aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
Diffstat
-rw-r--r--CHANGELOG1
-rw-r--r--backends/btor/btor.cc14
-rw-r--r--backends/btor/test_cells.sh2
-rw-r--r--backends/firrtl/firrtl.cc1
-rw-r--r--backends/smt2/smt2.cc10
-rw-r--r--backends/smv/smv.cc5
-rw-r--r--backends/smv/test_cells.sh4
-rw-r--r--backends/verilog/verilog_backend.cc89
-rw-r--r--kernel/calc.cc47
-rw-r--r--kernel/celledges.cc2
-rw-r--r--kernel/celltypes.h4
-rw-r--r--kernel/rtlil.cc4
-rw-r--r--kernel/rtlil.h10
-rw-r--r--kernel/satgen.h42
-rw-r--r--manual/CHAPTER_CellLib.tex23
-rw-r--r--manual/PRESENTATION_Prog.tex2
-rw-r--r--passes/cmds/stat.cc2
-rw-r--r--passes/memory/memory_share.cc2
-rw-r--r--passes/opt/opt_expr.cc58
-rw-r--r--passes/opt/opt_share.cc4
-rw-r--r--passes/opt/share.cc6
-rw-r--r--passes/opt/wreduce.cc4
-rw-r--r--passes/tests/test_cell.cc4
-rw-r--r--techlibs/common/simlib.v91
-rw-r--r--techlibs/common/techmap.v107
-rw-r--r--tests/simple/constmuldivmod.v42
26 files changed, 540 insertions, 40 deletions
diff --git a/CHANGELOG b/CHANGELOG
index 3b36c3182..638ce558b 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -66,6 +66,7 @@ Yosys 0.9 .. Yosys 0.9-dev
- Added "design -delete"
- Added "select -unset"
- Use YosysHQ/abc instead of upstream berkeley-abc/abc
+ - Added $divfloor and $modfloor cells
Yosys 0.8 .. Yosys 0.9
----------------------
diff --git a/backends/btor/btor.cc b/backends/btor/btor.cc
index 14c8484e8..2816d3246 100644
--- a/backends/btor/btor.cc
+++ b/backends/btor/btor.cc
@@ -266,20 +266,26 @@ struct BtorWorker
goto okay;
}
- if (cell->type.in(ID($div), ID($mod)))
+ if (cell->type.in(ID($div), ID($mod), ID($modfloor)))
{
+ bool a_signed = cell->hasParam(ID::A_SIGNED) ? cell->getParam(ID::A_SIGNED).as_bool() : false;
+ bool b_signed = cell->hasParam(ID::B_SIGNED) ? cell->getParam(ID::B_SIGNED).as_bool() : false;
+
string btor_op;
if (cell->type == ID($div)) btor_op = "div";
+ // "rem" = truncating modulo
if (cell->type == ID($mod)) btor_op = "rem";
+ // "mod" = flooring modulo
+ if (cell->type == ID($modfloor)) {
+ // "umod" doesn't exist because it's the same as "urem"
+ btor_op = a_signed || b_signed ? "mod" : "rem";
+ }
log_assert(!btor_op.empty());
int width = GetSize(cell->getPort(ID::Y));
width = std::max(width, GetSize(cell->getPort(ID::A)));
width = std::max(width, GetSize(cell->getPort(ID::B)));
- bool a_signed = cell->hasParam(ID::A_SIGNED) ? cell->getParam(ID::A_SIGNED).as_bool() : false;
- bool b_signed = cell->hasParam(ID::B_SIGNED) ? cell->getParam(ID::B_SIGNED).as_bool() : false;
-
int nid_a = get_sig_nid(cell->getPort(ID::A), width, a_signed);
int nid_b = get_sig_nid(cell->getPort(ID::B), width, b_signed);
diff --git a/backends/btor/test_cells.sh b/backends/btor/test_cells.sh
index e0f1a0514..3f077201a 100644
--- a/backends/btor/test_cells.sh
+++ b/backends/btor/test_cells.sh
@@ -6,7 +6,7 @@ rm -rf test_cells.tmp
mkdir -p test_cells.tmp
cd test_cells.tmp
