* yosys -- Yosys Open SYnthesis Suite
*
* Copyright (C) 2012 Clifford Wolf <clifford@clifford.at>
- *
+ *
* Permission to use, copy, modify, and/or distribute this software for any
* purpose with or without fee is hereby granted, provided that the above
* copyright notice and this permission notice appear in all copies.
- *
+ *
* THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
* WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
* MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
*
*/
-#include "kernel/log.h"
-#include "kernel/rtlil.h"
+// [[CITE]] Power-Modulus Algorithm
+// Schneier, Bruce (1996). Applied Cryptography: Protocols, Algorithms, and Source Code in C,
+// Second Edition (2nd ed.). Wiley. ISBN 978-0-471-11709-4, page 244
+
+#include "kernel/yosys.h"
#include "libs/bigint/BigIntegerLibrary.hh"
-#include <assert.h>
-static void extend(RTLIL::Const &arg, int width, bool is_signed)
+YOSYS_NAMESPACE_BEGIN
+
+static void extend_u0(RTLIL::Const &arg, int width, bool is_signed)
{
RTLIL::State padding = RTLIL::State::S0;
- if (arg.bits.size() > 0 && (is_signed || arg.bits.back() > RTLIL::State::S1))
+ if (arg.bits.size() > 0 && is_signed)
padding = arg.bits.back();
while (int(arg.bits.size()) < width)
arg.bits.push_back(padding);
+
+ arg.bits.resize(width);
}
static BigInteger const2big(const RTLIL::Const &val, bool as_signed, int &undef_bit_pos)
{
- BigInteger result = 0, this_bit = 1;
- for (size_t i = 0; i < val.bits.size(); i++) {
- if (val.bits[i] == RTLIL::State::S1) {
- if (as_signed && i+1 == val.bits.size())
- result -= this_bit;
- else
- result += this_bit;
- }
- else if (val.bits[i] != RTLIL::State::S0) {
- if (undef_bit_pos < 0)
- undef_bit_pos = i;
- }
- this_bit *= 2;
+ BigUnsigned mag;
+
+ BigInteger::Sign sign = BigInteger::positive;
+ State inv_sign_bit = RTLIL::State::S1;
+ size_t num_bits = val.bits.size();
+
+ if (as_signed && num_bits && val.bits[num_bits-1] == RTLIL::State::S1) {
+ inv_sign_bit = RTLIL::State::S0;
+ sign = BigInteger::negative;
+ num_bits--;
}
- return result;
+
+ for (size_t i = 0; i < num_bits; i++)
+ if (val.bits[i] == RTLIL::State::S0 || val.bits[i] == RTLIL::State::S1)
+ mag.setBit(i, val.bits[i] == inv_sign_bit);
+ else if (undef_bit_pos < 0)
+ undef_bit_pos = i;
+
+ if (sign == BigInteger::negative)
+ mag += 1;
+
+ return BigInteger(mag, sign);
}
static RTLIL::Const big2const(const BigInteger &val, int result_len, int undef_bit_pos)
{
+ if (undef_bit_pos >= 0)
+ return RTLIL::Const(RTLIL::State::Sx, result_len);
+
BigUnsigned mag = val.getMagnitude();
RTLIL::Const result(0, result_len);
}
}
+#if 0
if (undef_bit_pos >= 0)
for (int i = undef_bit_pos; i < result_len; i++)
result.bits[i] = RTLIL::State::Sx;
+#endif
return result;
}
result_len = arg1.bits.size();
RTLIL::Const arg1_ext = arg1;
- extend(arg1_ext, result_len, signed1);
+ extend_u0(arg1_ext, result_len, signed1);
RTLIL::Const result(RTLIL::State::Sx, result_len);
for (size_t i = 0; i < size_t(result_len); i++) {
RTLIL::Const arg1, RTLIL::Const arg2, bool signed1, bool signed2, int result_len = -1)
{
if (result_len < 0)
- result_len = std::max(arg1.bits.size(), arg2.bits.size());
