		i->l &= ~CarryBit;
+		i->h |= 0x01;
+	}
+}
+
+static void
+normalise(Internal *i)
+{
+	while((i->h & HiddenBit) == 0)
+		shift(i);
+}
+
+static void
+renormalise(Internal *i)
+{
+	if(i->e < -2 * FractBits)
+		i->e = -2 * FractBits;
+	while(i->e < 1){
+		i->e++;
+		if(i->h & 0x01)
+			i->l |= CarryBit;
+		i->h >>= 1;
+		i->l = (i->l>>1)|(i->l & 0x01);
+	}
+	if(i->e >= ExpInfinity)
+		SetInfinity(i);
+}
+
+void
+fpinormalise(Internal *x)
+{
+	if(!IsWeird(x) && !IsZero(x))
+		normalise(x);
+}
+
+void
+fpiadd(Internal *x, Internal *y, Internal *i)
+{
+	Internal *t;
+
+	i->s = x->s;
+	if(IsWeird(x) || IsWeird(y)){
+		if(IsNaN(x) || IsNaN(y))
+			SetQNaN(i);
+		else
+			SetInfinity(i);
+		return;
+	}
+	if(x->e > y->e){
+		t = x;
+		x = y;
+		y = t;
+	}
+	matchexponents(x, y);
+	i->e = x->e;
+	i->h = x->h + y->h;
+	i->l = x->l + y->l;
+	if(i->l & CarryBit){
+		i->h++;
+		i->l &= ~CarryBit;
+	}
+	if(i->h & (HiddenBit<<1)){
+		if(i->h & 0x01)
+			i->l |= CarryBit;
+		i->l = (i->l>>1)|(i->l & 0x01);
+		i->h >>= 1;
+		i->e++;
+	}
+	if(IsWeird(i))
+		SetInfinity(i);
+}
+
+void
+fpisub(Internal *x, Internal *y, Internal *i)
+{
+	Internal *t;
+
+	if(y->e < x->e
+	   || (y->e == x->e && (y->h < x->h || (y->h == x->h && y->l < x->l)))){
+		t = x;
+		x = y;
+		y = t;
+	}
+	i->s = y->s;
+	if(IsNaN(y)){
+		SetQNaN(i);
+		return;
+	}
+	if(IsInfinity(y)){
+		if(IsInfinity(x))
+			SetQNaN(i);
+		else
+			SetInfinity(i);
+		return;
+	}
+	matchexponents(x, y);
+	i->e = y->e;
+	i->h = y->h - x->h;
+	i->l = y->l - x->l;
+	if(i->l < 0){
+		i->l += CarryBit;
+		i->h--;
+	}
+	if(i->h == 0 && i->l == 0)
+		SetZero(i);
+	else while(i->e > 1 && (i->h & HiddenBit) == 0)
+		shift(i);
+}
+
+#define	CHUNK		(FractBits/2)
+#define	CMASK		((1<<CHUNK)-1)
+#define	HI(x)		((short)((x)>>CHUNK) & CMASK)
+#define	LO(x)		((short)(x) & CMASK)
+#define	SPILL(x)	((x)>>CHUNK)
+#define	M(x, y)		((long)a[x]*(long)b[y])
+#define	C(h, l)		(((long)((h) & CMASK)<<CHUNK)|((l) & CMASK))
+
+void
+fpimul(Internal *x, Internal *y, Internal *i)
+{
+	long a[4], b[4], c[7], f[4];
+
+	i->s = x->s^y->s;
+	if(IsWeird(x) || IsWeird(y)){
+		if(IsNaN(x) || IsNaN(y) || IsZero(x) || IsZero(y))
+			SetQNaN(i);
+		else
+			SetInfinity(i);
+		return;
+	}
+	else if(IsZero(x) || IsZero(y)){
+		SetZero(i);
+		return;
+	}
+	normalise(x);
+	normalise(y);
+	i->e = x->e + y->e - (ExpBias - 1);
+
+	a[0] = HI(x->h); b[0] = HI(y->h);
+	a[1] = LO(x->h); b[1] = LO(y->h);
+	a[2] = HI(x->l); b[2] = HI(y->l);
+	a[3] = LO(x->l); b[3] = LO(y->l);
+
+	c[6] =                               M(3, 3);
+	c[5] =                     M(2, 3) + M(3, 2) + SPILL(c[6]);