-../../../yosys -p 'test_cell -n 5 -w test all /$alu /$fa /$lcu /$lut /$sop /$macc /$mul /$div /$mod'
+../../../yosys -p 'test_cell -n 5 -w test all /$alu /$fa /$lcu /$lut /$sop /$macc /$mul /$div /$mod /$divfloor /$modfloor'
for fn in test_*.il; do
../../../yosys -p "
diff --git a/backends/firrtl/firrtl.cc b/backends/firrtl/firrtl.cc
index a90b0b87a..b1d8500bb 100644
--- a/backends/firrtl/firrtl.cc
+++ b/backends/firrtl/firrtl.cc
@@ -585,6 +585,7 @@ struct FirrtlWorker
firrtl_is_signed = a_signed | b_signed;
firrtl_width = a_width;
} else if (cell->type == ID($mod)) {
+ // "rem" = truncating modulo
primop = "rem";
firrtl_width = min(a_width, b_width);
} else if (cell->type.in(ID($and), ID($_AND_))) {
diff --git a/backends/smt2/smt2.cc b/backends/smt2/smt2.cc
index 3e67e55f2..26f17bcb3 100644
--- a/backends/smt2/smt2.cc
+++ b/backends/smt2/smt2.cc
@@ -590,7 +590,17 @@ struct Smt2Worker
if (cell->type == ID($sub)) return export_bvop(cell, "(bvsub A B)");
if (cell->type == ID($mul)) return export_bvop(cell, "(bvmul A B)");
if (cell->type == ID($div)) return export_bvop(cell, "(bvUdiv A B)", 'd');
+ // "rem" = truncating modulo
if (cell->type == ID($mod)) return export_bvop(cell, "(bvUrem A B)", 'd');
+ // "mod" = flooring modulo
+ if (cell->type == ID($modfloor)) {
+ // bvumod doesn't exist because it's the same as bvurem
+ if (cell->getParam(ID::A_SIGNED).as_bool()) {
+ return export_bvop(cell, "(bvsmod A B)", 'd');
+ } else {
+ return export_bvop(cell, "(bvurem A B)", 'd');
+ }
+ }
if (cell->type.in(ID($reduce_and), ID($reduce_or), ID($reduce_bool)) &&
2*GetSize(cell->getPort(ID::A).chunks()) < GetSize(cell->getPort(ID::A))) {
diff --git a/backends/smv/smv.cc b/backends/smv/smv.cc
index 7113ebc97..2fc7099f4 100644
--- a/backends/smv/smv.cc
+++ b/backends/smv/smv.cc
@@ -358,7 +358,8 @@ struct SmvWorker
continue;
}
- if (cell->type.in(ID($div), ID($mod)))
+ // SMV has a "mod" operator, but its semantics don't seem to be well-defined - to be safe, don't generate it at all
+ if (cell->type.in(ID($div)/*, ID($mod), ID($modfloor)*/))
{
int width_y = GetSize(cell->getPort(ID::Y));
int width = max(width_y, GetSize(cell->getPort(ID::A)));
@@ -366,7 +367,7 @@ struct SmvWorker
string expr_a, expr_b, op;
if (cell->type == ID($div)) op = "/";
- if (cell->type == ID($mod)) op = "mod";
+ //if (cell->type == ID($mod)) op = "mod";
if (cell->getParam(ID::A_SIGNED).as_bool())
{
diff --git a/backends/smv/test_cells.sh b/backends/smv/test_cells.sh
index 63de465c0..145b9c33b 100644
--- a/backends/smv/test_cells.sh
+++ b/backends/smv/test_cells.sh
@@ -7,8 +7,8 @@ mkdir -p test_cells.tmp
cd test_cells.tmp
# don't test $mul to reduce runtime
-# don't test $div and $mod to reduce runtime and avoid "div by zero" message
-../../../yosys -p 'test_cell -n 5 -w test all /$alu /$fa /$lcu /$lut /$macc /$mul /$div /$mod'
+# don't test $div/$mod/$divfloor/$modfloor to reduce runtime and avoid "div by zero" message
+../../../yosys -p 'test_cell -n 5 -w test all /$alu /$fa /$lcu /$lut /$macc /$mul /$div /$mod /$divfloor /$modfloor'
