| #include <stdint.h> |
| #include <stdio.h> |
| #include <math.h> |
| #include <float.h> |
| #include <limits.h> |
| #include <errno.h> |
| #include <ctype.h> |
| |
| #include "shgetc.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 |
| |
| #elif LDBL_MANT_DIG == 64 && LDBL_MAX_EXP == 16384 |
| |
| #define LD_B1B_DIG 3 |
| #define LD_B1B_MAX 18, 446744073, 709551615 |
| #define KMAX 2048 |
| |
| #elif LDBL_MANT_DIG == 113 && LDBL_MAX_EXP == 16384 |
| |
| #define LD_B1B_DIG 4 |
| #define LD_B1B_MAX 10384593, 717069655, 257060992, 658440191 |
| #define KMAX 2048 |
| |
| #else |
| #error Unsupported long double representation |
| #endif |
| |
| #define MASK (KMAX - 1) |
| |
| #define CONCAT2(x, y) x##y |
| #define CONCAT(x, y) CONCAT2(x, y) |
| |
| static long long scanexp(FILE* f, int pok) { |
| int c; |
| int x; |
| long long y; |
| int neg = 0; |
| |
| c = shgetc(f); |
| if (c == '+' || c == '-') { |
| neg = (c == '-'); |
| c = shgetc(f); |
| if (c - '0' >= 10U && pok) |
| shunget(f); |
| } |
| if (c - '0' >= 10U) { |
| shunget(f); |
| return LLONG_MIN; |
| } |
| for (x = 0; c - '0' < 10U && x < INT_MAX / 10; c = shgetc(f)) |
| x = 10 * x + c - '0'; |
| for (y = x; c - '0' < 10U && y < LLONG_MAX / 100; c = shgetc(f)) |
| y = 10 * y + c - '0'; |
| for (; c - '0' < 10U; c = shgetc(f)) |
| ; |
| shunget(f); |
| return neg ? -y : y; |
| } |
| |
| static long double decfloat(FILE* f, |
| int c, |
| int bits, |
| int emin, |
| int sign, |
| int pok) { |
| uint32_t x[KMAX]; |
| static const uint32_t th[] = {LD_B1B_MAX}; |
| int i, j, k, a, z; |
| long long lrp = 0, dc = 0; |
| long long e10 = 0; |
| int lnz = 0; |
| int gotdig = 0, gotrad = 0; |
| int rp; |
| int e2; |
| int emax = -emin - bits + 3; |
| int denormal = 0; |
| long double y; |
| long double frac = 0; |
| long double bias = 0; |
| static const int p10s[] = {10, 100, 1000, 10000, |
| 100000, 1000000, 10000000, 100000000}; |
| |
| j = 0; |
| k = 0; |
| |
| /* Don't let leading zeros consume buffer space */ |
| for (; c == '0'; c = shgetc(f)) |
| gotdig = 1; |
| if (c == '.') { |
| gotrad = 1; |
| for (c = shgetc(f); c == '0'; c = shgetc(f)) |
| gotdig = 1, lrp--; |
| } |
| |
| x[0] = 0; |
| for (; c - '0' < 10U || c == '.'; c = shgetc(f)) { |
| if (c == '.') { |
| if (gotrad) |
| break; |
| gotrad = 1; |
| lrp = dc; |
| } else if (k < KMAX - 3) { |
| dc++; |
| if (c != '0') |
| lnz = 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++; |
| if (c != '0') |
| x[KMAX - 4] |= 1; |
| } |
| } |
| if (!gotrad) |
| lrp = dc; |
| |
| if (gotdig && (c | 32) == 'e') { |
| e10 = scanexp(f, pok); |
| if (e10 == LLONG_MIN) { |
| if (pok) { |
| shunget(f); |
| } else { |
| shlim(f, 0); |
| return 0; |
| } |
| e10 = 0; |
| } |
| lrp += e10; |
| } else if (c >= 0) { |
| shunget(f); |
| } |
| if (!gotdig) { |
| errno = EINVAL; |
| shlim(f, 0); |
| return 0; |
| } |
| |
| /* Handle zero specially to avoid nasty special cases later */ |
| if (!x[0]) |
| return sign * 0.0; |
