/* Copyright (C) 2007, 2009 Free Software Foundation, Inc. This file is part of GCC. GCC is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3, or (at your option) any later version. GCC is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. Under Section 7 of GPL version 3, you are granted additional permissions described in the GCC Runtime Library Exception, version 3.1, as published by the Free Software Foundation. You should have received a copy of the GNU General Public License and a copy of the GCC Runtime Library Exception along with this program; see the files COPYING3 and COPYING.RUNTIME respectively. If not, see . */ /***************************************************************************** * * Helper add functions (for fma) * * __BID_INLINE__ UINT64 get_add64( * UINT64 sign_x, int exponent_x, UINT64 coefficient_x, * UINT64 sign_y, int exponent_y, UINT64 coefficient_y, * int rounding_mode) * * __BID_INLINE__ UINT64 get_add128( * UINT64 sign_x, int exponent_x, UINT64 coefficient_x, * UINT64 sign_y, int final_exponent_y, UINT128 CY, * int extra_digits, int rounding_mode) * ***************************************************************************** * * Algorithm description: * * get_add64: same as BID64 add, but arguments are unpacked and there * are no special case checks * * get_add128: add 64-bit coefficient to 128-bit product (which contains * 16+extra_digits decimal digits), * return BID64 result * - the exponents are compared and the two coefficients are * properly aligned for addition/subtraction * - multiple paths are needed * - final result exponent is calculated and the lower term is * rounded first if necessary, to avoid manipulating * coefficients longer than 128 bits * ****************************************************************************/ #ifndef _INLINE_BID_ADD_H_ #define _INLINE_BID_ADD_H_ #include "bid_internal.h" #define MAX_FORMAT_DIGITS 16 #define DECIMAL_EXPONENT_BIAS 398 #define MASK_BINARY_EXPONENT 0x7ff0000000000000ull #define BINARY_EXPONENT_BIAS 0x3ff #define UPPER_EXPON_LIMIT 51 /////////////////////////////////////////////////////////////////////// // // get_add64() is essentially the same as bid_add(), except that // the arguments are unpacked // ////////////////////////////////////////////////////////////////////// __BID_INLINE__ UINT64 get_add64 (UINT64 sign_x, int exponent_x, UINT64 coefficient_x, UINT64 sign_y, int exponent_y, UINT64 coefficient_y, int rounding_mode, unsigned *fpsc) { UINT128 CA, CT, CT_new; UINT64 sign_a, sign_b, coefficient_a, coefficient_b, sign_s, sign_ab, rem_a; UINT64 saved_ca, saved_cb, C0_64, C64, remainder_h, T1, carry, tmp, C64_new; int_double tempx; int exponent_a, exponent_b, diff_dec_expon; int bin_expon_ca, extra_digits, amount, scale_k, scale_ca; unsigned rmode, status; // sort arguments by exponent if (exponent_x <= exponent_y) { sign_a = sign_y; exponent_a = exponent_y; coefficient_a = coefficient_y; sign_b = sign_x; exponent_b = exponent_x; coefficient_b = coefficient_x; } else { sign_a = sign_x; exponent_a = exponent_x; coefficient_a = coefficient_x; sign_b = sign_y; exponent_b = exponent_y; coefficient_b = coefficient_y; } // exponent difference diff_dec_expon = exponent_a - exponent_b; /* get binary coefficients of x and y */ //--- get number of bits in the coefficients of x and y --- tempx.d = (double) coefficient_a; bin_expon_ca = ((tempx.i & MASK_BINARY_EXPONENT) >> 52) - 0x3ff; if (!coefficient_a) { return get_BID64 (sign_b, exponent_b, coefficient_b, rounding_mode, fpsc); } if (diff_dec_expon > MAX_FORMAT_DIGITS) { // normalize a to a 16-digit coefficient scale_ca = estimate_decimal_digits[bin_expon_ca]; if (coefficient_a >= power10_table_128[scale_ca].w[0]) scale_ca++; scale_k = 16 - scale_ca; coefficient_a *= power10_table_128[scale_k].w[0]; diff_dec_expon -= scale_k; exponent_a -= scale_k; /* get binary coefficients of x and y */ //--- get