+ result_len = max(arg1.bits.size(), arg2.bits.size());
- extend(arg1, result_len, signed1);
- extend(arg2, result_len, signed2);
+ extend_u0(arg1, result_len, signed1);
+ extend_u0(arg2, result_len, signed2);
RTLIL::Const result(RTLIL::State::Sx, result_len);
for (size_t i = 0; i < size_t(result_len); i++) {
return result;
}
-static RTLIL::Const const_shift(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool sign_ext, int direction, int result_len)
+static RTLIL::Const const_shift_worker(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool sign_ext, int direction, int result_len)
{
int undef_bit_pos = -1;
BigInteger offset = const2big(arg2, false, undef_bit_pos) * direction;
BigInteger pos = BigInteger(i) + offset;
if (pos < 0)
result.bits[i] = RTLIL::State::S0;
- else if (pos >= arg1.bits.size())
+ else if (pos >= BigInteger(int(arg1.bits.size())))
result.bits[i] = sign_ext ? arg1.bits.back() : RTLIL::State::S0;
else
result.bits[i] = arg1.bits[pos.toInt()];
RTLIL::Const RTLIL::const_shl(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool, int result_len)
{
RTLIL::Const arg1_ext = arg1;
- extend(arg1_ext, result_len, signed1);
- return const_shift(arg1_ext, arg2, false, -1, result_len);
+ extend_u0(arg1_ext, result_len, signed1);
+ return const_shift_worker(arg1_ext, arg2, false, -1, result_len);
}
RTLIL::Const RTLIL::const_shr(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool, int result_len)
{
RTLIL::Const arg1_ext = arg1;
- extend(arg1_ext, result_len, signed1);
- return const_shift(arg1_ext, arg2, false, +1, result_len);
+ extend_u0(arg1_ext, max(result_len, GetSize(arg1)), signed1);
+ return const_shift_worker(arg1_ext, arg2, false, +1, result_len);
}
RTLIL::Const RTLIL::const_sshl(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
{
if (!signed1)
return const_shl(arg1, arg2, signed1, signed2, result_len);
- return const_shift(arg1, arg2, true, -1, result_len);
+ return const_shift_worker(arg1, arg2, true, -1, result_len);
}
RTLIL::Const RTLIL::const_sshr(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
{
if (!signed1)
return const_shr(arg1, arg2, signed1, signed2, result_len);
- return const_shift(arg1, arg2, true, +1, result_len);
+ return const_shift_worker(arg1, arg2, true, +1, result_len);
+}
+
+static RTLIL::Const const_shift_shiftx(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool, bool signed2, int result_len, RTLIL::State other_bits)
+{
+ int undef_bit_pos = -1;
+ BigInteger offset = const2big(arg2, signed2, undef_bit_pos);
+
+ if (result_len < 0)
+ result_len = arg1.bits.size();
+
+ RTLIL::Const result(RTLIL::State::Sx, result_len);
+ if (undef_bit_pos >= 0)
+ return result;
+
+ for (int i = 0; i < result_len; i++) {
+ BigInteger pos = BigInteger(i) + offset;
+ if (pos < 0 || pos >= BigInteger(int(arg1.bits.size())))
+ result.bits[i] = other_bits;
+ else
+ result.bits[i] = arg1.bits[pos.toInt()];
+ }
+
+ return result;
+}
+
+RTLIL::Const RTLIL::const_shift(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
+{
+ return const_shift_shiftx(arg1, arg2, signed1, signed2, result_len, RTLIL::State::S0);
+}
+
