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author | Rich Felker <dalias@aerifal.cx> | 2011-04-05 09:16:40 -0400 |
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committer | Rich Felker <dalias@aerifal.cx> | 2011-04-05 09:16:40 -0400 |
commit | f9569662c08d371b85c77f025dd5c6e00b4a4c8b (patch) | |
tree | 9d57f468465a14481945927f3ed60bcd445644fe /src/stdio/vfprintf.c | |
parent | bd1f6eba8ca41994e7b7aefbe1513bd1b24f1279 (diff) | |
download | musl-f9569662c08d371b85c77f025dd5c6e00b4a4c8b.zip musl-f9569662c08d371b85c77f025dd5c6e00b4a4c8b.tar.gz musl-f9569662c08d371b85c77f025dd5c6e00b4a4c8b.tar.bz2 |
fix various floating point rounding and formatting errors in *printf
Diffstat (limited to 'src/stdio/vfprintf.c')
-rw-r--r-- | src/stdio/vfprintf.c | 42 |
1 files changed, 25 insertions, 17 deletions
diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c index 8cbfd96..2245d1d 100644 --- 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; - 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; @@ -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) { - prefix++; + prefix+=3; } 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"; @@ -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; + 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 (pl && *prefix=='-') y=-y; 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); @@ -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; - *s++='0'; - *s++=t+('x'-'a'); 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); - 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); @@ -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); - 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; - 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; @@ -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) */ - 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 */ @@ -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 (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)); |