number of bits in the coefficients of x and y --- tempx.d = (double) coefficient_a; bin_expon_ca = ((tempx.i & MASK_BINARY_EXPONENT) >> 52) - 0x3ff; if (diff_dec_expon > MAX_FORMAT_DIGITS) { #ifdef SET_STATUS_FLAGS if (coefficient_b) { __set_status_flags (fpsc, INEXACT_EXCEPTION); } #endif #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST if (((rounding_mode) & 3) && coefficient_b) // not ROUNDING_TO_NEAREST { switch (rounding_mode) { case ROUNDING_DOWN: if (sign_b) { coefficient_a -= ((((SINT64) sign_a) >> 63) | 1); if (coefficient_a < 1000000000000000ull) { exponent_a--; coefficient_a = 9999999999999999ull; } else if (coefficient_a >= 10000000000000000ull) { exponent_a++; coefficient_a = 1000000000000000ull; } } break; case ROUNDING_UP: if (!sign_b) { coefficient_a += ((((SINT64) sign_a) >> 63) | 1); if (coefficient_a < 1000000000000000ull) { exponent_a--; coefficient_a = 9999999999999999ull; } else if (coefficient_a >= 10000000000000000ull) { exponent_a++; coefficient_a = 1000000000000000ull; } } break; default: // RZ if (sign_a != sign_b) { coefficient_a--; if (coefficient_a < 1000000000000000ull) { exponent_a--; coefficient_a = 9999999999999999ull; } } break; } } else #endif #endif // check special case here if ((coefficient_a == 1000000000000000ull) && (diff_dec_expon == MAX_FORMAT_DIGITS + 1) && (sign_a ^ sign_b) && (coefficient_b > 5000000000000000ull)) { coefficient_a = 9999999999999999ull; exponent_a--; } return get_BID64 (sign_a, exponent_a, coefficient_a, rounding_mode, fpsc); } } // test whether coefficient_a*10^(exponent_a-exponent_b) may exceed 2^62 if (bin_expon_ca + estimate_bin_expon[diff_dec_expon] < 60) { // coefficient_a*10^(exponent_a-exponent_b)<2^63 // multiply by 10^(exponent_a-exponent_b) coefficient_a *= power10_table_128[diff_dec_expon].w[0]; // sign mask sign_b = ((SINT64) sign_b) >> 63; // apply sign to coeff. of b coefficient_b = (coefficient_b + sign_b) ^ sign_b; // apply sign to coefficient a sign_a = ((SINT64) sign_a) >> 63; coefficient_a = (coefficient_a + sign_a) ^ sign_a; coefficient_a += coefficient_b; // get sign sign_s = ((SINT64) coefficient_a) >> 63; coefficient_a = (coefficient_a + sign_s) ^ sign_s; sign_s &= 0x8000000000000000ull; // coefficient_a < 10^16 ? if (coefficient_a < power10_table_128[MAX_FORMAT_DIGITS].w[0]) { #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST if (rounding_mode == ROUNDING_DOWN && (!coefficient_a) && sign_a != sign_b) sign_s = 0x8000000000000000ull; #endif #endif return get_BID64 (sign_s, exponent_b, coefficient_a, rounding_mode, fpsc); } // otherwise rounding is necessary // already know coefficient_a<10^19 // coefficient_a < 10^17 ? if (coefficient_a < power10_table_128[17].w[0]) extra_digits = 1; else if (coefficient_a < power10_table_128[18].w[0]) extra_digits = 2; else extra_digits = 3; #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST rmode = rounding_mode; if (sign_s && (unsigned) (rmode - 1) < 2) rmode = 3 - rmode; #else rmode = 0; #endif #else rmode = 0; #endif coefficient_a += round_const_table[rmode][extra_digits]; // get P*(2^M[extra_digits])/10^extra_digits __mul_64x64_to_128 (CT, coefficient_a, reciprocals10_64[extra_digits]); // now get P/10^extra_digits: shift C64 right by M[extra_digits]-128 amount = short_recip_scale[extra_digits]; C64 = CT.w[1] >> amount; } else { // coefficient_a*10^(exponent_a-exponent_b) is large sign_s = sign_a; #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST rmode = rounding_mode; if (sign_s && (unsigned) (rmode - 1) < 2) rmode = 3 - rmode; #else rmode = 0; #endif #else rmode = 0; #endif // check whether we can take faster path scale_ca = estimate_decimal_digits[bin_expon_ca]; sign_ab = sign_a ^ sign_b; sign_ab = ((SINT64) sign_ab) >> 63; // T1 = 10^(16-diff_dec_expon) T1 = power10_table_128[16 - diff_dec_expon].w[0]; // get number of digits in coefficient_a //P_ca = power10_table_128[scale_ca].w[0]; //P_ca_m1 = power10_table_128[scale_ca-1].w[0]; if (coefficient_a >= power10_table_128[scale_ca].w[0]) { scale_ca++; //P_ca_m1 = P_ca; //P_ca = power10_table_128[scale_ca].w[0]; } scale_k = 16 - scale_ca; // apply sign //Ts = (T1 + sign_ab) ^ sign_ab; // test range of ca //X = coefficient_a + Ts - P_ca_m1; // addition saved_ca = coefficient_a - T1; coefficient_a = (SINT64) saved_ca *(SINT64) power10_table_128[scale_k].w[0]; extra_digits = diff_dec_expon - scale_k; // apply sign saved_cb = (coefficient_b + sign_ab) ^ sign_ab; // add 10^16 and rounding constant coefficient_b = saved_cb + 10000000000000000ull + round_const_table[rmode][extra_digits]; // get P*(2^M[extra_digits])/10^extra_digits __mul_64x64_to_128 (CT, coefficient_b, reciprocals10_64[extra_digits]); // now get P/10^extra_digits: shift C64 right by M[extra_digits]-128 amount = short_recip_scale[extra_digits]; C0_64 = CT.w[1] >> amount; // result coefficient C64 = C0_64 + coefficient_a; // filter out difficult (corner) cases // the following test is equivalent to // ( (initial_coefficient_a + Ts) < P_ca && // (initial_coefficient_a + Ts) > P_ca_m1 ), // which ensures the number of digits in coefficient_a does not change // after adding (the appropriately scaled and rounded) coefficient_b if ((UINT64) (C64 - 1000000000000000ull - 1) > 9000000000000000ull - 2) { if (C64 >= 10000000000000000ull) { // result has more than 16 digits if (!scale_k) { // must divide coeff_a by 10 saved_ca = saved_ca + T1; __mul_64x64_to_128 (CA, saved_ca, 0x3333333333333334ull); //reciprocals10_64[1]); coefficient_a = CA.w[1] >> 1; rem_a = saved_ca - (coefficient_a << 3) - (coefficient_a << 1); coefficient_a = coefficient_a - T1; saved_cb += /*90000000000000000 */ +rem_a * power10_table_128[diff_dec_expon].w[0]; } else coefficient_a = (SINT64) (saved_ca - T1 - (T1 << 3)) * (SINT64) power10_table_128[scale_k - 1].w[0]; extra_digits++; coefficient_b = saved_cb + 100000000000000000ull + round_const_table[rmode][extra_digits]; // get P*(2^M[extra_digits])/10^extra_digits __mul_64x64_to_128 (CT, coefficient_b, reciprocals10_64[extra_digits]); // now get P/10^extra_digits: shift C64 right by M[extra_digits]-128 amount = short_recip_scale[extra_digits]; C0_64 = CT.w[1] >> amount; // result coefficient C64 = C0_64 + coefficient_a; } else if (C64 <= 1000000000000000ull) { // less than 16 digits in result coefficient_a = (SINT64) saved_ca *(SINT64) power10_table_128[scale_k + 1].w[0]; //extra_digits --; exponent_b--; coefficient_b = (saved_cb << 3) + (saved_cb << 1) + 100000000000000000ull + round_const_table[rmode][extra_digits]; // get P*(2^M[extra_digits])/10^extra_digits __mul_64x64_to_128 (CT_new, coefficient_b, reciprocals10_64[extra_digits]); // now get P/10^extra_digits: shift C64 right by M[extra_digits]-128 amount = short_recip_scale[extra_digits]; C0_64 = CT_new.w[1] >> amount; // result coefficient C64_new = C0_64 + coefficient_a; if (C64_new < 10000000000000000ull) { C64 = C64_new; #ifdef SET_STATUS_FLAGS CT = CT_new; #endif } else exponent_b++; } } } #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST if (rmode == 0) //ROUNDING_TO_NEAREST #endif if (C64 & 1) { // check whether fractional part of initial_P/10^extra_digits // is exactly .5 // this is the same as fractional part of // (initial_P + 0.5*10^extra_digits)/10^extra_digits is exactly zero // get remainder remainder_h = CT.w[1] << (64 - amount); // test whether fractional part is 0 if (!remainder_h && (CT.w[0] < reciprocals10_64[extra_digits])) { C64--; } } #endif #ifdef SET_STATUS_FLAGS status = INEXACT_EXCEPTION; // get remainder remainder_h = CT.w[1] << (64 - amount); switch (rmode) { case ROUNDING_TO_NEAREST: case ROUNDING_TIES_AWAY: // test whether fractional part is 0 if ((remainder_h == 0x8000000000000000ull) && (CT.w[0] < reciprocals10_64[extra_digits])) status = EXACT_STATUS; break; case ROUNDING_DOWN: case ROUNDING_TO_ZERO: if (!remainder_h && (CT.w[0] < reciprocals10_64[extra_digits])) status = EXACT_STATUS; break; default: // round up __add_carry_out (tmp, carry, CT.w[0], reciprocals10_64[extra_digits]); if ((remainder_h >> (64 - amount)) + carry >= (((UINT64) 1) << amount)) status = EXACT_STATUS; break; } __set_status_flags (fpsc, status); #endif return get_BID64 (sign_s, exponent_b + extra_digits, C64, rounding_mode, fpsc); } /////////////////////////////////////////////////////////////////// // round 128-bit coefficient and return result in BID64 format // do not worry about midpoint cases ////////////////////////////////////////////////////////////////// static UINT64 __bid_simple_round64_sticky (UINT64 sign, int exponent, UINT128 P, int extra_digits, int rounding_mode, unsigned *fpsc) { UINT128 Q_high, Q_low, C128; UINT64 C64; int amount, rmode; rmode = rounding_mode; #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST if (sign && (unsigned) (rmode - 1) < 2) rmode = 3 - rmode; #endif #endif __add_128_64 (P, P, round_const_table[rmode][extra_digits]); // get P*(2^M[extra_digits])/10^extra_digits __mul_128x128_full (Q_high, Q_low, P, reciprocals10_128[extra_digits]); // now get P/10^extra_digits: shift Q_high right by M[extra_digits]-128 amount = recip_scale[extra_digits]; __shr_128 (C128, Q_high, amount); C64 = __low_64 (C128); #ifdef SET_STATUS_FLAGS __set_status_flags (fpsc, INEXACT_EXCEPTION); #endif return get_BID64 (sign, exponent, C64, rounding_mode, fpsc); } /////////////////////////////////////////////////////////////////// // round 128-bit coefficient and return result in BID64 format /////////////////////////////////////////////////////////////////// static UINT64 __bid_full_round64 (UINT64 sign, int exponent, UINT128 P, int extra_digits, int rounding_mode, unsigned *fpsc) { UINT128 Q_high, Q_low, C128, Stemp, PU; UINT64 remainder_h, C64, carry, CY; int amount, amount2, rmode, status = 0; if (exponent < 0) { if (exponent >= -16 && (extra_digits + exponent < 0)) { extra_digits = -exponent; #ifdef SET_STATUS_FLAGS if (extra_digits > 0) { rmode = rounding_mode; if (sign && (unsigned) (rmode - 1) < 2) rmode = 3 - rmode; __add_128_128 (PU, P, round_const_table_128[rmode][extra_digits]); if (__unsigned_compare_gt_128 (power10_table_128[extra_digits + 15], PU)) status = UNDERFLOW_EXCEPTION; } #endif } } if (extra_digits > 0) { exponent += extra_digits; rmode = rounding_mode; if (sign && (unsigned) (rmode - 1) < 2) rmode = 3 - rmode; __add_128_128 (P, P, round_const_table_128[rmode][extra_digits]); // get P*(2^M[extra_digits])/10^extra_digits __mul_128x128_full (Q_high, Q_low, P, reciprocals10_128[extra_digits]); // now get P/10^extra_digits: shift Q_high right by M[extra_digits]-128 amount = recip_scale[extra_digits]; __shr_128_long (C128, Q_high, amount); C64 = __low_64 (C128); #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST if (rmode == 0) //ROUNDING_TO_NEAREST #endif if (C64 & 1) { // check whether fractional part of initial_P/10^extra_digits // is exactly .5 // get remainder amount2 = 64 - amount; remainder_h = 0; remainder_h--; remainder_h >>= amount2; remainder_h = remainder_h & Q_high.w[0]; if (!remainder_h && (Q_low.w[1] < reciprocals10_128[extra_digits].w[1] || (Q_low.w[1] == reciprocals10_128[extra_digits].w[1] && Q_low.w[0] < reciprocals10_128[extra_digits].w[0]))) { C64--; } } #endif #ifdef SET_STATUS_FLAGS status |= INEXACT_EXCEPTION; // get remainder remainder_h = Q_high.w[0] << (64 - amount); switch (rmode) { case ROUNDING_TO_NEAREST: case ROUNDING_TIES_AWAY: // test whether fractional part is 0 if (remainder_h == 0x8000000000000000ull && (Q_low.w[1] < reciprocals10_128[extra_digits].w[1] || (Q_low.w[1] == reciprocals10_128[extra_digits].w[1] && Q_low.w[0] < reciprocals10_128[extra_digits].w[0]))) status = EXACT_STATUS; break; case ROUNDING_DOWN: case ROUNDING_TO_ZERO: if (!remainder_h && (Q_low.w[1] < reciprocals10_128[extra_digits].w[1] || (Q_low.w[1] == reciprocals10_128[extra_digits].w[1] && Q_low.w[0] < reciprocals10_128[extra_digits].w[0]))) status = EXACT_STATUS; break; default: // round up __add_carry_out (Stemp.w[0], CY, Q_low.w[0], reciprocals10_128[extra_digits].w[0]); __add_carry_in_out (Stemp.w[1], carry, Q_low.w[1], reciprocals10_128[extra_digits].w[1], CY); if ((remainder_h >> (64 - amount)) + carry >= (((UINT64) 1) << amount)) status = EXACT_STATUS; } __set_status_flags (fpsc, status); #endif } else { C64 = P.w[0]; if (!C64) { sign = 0; if (rounding_mode == ROUNDING_DOWN) sign = 0x8000000000000000ull; } } return get_BID64 (sign, exponent, C64, rounding_mode, fpsc); } ///////////////////////////////////////////////////////////////////////////////// // round 192-bit coefficient (P, remainder_P) and return result in BID64 format // the lowest 64 bits (remainder_P) are used for midpoint checking only //////////////////////////////////////////////////////////////////////////////// static UINT64 __bid_full_round64_remainder (UINT64 sign, int exponent, UINT128 P, int extra_digits, UINT64 remainder_P, int rounding_mode, unsigned *fpsc, unsigned uf_status) { UINT128 Q_high, Q_low, C128, Stemp; UINT64 remainder_h, C64, carry, CY; int amount, amount2, rmode, status = uf_status; rmode = rounding_mode; if (sign && (unsigned) (rmode - 1) < 2) rmode = 3 - rmode; if (rmode == ROUNDING_UP && remainder_P) { P.w[0]++; if (!P.w[0]) P.w[1]++; } if (extra_digits) { __add_128_64 (P, P, round_const_table[rmode][extra_digits]); // get P*(2^M[extra_digits])/10^extra_digits __mul_128x128_full (Q_high, Q_low, P, reciprocals10_128[extra_digits]); // now get P/10^extra_digits: shift Q_high right by M[extra_digits]-128 amount = recip_scale[extra_digits]; __shr_128 (C128, Q_high, amount); C64 = __low_64 (C128); #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST if (rmode == 0) //ROUNDING_TO_NEAREST #endif if (!remainder_P && (C64 & 1)) { // check whether fractional part of initial_P/10^extra_digits // is exactly .5 // get remainder amount2 = 64 - amount; remainder_h = 0; remainder_h--; remainder_h >>= amount2; remainder_h = remainder_h & Q_high.w[0]; if (!remainder_h && (Q_low.w[1] < reciprocals10_128[extra_digits].w[1] || (Q_low.w[1] == reciprocals10_128[extra_digits].w[1] && Q_low.w[0] < reciprocals10_128[extra_digits].w[0]))) { C64--; } } #endif #ifdef SET_STATUS_FLAGS status |= INEXACT_EXCEPTION; if (!remainder_P) { // get remainder remainder_h = Q_high.w[0] << (64 - amount); switch (rmode) { case ROUNDING_TO_NEAREST: case ROUNDING_TIES_AWAY: // test whether fractional part is 0 if (remainder_h == 0x8000000000000000ull && (Q_low.w[1] < reciprocals10_128[extra_digits].w[1] || (Q_low.w[1] == reciprocals10_128[extra_digits].w[1] && Q_low.w[0] < reciprocals10_128[extra_digits].w[0]))) status = EXACT_STATUS; break; case ROUNDING_DOWN: case ROUNDING_TO_ZERO: if (!remainder_h && (Q_low.w[1] < reciprocals10_128[extra_digits].w[1] || (Q_low.w[1] == reciprocals10_128[extra_digits].w[1] && Q_low.w[0] < reciprocals10_128[extra_digits].w[0]))) status = EXACT_STATUS; break; default: // round up __add_carry_out (Stemp.w[0], CY, Q_low.w[0], reciprocals10_128[extra_digits].w[0]); __add_carry_in_out (Stemp.w[1], carry, Q_low.w[1], reciprocals10_128[extra_digits].w[1], CY); if ((remainder_h >> (64 - amount)) + carry >= (((UINT64) 1) << amount)) status = EXACT_STATUS; } } __set_status_flags (fpsc, status); #endif } else { C64 = P.w[0]; #ifdef SET_STATUS_FLAGS if (remainder_P) { __set_status_flags (fpsc, uf_status | INEXACT_EXCEPTION); } #endif } return get_BID64 (sign, exponent + extra_digits, C64, rounding_mode, fpsc); } /////////////////////////////////////////////////////////////////// // get P/10^extra_digits // result fits in 64 bits /////////////////////////////////////////////////////////////////// __BID_INLINE__ UINT64 __truncate (UINT128 P, int extra_digits) // extra_digits <= 16 { UINT128 