1 files changed, 33 insertions, 26 deletions

diff --git a/kernel/calc.cc b/kernel/calc.cc
index aa3e8b919..a24fa2abf 100644
--- a/kernel/calc.cc
+++ b/kernel/calc.cc
@@ -2,11 +2,11 @@
  *  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
@@ -41,21 +41,28 @@ static void extend_u0(RTLIL::Const &arg, int width, bool is_signed)
 
 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)
@@ -147,7 +154,7 @@ static RTLIL::Const logic_wrapper(RTLIL::State(*logic_func)(RTLIL::State, RTLIL:
 		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_u0(arg1, result_len, signed1);
 	extend_u0(arg2, result_len, signed2);
@@ -303,7 +310,7 @@ RTLIL::Const RTLIL::const_shl(const RTLIL::Const &arg1, const RTLIL::Const &arg2
 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_u0(arg1_ext, std::max(result_len, GetSize(arg1)), signed1);
+	extend_u0(arg1_ext, max(result_len, GetSize(arg1)), signed1);
 	return const_shift_worker(arg1_ext, arg2, false, +1, result_len);
 }
 
@@ -382,7 +389,7 @@ RTLIL::Const RTLIL::const_eq(const RTLIL::Const &arg1, const RTLIL::Const &arg2,
 	RTLIL::Const arg2_ext = arg2;
 	RTLIL::Const result(RTLIL::State::S0, result_len);
 
-	int width = std::max(arg1_ext.bits.size(), arg2_ext.bits.size());
+	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);
 
@@ -416,7 +423,7 @@ RTLIL::Const RTLIL::const_eqx(const RTLIL::Const &arg1, const RTLIL::Const &arg2
 	RTLIL::Const arg2_ext = arg2;
 	RTLIL::Const result(RTLIL::State::S0, result_len);
 
-	int width = std::max(arg1_ext.bits.size(), arg2_ext.bits.size());
+	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);
 
@@ -465,21 +472,21 @@ RTLIL::Const RTLIL::const_add(const RTLIL::Const &arg1, const RTLIL::Const &arg2
 {
 	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)
@@ -492,7 +499,7 @@ RTLIL::Const RTLIL::const_div(const RTLIL::Const &arg1, const RTLIL::Const &arg2
 	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)
@@ -505,7 +512,7 @@ RTLIL::Const RTLIL::const_mod(const RTLIL::Const &arg1, const RTLIL::Const &arg2
 	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)
@@ -556,7 +563,7 @@ RTLIL::Const RTLIL::const_pow(const RTLIL::Const &arg1, const RTLIL::Const &arg2
 			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)