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Diffstat (limited to 'src/systemc/dt/int/sc_nbutils.cc')
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diff --git a/src/systemc/dt/int/sc_nbutils.cc b/src/systemc/dt/int/sc_nbutils.cc new file mode 100644 index 000000000..df7cc554d --- /dev/null +++ b/src/systemc/dt/int/sc_nbutils.cc @@ -0,0 +1,1749 @@ +/***************************************************************************** + + Licensed to Accellera Systems Initiative Inc. (Accellera) under one or + more contributor license agreements. See the NOTICE file distributed + with this work for additional information regarding copyright ownership. + Accellera licenses this file to you under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with the + License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + implied. See the License for the specific language governing + permissions and limitations under the License. + + *****************************************************************************/ + +/***************************************************************************** + + sc_nbutils.cpp -- External and friend functions for both sc_signed and + sc_unsigned classes. + + Original Author: Ali Dasdan, Synopsys, Inc. + + *****************************************************************************/ + +/***************************************************************************** + + MODIFICATION LOG - modifiers, enter your name, affiliation, date and + changes you are making here. + + Name, Affiliation, Date: + Description of Modification: + + *****************************************************************************/ + + +// $Log: sc_nbutils.cpp,v $ +// Revision 1.4 2011/08/24 22:05:46 acg +// Torsten Maehne: initialization changes to remove warnings. +// +// Revision 1.3 2011/02/18 20:19:15 acg +// Andy Goodrich: updating Copyright notice. +// +// Revision 1.2 2007/11/04 21:26:40 acg +// Andy Goodrich: added a buffer to the allocation of the q array to address +// an issue with references outside the array by 1 byte detected by valgrind. +// +// Revision 1.1.1.1 2006/12/15 20:20:05 acg +// SystemC 2.3 +// +// Revision 1.3 2006/01/13 18:49:32 acg +// Added $Log command so that CVS check in comments are reproduced in the +// source. +// + +#include <cctype> +#include <cstdio> +#include <cstring> +#include <sstream> + +#include "systemc/ext/dt/int/sc_nbutils.hh" +#include "systemc/ext/utils/functions.hh" + +namespace sc_dt +{ + +// only used within vec_from_str (non-standard, deprecated) +static inline void +is_valid_base(sc_numrep base) +{ + switch (base) { + case SC_NOBASE: case SC_BIN: + case SC_OCT: case SC_DEC: + case SC_HEX: + break; + case SC_BIN_US: case SC_BIN_SM: + case SC_OCT_US: case SC_OCT_SM: + case SC_HEX_US: case SC_HEX_SM: + case SC_CSD: + SC_REPORT_ERROR("not implemented", + "is_valid_base( sc_numrep base ) : " + "bases SC_CSD, or ending in _US and _SM are " + "not supported"); + break; + default: + std::stringstream msg; + msg << "is_valid_base( sc_numrep base ) : base = " << base << + " is not valid"; + SC_REPORT_ERROR("value is not valid", msg.str().c_str() ); + } +} + +// ---------------------------------------------------------------------------- +// ENUM : sc_numrep +// +// Enumeration of number representations for character string conversion. +// ---------------------------------------------------------------------------- + +const std::string +to_string(sc_numrep numrep) +{ + switch (numrep) { +#define CASE_ENUM2STR(Value) case Value: return #Value + + CASE_ENUM2STR(SC_DEC); + + CASE_ENUM2STR(SC_BIN); + CASE_ENUM2STR(SC_BIN_US); + CASE_ENUM2STR(SC_BIN_SM); + + CASE_ENUM2STR(SC_OCT); + CASE_ENUM2STR(SC_OCT_US); + CASE_ENUM2STR(SC_OCT_SM); + + CASE_ENUM2STR(SC_HEX); + CASE_ENUM2STR(SC_HEX_US); + CASE_ENUM2STR(SC_HEX_SM); + + CASE_ENUM2STR(SC_CSD); + +#undef CASE_ENUM2STR + + default: + return "unknown"; + } +} + +// ---------------------------------------------------------------------------- +// SECTION: General utility functions. +// ---------------------------------------------------------------------------- + +// Return the number of characters to advance the source of c. This +// function implements one move of the FSM to parse the following +// regular expressions. Error checking is done in the caller. + +small_type +fsm_move(char c, small_type &b, small_type &s, small_type &state) +{ + // Possible regular expressions (REs): + // Let N = any digit depending on the base. + // 1. [0|1|..|9]N* + // 2. [+|-][0|1|..|9]N* + // 3. 0[b|B|d|D|o|O|x|X][0|1|..|F]N* + // 4. [+|-]?0[b|B|d|D|o|O|x|X][0|1|..|F]N* + // + // The finite state machine (FMS) to parse these regular expressions + // has 4 states, 0 to 3. 0 is the initial state and 3 is the final + // state. + // + // Default sign = SC_POS, default base = NB_DEFAULT_BASE. + + switch (state) { + case 0: // The initial state. + switch (c) { + case '0': s = SC_POS; state = 1; return 0; // RE 1 or 3 + case '+': s = SC_POS; state = 2; return 1; // RE 2 + case '-': s = SC_NEG; state = 2; return 1; // RE 2 + default: + s = SC_POS; b = NB_DEFAULT_BASE; state = 3; return 0; // RE 1 + } + // break; //unreachable code + case 1: // 0... + switch (c) { + case 'x': case 'X': b = SC_HEX; state = 3; return 2; // RE 3 or 4 + case 'd': case 'D': b = SC_DEC; state = 3; return 2; // RE 3 or 4 + case 'o': case 'O': b = SC_OCT; state = 3; return 2; // RE 3 or 4 + case 'b': case 'B': b = SC_BIN; state = 3; return 2; // RE 3 or 4 + default: b = NB_DEFAULT_BASE; state = 3; return 0; // RE 1 + } + // break; //unreachable code + case 2: // +... or -... + switch (c) { + case '0': state = 1; return 0; // RE 2 or 4 + default: b = NB_DEFAULT_BASE; state = 3; return 0; // RE 2 + } + // break; //unreachable code + case 3: // The final state. + break; + default: + // Any other state is not possible. + sc_assert((0 <= state) && (state <= 3)); + } // switch + return 0; +} + + +// Get base b and sign s of the number in the char string v. Return a +// pointer to the first char after the point where b and s are +// determined or where the end of v is reached. The input string v has +// to be null terminated. +const char * +get_base_and_sign(const char *v, small_type &b, small_type &s) +{ +#ifdef DEBUG_SYSTEMC + sc_assert(v != NULL); +#endif + const small_type STATE_START = 0; + const small_type STATE_FINISH = 3; + + // Default sign = SC_POS, default base = 10. + s = SC_POS; + b = NB_DEFAULT_BASE; + + small_type state = STATE_START; + small_type nskip = 0; // Skip that many chars. + const char *u = v; + + while (*u) { + if (isspace(*u)) { // Skip white space. + ++u; + } else { + nskip += fsm_move(*u, b, s, state); + if (state == STATE_FINISH) + break; + else + ++u; + } + } + + // Test to see if the above loop executed more than it should + // have. The max number of skipped chars is equal to the length of + // the longest format specifier, e.g., "-0x". + sc_assert(nskip <= 3); + + v += nskip; + + // Handles empty strings or strings without any digits after the + // base or base and sign specifier. + if (*v == '\0') { + static const char msg[] = + "get_base_and_sign( const char* v, small_type&, small_type& ) : " + "v = \"\" is not valid"; + SC_REPORT_ERROR("conversion failed", msg); + } + return v; +} + +//----------------------------------------------------------------------------- +//"parse_binary_bits" +// +// This function parses the supplied string into the supplied vector as a +// right justified bit value. +// src_p -> character string representing the bits to be parsed. +// dst_n = number of words in data_p and ctrl_p. +// data_p -> words w/BITS_PER_DIGIT bits to receive the value's data bits. +// ctrl_p -> words w/BITS_PER_DIGIT bits to receive the value's control +// bits, or zero. +// Result is true if value was non-zero. +//----------------------------------------------------------------------------- +void +parse_binary_bits(const char *src_p, int dst_n, + sc_digit *data_p, sc_digit *ctrl_p) +{ + int bit_i; // Number of bit now processing. + sc_digit ctrl; // Control word now assembling. + sc_digit data; // Data word now assembling. + int delta_n; // src_n - dst_n*BITS_PER_DIGIT. + int src_i; // Index in src_p now accessing (left to right). + int src_n; // Length of source that is left in bits. + int word_i; // Bit within word now accessing (left to right). + + // MAKE SURE WE HAVE A STRING TO PARSE: + if (src_p == 0) { + SC_REPORT_ERROR("conversion failed", + "character string is zero"); + return; + } + if (*src_p == 0) { + SC_REPORT_ERROR("conversion failed", + "character string is empty"); + return; + } + + + // INDEX INTO THE SOURCE TO A DEPTH THAT WILL ACCOMODATE OUR SIZE: + // + // If the source is smaller than our value initialize our value to zero. + + src_n = strlen(src_p); + delta_n = src_n - (dst_n*BITS_PER_DIGIT); + if (delta_n > 0) { + src_p = &src_p[delta_n]; + src_n -= delta_n; + } else { + for (word_i = 0; word_i < dst_n; word_i++) + data_p[word_i] = 0; + if (ctrl_p) + for (word_i = 0; word_i < dst_n; word_i++) + ctrl_p[word_i] = 0; + } + + // LOOP OVER THE SOURCE ASSEMBLING WORDS AND PLACING THEM IN OUR VALUE: + // + // We stride right to left through the source in BITS_PER_DIGIT chunks. + // Each of those chunks is processed from left to right a bit at a time. + // We process the high order word specially, since there are less bits. + src_n = src_n - BITS_PER_DIGIT; + for (word_i=0; word_i < dst_n; word_i++) { + src_i = src_n; + + // PARTIAL LAST WORD TO ASSEMBLE: + if (src_i < 0) { + src_n += BITS_PER_DIGIT; + data = 0; + ctrl = 0; + for (src_i = 0; src_i < src_n; src_i++) { + ctrl = ctrl << 1; + data = data << 1; + switch (src_p[src_i]) { + case 'X': + case 'x': ctrl = ctrl | 1; data = data | 1; break; + case '1': data = data | 1; break; + case 'Z': + case 'z': ctrl = ctrl | 1; break; + case '0': break; + default: + { + std::stringstream msg; + msg << "character string '" << src_p << + "' is not valid"; + SC_REPORT_ERROR("conversion failed", + msg.str().c_str()); + return; + } + break; + } + } + if (ctrl_p) + ctrl_p[word_i] = ctrl; + data_p[word_i] = data; + break; + } + + // FULL WORD TO BE ASSEMBLED: + ctrl = 0; + data = 0; + for (bit_i = 0; bit_i < BITS_PER_DIGIT; bit_i++) { + ctrl = ctrl << 1; + data = data << 1; + switch (src_p[src_i++]) { + case 'X': + case 'x': ctrl = ctrl | 1; data = data | 1; break; + case '1': data = data | 1; break; + case 'Z': + case 'z': ctrl = ctrl | 1; break; + case '0': break; + default: + { + std::stringstream msg; + msg << "character string '" << src_p << + "' is not valid"; + SC_REPORT_ERROR("conversion failed", + msg.str().c_str()); + return; + } + break; + } + } + if (ctrl_p) + ctrl_p[word_i] = ctrl; + data_p[word_i] = data; + src_n = src_n - BITS_PER_DIGIT; + } +} + + +//----------------------------------------------------------------------------- +//"parse_hex_bits" +// +// This function parses the supplied string into the supplied vector as a +// right justified bit value. +// src_p -> character string representing the bits to be parsed. +// dst_n = number of words in data_p and ctrl_p. +// data_p -> words w/32 