Q_high, Q_low, C128; UINT64 C64; int amount; // get P*(2^M[extra_digits])/10^extra_digits __mul_128x128_full (Q_high, Q_low, P, reciprocals10_128[extra_digits]); // now get P/10^extra_digits: shift Q_high right by M[extra_digits]-128 amount = recip_scale[extra_digits]; __shr_128 (C128, Q_high, amount); C64 = __low_64 (C128); return C64; } /////////////////////////////////////////////////////////////////// // return number of decimal digits in 128-bit value X /////////////////////////////////////////////////////////////////// __BID_INLINE__ int __get_dec_digits64 (UINT128 X) { int_double tempx; int digits_x, bin_expon_cx; if (!X.w[1]) { //--- get number of bits in the coefficients of x and y --- tempx.d = (double) X.w[0]; bin_expon_cx = ((tempx.i & MASK_BINARY_EXPONENT) >> 52) - 0x3ff; // get number of decimal digits in the coeff_x digits_x = estimate_decimal_digits[bin_expon_cx]; if (X.w[0] >= power10_table_128[digits_x].w[0]) digits_x++; return digits_x; } tempx.d = (double) X.w[1]; bin_expon_cx = ((tempx.i & MASK_BINARY_EXPONENT) >> 52) - 0x3ff; // get number of decimal digits in the coeff_x digits_x = estimate_decimal_digits[bin_expon_cx + 64]; if (__unsigned_compare_ge_128 (X, power10_table_128[digits_x])) digits_x++; return digits_x; } //////////////////////////////////////////////////////////////////////////////// // // add 64-bit coefficient to 128-bit coefficient, return result in BID64 format // //////////////////////////////////////////////////////////////////////////////// __BID_INLINE__ UINT64 get_add128 (UINT64 sign_x, int exponent_x, UINT64 coefficient_x, UINT64 sign_y, int final_exponent_y, UINT128 CY, int extra_digits, int rounding_mode, unsigned *fpsc) { UINT128 CY_L, CX, FS, F, CT, ST, T2; UINT64 CYh, CY0L, T, S, coefficient_y, remainder_y; SINT64 D = 0; int_double tempx; int diff_dec_expon, extra_digits2, exponent_y, status; int extra_dx, diff_dec2, bin_expon_cx, digits_x, rmode; // CY has more than 16 decimal digits exponent_y = final_exponent_y - extra_digits; #ifdef IEEE_ROUND_NEAREST_TIES_AWAY rounding_mode = 0; #endif #ifdef IEEE_ROUND_NEAREST rounding_mode = 0; #endif if (exponent_x > exponent_y) { // normalize x //--- get number of bits in the coefficients of x and y --- tempx.d = (double) coefficient_x; bin_expon_cx = ((tempx.i & MASK_BINARY_EXPONENT) >> 52) - 0x3ff; // get number of decimal digits in the coeff_x digits_x = estimate_decimal_digits[bin_expon_cx]; if (coefficient_x >= power10_table_128[digits_x].w[0]) digits_x++; extra_dx = 16 - digits_x; coefficient_x *= power10_table_128[extra_dx].w[0]; if ((sign_x ^ sign_y) && (coefficient_x == 1000000000000000ull)) { extra_dx++; coefficient_x = 10000000000000000ull; } exponent_x -= extra_dx; if (exponent_x > exponent_y) { // exponent_x > exponent_y diff_dec_expon = exponent_x - exponent_y; if (exponent_x <= final_exponent_y + 1) { __mul_64x64_to_128 (CX, coefficient_x, power10_table_128[diff_dec_expon].w[0]); if (sign_x == sign_y) { __add_128_128 (CT, CY, CX); if ((exponent_x > final_exponent_y) /*&& (final_exponent_y>0) */ ) extra_digits++; if (__unsigned_compare_ge_128 (CT, power10_table_128[16 + extra_digits])) extra_digits++; } else { __sub_128_128 (CT, CY, CX); if (((SINT64) CT.w[1]) < 0) { CT.w[0] = 0 - CT.w[0]; CT.w[1] = 0 - CT.w[1]; if (CT.w[0]) CT.w[1]--; sign_y = sign_x; } else if (!(CT.w[1] | CT.w[0])) { sign_y = (rounding_mode != ROUNDING_DOWN) ? 