URL
https://opencores.org/ocsvn/openrisc_me/openrisc_me/trunk
Subversion Repositories openrisc_me
[/] [openrisc/] [trunk/] [gnu-src/] [gcc-4.5.1/] [libgcc/] [config/] [libbid/] [bid_from_int.c] - Rev 300
Go to most recent revision | Compare with Previous | Blame | View Log
/* 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" /***************************************************************************** * BID64_round_integral_exact ****************************************************************************/ #if DECIMAL_CALL_BY_REFERENCE void bid64_from_int32 (UINT64 * pres, int *px _EXC_MASKS_PARAM _EXC_INFO_PARAM) { int x = *px; #else UINT64 bid64_from_int32 (int x _EXC_MASKS_PARAM _EXC_INFO_PARAM) { #endif UINT64 res; // if integer is negative, put the absolute value // in the lowest 32bits of the result if ((x & SIGNMASK32) == SIGNMASK32) { // negative int32 x = ~x + 1; // 2's complement of x res = (unsigned int) x | 0xb1c0000000000000ull; // (exp << 53)) = biased exp. is 0 } else { // positive int32 res = x | 0x31c0000000000000ull; // (exp << 53)) = biased exp. is 0 } BID_RETURN (res); } #if DECIMAL_CALL_BY_REFERENCE void bid64_from_uint32 (UINT64 * pres, unsigned int *px _EXC_MASKS_PARAM _EXC_INFO_PARAM) { unsigned int x = *px; #else UINT64 bid64_from_uint32 (unsigned int x _EXC_MASKS_PARAM _EXC_INFO_PARAM) { #endif UINT64 res; res = x | 0x31c0000000000000ull; // (exp << 53)) = biased exp. is 0 BID_RETURN (res); } #if DECIMAL_CALL_BY_REFERENCE void bid64_from_int64 (UINT64 * pres, SINT64 * px _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) { SINT64 x = *px; #if !DECIMAL_GLOBAL_ROUNDING unsigned int rnd_mode = *prnd_mode; #endif #else UINT64 bid64_from_int64 (SINT64 x _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) { #endif UINT64 res; UINT64 x_sign, C; unsigned int q, ind; int incr_exp = 0; int is_midpoint_lt_even = 0, is_midpoint_gt_even = 0; int is_inexact_lt_midpoint = 0, is_inexact_gt_midpoint = 0; x_sign = x & 0x8000000000000000ull; // if the integer is negative, use the absolute value if (x_sign) C = ~((UINT64) x) + 1; else C = x; if (C <= BID64_SIG_MAX) { // |C| <= 10^16-1 and the result is exact if (C < 0x0020000000000000ull) { // C < 2^53 res = x_sign | 0x31c0000000000000ull | C; } else { // C >= 2^53 res = x_sign | 0x6c70000000000000ull | (C & 0x0007ffffffffffffull); } } else { // |C| >= 10^16 and the result may be inexact // the smallest |C| is 10^16 which has 17 decimal digits // the largest |C| is 0x8000000000000000 = 9223372036854775808 w/ 19 digits if (C < 0x16345785d8a0000ull) { // x < 10^17 q = 17; ind = 1; // number of digits to remove for q = 17 } else if (C < 0xde0b6b3a7640000ull) { // C < 10^18 q = 18; ind = 2; // number of digits to remove for q = 18 } else { // C < 10^19 q = 19; ind = 3; // number of digits to remove for q = 19 } // overflow and underflow are not possible // Note: performace can be improved by inlining this call round64_2_18 ( // will work for 19 digits too if C fits in 64 bits q, ind, C, &res, &incr_exp, &is_midpoint_lt_even, &is_midpoint_gt_even, &is_inexact_lt_midpoint, &is_inexact_gt_midpoint); if (incr_exp) ind++; // set the inexact flag if (is_inexact_lt_midpoint || is_inexact_gt_midpoint || is_midpoint_lt_even || is_midpoint_gt_even) *pfpsf |= INEXACT_EXCEPTION; // general correction from RN to RA, RM, RP, RZ; result uses ind for exp if (rnd_mode != ROUNDING_TO_NEAREST) { if ((!x_sign && ((rnd_mode == ROUNDING_UP && is_inexact_lt_midpoint) || ((rnd_mode == ROUNDING_TIES_AWAY || rnd_mode == ROUNDING_UP) && is_midpoint_gt_even))) || (x_sign && ((rnd_mode == ROUNDING_DOWN && is_inexact_lt_midpoint) || ((rnd_mode == ROUNDING_TIES_AWAY || rnd_mode == ROUNDING_DOWN) && is_midpoint_gt_even)))) { res = res + 1; if (res == 0x002386f26fc10000ull) { // res = 10^16 => rounding overflow res = 0x00038d7ea4c68000ull; // 10^15 ind = ind + 1; } } else if ((is_midpoint_lt_even || is_inexact_gt_midpoint) && ((x_sign && (rnd_mode == ROUNDING_UP || rnd_mode == ROUNDING_TO_ZERO)) || (!x_sign && (rnd_mode == ROUNDING_DOWN || rnd_mode == ROUNDING_TO_ZERO)))) { res = res - 1; // check if we crossed into the lower decade if (res == 0x00038d7ea4c67fffull) { // 10^15 - 1 res = 0x002386f26fc0ffffull; // 10^16 - 1 ind = ind - 1; } } else { ; // exact, the result is already correct } } if (res < 0x0020000000000000ull) { // res < 2^53 res = x_sign | (((UINT64) ind + 398) << 53) | res; } else { // res >= 2^53 res = x_sign | 0x6000000000000000ull | (((UINT64) ind + 398) << 51) | (res & 0x0007ffffffffffffull); } } BID_RETURN (res); } #if DECIMAL_CALL_BY_REFERENCE void bid64_from_uint64 (UINT64 * pres, UINT64 * px _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) { UINT64 x = *px; #if !DECIMAL_GLOBAL_ROUNDING unsigned int rnd_mode = *prnd_mode; #endif #else UINT64 bid64_from_uint64 (UINT64 x _RND_MODE_PARAM _EXC_FLAGS_PARAM _EXC_MASKS_PARAM _EXC_INFO_PARAM) { #endif UINT64 res; UINT128 x128, res128; unsigned int q, ind; int incr_exp = 0; int is_midpoint_lt_even = 0, is_midpoint_gt_even = 0; int is_inexact_lt_midpoint = 0, is_inexact_gt_midpoint = 0; if (x <= BID64_SIG_MAX) { // x <= 10^16-1 and the result is exact if (x < 0x0020000000000000ull) { // x < 2^53 res = 0x31c0000000000000ull | x; } else { // x >= 2^53 res = 0x6c70000000000000ull | (x & 0x0007ffffffffffffull); } } else { // x >= 10^16 and the result may be inexact // the smallest x is 10^16 which has 17 decimal digits // the largest x is 0xffffffffffffffff = 18446744073709551615 w/ 20 digits if (x < 0x16345785d8a0000ull) { // x < 10^17 q = 17; ind = 1; // number of digits to remove for q = 17 } else if (x < 0xde0b6b3a7640000ull) { // x < 10^18 q = 18; ind = 2; // number of digits to remove for q = 18 } else if (x < 0x8ac7230489e80000ull) { // x < 10^19 q = 19; ind = 3; // number of digits to remove for q = 19 } else { // x < 10^20 q = 20; ind = 4; // number of digits to remove for q = 20 } // overflow and underflow are not possible // Note: performace can be improved by inlining this call if (q <= 19) { round64_2_18 ( // will work for 20 digits too if x fits in 64 bits q, ind, x, &res, &incr_exp, &is_midpoint_lt_even, &is_midpoint_gt_even, &is_inexact_lt_midpoint, &is_inexact_gt_midpoint); } else { // q = 20 