| |
| /* Optimize small integers (w/no exponent) and over/under-flow */ |
| if (lrp == dc && dc < 10 && (bits > 30 || x[0] >> bits == 0)) |
| return sign * (long double)x[0]; |
| if (lrp > -emin / 2) { |
| errno = ERANGE; |
| return sign * LDBL_MAX * LDBL_MAX; |
| } |
| if (lrp < emin - 2 * LDBL_MANT_DIG) { |
| errno = ERANGE; |
| return sign * LDBL_MIN * LDBL_MIN; |
| } |
| |
| /* Align incomplete final B1B digit */ |
| if (j) { |
| for (; j < 9; j++) |
| x[k] *= 10; |
| k++; |
| j = 0; |
| } |
| |
| a = 0; |
| z = k; |
| e2 = 0; |
| rp = lrp; |
| |
| /* Optimize small to mid-size integers (even in exp. notation) */ |
| if (lnz < 9 && lnz <= rp && rp < 18) { |
| if (rp == 9) |
| return sign * (long double)x[0]; |
| if (rp < 9) |
| return sign * (long double)x[0] / p10s[8 - rp]; |
| int bitlim = bits - 3 * (int)(rp - 9); |
| if (bitlim > 30 || x[0] >> bitlim == 0) |
| return sign * (long double)x[0] * p10s[rp - 10]; |
| } |
| |
| /* Align radix point to B1B digit boundary */ |
| if (rp % 9) { |
| int rpm9 = rp >= 0 ? rp % 9 : rp % 9 + 9; |
| int p10 = p10s[8 - rpm9]; |
| uint32_t carry = 0; |
| for (k = a; k != z; k++) { |
| 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) |
| x[z++] = carry; |
| rp += 9 - rpm9; |
| } |
| |
| /* Upscale until desired number of bits are left of radix point */ |
| while (rp < 9 * LD_B1B_DIG || (rp == 9 * LD_B1B_DIG && x[a] < th[0])) { |
| 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; |
| a = (a - 1 & MASK); |
| if (a == z) { |
| z = (z - 1 & MASK); |
| x[z - 1 & MASK] |= x[z]; |
| } |
| x[a] = carry; |
| } |
| } |
| |
| /* Downscale until exactly number of bits are left of radix point */ |
| 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); |
| i--; |
| rp -= 9; |
| } |
| } |
| if (carry) { |
| if ((z + 1 & MASK) != a) { |
| x[z] = carry; |
| z = (z + 1 & MASK); |
| } else |
| x[z - 1 & MASK] |= 1; |
| } |
| } |
| |
| /* Assemble desired bits into floating point variable */ |
| for (y = i = 0; i < LD_B1B_DIG; i++) { |
| if ((a + i & MASK) == z) |
| x[(z = (z + 1 & MASK)) - 1] = 0; |
| y = 1000000000.0L * y + x[a + i & MASK]; |
| } |
| |
| y *= sign; |
| |
| /* Limit precision for denormal results */ |
| if (bits > LDBL_MANT_DIG + e2 - emin) { |
| bits = LDBL_MANT_DIG + e2 - emin; |
| if (bits < 0) |
| bits = 0; |
| denormal = 1; |
| } |
| |
| /* Calculate bias term to force rounding, move out lower bits */ |
| 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; |
| } |
| |
| /* Process tail of decimal input so it can affect rounding */ |
| 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; |
| |
| if ((e2 + LDBL_MANT_DIG & INT_MAX) > emax - 5) { |
| if (fabs(y) >= CONCAT(0x1p, LDBL_MANT_DIG)) { |
| if (denormal && bits == LDBL_MANT_DIG + e2 - emin) |
| denormal = 0; |
| y *= 0.5; |
| e2++; |
| } |
| if (e2 + LDBL_MANT_DIG > emax || (denormal && frac)) |
| errno = ERANGE; |
| } |
| |
| return scalbnl(y, e2); |
| } |
| |
