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[/] [openrisc/] [tags/] [gnu-src/] [gcc-4.5.1/] [gcc-4.5.1-or32-1.0rc4/] [libgcc/] [config/] [libbid/] [bid128_rem.c] - Rev 594
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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/>. */ #define BID_128RES #include "bid_div_macros.h" BID128_FUNCTION_ARG2_NORND_CUSTOMRESTYPE (UINT128, bid128_rem, x, y) UINT256 P256; UINT128 CX, CY, CX2, CQ, CR, T, CXS, P128, res; UINT64 sign_x, sign_y, valid_y; SINT64 D; int_float f64, fx; int exponent_x, exponent_y, diff_expon, bin_expon_cx, scale, scale0; // unpack arguments, check for NaN or Infinity valid_y = unpack_BID128_value (&sign_y, &exponent_y, &CY, y); if (!unpack_BID128_value (&sign_x, &exponent_x, &CX, x)) { #ifdef SET_STATUS_FLAGS if ((y.w[1] & SNAN_MASK64) == SNAN_MASK64) // y is sNaN __set_status_flags (pfpsf, INVALID_EXCEPTION); #endif // test if x is NaN if ((x.w[1] & 0x7c00000000000000ull) == 0x7c00000000000000ull) { #ifdef SET_STATUS_FLAGS if ((x.w[1] & SNAN_MASK64) == SNAN_MASK64) // y is sNaN __set_status_flags (pfpsf, INVALID_EXCEPTION); #endif res.w[1] = CX.w[1] & QUIET_MASK64; res.w[0] = CX.w[0]; BID_RETURN (res); } // x is Infinity? if ((x.w[1] & 0x7800000000000000ull) == 0x7800000000000000ull) { // check if y is Inf. if (((y.w[1] & 0x7c00000000000000ull) != 0x7c00000000000000ull)) // return NaN { #ifdef SET_STATUS_FLAGS // set status flags __set_status_flags (pfpsf, INVALID_EXCEPTION); #endif res.w[1] = 0x7c00000000000000ull; res.w[0] = 0; BID_RETURN (res); } } // x is 0 if ((!CY.w[1]) && (!CY.w[0])) { #ifdef SET_STATUS_FLAGS // set status flags __set_status_flags (pfpsf, INVALID_EXCEPTION); #endif // x=y=0, return NaN res.w[1] = 0x7c00000000000000ull; res.w[0] = 0; BID_RETURN (res); } if (valid_y || ((y.w[1] & NAN_MASK64) == INFINITY_MASK64)) { // return 0 if ((exponent_x > exponent_y) && ((y.w[1] & NAN_MASK64) != INFINITY_MASK64)) exponent_x = exponent_y; res.w[1] = sign_x | (((UINT64) exponent_x) << 49); res.w[0] = 0; BID_RETURN (res); } } if (!valid_y) { // y is Inf. or NaN // test if y is NaN if ((y.w[1] & 0x7c00000000000000ull) == 0x7c00000000000000ull) { #ifdef SET_STATUS_FLAGS if ((y.w[1] & SNAN_MASK64) == SNAN_MASK64) // y is sNaN __set_status_flags (pfpsf, INVALID_EXCEPTION); #endif res.w[1] = CY.w[1] & QUIET_MASK64; res.w[0] = CY.w[0]; BID_RETURN (res); } // y is Infinity? if ((y.w[1] & 0x7800000000000000ull) == 0x7800000000000000ull) { // return x res.w[1] = x.w[1]; res.w[0] = x.w[0]; BID_RETURN (res); } // y is 0 #ifdef SET_STATUS_FLAGS // set status flags __set_status_flags (pfpsf, INVALID_EXCEPTION); #endif res.w[1] = 0x7c00000000000000ull; res.w[0] = 0; BID_RETURN (res); } diff_expon = exponent_x - exponent_y; if (diff_expon <= 0) { diff_expon = -diff_expon; if (diff_expon > 34) { // |x|<|y| in this case res = x; BID_RETURN (res); } // set exponent of y to exponent_x, scale coefficient_y T = power10_table_128[diff_expon]; __mul_128x128_to_256 (P256, CY, T); if (P256.w[2] || P256.w[3]) { // |x|<|y| in this case res = x; BID_RETURN (res); } CX2.w[1] = (CX.w[1] << 1) | (CX.w[0] >> 63); CX2.w[0] = CX.w[0] << 1; if (__unsigned_compare_ge_128 (P256, CX2)) { // |x|<|y| in this case res = x; BID_RETURN (res); } P128.w[0] = P256.w[0]; P128.w[1] = P256.w[1]; __div_128_by_128 (&CQ, &CR, CX, P128); CX2.w[1] = (CR.w[1] << 1) | (CR.w[0] >> 63); CX2.w[0] = CR.w[0] << 1; if ((__unsigned_compare_gt_128 (CX2, P256)) || (CX2.w[1] == P256.w[1] && CX2.w[0] == P256.w[0] && (CQ.w[0] & 1))) { __sub_128_128 (CR, P256, CR); sign_x ^= 0x8000000000000000ull; } get_BID128_very_fast (&res, sign_x, exponent_x, CR); BID_RETURN (res); } // 2^64 f64.i = 0x5f800000; scale0 = 38; if (!CY.w[1]) scale0 = 34; while (diff_expon > 0) { // get number of digits in CX and scale=38-digits // fx ~ CX fx.d = (float) CX.w[1] * f64.d + (float) CX.w[0]; bin_expon_cx = ((fx.i >> 23) & 0xff) - 0x7f; scale = scale0 - estimate_decimal_digits[bin_expon_cx]; // scale = 38-estimate_decimal_digits[bin_expon_cx]; D = CX.w[1] - power10_index_binexp_128[bin_expon_cx].w[1]; if (D > 0 || (!D && CX.w[0] >= power10_index_binexp_128[bin_expon_cx].w[0])) scale--; if (diff_expon >= scale) diff_expon -= scale; else { scale = diff_expon; diff_expon = 0; } T = power10_table_128[scale]; __mul_128x128_low (CXS, CX, T); __div_128_by_128 (&CQ, &CX, CXS, CY); // check for remainder == 0 if (!CX.w[1] && !CX.w[0]) { get_BID128_very_fast (&res, sign_x, exponent_y, CX); BID_RETURN (res); } } CX2.w[1] = (CX.w[1] << 1) | (CX.w[0] >> 63); CX2.w[0] = CX.w[0] << 1; if ((__unsigned_compare_gt_128 (CX2, CY)) || (CX2.w[1] == CY.w[1] && CX2.w[0] == CY.w[0] && (CQ.w[0] & 1))) { __sub_128_128 (CX, CY, CX); sign_x ^= 0x8000000000000000ull; } get_BID128_very_fast (&res, sign_x, exponent_y, CX); BID_RETURN (res); }
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