Import sources from 2011-03-30 iso image

1 files changed, 300 insertions, 0 deletions

diff --git a/sys/src/9/omap/fpi.c b/sys/src/9/omap/fpi.c
new file mode 100755
index 000000000..f341f2e4a
--- /dev/null
+++ b/sys/src/9/omap/fpi.c
@@ -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;
+}