0 : 0x8000000000000000ull; } if ((exponent_x + 1 >= final_exponent_y) /*&& (final_exponent_y>=0) */ ) { extra_digits = __get_dec_digits64 (CT) - 16; if (extra_digits <= 0) { if (!CT.w[0] && rounding_mode == ROUNDING_DOWN) sign_y = 0x8000000000000000ull; return get_BID64 (sign_y, exponent_y, CT.w[0], rounding_mode, fpsc); } } else if (__unsigned_compare_gt_128 (power10_table_128[15 + extra_digits], CT)) extra_digits--; } return __bid_full_round64 (sign_y, exponent_y, CT, extra_digits, rounding_mode, fpsc); } // diff_dec2+extra_digits is the number of digits to eliminate from // argument CY diff_dec2 = exponent_x - final_exponent_y; if (diff_dec2 >= 17) { #ifndef IEEE_ROUND_NEAREST #ifndef IEEE_ROUND_NEAREST_TIES_AWAY if ((rounding_mode) & 3) { switch (rounding_mode) { case ROUNDING_UP: if (!sign_y) { D = ((SINT64) (sign_x ^ sign_y)) >> 63; D = D + D + 1; coefficient_x += D; } break; case ROUNDING_DOWN: if (sign_y) { D = ((SINT64) (sign_x ^ sign_y)) >> 63; D = D + D + 1; coefficient_x += D; } break; case ROUNDING_TO_ZERO: if (sign_y != sign_x) { D = 0 - 1; coefficient_x += D; } break; } if (coefficient_x < 1000000000000000ull) { coefficient_x -= D; coefficient_x = D + (coefficient_x << 1) + (coefficient_x << 3); exponent_x--; } } #endif #endif #ifdef SET_STATUS_FLAGS if (CY.w[1] | CY.w[0]) __set_status_flags (fpsc, INEXACT_EXCEPTION); #endif return get_BID64 (sign_x, exponent_x, coefficient_x, rounding_mode, fpsc); } // here exponent_x <= 16+final_exponent_y // truncate CY to 16 dec. digits CYh = __truncate (CY, extra_digits); // get remainder T = power10_table_128[extra_digits].w[0]; __mul_64x64_to_64 (CY0L, CYh, T); remainder_y = CY.w[0] - CY0L; // align coeff_x, CYh __mul_64x64_to_128 (CX, coefficient_x, power10_table_128[diff_dec2].w[0]); if (sign_x == sign_y) { __add_128_64 (CT, CX, CYh); if (__unsigned_compare_ge_128 (CT, power10_table_128[16 + diff_dec2])) diff_dec2++; } else { if (remainder_y) CYh++; __sub_128_64 (CT, CX, CYh); if (__unsigned_compare_gt_128 (power10_table_128[15 + diff_dec2], CT)) diff_dec2--; } return __bid_full_round64_remainder (sign_x, final_exponent_y, CT, diff_dec2, remainder_y, rounding_mode, fpsc, 0); } } // Here (exponent_x <= exponent_y) { diff_dec_expon = exponent_y - exponent_x; if (diff_dec_expon > MAX_FORMAT_DIGITS) { rmode = rounding_mode; if ((sign_x ^ sign_y)) { if (!CY.w[0]) CY.w[1]--; CY.w[0]--; if (__unsigned_compare_gt_128 (power10_table_128[15 + extra_digits], CY)) { if (rmode & 3) { extra_digits--; final_exponent_y--; } else { CY.w[0] = 1000000000000000ull; CY.w[1] = 0; extra_digits = 0; } } } __scale128_10 (CY, CY); extra_digits++; CY.w[0] |= 1; return __bid_simple_round64_sticky (sign_y, final_exponent_y, CY, extra_digits, rmode, fpsc); } // apply sign to coeff_x sign_x ^= sign_y; sign_x = ((SINT64) sign_x) >> 63; CX.w[0] = (coefficient_x + sign_x) ^ sign_x; CX.w[1] = sign_x; // check whether CY (rounded to 16 digits) and CX have // any digits in the same position diff_dec2 = final_exponent_y - exponent_x; if (diff_dec2 <= 17) { // align CY to 10^ex S = power10_table_128[diff_dec_expon].w[0]; __mul_64x128_short (CY_L, S, CY); __add_128_128 (ST, CY_L, CX); extra_digits2 = __get_dec_digits64 (ST) - 16; return __bid_full_round64 (sign_y, exponent_x, ST, extra_digits2, rounding_mode, fpsc); } // truncate CY to 16 dec. digits CYh = __truncate (CY, extra_digits); // get remainder T = power10_table_128[extra_digits].w[0]; __mul_64x64_to_64 (CY0L, CYh, T); coefficient_y = CY.w[0] - CY0L; // add rounding constant rmode = rounding_mode; if (sign_y && (unsigned) (rmode - 1) < 2) rmode = 3 - rmode; #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST if (!(rmode & 3)) //ROUNDING_TO_NEAREST #endif #endif { coefficient_y += round_const_table[rmode][extra_digits]; } // align coefficient_y, coefficient_x S = power10_table_128[diff_dec_expon].w[0]; __mul_64x64_to_128 (F, coefficient_y, S); // fraction __add_128_128 (FS, F, CX); #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST if (rmode == 0) //ROUNDING_TO_NEAREST #endif { // rounding code, here RN_EVEN // 10^(extra_digits+diff_dec_expon) T2 = power10_table_128[diff_dec_expon + extra_digits]; if (__unsigned_compare_gt_128 (FS, T2) || ((CYh & 1) && __test_equal_128 (FS, T2))) { CYh++; __sub_128_128 (FS, FS, T2); } } #endif #ifndef IEEE_ROUND_NEAREST #ifndef IEEE_ROUND_NEAREST_TIES_AWAY if (rmode == 4) //ROUNDING_TO_NEAREST #endif { // rounding code, here