diff options
Diffstat (limited to 'src')
| -rw-r--r-- | src/internal/floatscan.c | 438 | ||||
| -rw-r--r-- | src/internal/floatscan.h | 8 | ||||
| -rw-r--r-- | src/stdlib/strtod.c | 11 | ||||
| -rw-r--r-- | src/stdlib/strtof.c | 11 | ||||
| -rw-r--r-- | src/stdlib/strtold.c | 103 |
5 files changed, 477 insertions, 94 deletions
diff --git a/src/internal/floatscan.c b/src/internal/floatscan.c new file mode 100644 index 00000000..15ad5e12 --- /dev/null +++ b/src/internal/floatscan.c @@ -0,0 +1,438 @@ +#include <stdint.h> +#include <stdio.h> +#include <math.h> +#include <float.h> +#include <limits.h> + +#include "floatscan.h" + +#if LDBL_MANT_DIG == 53 && LDBL_MAX_EXP == 1024 + +#define LD_B1B_DIG 2 +#define LD_B1B_MAX 9007199, 254740991 +#define KMAX 128 + +#else /* LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 */ + +#define LD_B1B_DIG 3 +#define LD_B1B_MAX 18, 446744073, 709551615 +#define KMAX 2048 + +#endif + +#define MASK (KMAX-1) + + +#if 1 +#include "stdio_impl.h" +#undef ungetc +#define ungetc(c,f) ((f)->rpos--,(c)) +#undef getc +#define getc getc_unlocked +#endif + + +static long long scanexp(FILE *f, off_t *pcnt) +{ + int c; + int x; + long long y; + int neg = 0; + + *pcnt += (c=getc(f))>=0; + if (c=='+' || c=='-') { + neg = (c=='-'); + *pcnt += (c=getc(f))>=0; + if (c-'0'>=10U) { + if (c>=0) { + ungetc(c, f); + --*pcnt; + } + return LLONG_MIN; + } + } + for (x=0; c-'0'<10U && x<INT_MAX/10; *pcnt += (c=getc(f))>=0) + x = 10*x + c-'0'; + for (y=x; c-'0'<10U && x<LLONG_MAX/10; *pcnt += (c=getc(f))>=0) + y = 10*y + c-'0'; + for (; c-'0'<10U; *pcnt += (c=getc(f))>=0); + if (c>=0) { + ungetc(c, f); + --*pcnt; + } + return neg ? -y : y; +} + + +static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int pok, off_t *pcnt) +{ + uint32_t x[KMAX]; + static const uint32_t th[] = { LD_B1B_MAX }; + int i, j, k, a, z; + long long lrp=-1, dc=0; + int gotdig = 0; + int rp; + int e10=0; + int e2; + long double y; + long double frac=0; + long double bias=0; + + j=0; + k=0; + + if (c<0) *pcnt += (c=getc(f))>=0; + + /* Don't let leading zeros consume buffer space */ + for (; c=='0'; *pcnt += (c=getc(f))>=0) gotdig=1; + + x[0] = 0; + for (; c-'0'<10U || c=='.'; *pcnt += (c=getc(f))>=0) { + if (c == '.') { + if (lrp!=-1) break; + lrp = dc; + } else if (k < KMAX) { + dc++; + if (j) x[k] = x[k]*10 + c-'0'; + else x[k] = c-'0'; + if (++j==9) { + k++; + j=0; + } + gotdig=1; + } else { + dc++; + x[KMAX-1] |= c-'0'; + } + } + if (lrp==-1) lrp=dc; + + if (gotdig && (c|32)=='e') { + e10 = scanexp(f, pcnt); + if (e10 == LLONG_MIN) { + if (!pok) { + *pcnt = 0; + return 0; + } + e10 = 0; + } + lrp += e10; + } else if (c>=0) { + ungetc(c, f); + --*pcnt; + } + if (!gotdig) { + *pcnt = 0; + return 0; + } + + if (!x[0]) + return sign * 0.0; + if (lrp==dc && (!k || (k==1 && !j)) && (bits>30 || x[0]>>bits==0)) + return sign * (long double)x[0]; + if (lrp > -emin/2) + return sign * LDBL_MAX * LDBL_MAX; + if (lrp < emin-2*LDBL_MANT_DIG) + return sign * LDBL_MIN * LDBL_MIN; + + if (k<KMAX && j) { + for (; j<9; j++) x[k]*=10; + k++; + j=0; + } + + a = 0; + z = k; + e2 = 0; + rp = lrp; + + while (rp < 18+9*LD_B1B_DIG) { + uint32_t carry = 0; + e2 -= 29; + for (k=(z-1 & MASK); ; k=(k-1 & MASK)) { + uint64_t tmp = ((uint64_t)x[k] << 29) + carry; + if (tmp > 1000000000) { + carry = tmp / 1000000000; + x[k] = tmp % 1000000000; + } else { + carry = 0; + x[k] = tmp; + } + if (k==(z-1 & MASK) && k!