+	c[4] =           M(1, 3) + M(2, 2) + M(3, 1) + SPILL(c[5]);
+	c[3] = M(0, 3) + M(1, 2) + M(2, 1) + M(3, 0) + SPILL(c[4]);
+	c[2] = M(0, 2) + M(1, 1) + M(2, 0)           + SPILL(c[3]);
+	c[1] = M(0, 1) + M(1, 0)                     + SPILL(c[2]);
+	c[0] = M(0, 0)                               + SPILL(c[1]);
+
+	f[0] = c[0];
+	f[1] = C(c[1], c[2]);
+	f[2] = C(c[3], c[4]);
+	f[3] = C(c[5], c[6]);
+
+	if((f[0] & HiddenBit) == 0){
+		f[0] <<= 1;
+		f[1] <<= 1;
+		f[2] <<= 1;
+		f[3] <<= 1;
+		if(f[1] & CarryBit){
+			f[0] |= 1;
+			f[1] &= ~CarryBit;
+		}
+		if(f[2] & CarryBit){
+			f[1] |= 1;
+			f[2] &= ~CarryBit;
+		}
+		if(f[3] & CarryBit){
+			f[2] |= 1;
+			f[3] &= ~CarryBit;
+		}
+		i->e--;
+	}
+	i->h = f[0];
+	i->l = f[1];
+	if(f[2] || f[3])
+		i->l |= 1;
+	renormalise(i);
+}
+
+void
+fpidiv(Internal *x, Internal *y, Internal *i)
+{
+	i->s = x->s^y->s;
+	if(IsNaN(x) || IsNaN(y)
+	   || (IsInfinity(x) && IsInfinity(y)) || (IsZero(x) && IsZero(y))){
+		SetQNaN(i);
+		return;
+	}
+	else if(IsZero(x) || IsInfinity(y)){
+		SetInfinity(i);
+		return;
+	}
+	else if(IsInfinity(x) || IsZero(y)){
+		SetZero(i);
+		return;
+	}
+	normalise(x);
+	normalise(y);
+	i->h = 0;
+	i->l = 0;
+	i->e = y->e - x->e + (ExpBias + 2*FractBits - 1);
+	do{
+		if(y->h > x->h || (y->h == x->h && y->l >= x->l)){
+			i->l |= 0x01;
+			y->h -= x->h;
+			y->l -= x->l;
+			if(y->l < 0){
+				y->l += CarryBit;
+				y->h--;
+			}
+		}
+		shift(y);
+		shift(i);
+	}while ((i->h & HiddenBit) == 0);
+	if(y->h || y->l)
+		i->l |= 0x01;
+	renormalise(i);
+}
+
+int
+fpicmp(Internal *x, Internal *y)
+{
+	if(IsNaN(x) && IsNaN(y))
+		return 0;
+	if(IsInfinity(x) && IsInfinity(y))
+		return y->s - x->s;
+	if(x->e == y->e && x->h == y->h && x->l == y->l)
+		return y->s - x->s;
+	if(x->e < y->e
+	   || (x->e == y->e && (x->h < y->h || (x->h == y->h && x->l < y->l))))
+		return y->s ? 1: -1;
+	return x->s ? -1: 1;
+}

@@ 0,0 1,61 @@
+typedef long Word;
+typedef unsigned long Single;
+typedef struct {
+	unsigned long h;
+	unsigned long l;
+} Double;
+
+enum {
+	FractBits	= 28,
+	CarryBit	= 0x10000000,
+	HiddenBit	= 0x08000000,
+	MsBit		= HiddenBit,
+	NGuardBits	= 3,
+	GuardMask	= 0x07,
+	LsBit		= (1<<NGuardBits),
+
+	SingleExpBias	= 127,
+	SingleExpMax	= 255,
+	DoubleExpBias	= 1023,
+	DoubleExpMax	= 2047,
+
+	ExpBias		= DoubleExpBias,
+	ExpInfinity	= DoubleExpMax,
+};
+
+typedef struct {
+	unsigned char s;
+	short e;
+	long l;				/* 0000FFFFFFFFFFFFFFFFFFFFFFFFFGGG */
+	long h;				/* 0000HFFFFFFFFFFFFFFFFFFFFFFFFFFF */
+} Internal;
+
+#define IsWeird(n)	((n)->e >= ExpInfinity)