RN_AWAY // 10^(extra_digits+diff_dec_expon) T2 = power10_table_128[diff_dec_expon + extra_digits]; if (__unsigned_compare_ge_128 (FS, T2)) { CYh++; __sub_128_128 (FS, FS, T2); } } #endif #ifndef IEEE_ROUND_NEAREST #ifndef IEEE_ROUND_NEAREST_TIES_AWAY switch (rmode) { case ROUNDING_DOWN: case ROUNDING_TO_ZERO: if ((SINT64) FS.w[1] < 0) { CYh--; if (CYh < 1000000000000000ull) { CYh = 9999999999999999ull; final_exponent_y--; } } else { T2 = power10_table_128[diff_dec_expon + extra_digits]; if (__unsigned_compare_ge_128 (FS, T2)) { CYh++; __sub_128_128 (FS, FS, T2); } } break; case ROUNDING_UP: if ((SINT64) FS.w[1] < 0) break; T2 = power10_table_128[diff_dec_expon + extra_digits]; if (__unsigned_compare_gt_128 (FS, T2)) { CYh += 2; __sub_128_128 (FS, FS, T2); } else if ((FS.w[1] == T2.w[1]) && (FS.w[0] == T2.w[0])) { CYh++; FS.w[1] = FS.w[0] = 0; } else if (FS.w[1] | FS.w[0]) CYh++; break; } #endif #endif #ifdef SET_STATUS_FLAGS status = INEXACT_EXCEPTION; #ifndef IEEE_ROUND_NEAREST #ifndef IEEE_ROUND_NEAREST_TIES_AWAY if (!(rmode & 3)) #endif #endif { // RN modes if ((FS.w[1] == round_const_table_128[0][diff_dec_expon + extra_digits].w[1]) && (FS.w[0] == round_const_table_128[0][diff_dec_expon + extra_digits].w[0])) status = EXACT_STATUS; } #ifndef IEEE_ROUND_NEAREST #ifndef IEEE_ROUND_NEAREST_TIES_AWAY else if (!FS.w[1] && !FS.w[0]) status = EXACT_STATUS; #endif #endif __set_status_flags (fpsc, status); #endif return get_BID64 (sign_y, final_exponent_y, CYh, rounding_mode, fpsc); } } ////////////////////////////////////////////////////////////////////////// // // If coefficient_z is less than 16 digits long, normalize to 16 digits // ///////////////////////////////////////////////////////////////////////// static UINT64 BID_normalize (UINT64 sign_z, int exponent_z, UINT64 coefficient_z, UINT64 round_dir, int round_flag, int rounding_mode, unsigned *fpsc) { SINT64 D; int_double tempx; int digits_z, bin_expon, scale, rmode; #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST rmode = rounding_mode; if (sign_z && (unsigned) (rmode - 1) < 2) rmode = 3 - rmode; #else if (coefficient_z >= power10_table_128[15].w[0]) return z; #endif #endif //--- get number of bits in the coefficients of x and y --- tempx.d = (double) coefficient_z; bin_expon = ((tempx.i & MASK_BINARY_EXPONENT) >> 52) - 0x3ff; // get number of decimal digits in the coeff_x digits_z = estimate_decimal_digits[bin_expon]; if (coefficient_z >= power10_table_128[digits_z].w[0]) digits_z++; scale = 16 - digits_z; exponent_z -= scale; if (exponent_z < 0) { scale += exponent_z; exponent_z = 0; } coefficient_z *= power10_table_128[scale].w[0]; #ifdef SET_STATUS_FLAGS if (round_flag) { __set_status_flags (fpsc, INEXACT_EXCEPTION); if (coefficient_z < 1000000000000000ull) __set_status_flags (fpsc, UNDERFLOW_EXCEPTION); else if ((coefficient_z == 1000000000000000ull) && !exponent_z && ((SINT64) (round_dir ^ sign_z) < 0) && round_flag && (rmode == ROUNDING_DOWN || rmode == ROUNDING_TO_ZERO)) __set_status_flags (fpsc, UNDERFLOW_EXCEPTION); } #endif #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST if (round_flag && (rmode & 3)) { D = round_dir ^ sign_z; if (rmode == ROUNDING_UP) { if (D >= 0) coefficient_z++; } else { if (D < 0) coefficient_z--; if (coefficient_z < 1000000000000000ull && exponent_z) { coefficient_z = 9999999999999999ull; exponent_z--; } } } #endif #endif return get_BID64 (sign_z, exponent_z, coefficient_z, rounding_mode, fpsc); } ////////////////////////////////////////////////////////////////////////// // // 0*10^ey + cz*10^ez, ey> 52) - 0x3ff; scale_cz = estimate_decimal_digits[bin_expon]; if (coefficient_z >= power10_table_128[scale_cz].w[0]) scale_cz++; scale_k = 16 - scale_cz; if (diff_expon < scale_k) scale_k = diff_expon; coefficient_z *= power10_table_128[scale_k].w[0]; return get_BID64 (sign_z, exponent_z - scale_k, coefficient_z, *prounding_mode, fpsc); } #endif