=a && !x[k]) z = k; + if (k==a) break; + } + if (carry) { + rp += 9; + if (a == z) { + z = (z-1 & MASK); + x[z-1 & MASK] |= x[z]; + } + a = (a-1 & MASK); + x[a] = carry; + } + } + + if (rp % 9) { + static const int p10s[] = { + 100000000, 10000000, 1000000, 100000, + 10000, 1000, 100, 10 + }; + int rpm9 = rp % 9; + int p10 = p10s[rpm9-1]; + uint32_t carry = 0; + for (k=a; k!=z; k=(k+1 & MASK)) { + uint32_t tmp = x[k] % p10; + x[k] = x[k]/p10 + carry; + carry = 1000000000/p10 * tmp; + if (k==a && !x[k]) { + a = (a+1 & MASK); + rp -= 9; + } + } + if (carry) { + if ((z+1 & MASK) != a) { + x[z] = carry; + z = (z+1 & MASK); + } else x[z-1 & MASK] |= 1; + } + rp += 9-rpm9; + } + + for (;;) { + uint32_t carry = 0; + int sh = 1; + for (i=0; i<LD_B1B_DIG; i++) { + k = (a+i & MASK); + if (k == z || x[k] < th[i]) { + i=LD_B1B_DIG; + break; + } + if (x[a+i & MASK] > th[i]) break; + } + if (i==LD_B1B_DIG && rp==9*LD_B1B_DIG) break; + /* FIXME: find a way to compute optimal sh */ + if (rp > 9+9*LD_B1B_DIG) sh = 9; + e2 += sh; + for (k=a; k!=z; k=(k+1 & MASK)) { + uint32_t tmp = x[k] & (1<<sh)-1; + x[k] = (x[k]>>sh) + carry; + carry = (1000000000>>sh) * tmp; + if (k==a && !x[k]) { + a = (a+1 & MASK); + rp -= 9; + } + } + if (carry) { + if ((z+1 & MASK) != a) { + x[z] = carry; + z = (z+1 & MASK); + } else x[z-1 & MASK] |= 1; + } + } + + for (y=i=0; i<LD_B1B_DIG && (a+i & MASK)!=z; i++) + y = 1000000000.0L * y + x[a+i & MASK]; + + y *= sign; + + if (bits > LDBL_MANT_DIG+e2-emin) { + bits = LDBL_MANT_DIG+e2-emin; + if (bits<0) bits=0; + } + + if (bits < LDBL_MANT_DIG) { + bias = copysignl(scalbn(1, 2*LDBL_MANT_DIG-bits-1), y); + frac = fmodl(y, scalbn(1, LDBL_MANT_DIG-bits)); + y -= frac; + y += bias; + } + + if ((a+i & MASK) != z) { + uint32_t t = x[a+i & MASK]; + if (t < 500000000 && (t || (a+i+1 & MASK) != z)) + frac += 0.25*sign; + else if (t > 500000000) + frac += 0.75*sign; + else if (t == 500000000) { + if ((a+i+1 & MASK) == z) + frac += 0.5*sign; + else + frac += 0.75*sign; + } + if (LDBL_MANT_DIG-bits >= 2 && !fmodl(frac, 1)) + frac++; + } + + y += frac; + y -= bias; + + y = scalbnl(y, e2); + + return y; +} + +static long double hexfloat(FILE *f, int c, int bits, int emin, int sign, int pok, off_t *pcnt) +{ + uint32_t x = 0; + long double y = 0; + long double scale = 1; + long double bias = 0; + int gottail = 0, gotrad = 0, gotdig = 0; + long long rp = 0; + long long dc = 0; + long long e2 = 0; + int d; + + if (c<0) *pcnt += (c=getc(f))>=0; + + /* Skip leading zeros */ + for (; c=='0'; *pcnt += (c=getc(f))>=0) gotdig = 1; + + if (c=='.') { + gotrad = 1; + *pcnt += (c=getc(f))>=0; + /* Count zeros after the radix point before significand */ + for (rp=0; c=='0'; *pcnt += (c=getc(f))>=0, rp--) gotdig = 1; + } + + for (; c-'0'<10U || (c|32)-'a'<6U || c=='.'; *pcnt += (c=getc(f))>=0) { + if (c=='.') { + if (gotrad) break; + rp = dc; + gotrad = 1; + } else { + gotdig = 1; + if (c > '9') d = (c|32)+10-'a'; + else d = c-'0'; + if (dc<8) { + x = x*16 + d; + } else if (dc < LDBL_MANT_DIG/4+1) { + y += d*(scale/=16); + } else if (d && !gottail) { + y += 0.5*scale; + gottail = 1; + } + dc++; + } + } + if (!gotdig) { + if (c>=0) { + ungetc(c, f); + --*pcnt; + } + if (pok) *pcnt -= 1+gotrad; /* uncount the rp, x of 0x */ + else *pcnt = 0; + return 0; + } + if (!gotrad) rp = dc; + while (dc<8) x *= 16, dc++; + if ((c|32)=='p') { + e2 = scanexp(f, pcnt); + if (e2 == LLONG_MIN) { + if (!pok) { + *pcnt = 0; + return 0; + } + e2 = 0; + } + } + e2 += 4*rp - 32; + + if (!x) return sign * 0.0; + if (e2 > -emin) return sign * LDBL_MAX * LDBL_MAX; + if (e2 < emin-2*LDBL_MANT_DIG) return sign * LDBL_MIN * LDBL_MIN; + + while (x < 0x80000000) { + if (y>=0.5) { + x += x + 1; + y += y - 1; + } else { + x += x; + y += y; + } + e2--; + } + + if (bits > 32+e2-emin) { + bits = 32+e2-emin; + if (bits<0) bits=0; + } + + if (bits < LDBL_MANT_DIG) + bias = copysignl(scalbn(1, 32+LDBL_MANT_DIG-bits-1), sign); + + if (bits<32 && y && !(x&1)) x++, y=0; + + y = bias + sign*(long double)x + sign*y; + y -= bias; + + return scalbnl(y, e2); +} + +long double __floatscan(FILE *f, int c, int prec, int pok, off_t *pcnt) +{ + int sign = 1; + int i; + int bits; + int emin; + + *pcnt = 0; + + switch (prec) { + case 0: + bits = 24; + emin = -149; + break; + case 1: + bits = 53; + emin = -1074; + break; + case 2: + bits = LDBL_MANT_DIG; + emin = -16445; + break; + default: + return 0; + } + + if (c<0) *pcnt += (c=getc(f))>=0; + + if (c=='+' || c=='-') { + sign -= 2*(c=='-'); + *pcnt += (c=getc(f))>=0; + } + + for (i=0; i<8 && (c|32)=="infinity"[i]; i++) + if (i<7) c = getc(f); + if (i==3 || i==8 || (i>3 && pok)) { + if (i==3 && c>=0) ungetc(c, f); + if (i==8) *pcnt += 7; + else *pcnt += 2; + return sign * INFINITY; + } + if (!i) for (i=0; i<3 && (c|32)=="nan"[i]; i++) + if (i<3) c = getc(f); + if (i==3) { + *pcnt += 2; + return sign>0 ? NAN : -NAN; + } + + if (i) { + if (c>=0) ungetc(c, f); + *pcnt = 0; + return 0; + } + + if (c=='0') { + *pcnt += (c=getc(f))>=0; + if ((c|32) == 'x') + return hexfloat(f, -1, bits, emin, sign, pok, pcnt); + if (c>=0) { + ungetc(c, f); + --*pcnt; + } + c = '0'; + } + + return decfloat(f, c, bits, emin, sign, pok, pcnt); +} diff --git a/src/internal/floatscan.h b/src/internal/floatscan.h new file mode 100644 index 00000000..5ea74cc9 --- /dev/null +++ b/src/internal/floatscan.h @@ -0,0 +1,8 @@ +#ifndef FLOATSCAN_H +#define FLOATSCAN_H + +#include <stdio.h> + +long double __floatscan(FILE *, int, int, int, off_t *); + +#endif diff --git a/src/stdlib/strtod.c b/src/stdlib/strtod.c index 388058fe..98b992a1 100644 --- a/src/stdlib/strtod.c +++ b/src/stdlib/strtod.c @@ -1,6 +1,15 @@ #include <stdlib.h> +#include "floatscan.h" +#include "stdio_impl.h" double strtod(const char *s, char **p) { - return strtold(s, p); + FILE f = { + .buf = (void *)s, .rpos = (void *)s, + .rend = (void *)-1, .lock = -1 + }; + off_t cnt; + double y = __floatscan(&f, -1, 1, 1, &cnt); + if (p) *p = (char *)s + cnt; + return y; } diff --git a/src/stdlib/strtof.c b/src/stdlib/strtof.c index 07b32df4..2dc349a9 100644 --- a/src/stdlib/strtof.c +++ b/src/stdlib/strtof.c @@ -1,6 +1,15 @@ #include <stdlib.h> +#include "floatscan.h" +#include "stdio_impl.h" float strtof(const char *s, char **p) { - return strtold(s, p); + FILE f = { + .buf = (void *)s, .rpos = (void *)s, + .rend = (void *)-1, .lock = -1 + }; + off_t cnt; + float y = __floatscan(&f, -1, 0, 1, &cnt); + if (p) *p = (char *)s + cnt; + return y; } diff --git a/src/stdlib/strtold.c b/src/stdlib/strtold.c index ec464c15..40ecc122 100644 --- a/src/stdlib/strtold.c +++ b/src/stdlib/strtold.c @@ -1,96 +1,15 @@ #include <stdlib.h> -#include <errno.h> -#include <ctype.h> +#include "floatscan.h" +#include "stdio_impl.h" -static int valid_exp(const unsigned char *s) +long double strtold(const char *s, char **p) { - return isdigit(*s) || ((s[0]=='+'||s[0]=='-') && isdigit(s[1])); -} - -long double strtold(const char *s1, char **p) -{ - const unsigned char *s = (void *)s1; - long double x = 0; - long double frac; - int sign = 0; - int nonzero = 0; - int radix = '.'; - long e; - int saved_errno = errno; - - if (!p) p = (char **)&s1; - - /* Initial whitespace */ - for (; isspace(*s); s++); - - /* Optional sign */ - if (*s == '-') sign = *s++; - else if (*s == '+') s++; - - /* Handle infinities and NaNs. */ - if ((s[0]|32)=='i' && (s[1]|32)=='n' && (s[2]|32)=='f') { - *p = (char *)s + 3; - return sign ? -1.0/0.0 : 1.0/0.0; - } else if ((s[0]|32)=='n' && (s[1]|32)=='a' && (s[2]|32)=='n') { - *p = (char *)s + 3; - return 0.0/0.0; - } - - /* Possible hex float */ - if (s[0]=='0' && (s[1]|32)=='x') { - /* Mantissa must be non-degenerate */ - if (!isxdigit(s[2]) && (s[2]!=radix || !isxdigit(s[3]))) { - /* Decimal float 0, 'x' extraneous */ - *p = (char *)++s; - return 0; - } - /* We have a real hex float */ - s += 2; - for (; isxdigit(*s); s++) { - x = 16*x + (isdigit(*s)?*s-'0':(*s|32)-'a'+10); - if (*s!='0') nonzero=1; - } - if (*s == radix) { - frac = 1.0/16.0; - for (s++; isxdigit(*s); s++) { - x += frac * (isdigit(*s)?*s-'0':(*s|32)-'a'+10); - frac *= 1.0/16.0; - if (*s!='0') nonzero=1; - } - } - if ((*s|32) == 'p' && valid_exp(s+1)) { - e = strtol((void *)(s+1), (void *)&s, 10); - for (; e>0; e--) x *= 2.0; - for (; e<0; e++) x *= 0.5; - } - goto finish; - } - - /* Mantissa must be non-degenerate */ - if (!isdigit(s[0]) && (s[0]!=radix || !isdigit(s[1]))) { - *p = (char *)s1; - return 0; - } - - for (; isdigit(*s); s++) { - x = 10*x + *s-'0'; - if (*s!='0') nonzero=1; - } - if (*s == radix) { - frac = 10.0; - for (s++; isdigit(*s); s++) { - x += (*s-'0') / frac; - frac *= 10.0; - if (*s!='0') nonzero=1; - } - } - if ((*s|32)=='e' && valid_exp(s+1)) { - e = strtol((void *)++s, (void *)&s, 10); - for (; e>0; e--) x *= 10.0; - for (; e<0; e++) x /= 10.0; - } -finish: - errno = ((nonzero && !x) || !(1.0/x)) ? ERANGE : saved_errno; - *p = (char*)s; - return sign ? -x : x; + FILE f = { + .buf = (void *)s, .rpos = (void *)s, + .rend = (void *)-1, .lock = -1 + }; + off_t cnt; + long double y = __floatscan(&f, -1, 2, 1, &cnt); + if (p) *p = (char *)s + cnt; + return y; } |