+#define	IsInfinity(n)	(IsWeird(n) && (n)->h == HiddenBit && (n)->l == 0)
+#define	SetInfinity(n)	((n)->e = ExpInfinity, (n)->h = HiddenBit, (n)->l = 0)
+#define IsNaN(n)	(IsWeird(n) && (((n)->h & ~HiddenBit) || (n)->l))
+#define	SetQNaN(n)	((n)->s = 0, (n)->e = ExpInfinity, 		\
+			 (n)->h = HiddenBit|(LsBit<<1), (n)->l = 0)
+#define IsZero(n)	((n)->e == 1 && (n)->h == 0 && (n)->l == 0)
+#define SetZero(n)	((n)->e = 1, (n)->h = 0, (n)->l = 0)
+
+/*
+ * fpi.c
+ */
+extern void fpiround(Internal *);
+extern void fpiadd(Internal *, Internal *, Internal *);
+extern void fpisub(Internal *, Internal *, Internal *);
+extern void fpimul(Internal *, Internal *, Internal *);
+extern void fpidiv(Internal *, Internal *, Internal *);
+extern int fpicmp(Internal *, Internal *);
+extern void fpinormalise(Internal*);
+
+/*
+ * fpimem.c
+ */
+extern void fpis2i(Internal *, void *);
+extern void fpid2i(Internal *, void *);
+extern void fpiw2i(Internal *, void *);
+extern void fpii2s(void *, Internal *);
+extern void fpii2d(void *, Internal *);
+extern void fpii2w(Word *, Internal *);

@@ 0,0 1,488 @@
+/*
+ * this doesn't attempt to implement ARM floating-point properties
+ * that aren't visible in the Inferno environment.
+ * all arithmetic is done in double precision.
+ * the FP trap status isn't updated.
+ */
+#include "u.h"
+#include	"../port/lib.h"
+#include	"mem.h"
+#include	"dat.h"
+#include	"fns.h"
+#include	"io.h"
+
+#include	"ureg.h"
+
+#include "fpi.h"
+
+#define	R13OK
+/* undef this if correct kernel r13 isn't in Ureg;
+ * check calculation in fpiarm below
+ */
+
+
+#define	REG(x) (*(long*)(((char*)ur)+roff[(x)]))
+#define	FPENV	(*ufp)
+#define	FR(x) (*(Internal*)ufp->regs[(x)&7])
+
+/* BUG: check fetch (not worthwhile in Inferno) */
+#define	getubyte(a) (*(uchar*)(a))
+#define	getuword(a) (*(ushort*)(a))
+#define	getulong(a) (*(ulong*)(a))
+
+typedef struct FP2 FP2;
+typedef struct FP1 FP1;
+
+struct FP2 {
+	char*	name;
+	void	(*f)(Internal, Internal, Internal*);
+};
+
+struct FP1 {
+	char*	name;
+	void	(*f)(Internal*, Internal*);
+};
+
+enum {
+	N = 1<<31,
+	Z = 1<<30,
+	C = 1<<29,
+	V = 1<<28,
+	REGPC = 15,
+};
+
+int	fpemudebug = 0;
+
+#undef OFR
+#define	OFR(X)	((ulong)&((Ureg*)0)->X)
+
+static	int	roff[] = {
+	OFR(r0), OFR(r1), OFR(r2), OFR(r3),
+	OFR(r4), OFR(r5), OFR(r6), OFR(r7),
+	OFR(r8), OFR(r9), OFR(r10), OFR(r11),
+#ifdef R13OK
+	OFR(r12), OFR(r13), OFR(r14), OFR(pc),
+#else
+	OFR(r12), OFR(type), OFR(r14), OFR(pc),
+#endif
+};
+
+static Internal fpconst[8] = {	/* indexed by op&7 */
+	/* s, e, l, h */
+	{0, 0x1, 0x00000000, 0x00000000}, /* 0.0 */
