move old code into 'old' directory

add src/test dir

SVN=121166

1 files changed, 342 insertions, 0 deletions

diff --git a/src/old/c/mpatof.c b/src/old/c/mpatof.c
new file mode 100644
index 000000000..07bcf4a27
--- /dev/null
+++ b/src/old/c/mpatof.c
@@ -0,0 +1,342 @@
+// Copyright 2009 The Go Authors.  All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+#include	<u.h>
+#include	<libc.h>
+
+int	mpatof(char*, double*);
+int	mpatov(char *s, vlong *v);
+
+enum
+{
+	Mpscale	= 29,		/* safely smaller than bits in a long */
+	Mpprec	= 36,		/* Mpscale*Mpprec sb > largest fp exp */
+	Mpbase	= 1L<<Mpscale,
+};
+
+typedef
+struct
+{
+	long	a[Mpprec];
+	char	ovf;
+} Mp;
+
+static	void	mpint(Mp*, int);
+static	void	mppow(Mp*, int, int);
+static	void	mpmul(Mp*, int);
+static	void	mpadd(Mp*, Mp*);
+static	int	mptof(Mp*, double*);
+
+/*
+ * convert a string, s, to floating in *d
+ * return conversion overflow.
+ * required syntax is [+-]d*[.]d*[e[+-]d*]
+ */
+int
+mpatof(char *s, double *d)
+{
+	Mp a, b;
+	int dp, c, f, ef, ex, zer;
+	double d1, d2;
+
+	dp = 0;		/* digits after decimal point */
+	f = 0;		/* sign */
+	ex = 0;		/* exponent */
+	zer = 1;	/* zero */
+	memset(&a, 0, sizeof(a));
+	for(;;) {
+		switch(c = *s++) {
+		default:
+			goto bad;
+		case '-':
+			f = 1;
+		case ' ':
+		case  '\t':
+		case  '+':
+			continue;
+		case '.':
+			dp = 1;
+			continue;
+		case '1':
+		case '2':
+		case '3':
+		case '4':
+		case '5':
+		case '6':
+		case '7':
+		case '8':
+		case '9':
+			zer = 0;
+		case '0':
+			mpint(&b, c-'0');
+			mpmul(&a, 10);
+			mpadd(&a, &b);
+			if(dp)
+				dp++;
+			continue;
+		case 'E':
+		case 'e':
+			ex = 0;
+			ef = 0;
+			for(;;) {
+				c = *s++;
+				if(c == '+' || c == ' ' || c == '\t')
+					continue;
+				if(c == '-') {
+					ef = 1;
+					continue;
+				}
+				if(c >= '0' && c <= '9') {
+					ex = ex*10 + (c-'0');
+					continue;
+				}
+				break;
+			}
+			if(ef)
+				ex = -ex;
+		case 0:
+			break;
+		}
+		break;
+	}
+	if(a.ovf)
+		goto bad;
+	if(zer) {
+		*d = 0;
+		return 0;
+	}
+	if(dp)
+		dp--;
+	dp -= ex;
+	if(dp > 0) {
+		/*
+		 * must divide by 10**dp
+		 */
+		if(mptof(&a, &d1))
+			goto bad;
+
+		/*
+		 * trial exponent of 8**dp
+		 * 8 (being between 5 and 10)
+		 * should pick up all underflows
+		 * in the division of 5**dp.
+		 */
+		d2 = frexp(d1, &ex);
+		d2 = ldexp(d2, ex-3*dp);
+		if(d2 == 0)
+			goto bad;
+
+		/*
+		 * decompose each 10 into 5*2.
+		 * create 5**dp in fixed point
+		 * and then play with the exponent
+		 * for the remaining 2**dp.
+		 * note that 5**dp will overflow
+		 * with as few as 134 input digits.
+		 */
+		mpint(&a, 1);
+		mppow(&a, 5, dp);
+		if(mptof(&a, &d2))
+			goto bad;
+		d1 = frexp(d1/d2, &ex);
+		d1 = ldexp(d1, ex-dp);
