Import sources from 2011-03-30 iso image

1 files changed, 375 insertions, 0 deletions

diff --git a/sys/src/cmd/unix/drawterm/libc/fltfmt.c b/sys/src/cmd/unix/drawterm/libc/fltfmt.c
new file mode 100755
index 000000000..d14d67202
--- /dev/null
+++ b/sys/src/cmd/unix/drawterm/libc/fltfmt.c
@@ -0,0 +1,375 @@
+#include <u.h>
+#include <libc.h>
+#include <float.h>
+#include <ctype.h>
+#include "fmtdef.h"
+
+enum
+{
+	FDIGIT	= 30,
+	FDEFLT	= 6,
+	NSIGNIF	= 17
+};
+
+/*
+ * first few powers of 10, enough for about 1/2 of the
+ * total space for doubles.
+ */
+static double pows10[] =
+{
+	  1e0,   1e1,   1e2,   1e3,   1e4,   1e5,   1e6,   1e7,   1e8,   1e9,  
+	 1e10,  1e11,  1e12,  1e13,  1e14,  1e15,  1e16,  1e17,  1e18,  1e19,  
+	 1e20,  1e21,  1e22,  1e23,  1e24,  1e25,  1e26,  1e27,  1e28,  1e29,  
+	 1e30,  1e31,  1e32,  1e33,  1e34,  1e35,  1e36,  1e37,  1e38,  1e39,  
+	 1e40,  1e41,  1e42,  1e43,  1e44,  1e45,  1e46,  1e47,  1e48,  1e49,  
+	 1e50,  1e51,  1e52,  1e53,  1e54,  1e55,  1e56,  1e57,  1e58,  1e59,  
+	 1e60,  1e61,  1e62,  1e63,  1e64,  1e65,  1e66,  1e67,  1e68,  1e69,  
+	 1e70,  1e71,  1e72,  1e73,  1e74,  1e75,  1e76,  1e77,  1e78,  1e79,  
+	 1e80,  1e81,  1e82,  1e83,  1e84,  1e85,  1e86,  1e87,  1e88,  1e89,  
+	 1e90,  1e91,  1e92,  1e93,  1e94,  1e95,  1e96,  1e97,  1e98,  1e99,  
+	1e100, 1e101, 1e102, 1e103, 1e104, 1e105, 1e106, 1e107, 1e108, 1e109, 
+	1e110, 1e111, 1e112, 1e113, 1e114, 1e115, 1e116, 1e117, 1e118, 1e119, 
+	1e120, 1e121, 1e122, 1e123, 1e124, 1e125, 1e126, 1e127, 1e128, 1e129, 
+	1e130, 1e131, 1e132, 1e133, 1e134, 1e135, 1e136, 1e137, 1e138, 1e139, 
+	1e140, 1e141, 1e142, 1e143, 1e144, 1e145, 1e146, 1e147, 1e148, 1e149, 
+	1e150, 1e151, 1e152, 1e153, 1e154, 1e155, 1e156, 1e157, 1e158, 1e159, 
+};
+
+#undef pow10
+#define  pow10(x)  fmtpow10(x)
+
+static double
+pow10(int n)
+{
+	double d;
+	int neg;
+
+	neg = 0;
+	if(n < 0){
+		if(n < DBL_MIN_10_EXP){
+			return 0.;
+		}
+		neg = 1;
+		n = -n;
+	}else if(n > DBL_MAX_10_EXP){
+		return HUGE_VAL;
+	}
+	if(n < (int)(sizeof(pows10)/sizeof(pows10[0])))
+		d = pows10[n];
+	else{
+		d = pows10[sizeof(pows10)/sizeof(pows10[0]) - 1];
+		for(;;){
+			n -= sizeof(pows10)/sizeof(pows10[0]) - 1;
+			if(n < (int)(sizeof(pows10)/sizeof(pows10[0]))){
+				d *= pows10[n];
+				break;
+			}
+			d *= pows10[sizeof(pows10)/sizeof(pows10[0]) - 1];
+		}
+	}
+	if(neg){
+		return 1./d;
+	}
+	return d;
+}
+
+static int
+xadd(char *a, int n, int v)
+{
+	char *b;
+	int c;
+
+	if(n < 0 || n >= NSIGNIF)
+		return 0;
+	for(b = a+n; b >= a; b--) {
+		c = *b + v;