+	{0, 0x3FF, 0x00000000, 0x08000000},	/* 1.0 */
+	{0, 0x400, 0x00000000, 0x08000000},	/* 2.0 */
+	{0, 0x400, 0x00000000, 0x0C000000},	/* 3.0 */
+	{0, 0x401, 0x00000000, 0x08000000},	/* 4.0 */
+	{0, 0x401, 0x00000000, 0x0A000000},	/* 5.0 */
+	{0, 0x3FE, 0x00000000, 0x08000000},	/* 0.5 */
+	{0, 0x402, 0x00000000, 0x0A000000},	/* 10.0 */
+};
+
+/*
+ * arm binary operations
+ */
+
+static void
+fadd(Internal m, Internal n, Internal *d)
+{
+	(m.s == n.s? fpiadd: fpisub)(&m, &n, d);
+}
+
+static void
+fsub(Internal m, Internal n, Internal *d)
+{
+	m.s ^= 1;
+	(m.s == n.s? fpiadd: fpisub)(&m, &n, d);
+}
+
+static void
+fsubr(Internal m, Internal n, Internal *d)
+{
+	n.s ^= 1;
+	(n.s == m.s? fpiadd: fpisub)(&n, &m, d);
+}
+
+static void
+fmul(Internal m, Internal n, Internal *d)
+{
+	fpimul(&m, &n, d);
+}
+
+static void
+fdiv(Internal m, Internal n, Internal *d)
+{
+	fpidiv(&m, &n, d);
+}
+
+static void
+fdivr(Internal m, Internal n, Internal *d)
+{
+	fpidiv(&n, &m, d);
+}
+
+/*
+ * arm unary operations
+ */
+
+static void
+fmov(Internal *m, Internal *d)
+{
+	*d = *m;
+}
+
+static void
+fmovn(Internal *m, Internal *d)
+{
+	*d = *m;
+	d->s ^= 1;
+}
+
+static void
+fabsf(Internal *m, Internal *d)
+{
+	*d = *m;
+	d->s = 0;
+}
+
+static void
+frnd(Internal *m, Internal *d)
+{
+	short e;
+
+	(m->s? fsub: fadd)(fpconst[6], *m, d);
+	if(IsWeird(d))
+		return;
+	fpiround(d);
+	e = (d->e - ExpBias) + 1;
+	if(e <= 0)
+		SetZero(d);
+	else if(e > FractBits){
+		if(e < 2*FractBits)
+			d->l &= ~((1<<(2*FractBits - e))-1);
+	}else{
+		d->l = 0;
+		if(e < FractBits)
+			d->h &= ~((1<<(FractBits-e))-1);
+	}
+}
+
+static	FP1	optab1[16] = {	/* Fd := OP Fm */
+[0]	{"MOVF",	fmov},
+[1]	{"NEGF",	fmovn},
+[2]	{"ABSF",	fabsf},
+[3]	{"RNDF",	frnd},
+[4]	{"SQTF",	/*fsqt*/0},
+/* LOG, LGN, EXP, SIN, COS, TAN, ASN, ACS, ATN all `deprecated' */
+/* URD and NRM aren't implemented */
+};
+
+static	FP2	optab2[16] = {	/* Fd := Fn OP Fm */
+[0]	{"ADDF",	fadd},
+[1]	{"MULF",	fmul},
+[2]	{"SUBF",	fsub},
+[3]	{"RSUBF",	fsubr},
+[4]	{"DIVF",	fdiv},
+[5]	{"RDIVF",	fdivr},
+/* POW, RPW deprecated */
+[8]	{"REMF",	/*frem*/0},
+[9]	{"FMF",	fmul},	/* fast multiply */
+[10]	{"FDV",	fdiv},	/* fast divide */
+[11]	{"FRD",	fdivr},	/* fast reverse divide */
+/* POL deprecated */
+};
+
+static ulong
+fcmp(Internal *n, Internal *m)
+{
+	int i;
+
+	if(IsWeird(m) || IsWeird(n)){
+		/* BUG: should trap if not masked */
+		return V|C;
+	}
+	i = fpicmp(n, m);
+	if(i > 0)
+		return C;
+	else if(i == 0)
+		return C|Z;
+	else
+		return N;
+}
+
+static void
+fld(void (*f)(Internal*, void*), int d, ulong ea, int n, FPsave *ufp)
+{
+	void *mem;