+RTLIL::Const RTLIL::const_shiftx(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
+{
+ return const_shift_shiftx(arg1, arg2, signed1, signed2, result_len, RTLIL::State::Sx);
}
RTLIL::Const RTLIL::const_lt(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
RTLIL::Const arg2_ext = arg2;
RTLIL::Const result(RTLIL::State::S0, result_len);
- while (arg1_ext.bits.size() < arg2_ext.bits.size())
- arg1_ext.bits.push_back(signed1 && signed2 && arg1_ext.bits.size() > 0 ? arg1_ext.bits.back() : RTLIL::State::S0);
-
- while (arg2_ext.bits.size() < arg1_ext.bits.size())
- arg2_ext.bits.push_back(signed1 && signed2 && arg2_ext.bits.size() > 0 ? arg2_ext.bits.back() : RTLIL::State::S0);
+ int width = max(arg1_ext.bits.size(), arg2_ext.bits.size());
+ extend_u0(arg1_ext, width, signed1 && signed2);
+ extend_u0(arg2_ext, width, signed1 && signed2);
RTLIL::State matched_status = RTLIL::State::S1;
for (size_t i = 0; i < arg1_ext.bits.size(); i++) {
return result;
}
+RTLIL::Const RTLIL::const_eqx(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
+{
+ RTLIL::Const arg1_ext = arg1;
+ RTLIL::Const arg2_ext = arg2;
+ RTLIL::Const result(RTLIL::State::S0, result_len);
+
+ int width = max(arg1_ext.bits.size(), arg2_ext.bits.size());
+ extend_u0(arg1_ext, width, signed1 && signed2);
+ extend_u0(arg2_ext, width, signed1 && signed2);
+
+ for (size_t i = 0; i < arg1_ext.bits.size(); i++) {
+ if (arg1_ext.bits.at(i) != arg2_ext.bits.at(i))
+ return result;
+ }
+
+ result.bits.front() = RTLIL::State::S1;
+ return result;
+}
+
+RTLIL::Const RTLIL::const_nex(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
+{
+ RTLIL::Const result = RTLIL::const_eqx(arg1, arg2, signed1, signed2, result_len);
+ if (result.bits.front() == RTLIL::State::S0)
+ result.bits.front() = RTLIL::State::S1;
+ else if (result.bits.front() == RTLIL::State::S1)
+ result.bits.front() = RTLIL::State::S0;
+ return result;
+}
+
RTLIL::Const RTLIL::const_ge(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
{
int undef_bit_pos = -1;
{
int undef_bit_pos = -1;
BigInteger y = const2big(arg1, signed1, undef_bit_pos) + const2big(arg2, signed2, undef_bit_pos);
- return big2const(y, result_len >= 0 ? result_len : std::max(arg1.bits.size(), arg2.bits.size()), undef_bit_pos);
+ return big2const(y, result_len >= 0 ? result_len : max(arg1.bits.size(), arg2.bits.size()), undef_bit_pos);
}
RTLIL::Const RTLIL::const_sub(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
{
int undef_bit_pos = -1;
BigInteger y = const2big(arg1, signed1, undef_bit_pos) - const2big(arg2, signed2, undef_bit_pos);
- return big2const(y, result_len >= 0 ? result_len : std::max(arg1.bits.size(), arg2.bits.size()), undef_bit_pos);
+ return big2const(y, result_len >= 0 ? result_len : max(arg1.bits.size(), arg2.bits.size()), undef_bit_pos);
}
RTLIL::Const RTLIL::const_mul(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
{
int undef_bit_pos = -1;
BigInteger y = const2big(arg1, signed1, undef_bit_pos) * const2big(arg2, signed2, undef_bit_pos);
- return big2const(y, result_len >= 0 ? result_len : std::max(arg1.bits.size(), arg2.bits.size()), std::min(undef_bit_pos, 0));
