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[/] [openrisc/] [tags/] [gnu-src/] [gcc-4.5.1/] [gcc-4.5.1-or32-1.0rc1/] [libgcc/] [config/] [libbid/] [bid32_to_bid64.c] - Rev 338
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/* 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 <http://www.gnu.org/licenses/>. */ #include "bid_internal.h" /* * Takes a BID32 as input and converts it to a BID64 and returns it. */ TYPE0_FUNCTION_ARGTYPE1_NORND (UINT64, bid32_to_bid64, UINT32, x) UINT64 res; UINT32 sign_x; int exponent_x; UINT32 coefficient_x; if (!unpack_BID32 (&sign_x, &exponent_x, &coefficient_x, x)) { // Inf, NaN, 0 if (((x) & 0x78000000) == 0x78000000) { if (((x) & 0x7e000000) == 0x7e000000) { // sNaN #ifdef SET_STATUS_FLAGS __set_status_flags (pfpsf, INVALID_EXCEPTION); #endif } res = (coefficient_x & 0x000fffff); res *= 1000000000; res |= ((((UINT64) coefficient_x) << 32) & 0xfc00000000000000ull); BID_RETURN (res); } } res = very_fast_get_BID64_small_mantissa (((UINT64) sign_x) << 32, exponent_x + DECIMAL_EXPONENT_BIAS - DECIMAL_EXPONENT_BIAS_32, (UINT64) coefficient_x); BID_RETURN (res); } // convert_bid32_to_bid64 /* * Takes a BID64 as input and converts it to a BID32 and returns it. */ #if DECIMAL_CALL_BY_REFERENCE void bid64_to_bid32 (UINT32 * pres, UINT64 * px _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) { UINT64 x; #else UINT32 bid64_to_bid32 (UINT64 x _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) { #endif UINT128 Q; UINT64 sign_x, coefficient_x, remainder_h, carry, Stemp; UINT32 res; int_float tempx; int exponent_x, bin_expon_cx, extra_digits, rmode = 0, amount; unsigned status = 0; #if DECIMAL_CALL_BY_REFERENCE #if !DECIMAL_GLOBAL_ROUNDING _IDEC_round rnd_mode = *prnd_mode; #endif x = *px; #endif // unpack arguments, check for NaN or Infinity, 0 if (!unpack_BID64 (&sign_x, &exponent_x, &coefficient_x, x)) { if (((x) & 0x7800000000000000ull) == 0x7800000000000000ull) { res = (coefficient_x & 0x0003ffffffffffffull); res /= 1000000000ull; res |= ((coefficient_x >> 32) & 0xfc000000); #ifdef SET_STATUS_FLAGS if ((x & SNAN_MASK64) == SNAN_MASK64) // sNaN __set_status_flags (pfpsf, INVALID_EXCEPTION); #endif BID_RETURN (res); } exponent_x = exponent_x - DECIMAL_EXPONENT_BIAS + DECIMAL_EXPONENT_BIAS_32; if (exponent_x < 0) exponent_x = 0; if (exponent_x > DECIMAL_MAX_EXPON_32) exponent_x = DECIMAL_MAX_EXPON_32; res = (sign_x >> 32) | (exponent_x << 23); BID_RETURN (res); } exponent_x = exponent_x - DECIMAL_EXPONENT_BIAS + DECIMAL_EXPONENT_BIAS_32; // check number of digits if (coefficient_x >= 10000000) { tempx.d = (float) coefficient_x; bin_expon_cx = ((tempx.i >> 23) & 0xff) - 0x7f; extra_digits = estimate_decimal_digits[bin_expon_cx] - 7; // add test for range if (coefficient_x >= power10_index_binexp[bin_expon_cx]) extra_digits++; #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST rmode = rnd_mode; if (sign_x && (unsigned) (rmode - 1) < 2) rmode = 3 - rmode; #else rmode = 0; #endif #else rmode = 0; #endif exponent_x += extra_digits; if ((exponent_x < 0) && (exponent_x + MAX_FORMAT_DIGITS_32 >= 0)) { status = UNDERFLOW_EXCEPTION; if (exponent_x == -1) if (coefficient_x + round_const_table[rmode][extra_digits] >= power10_table_128[extra_digits + 7].w[0]) status = 0; extra_digits -= exponent_x; exponent_x = 0; } coefficient_x += round_const_table[rmode][extra_digits]; __mul_64x64_to_128 (Q, coefficient_x, reciprocals10_64[extra_digits]); // now get P/10^extra_digits: shift Q_high right by M[extra_digits]-128 amount = short_recip_scale[extra_digits]; coefficient_x = Q.w[1] >> amount; #ifndef IEEE_ROUND_NEAREST_TIES_AWAY #ifndef IEEE_ROUND_NEAREST if (rmode == 0) //ROUNDING_TO_NEAREST #endif if (coefficient_x & 1) { // check whether fractional part of initial_P/10^extra_digits // is exactly .5 // get remainder remainder_h = Q.w[1] << (64 - amount); if (!remainder_h && (Q.w[0] < reciprocals10_64[extra_digits])) coefficient_x--; } #endif #ifdef SET_STATUS_FLAGS { status |= INEXACT_EXCEPTION; // get remainder remainder_h = Q.w[1] << (64 - amount); switch (rmode) { case ROUNDING_TO_NEAREST: case ROUNDING_TIES_AWAY: // test whether fractional part is 0 if (remainder_h == 0x8000000000000000ull && (Q.w[0] < reciprocals10_64[extra_digits])) status = EXACT_STATUS; break; case ROUNDING_DOWN: case ROUNDING_TO_ZERO: if (!remainder_h && (Q.w[0] < reciprocals10_64[extra_digits])) status = EXACT_STATUS; break; default: // round up __add_carry_out (Stemp, carry, Q.w[0], reciprocals10_64[extra_digits]); if ((remainder_h >> (64 - amount)) + carry >= (((UINT64) 1) << amount)) status = EXACT_STATUS; } if (status != EXACT_STATUS) __set_status_flags (pfpsf, status); } #endif } res = get_BID32 ((UINT32) (sign_x >> 32), exponent_x, coefficient_x, rnd_mode, pfpsf); BID_RETURN (res); }