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accelerate integer sprintf() a little bit

This commit is contained in:
Heng Li 2011-07-25 22:19:20 -04:00
parent 9172515431
commit 4b91eead77
2 changed files with 15 additions and 14 deletions
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28
kstring.c
View File

@ -211,12 +211,12 @@ double frexp10(double x, int *e)
int ksprintf_fast(kstring_t *s, const char *fmt, ...)
{
#define write_integer0(_c, _s, _type, _z, _conv) do { \
#define write_integer0(_c, _s, _type, _z, _base, _conv) do { \
char buf[32]; \
int l = 0, k, w, f; \
_type x; \
if (_c != 0) { \
for (x = _c < 0? -_c : _c; x > 0; x /= _z.base) buf[l++] = _conv[x%_z.base]; \
for (x = _c < 0? -_c : _c; x > 0; x /= _base) buf[l++] = _conv[x%_base]; \
if (_c < 0) buf[l++] = '-'; \
} else buf[l++] = '0'; \
f = l > _z.f? l : _z.f; \
@ -231,9 +231,9 @@ int ksprintf_fast(kstring_t *s, const char *fmt, ...)
for (k = f; k < w; ++k) _s->s[_s->l++] = ' '; \
} while (0)
#define write_integer(_ap, _s, _type, _z, _conv) do { \
#define write_integer(_ap, _s, _type, _z, _base, _conv) do { \
_type c = va_arg(_ap, _type); \
write_integer0(c, _s, _type, _z, _conv); \
write_integer0(c, _s, _type, _z, _base, _conv); \
} while (0)
va_list ap;
@ -297,18 +297,18 @@ int ksprintf_fast(kstring_t *s, const char *fmt, ...)
finished = 1;
} else if (*p == 'd' || *p == 'i') { // %d or %i
z.base = 10;
if (z.n_ell == 0) write_integer(ap, s, int, z, "0123456789");
else if (z.n_ell == 1) write_integer(ap, s, long, z, "0123456789");
else write_integer(ap, s, long long, z, "0123456789");
if (z.n_ell == 0) write_integer(ap, s, int, z, 10, "0123456789");
else if (z.n_ell == 1) write_integer(ap, s, long, z, 10, "0123456789");
else write_integer(ap, s, long long, z, 10, "0123456789");
finished = 1;
} else if (*p == 'u' || *p == 'o' || *p == 'x' || *p == 'X') { // %u, %o or %x
const char *conv = (*p == 'X')? "0123456789ABCDEF" : "0123456789abcdef";
if (*p == 'u') z.base = 10;
else if (*p == 'o') z.base = 8;
else if (*p == 'x' || *p == 'X') z.base = 16;
if (z.n_ell == 0) write_integer(ap, s, unsigned, z, conv);
else if (z.n_ell == 1) write_integer(ap, s, unsigned long, z, conv);
else write_integer(ap, s, unsigned long long, z, conv);
if (z.n_ell == 0) write_integer(ap, s, unsigned, z, z.base, conv);
else if (z.n_ell == 1) write_integer(ap, s, unsigned long, z, z.base, conv);
else write_integer(ap, s, unsigned long long, z, z.base, conv);
finished = 1;
} else if (*p == 'g' || *p == 'e' || *p == 'f' || *p == 'G' || *p == 'E' || *p == 'F') { // double-precision
double x = va_arg(ap, double);
@ -341,19 +341,19 @@ int ksprintf_fast(kstring_t *s, const char *fmt, ...)
enlarge(s, z.w > z.f + 7? z.w : z.f + 7);
if (type == 'e') { // scientific number
int j, l0 = s->l;
ztmp.f = -1; write_integer0(y, s, int64_t, ztmp, "0123456789");
ztmp.f = -1; write_integer0(y, s, int64_t, ztmp, 10, "0123456789");
if (s->l - l0 > z.f) ++e; // in case x=9.9999999e100
while (s->s[s->l - 1] == '0') --s->l; // trim trailing zeros
for (j = s->l; j > l0 + 1; --j) s->s[j] = s->s[j - 1]; // shift for the dot
s->s[j] = '.'; ++s->l; // add the dot
s->s[s->l++] = isupper(*p)? 'E' : 'e';
if (e >= 0) s->s[s->l++] = '+';
ztmp.f = 2; write_integer0(e, s, int, ztmp, "0123456789"); // write the exp
ztmp.f = 2; write_integer0(e, s, int, ztmp, 10, "0123456789"); // write the exp
} else { // type == 'f'
int j;
if (e >= 0) { // NB: here e < z.f by the definition of type
int l0 = s->l;
ztmp.f = -1; write_integer0(y, s, int64_t, ztmp, "0123456789");
ztmp.f = -1; write_integer0(y, s, int64_t, ztmp, 10, "0123456789");
if (s->l - l0 > z.f) ++e;
for (j = s->l; j > l0 + e + 1; --j) s->s[j] = s->s[j - 1]; // shift for the dot
s->s[j] = '.'; ++s->l; // add the dot
@ -363,7 +363,7 @@ int ksprintf_fast(kstring_t *s, const char *fmt, ...)
s->s[s->l++] = '0';
s->s[s->l++] = '.';
for (j = 0; j < -e - 1; ++j) s->s[s->l++] = '0'; // fill enough zeros
ztmp.f = -1; write_integer0(y, s, int64_t, ztmp, "0123456789");
ztmp.f = -1; write_integer0(y, s, int64_t, ztmp, 10, "0123456789");
while (s->s[s->l - 1] == '0') --s->l;
}
}

1
kstring.h
View File

@ -53,6 +53,7 @@ extern "C" {
#endif
int ksprintf(kstring_t *s, const char *fmt, ...);
int ksprintf_fast(kstring_t *s, const char *fmt, ...);
int ksplit_core(char *s, int delimiter, int *_max, int **_offsets);
char *kstrstr(const char *str, const char *pat, int **_prep);
char *kstrnstr(const char *str, const char *pat, int n, int **_prep);