+		if(c <= '9') {
+			*b = c;
+			return 0;
+		}
+		*b = '0';
+		v = 1;
+	}
+	*a = '1';	/* overflow adding */
+	return 1;
+}
+
+static int
+xsub(char *a, int n, int v)
+{
+	char *b;
+	int c;
+
+	for(b = a+n; b >= a; b--) {
+		c = *b - v;
+		if(c >= '0') {
+			*b = c;
+			return 0;
+		}
+		*b = '9';
+		v = 1;
+	}
+	*a = '9';	/* underflow subtracting */
+	return 1;
+}
+
+static void
+xdtoa(Fmt *fmt, char *s2, double f)
+{
+	char s1[NSIGNIF+10];
+	double g, h;
+	int e, d, i, n;
+	int c1, c2, c3, c4, ucase, sign, chr, prec;
+
+	prec = FDEFLT;
+	if(fmt->flags & FmtPrec)
+		prec = fmt->prec;
+	if(prec > FDIGIT)
+		prec = FDIGIT;
+	if(__isNaN(f)) {
+		strcpy(s2, "NaN");
+		return;
+	}
+	if(__isInf(f, 1)) {
+		strcpy(s2, "+Inf");
+		return;
+	}
+	if(__isInf(f, -1)) {
+		strcpy(s2, "-Inf");
+		return;
+	}
+	sign = 0;
+	if(f < 0) {
+		f = -f;
+		sign++;
+	}
+	ucase = 0;
+	chr = fmt->r;
+	if(isupper(chr)) {
+		ucase = 1;
+		chr = tolower(chr);
+	}
+
+	e = 0;
+	g = f;
+	if(g != 0) {
+		frexp(f, &e);
+		e = e * .301029995664;
+		if(e >= -150 && e <= +150) {
+			d = 0;
+			h = f;
+		} else {
+			d = e/2;
+			h = f * pow10(-d);
+		}
+		g = h * pow10(d-e);
+		while(g < 1) {
+			e--;
+			g = h * pow10(d-e);
+		}
+		while(g >= 10) {
+			e++;
+			g = h * pow10(d-e);
+		}
+	}
+
+	/*
+	 * convert NSIGNIF digits and convert
+	 * back to get accuracy.
+	 */
+	for(i=0; i<NSIGNIF; i++) {
+		d = g;
+		s1[i] = d + '0';
+		g = (g - d) * 10;
+	}
+	s1[i] = 0;
+
+	/*
+	 * try decimal rounding to eliminate 9s
+	 */
+	c2 = prec + 1;
+	if(chr == 'f')
+		c2 += e;
+	if(c2 >= NSIGNIF-2) {
+		strcpy(s2, s1);
+		d = e;
+		s1[NSIGNIF-2] = '0';
+		s1[NSIGNIF-1] = '0';
+		sprint(s1+NSIGNIF, "e%d", e-NSIGNIF+1);
+		g = strtod(s1, nil);
+		if(g == f)
+			goto found;
+		if(xadd(s1, NSIGNIF-3, 1)) {
+			e++;
+			sprint(s1+NSIGNIF, "e%d", e-NSIGNIF+1);
+		}
+		g = strtod(s1, nil);
+		if(g == f)
+			goto found;
+		strcpy(s1, s2);
+		e = d;
+	}
+
+	/*
+	 * convert back so s1 gets exact answer
+	 */
+	for(;;) {
+		sprint(s1+NSIGNIF, "e%d", e-NSIGNIF+1);
+		g = strtod(s1, nil);
+		if(f > g) {
+			if(xadd(s1, NSIGNIF-1, 1))
+				e--;
+			continue;
+		}
+		if(f < g) {
+			if(xsub(s1, NSIGNIF-1, 1))
+				e++;
+			continue;
+		}
+		break;
+	}
+
+found:
+	/*
+	 * sign
+	 */
+	d = 0;
+	i = 0;
+	if(sign)
+		s2[d++] = '-';
+	else if(fmt->flags & FmtSign)
+		s2[d++] = '+';
+	else if(fmt->flags & FmtSpace)
+		s2[d++] = ' ';
+
+	/*
+	 * copy into final place
+	 * c1 digits of leading '0'
+	 * c2 digits from conversion
+	 * c3 digits of trailing '0'
+	 * c4 digits after '.'