bits to receive the value's data bits. +// ctrl_p -> words w/32 bits to receive the value's control bits, +// or zero. +// Result is true if value was non-zero. +//----------------------------------------------------------------------------- +void +parse_hex_bits(const char *src_p, int dst_n, + sc_digit *data_p, sc_digit *ctrl_p) +{ + sc_digit ctrl; // Control word now assembling. + sc_digit data; // Data word now assembling. + int delta_n; // src_n - dst_n*BITS_PER_DIGIT. + int digit_i; // Number of digit now processing. + int src_i; // Index in src_p now accessing (left to right). + int src_n; // Length of source that is left in bits. + int word_i; // Bit within word now accessing (left to right). + + // MAKE SURE WE HAVE A STRING TO PARSE: + if (src_p == 0) { + SC_REPORT_ERROR("conversion failed", + "character string is zero"); + return; + } + if (*src_p == 0) { + SC_REPORT_ERROR("conversion failed", + "character string is empty"); + return; + } + + // INDEX INTO THE SOURCE TO A DEPTH THAT WILL ACCOMODATE OUR SIZE: + // + // If the source is smaller than our value initialize our value to zero. + src_n = strlen(src_p); + delta_n = src_n - (dst_n*8); + if (delta_n > 0) { + src_p = &src_p[delta_n]; + src_n -= delta_n; + } else { + for (word_i = 0; word_i < dst_n; word_i++) + data_p[word_i] = 0; + if (ctrl_p) + for (word_i = 0; word_i < dst_n; word_i++) + ctrl_p[word_i] = 0; + } + + // LOOP OVER THE SOURCE ASSEMBLING WORDS AND PLACING THEM IN OUR VALUE: + // + // We stride right to left through the source in BITS_PER_DIGIT chunks. + // Each of those chunks is processed from left to right a bit at a time. + // We process the high order word specially, since there are less bits. + src_n = src_n - 8; + for (word_i = 0; word_i < dst_n; word_i++) { + src_i = src_n; + + // PARTIAL LAST WORD TO ASSEMBLE: + if (src_i < 0) { + src_n += 8; + data = 0; + ctrl = 0; + for (src_i = 0; src_i < src_n; src_i++) { + ctrl = ctrl << 4; + data = data << 4; + switch (src_p[src_i]) { + case 'X': + case 'x': ctrl = ctrl | 15; data = data | 15; break; + case 'F': + case 'f': data = data | 15; break; + case 'E': + case 'e': data = data | 14; break; + case 'D': + case 'd': data = data | 13; break; + case 'C': + case 'c': data = data | 12; break; + case 'B': + case 'b': data = data | 11; break; + case 'A': + case 'a': data = data | 10; break; + case '9': data = data | 9; break; + case '8': data = data | 8; break; + case '7': data = data | 7; break; + case '6': data = data | 6; break; + case '5': data = data | 5; break; + case '4': data = data | 4; break; + case '3': data = data | 3; break; + case '2': data = data | 2; break; + case '1': data = data | 1; break; + case '0': break; + case 'Z': + case 'z': ctrl = ctrl | 15; break; + default: + { + std::stringstream msg; + msg << "character string '" << src_p << + "' is not valid"; + SC_REPORT_ERROR("conversion failed", + msg.str().c_str()); + return; + } + break; + } + } + if (ctrl_p) + ctrl_p[word_i] = ctrl; + data_p[word_i] = data; + break; + } + + // FULL WORD TO BE ASSEMBLED: + ctrl = 0; + data = 0; + for (digit_i = 0; digit_i < 8; digit_i++) { + ctrl = ctrl << 4; + data = data << 4; + switch (src_p[src_i++]) { + case 'X': + case 'x': ctrl = ctrl | 15; data = data | 15; break; + case 'F': + case 'f': data = data | 15; break; + case 'E': + case 'e': data = data | 14; break; + case 'D': + case 'd': data = data | 13; break; + case 'C': + case 'c': data = data | 12; break; + case 'B': + case 'b': data = data | 11; break; + case 'A': + case 'a': data = data | 10; break; + case '9': data = data | 9; break; + case '8': data = data | 8; break; + case '7': data = data | 7; break; + case '6': data = data | 6; break; + case '5': data = data | 5; break; + case '4': data = data | 4; break; + case '3': data = data | 3; break; + case '2': data = data | 2; break; + case '1': data = data | 1; break; + case '0': break; + case 'Z': + case 'z': ctrl = ctrl | 15; break; + default: + { + std::stringstream msg; + msg << "character string '" << src_p << "' is not valid"; + SC_REPORT_ERROR("conversion failed", + msg.str().c_str() ); + return; + } + break; + } + } + if (ctrl_p) + ctrl_p[word_i] = ctrl; + data_p[word_i] = data; + src_n = src_n - BITS_PER_DIGIT; + } +} + + +// ---------------------------------------------------------------------------- +// SECTION: Utility functions involving unsigned vectors. +// ---------------------------------------------------------------------------- + +// Read u from a null terminated char string v. Note that operator>> +// in sc_nbcommon.cpp is similar to this function. +small_type +vec_from_str(int unb, int und, sc_digit *u, const char *v, sc_numrep base) +{ + +#ifdef DEBUG_SYSTEMC + sc_assert((unb > 0) && (und > 0) && (u != NULL)); + sc_assert(v != NULL); +#endif + is_valid_base(base); + + small_type b, s; // base and sign. + + v = get_base_and_sign(v, b, s); + + if (base != SC_NOBASE) { + if (b == NB_DEFAULT_BASE) { + b = base; + } else { + std::stringstream msg; + msg << "vec_from_str( int, int, sc_digit*, const char*, " << + "sc_numrep base ) : base = " << base << + " does not match the default base"; + SC_REPORT_ERROR("conversion failed", + msg.str().c_str()); + return 0; + } + } + + vec_zero(und, u); + + char c; + for (; (c = *v); ++v) { + if (isalnum(c)) { + small_type val; // Numeric value of a char. + + if (isalpha(c)) // Hex digit. + val = toupper(c) - 'A' + 10; + else + val = c - '0'; + + if (val >= b) { + std::stringstream msg; + msg << "vec_from_str( int, int, sc_digit*, const char*, " << + "sc_numrep base ) : '" << *v << "' is not a valid " << + "digit in base " << b; + SC_REPORT_ERROR("conversion failed", + msg.str().c_str()); + return 0; + } + + // digit = digit * b + val; + vec_mul_small_on(und, u, b); + + if (val) + vec_add_small_on(und, u, val); + } else { + std::stringstream msg; + msg << "vec_from_str( int, int, sc_digit*, const char*, " << + "sc_numrep base ) : '" << *v << "' is not a valid " << + "digit in base " << b; + SC_REPORT_ERROR("conversion failed", + msg.str().c_str()); + return 0; + } + } + + return convert_signed_SM_to_2C_to_SM(s, unb, und, u); +} + + +// All vec_ functions assume that the vector to hold the result, +// called w, has sufficient length to hold the result. For efficiency +// reasons, we do not test whether or not we are out of bounds. + +// Compute w = u + v, where w, u, and v are vectors. +// - ulen >= vlen +// - wlen >= sc_max(ulen, vlen) + 1 +void +vec_add(int ulen, const sc_digit *u, int vlen, const sc_digit *v, sc_digit *w) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert((vlen > 0) && (v != NULL)); + sc_assert(w != NULL); + sc_assert(ulen >= vlen); +#endif + + const sc_digit *uend = (u + ulen); + const sc_digit *vend = (v + vlen); + + sc_digit carry = 0; // Also used as sum to save space. + + // Add along the shorter v. + while (v < vend) { + carry += (*u++) + (*v++); + (*w++) = carry & DIGIT_MASK; + carry >>= BITS_PER_DIGIT; + } + + // Propagate the carry. + while (carry && (u < uend)) { + carry = (*u++) + 1; + (*w++) = carry & DIGIT_MASK; + carry >>= BITS_PER_DIGIT; + } + + // Copy the rest of u to the result. + while (u < uend) + (*w++) = (*u++); + + // Propagate the carry if it is still 1. + if (carry) + (*w) = 1; +} + + +// Compute u += v, where u and v are vectors. +// - ulen >= vlen +void +vec_add_on(int ulen, sc_digit *ubegin, int vlen, const sc_digit *v) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (ubegin != NULL)); + sc_assert((vlen > 0) && (v != NULL)); + sc_assert(ulen >= vlen); +#endif + + sc_digit *u = ubegin; + const sc_digit *uend = (u + ulen); + const sc_digit *vend = (v + vlen); + + sc_digit carry = 0; // Also used as sum to save space. + + // Add along the shorter v. + while (v < vend) { + carry += (*u) + (*v++); + (*u++) = carry & DIGIT_MASK; + carry >>= BITS_PER_DIGIT; + } + + // Propagate the carry. + while (carry && (u < uend)) { + carry = (*u) + 1; + (*u++) = carry & DIGIT_MASK; + carry >>= BITS_PER_DIGIT; + } + +#ifdef DEBUG_SYSTEMC + if (carry != 0) { + SC_REPORT_WARNING(sc_core::SC_ID_WITHOUT_MESSAGE_, + "vec_add_on( int, sc_digit*, int, const " + "sc_digit* ) : " + "result of addition is wrapped around"); + } +#endif +} + + +// Compute u += v, where u and v are vectors. +// - ulen < vlen +void +vec_add_on2(int ulen, sc_digit *ubegin, int, +#ifdef DEBUG_SYSTEMC + vlen, +#endif + const sc_digit *v) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (ubegin != NULL)); + sc_assert((vlen > 0) && (v != NULL)); + sc_assert(ulen < vlen); +#endif + + sc_digit *u = ubegin; + const sc_digit *uend = (u + ulen); + + sc_digit carry = 0; // Also used as sum to save space. + + // Add along the shorter u. + while (u < uend) { + carry += (*u) + (*v++); + (*u++) = carry & DIGIT_MASK; + carry >>= BITS_PER_DIGIT; + } + +#ifdef DEBUG_SYSTEMC + if (carry != 0) { + SC_REPORT_WARNING(sc_core::SC_ID_WITHOUT_MESSAGE_, + "vec_add_on2( int, sc_digit*, int, const " + "sc_digit* ) : " + "result of addition is wrapped around"); + } +#endif +} + + +// Compute w = u + v, where w and u are vectors, and v is a scalar. +void +vec_add_small(int ulen, const sc_digit *u, sc_digit v, sc_digit *w) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert(w != NULL); +#endif + + const sc_digit *uend = (u + ulen); + + // Add along the shorter v. + sc_digit carry = (*u++) + v; + (*w++) = carry & DIGIT_MASK; + carry >>= BITS_PER_DIGIT; + + // Propagate the carry. + while (carry && (u < uend)) { + carry = (*u++) + 1; + (*w++) = carry & DIGIT_MASK; + carry >>= BITS_PER_DIGIT; + } + + // Copy the rest of u to the result. + while (u < uend) + (*w++) = (*u++); + + // Propagate the carry if it is still 1. + if (carry) + (*w) = 1; +} + +// Compute u += v, where u is vectors, and v is a scalar. +void +vec_add_small_on(int ulen, sc_digit *u, sc_digit v) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); +#endif + + int i = 0; + + while (v && (i < ulen)) { + v += u[i]; + u[i++] = v & DIGIT_MASK; + v >>= BITS_PER_DIGIT; + } + +#ifdef DEBUG_SYSTEMC + if (v != 0) { + SC_REPORT_WARNING(sc_core::SC_ID_WITHOUT_MESSAGE_, + "vec_add_small_on( int, sc_digit*, unsigned " + "long ) : " + "result of addition is wrapped around"); + } +#endif +} + +// Compute w = u - v, where w, u, and v are vectors. +// - ulen >= vlen +// - wlen >= sc_max(ulen, vlen) +void +vec_sub(int ulen, const sc_digit *u, int vlen, const sc_digit *v, sc_digit *w) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert((vlen > 0) && (v != NULL)); + sc_assert(w != NULL); + sc_assert(ulen >= vlen); +#endif + + const sc_digit *uend = (u + ulen); + const sc_digit *vend = (v + vlen); + + sc_digit borrow = 0; // Also used as diff to save space. + + // Subtract along the shorter v. + while (v < vend) { + borrow = ((*u++) + DIGIT_RADIX) - (*v++) - borrow; + (*w++) = borrow & DIGIT_MASK; + borrow = 1 - (borrow >> BITS_PER_DIGIT); + } + + // Propagate the borrow. + while (borrow && (u < uend)) { + borrow = ((*u++) + DIGIT_RADIX) - 1; + (*w++) = borrow & DIGIT_MASK; + borrow = 1 - (borrow >> BITS_PER_DIGIT); + } + +#ifdef DEBUG_SYSTEMC + sc_assert(borrow == 0); +#endif + + // Copy the rest of u to the