+
+	mem = (void*)ea;
+	(*f)(&FR(d), mem);
+	if(fpemudebug)
+		print("MOV%c #%lux, F%d\n", n==8? 'D': 'F', ea, d);
+}
+
+static void
+fst(void (*f)(void*, Internal*), ulong ea, int s, int n, FPsave *ufp)
+{
+	Internal tmp;
+	void *mem;
+
+	mem = (void*)ea;
+	tmp = FR(s);
+	if(fpemudebug)
+		print("MOV%c	F%d,#%lux\n", n==8? 'D': 'F', s, ea);
+	(*f)(mem, &tmp);
+}
+
+static int
+condok(int cc, int c)
+{
+	switch(c){
+	case 0:	/* Z set */
+		return cc&Z;
+	case 1:	/* Z clear */
+		return (cc&Z) == 0;
+	case 2:	/* C set */
+		return cc&C;
+	case 3:	/* C clear */
+		return (cc&C) == 0;
+	case 4:	/* N set */
+		return cc&N;
+	case 5:	/* N clear */
+		return (cc&N) == 0;
+	case 6:	/* V set */
+		return cc&V;
+	case 7:	/* V clear */
+		return (cc&V) == 0;
+	case 8:	/* C set and Z clear */
+		return cc&C && (cc&Z) == 0;
+	case 9:	/* C clear or Z set */
+		return (cc&C) == 0 || cc&Z;
+	case 10:	/* N set and V set, or N clear and V clear */
+		return (~cc&(N|V))==0 || (cc&(N|V)) == 0;
+	case 11:	/* N set and V clear, or N clear and V set */
+		return (cc&(N|V))==N || (cc&(N|V))==V;
+	case 12:	/* Z clear, and either N set and V set or N clear and V clear */
+		return (cc&Z) == 0 && ((~cc&(N|V))==0 || (cc&(N|V))==0);
+	case 13:	/* Z set, or N set and V clear or N clear and V set */
+		return (cc&Z) || (cc&(N|V))==N || (cc&(N|V))==V;
+	case 14:	/* always */
+		return 1;
+	case 15:	/* never (reserved) */
+		return 0;
+	}
+	return 0;	/* not reached */
+}
+
+static void
+unimp(ulong pc, ulong op)
+{
+	char buf[60];
+
+	snprint(buf, sizeof(buf), "sys: fp: pc=%lux unimp fp 0x%.8lux", pc, op);
+	if(fpemudebug)
+		print("FPE: %s\n", buf);
+	error(buf);
+	/* no return */
+}
+
+static void
+fpemu(ulong pc, ulong op, Ureg *ur, FPsave *ufp)
+{
+	int rn, rd, tag, o;
+	long off;
+	ulong ea;
+	Internal tmp, *fm, *fn;
+
+	/* note: would update fault status here if we noted numeric exceptions */
+
+	/*
+	 * LDF, STF; 10.1.1
+	 */
+	if(((op>>25)&7) == 6){
+		if(op & (1<<22))
+			unimp(pc, op);	/* packed or extended */
+		rn = (op>>16)&0xF;
+		off = (op&0xFF)<<2;
+		if((op & (1<<23)) == 0)
+			off = -off;
+		ea = REG(rn);
+		if(rn == REGPC)
+			ea += 8;
+		if(op & (1<<24))
+			ea += off;
+		rd = (op>>12)&7;
+		if(op & (1<<20)){
+			if(op & (1<<15))
+				fld(fpid2i, rd, ea, 8, ufp);
+			else
+				fld(fpis2i, rd, ea, 4, ufp);
+		}else{
+			if(op & (1<<15))
+				fst(fpii2d, ea, rd, 8, ufp);
+			else
+				fst(fpii2s, ea, rd, 4, ufp);
+		}
+		if((op & (1<<24)) == 0)
+			ea += off;
+		if(op & (1<<21))
+			REG(rn) = ea;
+		return;
+	}
+
+	/*
+	 * CPRT/transfer, 10.3
+	 */
+	if(op & (1<<4)){