cat > template.txt << "EOT"
%module main
diff --git a/backends/verilog/verilog_backend.cc b/backends/verilog/verilog_backend.cc
index 11b2ae10f..4f44a053a 100644
--- a/backends/verilog/verilog_backend.cc
+++ b/backends/verilog/verilog_backend.cc
@@ -740,6 +740,95 @@ bool dump_cell_expr(std::ostream &f, std::string indent, RTLIL::Cell *cell)
#undef HANDLE_UNIOP
#undef HANDLE_BINOP
+ if (cell->type == ID($divfloor))
+ {
+ // wire [MAXLEN+1:0] _0_, _1_, _2_;
+ // assign _0_ = $signed(A);
+ // assign _1_ = $signed(B);
+ // assign _2_ = (A[-1] == B[-1]) || A == 0 ? _0_ : $signed(_0_ - (B[-1] ? _1_ + 1 : _1_ - 1));
+ // assign Y = $signed(_2_) / $signed(_1_);
+
+ if (cell->getParam(ID::A_SIGNED).as_bool() && cell->getParam(ID::B_SIGNED).as_bool()) {
+ SigSpec sig_a = cell->getPort(ID::A);
+ SigSpec sig_b = cell->getPort(ID::B);
+
+ std::string buf_a = next_auto_id();
+ std::string buf_b = next_auto_id();
+ std::string buf_num = next_auto_id();
+ int size_a = GetSize(sig_a);
+ int size_b = GetSize(sig_b);
+ int size_y = GetSize(cell->getPort(ID::Y));
+ int size_max = std::max(size_a, std::max(size_b, size_y));
+
+ // intentionally one wider than maximum width
+ f << stringf("%s" "wire [%d:0] %s, %s, %s;\n", indent.c_str(), size_max, buf_a.c_str(), buf_b.c_str(), buf_num.c_str());
+ f << stringf("%s" "assign %s = ", indent.c_str(), buf_a.c_str());
+ dump_cell_expr_port(f, cell, "A", true);
+ f << stringf(";\n");
+ f << stringf("%s" "assign %s = ", indent.c_str(), buf_b.c_str());
+ dump_cell_expr_port(f, cell, "B", true);
+ f << stringf(";\n");
+
+ f << stringf("%s" "assign %s = ", indent.c_str(), buf_num.c_str());
+ f << stringf("(");
+ dump_sigspec(f, sig_a.extract(sig_a.size()-1));
+ f << stringf(" == ");
+ dump_sigspec(f, sig_b.extract(sig_b.size()-1));
+ f << stringf(") || ");
+ dump_sigspec(f, sig_a);
+ f << stringf(" == 0 ? %s : ", buf_a.c_str());
+ f << stringf("$signed(%s - (", buf_a.c_str());
+ dump_sigspec(f, sig_b.extract(sig_b.size()-1));
+ f << stringf(" ? %s + 1 : %s - 1));\n", buf_b.c_str(), buf_b.c_str());
+
+
+ f << stringf("%s" "assign ", indent.c_str());
+ dump_sigspec(f, cell->getPort(ID::Y));
+ f << stringf(" = $signed(%s) / ", buf_num.c_str());
+ dump_attributes(f, "", cell->attributes, ' ');
+ f << stringf("$signed(%s);\n", buf_b.c_str());
+ return true;
+ } else {
+ // same as truncating division
+ dump_cell_expr_binop(f, indent, cell, "/");
+ return true;
+ }
+ }
+
+ if (cell->type == ID($modfloor))
+ {
+ // wire truncated = $signed(A) % $signed(B);
+ // assign Y = (A[-1] == B[-1]) || truncated == 0 ? truncated : $signed(B) + $signed(truncated);
+
+ if (cell->getParam(ID::A_SIGNED).as_bool() && cell->getParam(ID::B_SIGNED).as_bool()) {
+ SigSpec sig_a = cell->getPort(ID::A);
+ SigSpec sig_b = cell->getPort(ID::B);
+
+ std::string temp_id = next_auto_id();
+ f << stringf("%s" "wire [%d:0] %s = ", indent.c_str(), GetSize(cell->getPort(ID::A))-1, temp_id.c_str());
