fix various floating point rounding and formatting errors in *printf

diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
index 8cbfd96..2245d1d 100644 (file)
--- a/src/stdio/vfprintf.c
+++ b/src/stdio/vfprintf.c
@@ -193,7 +193,7 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
        uint32_t *a, *d, *r, *z;
        int e2=0, e, i, j, l;
        char buf[9+LDBL_MANT_DIG/4], *s;
        uint32_t *a, *d, *r, *z;
        int e2=0, e, i, j, l;
        char buf[9+LDBL_MANT_DIG/4], *s;

-       const char *prefix="-+ ";
+       const char *prefix="-0X+0X 0X-0x+0x 0x";

        int pl;
        char ebuf0[3*sizeof(int)], *ebuf=&ebuf0[3*sizeof(int)], *estr;
 
        int pl;
        char ebuf0[3*sizeof(int)], *ebuf=&ebuf0[3*sizeof(int)], *estr;
 


@@ -201,10 +201,10 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
        if (y<0 || 1/y<0) {
                y=-y;
        } else if (fl & MARK_POS) {
        if (y<0 || 1/y<0) {
                y=-y;
        } else if (fl & MARK_POS) {

-               prefix++;
+               prefix+=3;

        } else if (fl & PAD_POS) {
        } else if (fl & PAD_POS) {

-               prefix+=2;
-       } else pl=0;
+               prefix+=6;
+       } else prefix++, pl=0;

 
        if (!isfinite(y)) {
                char *s = (t&32)?"inf":"INF";
 
        if (!isfinite(y)) {
                char *s = (t&32)?"inf":"INF";


@@ -223,15 +223,23 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
                long double round = 8.0;
                int re;
 
                long double round = 8.0;
                int re;
 

+               if (t&32) prefix += 9;
+               pl += 2;
+

                if (p<0 || p>=LDBL_MANT_DIG/4-1) re=0;
                else re=LDBL_MANT_DIG/4-1-p;
 
                if (re) {
                if (p<0 || p>=LDBL_MANT_DIG/4-1) re=0;
                else re=LDBL_MANT_DIG/4-1-p;
 
                if (re) {

-                       if (pl && *prefix=='-') y=-y;

                        while (re--) round*=16;
                        while (re--) round*=16;

-                       y+=round;
-                       y-=round;
-                       if (y<0) y=-y;
+                       if (*prefix=='-') {
+                               y=-y;
+                               y-=round;
+                               y+=round;
+                               y=-y;
+                       } else {
+                               y+=round;
+                               y-=round;
+                       }

                }
 
                estr=fmt_u(e2<0 ? -e2 : e2, ebuf);
                }
 
                estr=fmt_u(e2<0 ? -e2 : e2, ebuf);


@@ -240,17 +248,17 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
                *--estr = t+('p'-'a');
 
                s=buf;
                *--estr = t+('p'-'a');
 
                s=buf;

-               *s++='0';
-               *s++=t+('x'-'a');

                do {
                        int x=y;
                        *s++=xdigits[x]|(t&32);
                        y=16*(y-x);
                do {
                        int x=y;
                        *s++=xdigits[x]|(t&32);
                        y=16*(y-x);

-                       if (s-buf==3 && (y||p>0||(fl&ALT_FORM))) *s++='.';
+                       if (s-buf==1 && (y||p>0||(fl&ALT_FORM))) *s++='.';

                } while (y);
 
                } while (y);
 

-               if (p<0) p = s-buf-4;
-               l = 1 + p + (p || (fl&ALT_FORM)) + ebuf-estr;
+               if (p && s-buf-2 < p)
+                       l = (p+2) + (ebuf-estr);
+               else
+                       l = (s-buf) + (ebuf-estr);

 
                pad(f, ' ', w, pl+l, fl);
                out(f, prefix, pl);
 
                pad(f, ' ', w, pl+l, fl);
                out(f, prefix, pl);


@@ -258,12 +266,12 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
                out(f, buf, s-buf);
                pad(f, '0', l-(ebuf-estr)-(s-buf), 0, 0);
                out(f, estr, ebuf-estr);
                out(f, buf, s-buf);
                pad(f, '0', l-(ebuf-estr)-(s-buf), 0, 0);
                out(f, estr, ebuf-estr);

-               pad(f, '0', w, pl+l, fl^LEFT_ADJ);
+               pad(f, ' ', w, pl+l, fl^LEFT_ADJ);

                return MAX(w, pl+l);
        }
        if (p<0) p=6;
 
                return MAX(w, pl+l);
        }
        if (p<0) p=6;
 

-       y *= 0x1p28; e2-=28;
+       if (y) y *= 0x1p28, e2-=28;

 
        if (e2<0) a=r=z=big;
        else a=r=z=big+sizeof(big)/sizeof(*big) - LDBL_MANT_DIG - 1;
 
        if (e2<0) a=r=z=big;
        else a=r=z=big+sizeof(big)/sizeof(*big) - LDBL_MANT_DIG - 1;


@@ -305,7 +313,7 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
        else e=0;
 
        /* Perform rounding: j is precision after the radix (possibly neg) */
        else e=0;
 
        /* Perform rounding: j is precision after the radix (possibly neg) */

-       j = p - ((t|32)!='f')*e - ((t|32)=='g');
+       j = p - ((t|32)!='f')*e - ((t|32)=='g' && p);

        if (j < 9*(z-r-1)) {
                uint32_t x;
                /* We avoid C's broken division of negative numbers */
        if (j < 9*(z-r-1)) {
                uint32_t x;
                /* We avoid C's broken division of negative numbers */


@@ -347,7 +355,7 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
                }
                if (!(fl&ALT_FORM)) {
                        /* Count trailing zeros in last place */
                }
                if (!(fl&ALT_FORM)) {
                        /* Count trailing zeros in last place */

-                       if (z>a) for (i=10, j=0; z[-1]%i==0; i*=10, j++);
+                       if (z>a && z[-1]) for (i=10, j=0; z[-1]%i==0; i*=10, j++);

                        else j=9;
                        if ((t|32)=='f')
                                p = MIN(p,MAX(0,9*(z-r-1)-j));
                        else j=9;
                        if ((t|32)=='f')
                                p = MIN(p,MAX(0,9*(z-r-1)-j));