+		rd = (op>>12) & 0xF;
+
+		/*
+		 * compare, 10.3.1
+		 */
+		if(rd == 15 && op & (1<<20)){
+			rn = (op>>16)&7;
+			fn = &FR(rn);
+			if(op & (1<<3)){
+				fm = &fpconst[op&7];
+				tag = 'C';
+			}else{
+				fm = &FR(op&7);
+				tag = 'F';
+			}
+			switch((op>>21)&7){
+			default:
+				unimp(pc, op);
+			case 4:	/* CMF: Fn :: Fm */
+			case 6:	/* CMFE: Fn :: Fm (with exception) */
+				ur->psr &= ~(N|C|Z|V);
+				ur->psr |= fcmp(fn, fm);
+				break;
+			case 5:	/* CNF: Fn :: -Fm */
+			case 7:	/* CNFE: Fn :: -Fm (with exception) */
+				tmp = *fm;
+				tmp.s ^= 1;
+				ur->psr &= ~(N|C|Z|V);
+				ur->psr |= fcmp(fn, &tmp);
+				break;
+			}
+			if(fpemudebug)
+				print("CMPF	%c%d,F%ld =%lux\n", tag, rn, op&7, ur->psr>>28);
+			return;
+		}
+
+		/*
+		 * other transfer, 10.3
+		 */
+		switch((op>>20)&0xF){
+		default:
+			unimp(pc, op);
+		case 0:	/* FLT */
+			rn = (op>>16) & 7;
+			fpiw2i(&FR(rn), &REG(rd));
+			if(fpemudebug)
+				print("MOVW[FD]	R%d, F%d\n", rd, rn);
+			break;
+		case 1:	/* FIX */
+			if(op & (1<<3))
+				unimp(pc, op);
+			rn = op & 7;
+			tmp = FR(rn);
+			fpii2w(&REG(rd), &tmp);
+			if(fpemudebug)
+				print("MOV[FD]W	F%d, R%d =%ld\n", rn, rd, REG(rd));
+			break;
+		case 2:	/* FPSR := Rd */
+			FPENV.status = REG(rd);
+			if(fpemudebug)
+				print("MOVW	R%d, FPSR\n", rd);
+			break;
+		case 3:	/* Rd := FPSR */
+			REG(rd) = FPENV.status;
+			if(fpemudebug)
+				print("MOVW	FPSR, R%d\n", rd);
+			break;
+		case 4:	/* FPCR := Rd */
+			FPENV.control = REG(rd);
+			if(fpemudebug)
+				print("MOVW	R%d, FPCR\n", rd);
+			break;
+		case 5:	/* Rd := FPCR */
+			REG(rd) = FPENV.control;
+			if(fpemudebug)
+				print("MOVW	FPCR, R%d\n", rd);
+			break;
+		}
+		return;
+	}
+
+	/*
+	 * arithmetic
+	 */
+
+	if(op & (1<<3)){	/* constant */
+		fm = &fpconst[op&7];
+		tag = 'C';
+	}else{
+		fm = &FR(op&7);
+		tag = 'F';
+	}
+	rd = (op>>12)&7;
+	o = (op>>20)&0xF;
+	if(op & (1<<15)){	/* monadic */
+		FP1 *fp;
+		fp = &optab1[o];
+		if(fp->f == nil)
+			unimp(pc, op);
+		if(fpemudebug)
+			print("%s	%c%ld,F%d\n", fp->name, tag, op&7, rd);
+		(*fp->f)(fm, &FR(rd));
+	} else {
+		FP2 *fp;
+		fp = &optab2[o];
+		if(fp->f == nil)
+			unimp(pc, op);
+		rn = (op>>16)&7;
+		if(fpemudebug)
+			print("%s	%c%ld,F%d,F%d\n", fp->name, tag, op&7, rn, rd);
+		(*fp->f)(*fm, FR(rn), &FR(rd));
+	}
+}
+
+/*
+ * returns the number of FP instructions emulated
+ */
+int
+fpiarm(Ureg *ur)
+{
+	ulong op, o;
+	FPsave *ufp;
+	int n;
+
+#ifndef R13OK
+/*	ur->type = &ur->pc+1;	/* calculate kernel sp/R13 and put it here for roff[13] */
+	ur->type = (ulong)(ur + 1);
+#endif