+ return big2const(y, result_len >= 0 ? result_len : max(arg1.bits.size(), arg2.bits.size()), min(undef_bit_pos, 0));
}
RTLIL::Const RTLIL::const_div(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
bool result_neg = (a.getSign() == BigInteger::negative) != (b.getSign() == BigInteger::negative);
a = a.getSign() == BigInteger::negative ? -a : a;
b = b.getSign() == BigInteger::negative ? -b : b;
- return big2const(result_neg ? -(a / b) : (a / b), result_len >= 0 ? result_len : std::max(arg1.bits.size(), arg2.bits.size()), std::min(undef_bit_pos, 0));
+ return big2const(result_neg ? -(a / b) : (a / b), result_len >= 0 ? result_len : max(arg1.bits.size(), arg2.bits.size()), min(undef_bit_pos, 0));
}
RTLIL::Const RTLIL::const_mod(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
bool result_neg = a.getSign() == BigInteger::negative;
a = a.getSign() == BigInteger::negative ? -a : a;
b = b.getSign() == BigInteger::negative ? -b : b;
- return big2const(result_neg ? -(a % b) : (a % b), result_len >= 0 ? result_len : std::max(arg1.bits.size(), arg2.bits.size()), std::min(undef_bit_pos, 0));
+ return big2const(result_neg ? -(a % b) : (a % b), result_len >= 0 ? result_len : max(arg1.bits.size(), arg2.bits.size()), min(undef_bit_pos, 0));
}
RTLIL::Const RTLIL::const_pow(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
BigInteger b = const2big(arg2, signed2, undef_bit_pos);
BigInteger y = 1;
- if (b < 0 || a == 0) {
- y = 0;
- } else {
+ if (a == 0 && b < 0)
+ return RTLIL::Const(RTLIL::State::Sx, result_len);
+
+ if (a == 0 && b > 0)
+ return RTLIL::Const(RTLIL::State::S0, result_len);
+
+ if (b < 0)
+ {
+ if (a < -1 || a > 1)
+ y = 0;
+ if (a == -1)
+ y = (-b % 2) == 0 ? 1 : -1;
+ }
+
+ if (b > 0)
+ {
+ // Power-modulo with 2^result_len as modulus
+ BigInteger modulus = 1;
+ int modulus_bits = (result_len >= 0 ? result_len : 1024);
+ for (int i = 0; i < modulus_bits; i++)
+ modulus *= 2;
+
+ bool flip_result_sign = false;
+ if (a < 0) {
+ a *= -1;
+ if (b % 2 == 1)
+ flip_result_sign = true;
+ }
+
while (b > 0) {
- y = y * a;
- if (y.getLength() > 0x10000) {
- undef_bit_pos = 0;
- break;
- }
- b--;
+ if (b % 2 == 1)
+ y = (y * a) % modulus;
+ b = b / 2;
+ a = (a * a) % modulus;
}
+
+ if (flip_result_sign)
+ y *= -1;
}
- return big2const(y, result_len >= 0 ? result_len : std::max(arg1.bits.size(), arg2.bits.size()), std::min(undef_bit_pos, 0));
+ return big2const(y, result_len >= 0 ? result_len : max(arg1.bits.size(), arg2.bits.size()), min(undef_bit_pos, 0));
}
RTLIL::Const RTLIL::const_pos(const RTLIL::Const &arg1, const RTLIL::Const&, bool signed1, bool, int result_len)
{
RTLIL::Const arg1_ext = arg1;
- extend(arg1_ext, result_len, signed1);
+ extend_u0(arg1_ext, result_len, signed1);
return arg1_ext;
}
RTLIL::Const RTLIL::const_neg(const RTLIL::Const &arg1, const RTLIL::Const&, bool signed1, bool, int result_len)
{
RTLIL::Const arg1_ext = arg1;
- extend(arg1_ext, result_len, signed1);
-
RTLIL::Const zero(RTLIL::State::S0, 1);
- return RTLIL::const_sub(zero, arg1_ext, false, signed1, result_len);
+
+ return RTLIL::const_sub(zero, arg1_ext, true, signed1, result_len);
}
+YOSYS_NAMESPACE_END
+