| static long double hexfloat(FILE* f, int bits, int emin, int sign, int pok) { |
| 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; |
| int c; |
| |
| c = shgetc(f); |
| |
| /* Skip leading zeros */ |
| for (; c == '0'; c = shgetc(f)) |
| gotdig = 1; |
| |
| if (c == '.') { |
| gotrad = 1; |
| c = shgetc(f); |
| /* Count zeros after the radix point before significand */ |
| for (rp = 0; c == '0'; c = shgetc(f), rp--) |
| gotdig = 1; |
| } |
| |
| for (; c - '0' < 10U || (c | 32) - 'a' < 6U || c == '.'; c = shgetc(f)) { |
| 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) { |
| shunget(f); |
| if (pok) { |
| shunget(f); |
| if (gotrad) |
| shunget(f); |
| } else { |
| shlim(f, 0); |
| } |
| return sign * 0.0; |
| } |
| if (!gotrad) |
| rp = dc; |
| while (dc < 8) |
| x *= 16, dc++; |
| if ((c | 32) == 'p') { |
| e2 = scanexp(f, pok); |
| if (e2 == LLONG_MIN) { |
| if (pok) { |
| shunget(f); |
| } else { |
| shlim(f, 0); |
| return 0; |
| } |
| e2 = 0; |
| } |
| } else { |
| shunget(f); |
| } |
| e2 += 4 * rp - 32; |
| |
| if (!x) |
| return sign * 0.0; |
| if (e2 > -emin) { |
| errno = ERANGE; |
| return sign * LDBL_MAX * LDBL_MAX; |
| } |
| if (e2 < emin - 2 * LDBL_MANT_DIG) { |
| errno = ERANGE; |
| 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; |
| |
| if (!y) |
| errno = ERANGE; |
| |
| return scalbnl(y, e2); |
| } |
| |
| long double __floatscan(FILE* f, int prec, int pok) { |
| int sign = 1; |
| size_t i; |
| int bits; |
| int emin; |
| int c; |
| |
| switch (prec) { |
| case 0: |
| bits = FLT_MANT_DIG; |
| emin = FLT_MIN_EXP - bits; |
| break; |
| case 1: |
| bits = DBL_MANT_DIG; |
| emin = DBL_MIN_EXP - bits; |
| break; |
| case 2: |
| bits = LDBL_MANT_DIG; |
| emin = LDBL_MIN_EXP - bits; |
| break; |
| default: |
| return 0; |
| } |
| |
| while (isspace((c = shgetc(f)))) |
| ; |
| |
| if (c == '+' || c == '-') { |
| sign -= 2 * (c == '-'); |
| c = shgetc(f); |
| } |
| |
| for (i = 0; i < 8 && (c | 32) == "infinity"[i]; i++) |
| if (i < 7) |
| c = shgetc(f); |
| if (i == 3 || i == 8 || (i > 3 && pok)) { |
| if (i != 8) { |
| shunget(f); |
| if (pok) |
| for (; i > 3; i--) |
| shunget(f); |
| } |
| return sign * INFINITY; |
| } |
| if (!i) |
| for (i = 0; i < 3 && (c | 32) == "nan"[i]; i++) |
| if (i < 2) |
| c = shgetc(f); |
| if (i == 3) { |
| if (shgetc(f) != '(') { |
| shunget(f); |
| return NAN; |
| } |
| for (i = 1;; i++) { |
| c = shgetc(f); |
| if (c - '0' < 10U || c - 'A' < 26U || c - 'a' < 26U || c == '_') |
| continue; |
| if (c == ')') |
| return NAN; |
| shunget(f); |
| if (!pok) { |
| errno = EINVAL; |
| shlim(f, 0); |
| return 0; |
| } |
| while (i--) |
| shunget(f); |
| return NAN; |
| } |
| return NAN; |
| } |
| |
| if (i) { |
| shunget(f); |
| errno = EINVAL; |
| shlim(f, 0); |
| return 0; |
| } |
| |
| if (c == '0') { |
| c = shgetc(f); |
| if ((c | 32) == 'x') |
| return hexfloat(f, bits, emin, sign, pok); |
| shunget(f); |
| c = '0'; |
| } |
| |
| return decfloat(f, c, bits, emin, sign, pok); |
| } |