result. + while (u < uend) + (*w++) = (*u++); +} + +// Compute u = u - v, where u and v are vectors. +// - u > v +// - ulen >= vlen +void +vec_sub_on(int ulen, sc_digit *ubegin, int vlen, const sc_digit *v) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (ubegin != NULL)); + sc_assert((vlen > 0) && (v != NULL)); + sc_assert(ulen >= vlen); +#endif + + sc_digit *u = ubegin; + const sc_digit *uend = (u + ulen); + const sc_digit *vend = (v + vlen); + + sc_digit borrow = 0; // Also used as diff to save space. + + // Subtract along the shorter v. + while (v < vend) { + borrow = ((*u) + DIGIT_RADIX) - (*v++) - borrow; + (*u++) = borrow & DIGIT_MASK; + borrow = 1 - (borrow >> BITS_PER_DIGIT); + } + + // Propagate the borrow. + while (borrow && (u < uend)) { + borrow = ((*u) + DIGIT_RADIX) - 1; + (*u++) = borrow & DIGIT_MASK; + borrow = 1 - (borrow >> BITS_PER_DIGIT); + } + +#ifdef DEBUG_SYSTEMC + sc_assert(borrow == 0); +#endif +} + +// Compute u = v - u, where u and v are vectors. +// - v > u +// - ulen <= vlen or ulen > ulen +void +vec_sub_on2(int ulen, sc_digit *ubegin, int vlen, const sc_digit *v) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (ubegin != NULL)); + sc_assert((vlen > 0) && (v != NULL)); +#endif + + sc_digit *u = ubegin; + const sc_digit *uend = (u + sc_min(ulen, vlen)); + + sc_digit borrow = 0; // Also used as diff to save space. + + // Subtract along the shorter u. + while (u < uend) { + borrow = ((*v++) + DIGIT_RADIX) - (*u) - borrow; + (*u++) = borrow & DIGIT_MASK; + borrow = 1 - (borrow >> BITS_PER_DIGIT); + } + +#ifdef DEBUG_SYSTEMC + if (borrow != 0) { + SC_REPORT_WARNING(sc_core::SC_ID_WITHOUT_MESSAGE_, + "vec_sub_on2( int, sc_digit*, int, const " + "sc_digit* ) : " + "result of subtraction is wrapped around"); + } +#endif +} + +// Compute w = u - v, where w and u are vectors, and v is a scalar. +void +vec_sub_small(int ulen, const sc_digit *u, sc_digit v, sc_digit *w) +{ +#ifdef DEBUG_SYSTEMC + sc_assert(ulen > 0); + sc_assert(u != NULL); +#endif + + const sc_digit *uend = (u + ulen); + + // Add along the shorter v. + sc_digit borrow = ((*u++) + DIGIT_RADIX) - v; + (*w++) = borrow & DIGIT_MASK; + borrow = 1 - (borrow >> BITS_PER_DIGIT); + + // Propagate the borrow. + while (borrow && (u < uend)) { + borrow = ((*u++) + DIGIT_RADIX) - 1; + (*w++) = borrow & DIGIT_MASK; + borrow = 1 - (borrow >> BITS_PER_DIGIT); + } + +#ifdef DEBUG_SYSTEMC + sc_assert(borrow == 0); +#endif + + // Copy the rest of u to the result. + while (u < uend) + (*w++) = (*u++); +} + + +// Compute u -= v, where u is vectors, and v is a scalar. +void +vec_sub_small_on(int ulen, sc_digit *u, sc_digit v) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); +#endif + + for (int i = 0; i < ulen; ++i) { + v = (u[i] + DIGIT_RADIX) - v; + u[i] = v & DIGIT_MASK; + v = 1 - (v >> BITS_PER_DIGIT); + } + +#ifdef DEBUG_SYSTEMC + sc_assert(v == 0); +#endif +} + +// Compute w = u * v, where w, u, and v are vectors. +void +vec_mul(int ulen, const sc_digit *u, int vlen, const sc_digit *vbegin, + sc_digit *wbegin) +{ + + /* Consider u = Ax + B and v = Cx + D where x is equal to + HALF_DIGIT_RADIX. In other words, A is the higher half of u and + B is the lower half of u. The interpretation for v is + similar. Then, we have the following picture: + + u_h u_l + u: -------- -------- + A B + + v_h v_l + v: -------- -------- + C D + + result (d): + carry_before: -------- -------- + carry_h carry_l + result_before: -------- -------- -------- -------- + R1_h R1_l R0_h R0_l + -------- -------- + BD_h BD_l + -------- -------- + AD_h AD_l + -------- -------- + BC_h BC_l + -------- -------- + AC_h AC_l + result_after: -------- -------- -------- -------- + R1_h' R1_l' R0_h' R0_l' + + prod_l = R0_h|R0_l + B * D + 0|carry_l + = R0_h|R0_l + BD_h|BD_l + 0|carry_l + + prod_h = A * D + B * C + high_half(prod_l) + carry_h + = AD_h|AD_l + BC_h|BC_l + high_half(prod_l) + 0|carry_h + + carry = A * C + high_half(prod_h) + = AC_h|AC_l + high_half(prod_h) + + R0_l' = low_half(prod_l) + + R0_h' = low_half(prod_h) + + R0 = high_half(prod_h)|low_half(prod_l) + + where '|' is the concatenation operation and the suffixes 0 and 1 + show the iteration number, i.e., 0 is the current iteration and 1 + is the next iteration. + + NOTE: sc_max(prod_l, prod_h, carry) <= 2 * x^2 - 1, so any + of these numbers can be stored in a digit. + + NOTE: low_half(u) returns the lower BITS_PER_HALF_DIGIT of u, + whereas high_half(u) returns the rest of the bits, which may + contain more bits than BITS_PER_HALF_DIGIT. + */ + +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert((vlen > 0) && (vbegin != NULL)); + sc_assert(wbegin != NULL); +#endif + +#define prod_h carry + const sc_digit *uend = (u + ulen); + const sc_digit *vend = (vbegin + vlen); + + while (u < uend) { + sc_digit u_h = (*u++); // A|B + sc_digit u_l = low_half(u_h); // B + u_h = high_half(u_h); // A + +#ifdef DEBUG_SYSTEMC + // The overflow bits must be zero. + sc_assert(u_h == (u_h & HALF_DIGIT_MASK)); +#endif + sc_digit carry = 0; + sc_digit *w = (wbegin++); + const sc_digit *v = vbegin; + + while (v < vend) { + sc_digit v_h = (*v++); // C|D + sc_digit v_l = low_half(v_h); // D + + v_h = high_half(v_h); // C + +#ifdef DEBUG_SYSTEMC + // The overflow bits must be zero. + sc_assert(v_h == (v_h & HALF_DIGIT_MASK)); +#endif + + sc_digit prod_l = (*w) + u_l * v_l + low_half(carry); + prod_h = u_h * v_l + u_l * v_h + + high_half(prod_l) + high_half(carry); + (*w++) = concat(low_half(prod_h), low_half(prod_l)); + carry = u_h * v_h + high_half(prod_h); + } + (*w) = carry; + } +#undef