+ dump_cell_expr_port(f, cell, "A", true);
+ f << stringf(" %% ");
+ dump_attributes(f, "", cell->attributes, ' ');
+ dump_cell_expr_port(f, cell, "B", true);
+ f << stringf(";\n");
+
+ f << stringf("%s" "assign ", indent.c_str());
+ dump_sigspec(f, cell->getPort(ID::Y));
+ f << stringf(" = (");
+ dump_sigspec(f, sig_a.extract(sig_a.size()-1));
+ f << stringf(" == ");
+ dump_sigspec(f, sig_b.extract(sig_b.size()-1));
+ f << stringf(") || %s == 0 ? %s : ", temp_id.c_str(), temp_id.c_str());
+ dump_cell_expr_port(f, cell, "B", true);
+ f << stringf(" + $signed(%s);\n", temp_id.c_str());
+ return true;
+ } else {
+ // same as truncating modulo
+ dump_cell_expr_binop(f, indent, cell, "%");
+ return true;
+ }
+ }
+
if (cell->type == ID($shift))
{
f << stringf("%s" "assign ", indent.c_str());
diff --git a/kernel/calc.cc b/kernel/calc.cc
index 4a4840771..ae18809d3 100644
--- a/kernel/calc.cc
+++ b/kernel/calc.cc
@@ -489,6 +489,7 @@ RTLIL::Const RTLIL::const_mul(const RTLIL::Const &arg1, const RTLIL::Const &arg2
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;
@@ -502,6 +503,7 @@ RTLIL::Const RTLIL::const_div(const RTLIL::Const &arg1, const RTLIL::Const &arg2
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;
@@ -515,6 +517,51 @@ RTLIL::Const RTLIL::const_mod(const RTLIL::Const &arg1, const RTLIL::Const &arg2
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)
{
int undef_bit_pos = -1;
diff --git a/kernel/celledges.cc b/kernel/celledges.cc
index 54e0168e2..314e7c77e 100644
--- a/kernel/celledges.cc
+++ b/kernel/celledges.cc
@@ -187,7 +187,7 @@ bool YOSYS_NAMESPACE_PREFIX AbstractCellEdgesDatabase::add_edges_from_cell(RTLIL
return true;
}
- // FIXME: $mul $div $mod $slice $concat
+ // FIXME: $mul $div $mod $divfloor $modfloor $slice $concat
// FIXME: $lut $sop $alu $lcu $macc $fa
return false;
diff --git a/kernel/celltypes.h b/kernel/celltypes.h
index 450865ce9..db54436cb 100644
--- a/kernel/celltypes.h
+++ b/kernel/celltypes.h
@@ -114,7 +114,7 @@ struct CellTypes
ID($and), ID($or), ID($xor), ID($xnor),
ID($shl), ID($shr), ID($sshl), ID($sshr), ID($shift), ID($shiftx),
ID($lt), ID($le), ID($eq), ID($ne), ID($eqx), ID($nex), ID($ge), ID($gt),
- ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($pow),
+ ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($divfloor), ID($modfloor), ID($pow),
ID($logic_and), ID($logic_or), ID($concat), ID($macc)
};
@@ -304,6 +304,8 @@ struct CellTypes
HANDLE_CELL_TYPE(mul)
HANDLE_CELL_TYPE(div)
HANDLE_CELL_TYPE(mod)
+ HANDLE_CELL_TYPE(divfloor)
+ HANDLE_CELL_TYPE(modfloor)
HANDLE_CELL_TYPE(pow)
HANDLE_CELL_TYPE(pos)
HANDLE_CELL_TYPE(neg)
diff --git a/kernel/rtlil.cc b/kernel/rtlil.cc
index 196e301b6..ca4201b53 100644
--- a/kernel/rtlil.cc
+++ b/kernel/rtlil.cc
@@ -948,7 +948,7 @@ namespace {
return;
}
- if (cell->type.in(ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($pow))) {
+ if (cell->type.in(ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($divfloor), ID($modfloor), ID($pow))) {