+	if (up == nil)
+		panic("fpiarm not in a process");
+	ufp = &up->fpsave;
+		/* because all the state is in the proc structure,
+		 * it need not be saved/restored
+		 */
+	if(up->fpstate != FPACTIVE) {
+		up->fpstate = FPACTIVE;
+		ufp->control = 0;
+		ufp->status = (0x01<<28)|(1<<12);	/* software emulation, alternative C flag */
+		for(n = 0; n < 8; n++)
+			FR(n) = fpconst[0];
+	}
+	for(n=0;;n++){
+		op = getulong(ur->pc);
+		o = (op>>24) & 0xF;
+		if(((op>>8) & 0xF) != 1 || o != 0xE && (o&~1) != 0xC)
+			break;
+		if(condok(ur->psr, op>>28))
+			fpemu(ur->pc, op, ur, ufp);
+		ur->pc += 4;
+	}
+	return n;
+}

@@ 0,0 1,136 @@
+#include "fpi.h"
+
+/*
+ * the following routines depend on memory format, not the machine
+ */
+
+void
+fpis2i(Internal *i, void *v)
+{
+	Single *s = v;
+
+	i->s = (*s & 0x80000000) ? 1: 0;
+	if((*s & ~0x80000000) == 0){
+		SetZero(i);
+		return;
+	}
+	i->e = ((*s>>23) & 0x00FF) - SingleExpBias + ExpBias;
+	i->h = (*s & 0x007FFFFF)<<(1+NGuardBits);
+	i->l = 0;
+	if(i->e)
+		i->h |= HiddenBit;
+	else
+		i->e++;
+}
+
+void
+fpid2i(Internal *i, void *v)
+{
+	Double *d = v;
+
+	i->s = (d->h & 0x80000000) ? 1: 0;
+	i->e = (d->h>>20) & 0x07FF;
+	i->h = ((d->h & 0x000FFFFF)<<(4+NGuardBits))|((d->l>>25) & 0x7F);
+	i->l = (d->l & 0x01FFFFFF)<<NGuardBits;
+	if(i->e)
+		i->h |= HiddenBit;
+	else
+		i->e++;
+}
+
+void
+fpiw2i(Internal *i, void *v)
+{
+	Word w, word = *(Word*)v;
+	short e;
+
+	if(word < 0){
+		i->s = 1;
+		word = -word;
+	}
+	else
+		i->s = 0;
+	if(word == 0){
+		SetZero(i);
+		return;
+	}
+	if(word > 0){
+		for (e = 0, w = word; w; w >>= 1, e++)
+			;
+	} else
+		e = 32;
+	if(e > FractBits){
+		i->h = word>>(e - FractBits);
+		i->l = (word & ((1<<(e - FractBits)) - 1))<<(2*FractBits - e);
+	}
+	else {
+		i->h = word<<(FractBits - e);
+		i->l = 0;
+	}
+	i->e = (e - 1) + ExpBias;
+}
+
+void
+fpii2s(void *v, Internal *i)
+{
+	short e;
+	Single *s = (Single*)v;
+
+	fpiround(i);
+	if(i->h & HiddenBit)
+		i->h &= ~HiddenBit;
+	else
+		i->e--;
+	*s = i->s ? 0x80000000: 0;
+	e = i->e;
+	if(e < ExpBias){
+		if(e <= (ExpBias - SingleExpBias))
+			return;
+		e = SingleExpBias - (ExpBias - e);
+	}
+	else  if(e >= (ExpBias + (SingleExpMax-SingleExpBias))){
+		*s |= SingleExpMax<<23;
+		return;
+	}
+	else
+		e = SingleExpBias + (e - ExpBias);
+	*s |= (e<<23)|(i->h>>(1+NGuardBits));
+}
+
+void
+fpii2d(void *v, Internal *i)
+{
+	Double *d = (Double*)v;
+
+	fpiround(i);
+	if(i->h & HiddenBit)
+		i->h &= ~HiddenBit;
+	else
+		i->e--;
+	i->l = ((i->h & GuardMask)<<25)|(i->l>>NGuardBits);
+	i->h >>= NGuardBits;
+	d->h = i->s ? 0x80000000: 0;