prod_h +} + +// Compute w = u * v, where w and u are vectors, and v is a scalar. +// - 0 < v < HALF_DIGIT_RADIX. +void +vec_mul_small(int ulen, const sc_digit *u, sc_digit v, sc_digit *w) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert(w != NULL); + sc_assert((0 < v) && (v < HALF_DIGIT_RADIX)); +#endif + +#define prod_h carry + + const sc_digit *uend = (u + ulen); + sc_digit carry = 0; + while (u < uend) { + sc_digit u_AB = (*u++); +#ifdef DEBUG_SYSTEMC + // The overflow bits must be zero. + sc_assert(high_half(u_AB) == high_half_masked(u_AB)); +#endif + sc_digit prod_l = v * low_half(u_AB) + low_half(carry); + prod_h = v * high_half(u_AB) + high_half(prod_l) + high_half(carry); + (*w++) = concat(low_half(prod_h), low_half(prod_l)); + carry = high_half(prod_h); + } + (*w) = carry; +#undef prod_h +} + +// Compute u = u * v, where u is a vector, and v is a scalar. +// - 0 < v < HALF_DIGIT_RADIX. +void +vec_mul_small_on(int ulen, sc_digit *u, sc_digit v) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert((0 < v) && (v < HALF_DIGIT_RADIX)); +#endif + +#define prod_h carry + sc_digit carry = 0; + for (int i = 0; i < ulen; ++i) { +#ifdef DEBUG_SYSTEMC + // The overflow bits must be zero. + sc_assert(high_half(u[i]) == high_half_masked(u[i])); +#endif + sc_digit prod_l = v * low_half(u[i]) + low_half(carry); + prod_h = v * high_half(u[i]) + high_half(prod_l) + high_half(carry); + u[i] = concat(low_half(prod_h), low_half(prod_l)); + carry = high_half(prod_h); + } +#undef prod_h + +#ifdef DEBUG_SYSTEMC + if (carry != 0) { + SC_REPORT_WARNING(sc_core::SC_ID_WITHOUT_MESSAGE_, + "vec_mul_small_on( int, sc_digit*, unsigned " + "long ) : " + "result of multiplication is wrapped around"); + } +#endif +} + +// Compute w = u / v, where w, u, and v are vectors. +// - u and v are assumed to have at least two digits as uchars. +void +vec_div_large(int ulen, const sc_digit *u, int vlen, const sc_digit *v, + sc_digit *w) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert((vlen > 0) && (v != NULL)); + sc_assert(w != NULL); + sc_assert(BITS_PER_DIGIT >= 3 * BITS_PER_BYTE); +#endif + + // We will compute q = x / y where x = u and y = v. The reason for + // using x and y is that x and y are BYTE_RADIX copies of u and v, + // respectively. The use of BYTE_RADIX radix greatly simplifies the + // complexity of the division operation. These copies are also + // needed even when we use DIGIT_RADIX representation. + + int xlen = BYTES_PER_DIGIT * ulen + 1; + int ylen = BYTES_PER_DIGIT * vlen; + +#ifdef SC_MAX_NBITS + uchar x[DIV_CEIL2(SC_MAX_NBITS, BITS_PER_BYTE)]; + uchar y[DIV_CEIL2(SC_MAX_NBITS, BITS_PER_BYTE)]; + uchar q[DIV_CEIL2(SC_MAX_NBITS, BITS_PER_BYTE)]; +#else + uchar *x = new uchar[xlen]; + uchar *y = new uchar[ylen]; + // valgrind complains about us accessing too far to so leave a buffer. + uchar *q = new uchar[(xlen - ylen) + 10]; +#endif + + // q corresponds to w. + + // Set (uchar) x = (sc_digit) u. + xlen = vec_to_char(ulen, u, xlen, x); + + // Skip all the leading zeros in x. + while ((--xlen >= 0) && (! x[xlen])) + continue; + xlen++; + + // Set (uchar) y = (sc_digit) v. + ylen = vec_to_char(vlen, v, ylen, y); + + // Skip all the leading zeros in y. + while ((--ylen >= 0) && (! y[ylen])) + continue; + ylen++; + +#ifdef DEBUG_SYSTEMC + sc_assert(xlen > 1); + sc_assert(ylen > 1); +#endif + + // At this point, all the leading zeros are eliminated from x and y. + + // Zero the last digit of x. + x[xlen] = 0; + + // The first two digits of y. + sc_digit y2 = (y[ylen - 1] << BITS_PER_BYTE) + y[ylen - 2]; + + const sc_digit DOUBLE_BITS_PER_BYTE = 2 * BITS_PER_BYTE; + + // Find each q[k]. + for (int k = (xlen - ylen); k >= 0; --k) { + // qk is a guess for q[k] such that q[k] = qk or qk - 1. + sc_digit qk; + + // Find qk by just using 2 digits of y and 3 digits of x. The + // following code assumes that sizeof(sc_digit) >= 3 BYTEs. + int k2 = k + ylen; + + qk = ((x[k2] << DOUBLE_BITS_PER_BYTE) + + (x[k2 - 1] << BITS_PER_BYTE) + x[k2 - 2]) / y2; + + if (qk >= BYTE_RADIX) // qk cannot be larger than the largest + qk = BYTE_RADIX - 1; // digit in BYTE_RADIX. + + // q[k] = qk or qk - 1. The following if-statement determines which: + if (qk) { + uchar *xk = (x + k); // A shortcut for x[k]. + + // x = x - y * qk : + sc_digit carry = 0; + + for (int i = 0; i < ylen; ++i) { + carry += y[i] * qk; + sc_digit diff = (xk[i] + BYTE_RADIX) - (carry & BYTE_MASK); + xk[i] = (uchar)(diff & BYTE_MASK); + carry = (carry >> BITS_PER_BYTE) + + (1 - (diff >> BITS_PER_BYTE)); + } + + // If carry, qk may be one too large. + if (carry) { + // 2's complement the last digit. + carry = (xk[ylen] + BYTE_RADIX) - carry; + xk[ylen] = (uchar)(carry & BYTE_MASK); + carry = 1 - (carry >> BITS_PER_BYTE); + + if (carry) { + + // qk was one too large, so decrement it. + --qk; + + // Since qk was decreased by one, y must be added to x: + // x = x - y * (qk - 1) = x - y * qk + y = x_above + y. + carry = 0; + + for (int i = 0; i < ylen; ++i) { + carry += xk[i] + y[i]; + xk[i] = (uchar)(carry & BYTE_MASK); + carry >>= BITS_PER_BYTE; + } + + if (carry) + xk[ylen] = (uchar)((xk[ylen] + 1) & BYTE_MASK); + + } // second if carry + } // first if carry + } // if qk + q[k] = (uchar)qk; + } // for k + + // Set (sc_digit) w = (uchar) q. + vec_from_char(xlen - ylen + 1, q, ulen, w); + +#ifndef SC_MAX_NBITS + delete [] x; + delete [] y; + delete [] q; +#endif + +} + +// Compute w = u / v, where u and w are vectors, and v is a scalar. +// - 0 < v < HALF_DIGIT_RADIX. Below, we rename w to q. +void +vec_div_small(int