param_bool(ID::A_SIGNED);
param_bool(ID::B_SIGNED);
port(ID::A, param(ID::A_WIDTH));
@@ -1949,6 +1949,8 @@ DEF_METHOD(Sub, max(sig_a.size(), sig_b.size()), ID($sub))
DEF_METHOD(Mul, max(sig_a.size(), sig_b.size()), ID($mul))
DEF_METHOD(Div, max(sig_a.size(), sig_b.size()), ID($div))
DEF_METHOD(Mod, max(sig_a.size(), sig_b.size()), ID($mod))
+DEF_METHOD(DivFloor, max(sig_a.size(), sig_b.size()), ID($divfloor))
+DEF_METHOD(ModFloor, max(sig_a.size(), sig_b.size()), ID($modfloor))
DEF_METHOD(LogicAnd, 1, ID($logic_and))
DEF_METHOD(LogicOr, 1, ID($logic_or))
#undef DEF_METHOD
diff --git a/kernel/rtlil.h b/kernel/rtlil.h
index 91d6a9f77..8228523d5 100644
--- a/kernel/rtlil.h
+++ b/kernel/rtlil.h
@@ -468,6 +468,8 @@ namespace RTLIL
RTLIL::Const const_sub (const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len);
RTLIL::Const const_mul (const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len);
RTLIL::Const const_div (const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len);
+ RTLIL::Const const_divfloor (const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len);
+ RTLIL::Const const_modfloor (const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len);
RTLIL::Const const_mod (const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len);
RTLIL::Const const_pow (const RTLIL::Const &arg1, const RTLIL::Const &arg2, bool signed1, bool signed2, int result_len);
@@ -1204,8 +1206,12 @@ public:
RTLIL::Cell* addAdd (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, const RTLIL::SigSpec &sig_y, bool is_signed = false, const std::string &src = "");
RTLIL::Cell* addSub (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, const RTLIL::SigSpec &sig_y, bool is_signed = false, const std::string &src = "");
RTLIL::Cell* addMul (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, const RTLIL::SigSpec &sig_y, bool is_signed = false, const std::string &src = "");
+ // truncating division
RTLIL::Cell* addDiv (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, const RTLIL::SigSpec &sig_y, bool is_signed = false, const std::string &src = "");
+ // truncating modulo
RTLIL::Cell* addMod (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, const RTLIL::SigSpec &sig_y, bool is_signed = false, const std::string &src = "");
+ RTLIL::Cell* addDivFloor (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, const RTLIL::SigSpec &sig_y, bool is_signed = false, const std::string &src = "");
+ RTLIL::Cell* addModFloor (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, const RTLIL::SigSpec &sig_y, bool is_signed = false, const std::string &src = "");
RTLIL::Cell* addPow (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, const RTLIL::SigSpec &sig_y, bool a_signed = false, bool b_signed = false, const std::string &src = "");
RTLIL::Cell* addLogicNot (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_y, bool is_signed = false, const std::string &src = "");
@@ -1303,8 +1309,12 @@ public:
RTLIL::SigSpec Add (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, bool is_signed = false, const std::string &src = "");
RTLIL::SigSpec Sub (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, bool is_signed = false, const std::string &src = "");
RTLIL::SigSpec Mul (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, bool is_signed = false, const std::string &src = "");
+ // truncating division
RTLIL::SigSpec Div (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, bool is_signed = false, const std::string &src = "");
+ // truncating modulo
RTLIL::SigSpec Mod (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, bool is_signed = false, const std::string &src = "");
+ RTLIL::SigSpec DivFloor (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, bool is_signed = false, const std::string &src = "");
+ RTLIL::SigSpec ModFloor (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, bool is_signed = false, const std::string &src = "");
RTLIL::SigSpec Pow (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, const RTLIL::SigSpec &sig_b, bool a_signed = false, bool b_signed = false, const std::string &src = "");
RTLIL::SigSpec LogicNot (RTLIL::IdString name, const RTLIL::SigSpec &sig_a, bool is_signed = false, const std::string &src = "");
diff --git a/kernel/satgen.h b/kernel/satgen.h
index 88b84b7e6..3929a8708 100644
--- a/kernel/satgen.h
+++ b/kernel/satgen.h
@@ -279,7 +279,7 @@ struct SatGen
bool arith_undef_handled = false;
bool is_arith_compare = cell->type.in(ID($lt), ID($le), ID($ge), ID($gt));
- if (model_undef && (cell->type.in(ID($add), ID($sub), ID($mul), ID($div), ID($mod)) || is_arith_compare))
+ if (model_undef && (cell->type.in(ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($divfloor), ID($modfloor)) || is_arith_compare))
{
std::vector<int> undef_a = importUndefSigSpec(cell->getPort(ID::A), timestep);
std::vector<int> undef_b = importUndefSigSpec(cell->getPort(ID::B), timestep);
@@ -293,7 +293,7 @@ struct SatGen
int undef_any_b = ez->expression(ezSAT::OpOr, undef_b);
int undef_y_bit = ez->OR(undef_any_a, undef_any_b);
- if (cell->type.in(ID($div), ID($mod))) {
+ if (cell->type.in(ID($div), ID($mod), ID($divfloor), ID($modfloor))) {
std::vector<int> b = importSigSpec(cell->getPort(ID::B), timestep);
undef_y_bit = ez->OR(undef_y_bit, ez->NOT(ez->expression(ezSAT::OpOr, b)));
}
@@ -935,7 +935,7 @@ struct SatGen
return true;
}
- if (cell->type.in(ID($div), ID($mod)))
+ if (cell->type.in(ID($div), ID($mod), ID($divfloor), ID($modfloor)))
{
std::vector<int> a = importDefSigSpec(cell->getPort(ID::A), timestep);
std::vector<int> b = importDefSigSpec(cell->getPort(ID::B), timestep);
@@ -970,23 +970,48 @@ struct SatGen
}
std::vector<int> y_tmp = ignore_div_by_zero ? yy : ez->vec_var(y.size());
+
+ // modulo calculation
+ std::vector<int> modulo_trunc;
+ int floored_eq_trunc;
+ if (cell->parameters[ID::A_SIGNED].as_bool() && cell->parameters[ID::B_SIGNED].as_bool()) {