x128.w[1] = 0x0; x128.w[0] = x; round128_19_38 (q, ind, x128, &res128, &incr_exp, &is_midpoint_lt_even, &is_midpoint_gt_even, &is_inexact_lt_midpoint, &is_inexact_gt_midpoint); res = res128.w[0]; // res.w[1] is 0 } if (incr_exp) ind++; // set the inexact flag if (is_inexact_lt_midpoint || is_inexact_gt_midpoint || is_midpoint_lt_even || is_midpoint_gt_even) *pfpsf |= INEXACT_EXCEPTION; // general correction from RN to RA, RM, RP, RZ; result uses ind for exp if (rnd_mode != ROUNDING_TO_NEAREST) { if ((rnd_mode == ROUNDING_UP && is_inexact_lt_midpoint) || ((rnd_mode == ROUNDING_TIES_AWAY || rnd_mode == ROUNDING_UP) && is_midpoint_gt_even)) { res = res + 1; if (res == 0x002386f26fc10000ull) { // res = 10^16 => rounding overflow res = 0x00038d7ea4c68000ull; // 10^15 ind = ind + 1; } } else if ((is_midpoint_lt_even || is_inexact_gt_midpoint) && (rnd_mode == ROUNDING_DOWN || rnd_mode == ROUNDING_TO_ZERO)) { res = res - 1; // check if we crossed into the lower decade if (res == 0x00038d7ea4c67fffull) { // 10^15 - 1 res = 0x002386f26fc0ffffull; // 10^16 - 1 ind = ind - 1; } } else { ; // exact, the result is already correct } } if (res < 0x0020000000000000ull) { // res < 2^53 res = (((UINT64) ind + 398) << 53) | res; } else { // res >= 2^53 res = 0x6000000000000000ull | (((UINT64) ind + 398) << 51) | (res & 0x0007ffffffffffffull); } } BID_RETURN (res); } #if DECIMAL_CALL_BY_REFERENCE void bid128_from_int32 (UINT128 * pres, int *px _EXC_MASKS_PARAM _EXC_INFO_PARAM) { int x = *px; #else UINT128 bid128_from_int32 (int x _EXC_MASKS_PARAM _EXC_INFO_PARAM) { #endif UINT128 res; // if integer is negative, use the absolute value if ((x & SIGNMASK32) == SIGNMASK32) { res.w[HIGH_128W] = 0xb040000000000000ull; res.w[LOW_128W] = ~((unsigned int) x) + 1; // 2's complement of x } else { res.w[HIGH_128W] = 0x3040000000000000ull; res.w[LOW_128W] = (unsigned int) x; } BID_RETURN (res); } #if DECIMAL_CALL_BY_REFERENCE void bid128_from_uint32 (UINT128 * pres, unsigned int *px _EXC_MASKS_PARAM _EXC_INFO_PARAM) { unsigned int x = *px; #else UINT128 bid128_from_uint32 (unsigned int x _EXC_MASKS_PARAM _EXC_INFO_PARAM) { #endif UINT128 res; res.w[HIGH_128W] = 0x3040000000000000ull; res.w[LOW_128W] = x; BID_RETURN (res); } #if DECIMAL_CALL_BY_REFERENCE void bid128_from_int64 (UINT128 * pres, SINT64 * px _EXC_MASKS_PARAM _EXC_INFO_PARAM) { SINT64 x = *px; #else UINT128 bid128_from_int64 (SINT64 x _EXC_MASKS_PARAM _EXC_INFO_PARAM) { #endif UINT128 res; // if integer is negative, use the absolute value if ((x & SIGNMASK64) == SIGNMASK64) { res.w[HIGH_128W] = 0xb040000000000000ull; res.w[LOW_128W] = ~x + 1; // 2's complement of x } else { res.w[HIGH_128W] = 0x3040000000000000ull; res.w[LOW_128W] = x; } BID_RETURN (res); } #if DECIMAL_CALL_BY_REFERENCE void bid128_from_uint64 (UINT128 * pres, UINT64 * px _EXC_MASKS_PARAM _EXC_INFO_PARAM) { UINT64 x = *px; #else UINT128 bid128_from_uint64 (UINT64 x _EXC_MASKS_PARAM _EXC_INFO_PARAM) { #endif UINT128 res; res.w[HIGH_128W] = 0x3040000000000000ull; res.w[LOW_128W] = x; BID_RETURN (res); }
Go to most recent revision | Compare with Previous | Blame | View Log