ulen, const sc_digit *u, sc_digit v, sc_digit *q) +{ + // Given (u = u_1u_2...u_n)_b = (q = q_1q_2...q_n) * v + r, where b + // is the base, and 0 <= r < v. Then, the algorithm is as follows: + // + // r = 0; + // for (j = 1; j <= n; j++) { + // q_j = (r * b + u_j) / v; + // r = (r * b + u_j) % v; + // } + // + // In our case, b = DIGIT_RADIX, and u = Ax + B and q = Cx + D where + // x = HALF_DIGIT_RADIX. Note that r < v < x and b = x^2. Then, a + // typical situation is as follows: + // + // ---- ---- + // 0 r + // ---- ---- + // A B + // ---- ---- ---- + // r A B = r * b + u + // + // Hence, C = (r|A) / v. + // D = (((r|A) % v)|B) / v + // r = (((r|A) % v)|B) % v + +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert(q != NULL); + sc_assert((0 < v) && (v < HALF_DIGIT_RADIX)); +#endif + +#define q_h r + sc_digit r = 0; + const sc_digit *ubegin = u; + + u += ulen; + q += ulen; + + while (ubegin < u) { + sc_digit u_AB = (*--u); // A|B + +#ifdef DEBUG_SYSTEMC + // The overflow bits must be zero. + sc_assert(high_half(u_AB) == high_half_masked(u_AB)); +#endif + + sc_digit num = concat(r, high_half(u_AB)); // num = r|A + q_h = num / v; // C + num = concat((num % v), low_half(u_AB)); // num = (((r|A) % v)|B) + (*--q) = concat(q_h, num / v); // q = C|D + r = num % v; + } +#undef q_h +} + +// Compute w = u % v, where w, u, and v are vectors. +// - u and v are assumed to have at least two digits as uchars. +void +vec_rem_large(int ulen, const sc_digit *u, int vlen, const sc_digit *v, + sc_digit *w) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert((vlen > 0) && (v != NULL)); + sc_assert(w != NULL); + sc_assert(BITS_PER_DIGIT >= 3 * BITS_PER_BYTE); +#endif + + // This function is adapted from vec_div_large. + int xlen = BYTES_PER_DIGIT * ulen + 1; + int ylen = BYTES_PER_DIGIT * vlen; + +#ifdef SC_MAX_NBITS + uchar x[DIV_CEIL2(SC_MAX_NBITS, BITS_PER_BYTE)]; + uchar y[DIV_CEIL2(SC_MAX_NBITS, BITS_PER_BYTE)]; +#else + uchar *x = new uchar[xlen]; + uchar *y = new uchar[ylen]; +#endif + + // r corresponds to w. + + // Set (uchar) x = (sc_digit) u. + xlen = vec_to_char(ulen, u, xlen, x); + + // Skip all the leading zeros in x. + while ((--xlen >= 0) && (!x[xlen])) + continue; + xlen++; + + // Set (uchar) y = (sc_digit) v. + ylen = vec_to_char(vlen, v, ylen, y); + + // Skip all the leading zeros in y. + while ((--ylen >= 0) && (!y[ylen])) + continue; + ylen++; + +#ifdef DEBUG_SYSTEMC + sc_assert(xlen > 1); + sc_assert(ylen > 1); +#endif + + // At this point, all the leading zeros are eliminated from x and y. + + // Zero the last digit of x. + x[xlen] = 0; + + // The first two digits of y. + sc_digit y2 = (y[ylen - 1] << BITS_PER_BYTE) + y[ylen - 2]; + + const sc_digit DOUBLE_BITS_PER_BYTE = 2 * BITS_PER_BYTE; + + // Find each q[k]. + for (int k = xlen - ylen; k >= 0; --k) { + // qk is a guess for q[k] such that q[k] = qk or qk - 1. + sc_digit qk; + + // Find qk by just using 2 digits of y and 3 digits of x. The + // following code assumes that sizeof(sc_digit) >= 3 BYTEs. + int k2 = k + ylen; + + qk = ((x[k2] << DOUBLE_BITS_PER_BYTE) + + (x[k2 - 1] << BITS_PER_BYTE) + x[k2 - 2]) / y2; + + if (qk >= BYTE_RADIX) // qk cannot be larger than the largest + qk = BYTE_RADIX - 1; // digit in BYTE_RADIX. + + // q[k] = qk or qk - 1. The following if-statement determines which. + if (qk) { + uchar *xk = (x + k); // A shortcut for x[k]. + + // x = x - y * qk; + sc_digit carry = 0; + + for (int i = 0; i < ylen; ++i) { + carry += y[i] * qk; + sc_digit diff = (xk[i] + BYTE_RADIX) - (carry & BYTE_MASK); + xk[i] = (uchar)(diff & BYTE_MASK); + carry = (carry >> BITS_PER_BYTE) + + (1 - (diff >> BITS_PER_BYTE)); + } + + if (carry) { + // 2's complement the last digit. + carry = (xk[ylen] + BYTE_RADIX) - carry; + xk[ylen] = (uchar)(carry & BYTE_MASK); + carry = 1 - (carry >> BITS_PER_BYTE); + + if (carry) { + // qk was one too large, so decrement it. + // --qk; + + // x = x - y * (qk - 1) = x - y * qk + y = x_above + y. + carry = 0; + + for (int i = 0; i < ylen; ++i) { + carry += xk[i] + y[i]; + xk[i] = (uchar)(carry & BYTE_MASK); + carry >>= BITS_PER_BYTE; + } + + if (carry) + xk[ylen] = (uchar)((xk[ylen] + 1) & BYTE_MASK); + } // second if carry + } // first if carry + } // if qk + } // for k + + // Set (sc_digit) w = (uchar) x for the remainder. + vec_from_char(ylen, x, ulen, w); + +#ifndef SC_MAX_NBITS + delete [] x; + delete [] y; +#endif + +} + +// Compute r = u % v, where u is a vector, and r and v are scalars. +// - 0 < v < HALF_DIGIT_RADIX. +// - The remainder r is returned. +sc_digit +vec_rem_small(int ulen, const sc_digit *u, sc_digit v) +{ + +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert((0 < v) && (v < HALF_DIGIT_RADIX)); +#endif + + // This function is adapted from vec_div_small(). + + sc_digit r = 0; + const sc_digit *ubegin = u; + + u += ulen; + + while (ubegin < u) { + sc_digit u_AB = (*--u); // A|B +#ifdef DEBUG_SYSTEMC + // The overflow bits must be zero. + sc_assert(high_half(u_AB) == high_half_masked(u_AB)); +#endif + // r = (((r|A) % v)|B) % v + r = (concat(((concat(r, high_half(u_AB))) % v), low_half(u_AB))) % v; + } + + return r; +} + +// u = u / v, r = u % v. +sc_digit +vec_rem_on_small(int ulen, sc_digit *u, sc_digit v) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert(v > 0); +#endif + +#define q_h r + sc_digit r = 0; + const sc_digit *ubegin = u; + + u += ulen; + while (ubegin < u) { + sc_digit u_AB = (*--u); // A|B +#ifdef DEBUG_SYSTEMC + // The overflow bits must be zero. + sc_assert(high_half(u_AB) == high_half_masked(u_AB)); +#endif + sc_digit num = concat(r, high_half(u_AB)); // num = r|A + q_h = num / v; // C + num = concat((num % v), low_half(u_AB)); // num = (((r|A) % v)|B) + (*u) = concat(q_h, num / v); // q = C|D + r = num % v; + } +#undef q_h + return r; +} + +// Set (uchar) v = (sc_digit) u. Return the new vlen. +int +vec_to_char(int ulen, const sc_digit *u, int vlen, uchar *v) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert((vlen > 0) && (v != NULL)); +#endif + + int nbits = ulen * BITS_PER_DIGIT; + int right = 0; + int left = right + BITS_PER_BYTE - 1; + + vlen = 0; + while (nbits > 0) { + int left_digit = left / BITS_PER_DIGIT; + int right_digit = right / BITS_PER_DIGIT; + int nsr = ((vlen << LOG2_BITS_PER_BYTE) % BITS_PER_DIGIT); + int d = u[right_digit] >> nsr; + + if (left_digit != right_digit) { + if (left_digit < ulen) + d |= u[left_digit] << (BITS_PER_DIGIT - nsr); + } + + v[vlen++] = (uchar)(d & BYTE_MASK); + + left += BITS_PER_BYTE; + right += BITS_PER_BYTE; + nbits -= BITS_PER_BYTE; + } + return vlen; +} + +// Set (sc_digit) v = (uchar) u. +// - sizeof(uchar) <= sizeof(sc_digit), +void +vec_from_char(int ulen, const uchar *u, int vlen, sc_digit *v) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); + sc_assert((vlen > 0) && (v != NULL)); + sc_assert(sizeof(uchar) <= sizeof(sc_digit)); +#endif + + sc_digit *vend = (v + vlen); + + const int nsr = BITS_PER_DIGIT - BITS_PER_BYTE; + const sc_digit mask = one_and_ones(nsr); + + (*v) = (sc_digit) u[ulen - 1]; + + for (int i = ulen - 2; i >= 0; --i) { + // Manual inlining of vec_shift_left(). + sc_digit *viter = v; + sc_digit carry = 0; + while (viter < vend) { + sc_digit vval = (*viter); + (*viter++) = (((vval & mask) << BITS_PER_BYTE) | carry); + carry = vval >> nsr; + } + + if (viter < vend) + (*viter) = carry; + + (*v) |= (sc_digit)u[i]; + } +} + +// Set u <<= nsl. +// If nsl is negative, it is ignored. +void +vec_shift_left(int ulen, sc_digit *u, int nsl) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); +#endif + + if (nsl <= 0) + return; + + // Shift left whole digits if nsl is large enough. + if (nsl >= (int) BITS_PER_DIGIT) { + int nd; + if (nsl % BITS_PER_DIGIT == 0) { + nd = nsl / BITS_PER_DIGIT; // No need to use DIV_CEIL(nsl). + nsl = 0; + } else { + nd = DIV_CEIL(nsl) - 1; + nsl -= nd * BITS_PER_DIGIT; + } + + if (nd) { + // Shift left for nd digits. + for (int j = ulen - 1; j >= nd; --j) + u[j] = u[j - nd]; + + vec_zero(sc_min(nd, ulen), u); + } + if (nsl == 0) + return; + } + + // Shift left if nsl < BITS_PER_DIGIT. + sc_digit *uiter = u; + sc_digit *uend = uiter + ulen; + + int nsr = BITS_PER_DIGIT - nsl; + sc_digit mask = one_and_ones(nsr); + + sc_digit carry = 0; + + while (uiter < uend) { + sc_digit uval = (*uiter); + (*uiter++) = (((uval & mask) << nsl) | carry); + carry = uval >> nsr; + } + + if (uiter < uend) + (*uiter) = carry; +} + +// Set u >>= nsr. +// If nsr is negative, it is ignored. +void +vec_shift_right(int ulen, sc_digit *u, int nsr, sc_digit fill) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((ulen > 0) && (u != NULL)); +#endif + + // fill is usually either 0 or DIGIT_MASK; it can be any value. + if (nsr <= 0) + return; + + // Shift right whole digits if nsr is large enough. + if (nsr >= (int) BITS_PER_DIGIT) { + int nd; + if (nsr % BITS_PER_DIGIT == 0) { + nd = nsr / BITS_PER_DIGIT; + nsr = 0; + } else { + nd = DIV_CEIL(nsr) - 1; + nsr -= nd * BITS_PER_DIGIT; + } + + if (nd) { + // Shift right for nd digits. + for (int j = 0; j < (ulen - nd); ++j) + u[j] = u[j + nd]; + + if (fill) { + for (int j = ulen - sc_min( nd, ulen ); j < ulen; ++j) + u[j] = fill; + } else { + vec_zero(ulen - sc_min( nd, ulen ), ulen, u); + } + } + if (nsr == 0) + return; + } + + // Shift right if nsr < BITS_PER_DIGIT. + sc_digit *ubegin = u; + sc_digit *uiter = (ubegin + ulen); + + int nsl = BITS_PER_DIGIT - nsr; + sc_digit mask = one_and_ones(nsr); + + sc_digit carry = (fill & mask) << nsl; + + while (ubegin < uiter) { + sc_digit uval = (*--uiter); + (*uiter) = (uval >> nsr) | carry; + carry = (uval & mask) << nsl; + } +} + + +// Let u[l..r], where l and r are left and right bit positions +// respectively, be equal to its mirror image. +void +vec_reverse(int unb, int und, sc_digit *ud, int l, int r) +{ +#ifdef DEBUG_SYSTEMC + sc_assert((unb > 0) && (und > 0) && (ud != NULL)); + sc_assert((0 <= r) && (r <= l) && (l < unb)); +#endif + + if (l < r) { + std::stringstream msg; + msg << "vec_reverse( int, int, sc_digit*, int l, int r ) : " << + "l = " << l << " < r = " << r << " is not valid", + SC_REPORT_ERROR("conversion failed", msg.str().c_str()); + return; + } + + // Make sure that l and r are within bounds. + r = sc_max(r, 0); + l = sc_min(l, unb - 1); + + // Allocate memory for processing. +#ifdef SC_MAX_NBITS + sc_digit d[MAX_NDIGITS]; +#else + sc_digit *d = new sc_digit[und]; +#endif + + // d is a copy of ud. + vec_copy(und, d, ud); + + // Based on the value of the ith in d, find the value of the jth bit + // in ud. + for (int i = l, j = r; i >= r; --i, ++j) { + if ((d[digit_ord(i)] & one_and_zeros(bit_ord(i))) != 0) // Test. + ud[digit_ord(j)] |= one_and_zeros(bit_ord(j)); // Set. + else + ud[digit_ord(j)] &= ~(one_and_zeros(bit_ord(j))); // Clear. + } + +#ifndef SC_MAX_NBITS + delete [] d; +#endif +} + +#ifdef SC_MAX_NBITS +void test_bound_failed(int nb) +{ + std::stringstream msg; + msg << "test_bound( int nb ) : " + "nb = " << nb << " > SC_MAX_NBITS = " << SC_MAX_NBITS << + " is not valid"; + SC_REPORT_ERROR(sc_core::SC_ID_OUT_OF_BOUNDS_, msg.str().c_str()); +} +#endif // SC_MAX_NBITS + +} // namespace sc_dt |