Change implicit conversions from bool to Sig* to explicit.

[yosys.git] / kernel / calc.cc

diff --git a/kernel/calc.cc b/kernel/calc.cc
index 32c06c189d4bdb84798663db62c0ce21fe6fd719..1e6410f7dbf0e90de971b99523f363da04c740bc 100644 (file)
--- a/kernel/calc.cc
+++ b/kernel/calc.cc
@@ -1,7 +1,7 @@
 /*
  *  yosys -- Yosys Open SYnthesis Suite
  *
- *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *  Copyright (C) 2012  Claire Xenia Wolf <claire@yosyshq.com>
  *
  *  Permission to use, copy, modify, and/or distribute this software for any
  *  purpose with or without fee is hereby granted, provided that the above
@@ -154,7 +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);
@@ -275,10 +275,15 @@ RTLIL::Const RTLIL::const_logic_or(const RTLIL::Const &arg1, const RTLIL::Const
        return result;
 }
 
-static RTLIL::Const const_shift_worker(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool sign_ext, int direction, int result_len)
+// Shift `arg1` by `arg2` bits.
+// If `direction` is +1, `arg1` is shifted right by `arg2` bits; if `direction` is -1, `arg1` is shifted left by `arg2` bits.
+// If `signed2` is true, `arg2` is interpreted as a signed integer; a negative `arg2` will cause a shift in the opposite direction.
+// Any required bits outside the bounds of `arg1` are padded with `vacant_bits` unless `sign_ext` is true, in which case any bits outside the left
+// bounds are filled with the leftmost bit of `arg1` (arithmetic shift).
+static RTLIL::Const const_shift_worker(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool sign_ext, bool signed2, int direction, int result_len, RTLIL::State vacant_bits = RTLIL::State::S0)
 {
        int undef_bit_pos = -1;
-       BigInteger offset = const2big(arg2, false, undef_bit_pos) * direction;
+       BigInteger offset = const2big(arg2, signed2, undef_bit_pos) * direction;
 
        if (result_len < 0)
                result_len = arg1.bits.size();
@@ -290,9 +295,9 @@ static RTLIL::Const const_shift_worker(const RTLIL::Const &arg1, const RTLIL::Co
        for (int i = 0; i < result_len; i++) {
                BigInteger pos = BigInteger(i) + offset;
                if (pos < 0)
-                       result.bits[i] = RTLIL::State::S0;
-               else if (pos >= arg1.bits.size())
-                       result.bits[i] = sign_ext ? arg1.bits.back() : RTLIL::State::S0;
+                       result.bits[i] = vacant_bits;
+               else if (pos >= BigInteger(int(arg1.bits.size())))
+                       result.bits[i] = sign_ext ? arg1.bits.back() : vacant_bits;
                else
                        result.bits[i] = arg1.bits[pos.toInt()];
        }
@@ -304,61 +309,36 @@ RTLIL::Const RTLIL::const_shl(const RTLIL::Const &arg1, const RTLIL::Const &arg2
 {
        RTLIL::Const arg1_ext = arg1;
        extend_u0(arg1_ext, result_len, signed1);
-       return const_shift_worker(arg1_ext, arg2, false, -1, result_len);
+       return const_shift_worker(arg1_ext, arg2, false, 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_u0(arg1_ext, std::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_worker(arg1, arg2, true, -1, result_len);
+       extend_u0(arg1_ext, max(result_len, GetSize(arg1)), signed1);
+       return const_shift_worker(arg1_ext, arg2, false, false, +1, result_len);
 }
 
-RTLIL::Const RTLIL::const_sshr(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
+RTLIL::Const RTLIL::const_sshl(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool, int result_len)
 {
-       if (!signed1)
-               return const_shr(arg1, arg2, signed1, signed2, result_len);
-       return const_shift_worker(arg1, arg2, true, +1, result_len);
+       return const_shift_worker(arg1, arg2, signed1, false, -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)
+RTLIL::Const RTLIL::const_sshr(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool, int result_len)
 {
-       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 >= arg1.bits.size())
-                       result.bits[i] = other_bits;
-               else
-                       result.bits[i] = arg1.bits[pos.toInt()];
-       }
-
-       return result;
+       return const_shift_worker(arg1, arg2, signed1, false, +1, result_len);
 }
 
 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 arg1_ext = arg1;
+       extend_u0(arg1_ext, max(result_len, GetSize(arg1)), signed1);
+       return const_shift_worker(arg1_ext, arg2, false, signed2, +1, result_len);
 }
 
-RTLIL::Const RTLIL::const_shiftx(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
+RTLIL::Const RTLIL::const_shiftx(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool, bool signed2, int result_len)
 {
-       return const_shift_shiftx(arg1, arg2, signed1, signed2, result_len, RTLIL::State::Sx);
+       return const_shift_worker(arg1, arg2, false, signed2, +1, 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)
@@ -389,7 +369,7 @@ 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);
 
@@ -423,7 +403,7 @@ 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);
 
@@ -472,23 +452,24 @@ 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));
 }
 
+// truncating division
 RTLIL::Const RTLIL::const_div(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
 {
        int undef_bit_pos = -1;
@@ -499,9 +480,10 @@ 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));
 }
 
+// truncating modulo
 RTLIL::Const RTLIL::const_mod(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
 {
        int undef_bit_pos = -1;
@@ -512,7 +494,52 @@ 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_divfloor(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
+{
+       int undef_bit_pos = -1;
+       BigInteger a = const2big(arg1, signed1, undef_bit_pos);
+       BigInteger b = const2big(arg2, signed2, undef_bit_pos);
+       if (b.isZero())
+               return RTLIL::Const(RTLIL::State::Sx, result_len);
+
+       bool result_pos = (a.getSign() == BigInteger::negative) == (b.getSign() == BigInteger::negative);
+       a = a.getSign() == BigInteger::negative ? -a : a;
+       b = b.getSign() == BigInteger::negative ? -b : b;
+       BigInteger result;
+
+       if (result_pos || a == 0) {
+               result = a / b;
+       } else {
+               // bigint division with negative numbers is wonky, make sure we only negate at the very end
+               result = -((a + b - 1) / b);
+       }
+       return big2const(result, result_len >= 0 ? result_len : max(arg1.bits.size(), arg2.bits.size()), min(undef_bit_pos, 0));
+}
+
+RTLIL::Const RTLIL::const_modfloor(const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len)
+{
+       int undef_bit_pos = -1;
+       BigInteger a = const2big(arg1, signed1, undef_bit_pos);
+       BigInteger b = const2big(arg2, signed2, undef_bit_pos);
+       if (b.isZero())
+               return RTLIL::Const(RTLIL::State::Sx, result_len);
+
+       BigInteger::Sign a_sign = a.getSign();
+       BigInteger::Sign b_sign = b.getSign();
+       a = a_sign == BigInteger::negative ? -a : a;
+       b = b_sign == BigInteger::negative ? -b : b;
+       BigInteger truncated = a_sign == BigInteger::negative ? -(a % b) : (a % b);
+       BigInteger modulo;
+
+       if (truncated == 0 || (a_sign == b_sign)) {
+               modulo = truncated;
+       } else {
+               modulo = b_sign == BigInteger::negative ? truncated - b : truncated + b;
+       }
+       return big2const(modulo, 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)
@@ -563,7 +590,7 @@ 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)