+		if(d1 == 0)
+			goto bad;
+	} else {
+		/*
+		 * must multiply by 10**|dp| --
+		 * just do it in fixed point.
+		 */
+		mppow(&a, 10, -dp);
+		if(mptof(&a, &d1))
+			goto bad;
+	}
+	if(f)
+		d1 = -d1;
+	*d = d1;
+	return 0;
+
+bad:
+	return 1;
+}
+
+/*
+ * convert a to floating in *d
+ * return conversion overflow
+ */
+static int
+mptof(Mp *a, double *d)
+{
+	double f, g;
+	long x, *a1;
+	int i;
+
+	if(a->ovf)
+		return 1;
+	a1 = a->a;
+	f = ldexp(*a1++, 0);
+	for(i=Mpscale; i<Mpprec*Mpscale; i+=Mpscale)
+		if(x = *a1++) {
+			g = ldexp(x, i);
+			/*
+			 * NOTE: the test (g==0) is plan9
+			 * specific. ansi compliant overflow
+			 * is signaled by HUGE and errno==ERANGE.
+			 * change this for your particular ldexp.
+			 */
+			if(g == 0)
+				return 1;
+			f += g;		/* this could bomb! */
+		}
+	*d = f;
+	return 0;
+}
+
+/*
+ * return a += b
+ */
+static void
+mpadd(Mp *a, Mp *b)
+{
+	int i, c;
+	long x, *a1, *b1;
+
+	if(b->ovf)
+		a->ovf = 1;
+	if(a->ovf)
+		return;
+	c = 0;
+	a1 = a->a;
+	b1 = b->a;
+	for(i=0; i<Mpprec; i++) {
+		x = *a1 + *b1++ + c;
+		c = 0;
+		if(x >= Mpbase) {
+			x -= Mpbase;
+			c = 1;
+		}
+		*a1++ = x;
+	}
+	a->ovf = c;
+}
+
+/*
+ * return a = c
+ */
+static void
+mpint(Mp *a, int c)
+{
+
+	memset(a, 0, sizeof(*a));
+	a->a[0] = c;
+}
+
+/*
+ * return a *= c
+ */
+static void
+mpmul(Mp *a, int c)
+{
+	Mp p;
+	int b;
+	memmove(&p, a, sizeof(p));
+	if(!(c & 1))
+		memset(a, 0, sizeof(*a));
+	c &= ~1;
+	for(b=2; c; b<<=1) {
+		mpadd(&p, &p);
+		if(c & b) {
+			mpadd(a, &p);
+			c &= ~b;
+		}
+	}
+}
+
+/*
+ * return a *= b**e
+ */
+static void
+mppow(Mp *a, int b, int e)
+{
+	int b1;
+
+	b1 = b*b;
+	b1 = b1*b1;
+	while(e >= 4) {
+		mpmul(a, b1);
+		e -= 4;
+		if(a->ovf)
+			return;
+	}
+	while(e > 0) {
+		mpmul(a, b);
+		e--;
+	}
+}
+
+/*
+ * convert a string, s, to vlong in *v
+ * return conversion overflow.
+ * required syntax is [0[x]]d*
+ */
+int
+mpatov(char *s, vlong *v)
+{
+	vlong n, nn;
+	int c;
+	n = 0;
+	c = *s;
+	if(c == '0')
+		goto oct;
+	while(c = *s++) {
+		if(c >= '0' && c <= '9')
+			nn = n*10 + c-'0';
+		else
+			goto bad;
+		if(n < 0 && nn >= 0)
+			goto bad;
+		n = nn;
+	}
+	goto out;
+oct:
+	s++;
+	c = *s;
+	if(c == 'x' || c == 'X')
+		goto hex;
+	while(c = *s++) {
+		if(c >= '0' || c <= '7')
+			nn = n*8 + c-'0';
+		else
+			goto bad;
+		if(n < 0 && nn >= 0)
+			goto bad;
+		n = nn;
+	}
+	goto out;
+hex:
+	s++;
+	while(c = *s++) {
+		if(c >= '0' && c <= '9')
+			c += 0-'0';
+		else
+		if(c >= 'a' && c <= 'f')
+			c += 10-'a';
+		else
+		if(c >= 'A' && c <= 'F')
+			c += 10-'A';
+		else
+			goto bad;
+		nn = n*16 + c;
+		if(n < 0 && nn >= 0)
+			goto bad;
+		n = nn;
+	}
+out:
+	*v = n;
+	return 0;
+
+bad:
+	*v = ~0;
+	return 1;
+}