+	d->h |= (i->e<<20)|((i->h & 0x00FFFFFF)>>4);
+	d->l = (i->h<<28)|i->l;
+}
+
+void
+fpii2w(Word *word, Internal *i)
+{
+	Word w;
+	short e;
+
+	fpiround(i);
+	e = (i->e - ExpBias) + 1;
+	if(e <= 0)
+		w = 0;
+	else if(e > 31)
+		w = 0x7FFFFFFF;
+	else if(e > FractBits)
+		w = (i->h<<(e - FractBits))|(i->l>>(2*FractBits - e));
+	else
+		w = i->h>>(FractBits-e);
+	if(i->s)
+		w = -w;
+	*word = w;
+}

@@ 229,7 229,7 @@ userinit(void)
 void
 procsetup(Proc *p)
 {
-	p->fpstate = FPinit;
+	p->fpstate = FPINIT;
 }
 
 /*

@@ 297,8 297,8 @@ screenwin(void)
 	grey = allocmemimage(Rect(0,0,1,1), RGB16);
 	grey->flags |= Frepl;
 	grey->clipr = gscreen->r;
-	grey->data->bdata[0] = 0x77;
-	grey->data->bdata[1] = 0x77;
+	grey->data->bdata[0] = 0x40;
+	grey->data->bdata[1] = 0xfd;
 
 	w = memdefont->info[' '].width;
 	h = memdefont->height;

@@ 16,7 16,6 @@ struct Intrregs
 	ulong	icfp;	/* pending FIQs */
 	ulong	dummy1[3];
 	ulong	icpr;	/* pending interrupts */
-	
 };
 
 struct Intrregs *intrregs;


@@ 35,7 34,6 @@ typedef struct Vctl {
 static Lock vctllock;
 static Vctl *vctl;
 
-
 /*
  *   Layout at virtual address 0.
  */


@@ 267,14 265,52 @@ trap(Ureg *ureg)
 		}
 		break;
 	case PsrMund:	/* undefined instruction */
+#ifdef NOTDEF
+		/* Inferno break handling, something for us? [SJM] */
+		if(*(ulong*)ureg->pc == BREAK && breakhandler) {
+			int s;
+			Proc *p;
+
+			p = up;
+			/* if (!waslo(ureg->psr) || (ureg->pc >= (ulong)splhi && ureg->pc < (ulong)islo))
+				p = 0; */
+			s = breakhandler(ureg, p);
+			if(s == BrkSched) {
+				c.callsched = 1;
+				sched();
+			} else if(s == BrkNoSched) {
+				c.callsched = 0;
+				if(up)
+					up->dbgreg = 0;
+				return;
+			}
+			break;
+		}
+		/* End of Inferno break handling [SJM] */
+#endif
+		/* start of Inferno code [SJM] */
+		spllo();
+		if (waserror()) {
+			warnregs(ureg, "floating point error");
+			panic("floating point error");
+		}
+		if (!fpiarm(ureg)) {
+			warnregs(ureg, "illegal instruction");
+			panic("illegal instruction");
+		}
+		poperror();
+		/* end of Inferno code [SJM] */
+#ifdef NOTDEF
+		/* We'll see what we do with this later [SJM] */
 		if(user){
-			sprint(buf, "sys: undefined instruction: pc 0x%lux\n",
+			sprint(buf, "undefined instruction: pc 0x%lux\n",
 					ureg->pc);
 			postnote(up, 1, buf, NDebug);
 		}else{
 			warnregs(ureg, "undefined instruction");
 			panic("undefined instruction");
 		}
+#endif
 		break;
 	}
 

@@ 327,7 327,7 @@ newproc(void)
 	p->fgrp = 0;
 	p->rgrp = 0;
 	p->pdbg = 0;
-	p->fpstate = FPinit;
+	p->fpstate = FPINIT;
 	p->kp = 0;
 	p->procctl = 0;
 	p->notepending = 0;