+	 */
+	c1 = 0;
+	c2 = prec + 1;
+	c3 = 0;
+	c4 = prec;
+	switch(chr) {
+	default:
+		if(xadd(s1, c2, 5))
+			e++;
+		break;
+	case 'g':
+		/*
+		 * decide on 'e' of 'f' style convers
+		 */
+		if(xadd(s1, c2, 5))
+			e++;
+		if(e >= -5 && e <= prec) {
+			c1 = -e - 1;
+			c4 = prec - e;
+			chr = 'h';	// flag for 'f' style
+		}
+		break;
+	case 'f':
+		if(xadd(s1, c2+e, 5))
+			e++;
+		c1 = -e;
+		if(c1 > prec)
+			c1 = c2;
+		c2 += e;
+		break;
+	}
+
+	/*
+	 * clean up c1 c2 and c3
+	 */
+	if(c1 < 0)
+		c1 = 0;
+	if(c2 < 0)
+		c2 = 0;
+	if(c2 > NSIGNIF) {
+		c3 = c2-NSIGNIF;
+		c2 = NSIGNIF;
+	}
+
+	/*
+	 * copy digits
+	 */
+	while(c1 > 0) {
+		if(c1+c2+c3 == c4)
+			s2[d++] = '.';
+		s2[d++] = '0';
+		c1--;
+	}
+	while(c2 > 0) {
+		if(c2+c3 == c4)
+			s2[d++] = '.';
+		s2[d++] = s1[i++];
+		c2--;
+	}
+	while(c3 > 0) {
+		if(c3 == c4)
+			s2[d++] = '.';
+		s2[d++] = '0';
+		c3--;
+	}
+
+	/*
+	 * strip trailing '0' on g conv
+	 */
+	if(fmt->flags & FmtSharp) {
+		if(0 == c4)
+			s2[d++] = '.';
+	} else
+	if(chr == 'g' || chr == 'h') {
+		for(n=d-1; n>=0; n--)
+			if(s2[n] != '0')
+				break;
+		for(i=n; i>=0; i--)
+			if(s2[i] == '.') {
+				d = n;
+				if(i != n)
+					d++;
+				break;
+			}
+	}
+	if(chr == 'e' || chr == 'g') {
+		if(ucase)
+			s2[d++] = 'E';
+		else
+			s2[d++] = 'e';
+		c1 = e;
+		if(c1 < 0) {
+			s2[d++] = '-';
+			c1 = -c1;
+		} else
+			s2[d++] = '+';
+		if(c1 >= 100) {
+			s2[d++] = c1/100 + '0';
+			c1 = c1%100;
+		}
+		s2[d++] = c1/10 + '0';
+		s2[d++] = c1%10 + '0';
+	}
+	s2[d] = 0;
+}
+
+static int
+floatfmt(Fmt *fmt, double f)
+{
+	char s[341];		/* precision+exponent+sign+'.'+null */
+
+	xdtoa(fmt, s, f);
+	fmt->flags &= FmtWidth|FmtLeft;
+	__fmtcpy(fmt, s, strlen(s), strlen(s));
+	return 0;
+}
+
+int
+__efgfmt(Fmt *f)
+{
+	double d;
+
+	d = va_arg(f->args, double);
+	return floatfmt(f, d);
+}