+ modulo_trunc = ez->vec_ite(a.back(), ez->vec_neg(chain_buf), chain_buf);
+ // floor == trunc when sgn(a) == sgn(b) or trunc == 0
+ floored_eq_trunc = ez->OR(ez->IFF(a.back(), b.back()), ez->NOT(ez->expression(ezSAT::OpOr, modulo_trunc)));
+ } else {
+ modulo_trunc = chain_buf;
+ floored_eq_trunc = ez->CONST_TRUE;
+ }
+
if (cell->type == ID($div)) {
if (cell->parameters[ID::A_SIGNED].as_bool() && cell->parameters[ID::B_SIGNED].as_bool())
ez->assume(ez->vec_eq(y_tmp, ez->vec_ite(ez->XOR(a.back(), b.back()), ez->vec_neg(y_u), y_u)));
else
ez->assume(ez->vec_eq(y_tmp, y_u));
- } else {
+ } else if (cell->type == ID($mod)) {
+ ez->assume(ez->vec_eq(y_tmp, modulo_trunc));
+ } else if (cell->type == ID($divfloor)) {
if (cell->parameters[ID::A_SIGNED].as_bool() && cell->parameters[ID::B_SIGNED].as_bool())
- ez->assume(ez->vec_eq(y_tmp, ez->vec_ite(a.back(), ez->vec_neg(chain_buf), chain_buf)));
+ ez->assume(ez->vec_eq(y_tmp, ez->vec_ite(
+ ez->XOR(a.back(), b.back()),
+ ez->vec_neg(ez->vec_ite(
+ ez->vec_reduce_or(modulo_trunc),
+ ez->vec_add(y_u, ez->vec_const_unsigned(1, y_u.size())),
+ y_u
+ )),
+ y_u
+ )));
else
- ez->assume(ez->vec_eq(y_tmp, chain_buf));
+ ez->assume(ez->vec_eq(y_tmp, y_u));
+ } else if (cell->type == ID($modfloor)) {
+ ez->assume(ez->vec_eq(y_tmp, ez->vec_ite(floored_eq_trunc, modulo_trunc, ez->vec_add(modulo_trunc, b))));
}
if (ignore_div_by_zero) {
ez->assume(ez->expression(ezSAT::OpOr, b));
} else {
std::vector<int> div_zero_result;
- if (cell->type == ID($div)) {
+ if (cell->type.in(ID($div), ID($divfloor))) {
if (cell->parameters[ID::A_SIGNED].as_bool() && cell->parameters[ID::B_SIGNED].as_bool()) {
std::vector<int> all_ones(y.size(), ez->CONST_TRUE);
std::vector<int> only_first_one(y.size(), ez->CONST_FALSE);
@@ -996,7 +1021,8 @@ struct SatGen
div_zero_result.insert(div_zero_result.end(), cell->getPort(ID::A).size(), ez->CONST_TRUE);
div_zero_result.insert(div_zero_result.end(), y.size() - div_zero_result.size(), ez->CONST_FALSE);
}
- } else {
+ } else if (cell->type.in(ID($mod), ID($modfloor))) {
+ // a mod 0 = a
int copy_a_bits = min(cell->getPort(ID::A).size(), cell->getPort(ID::B).size());
div_zero_result.insert(div_zero_result.end(), a.begin(), a.begin() + copy_a_bits);
if (cell->parameters[ID::A_SIGNED].as_bool() && cell->parameters[ID::B_SIGNED].as_bool())
diff --git a/manual/CHAPTER_CellLib.tex b/manual/CHAPTER_CellLib.tex
index 55abd9b96..32c530582 100644
--- a/manual/CHAPTER_CellLib.tex
+++ b/manual/CHAPTER_CellLib.tex
@@ -139,6 +139,8 @@ Verilog & Cell Type \\
\lstinline[language=Verilog]; Y = A * B; & {\tt \$mul} \\
\lstinline[language=Verilog]; Y = A / B; & {\tt \$div} \\
\lstinline[language=Verilog]; Y = A % B; & {\tt \$mod} \\
+\multicolumn{1}{c}{\tt [N/A]} & {\tt \$divfloor} \\
+\multicolumn{1}{c}{\tt [N/A]} & {\tt \$modfoor} \\
\lstinline[language=Verilog]; Y = A ** B; & {\tt \$pow} \\
\end{tabular}
\caption{Cell types for binary operators with their corresponding Verilog expressions.}
@@ -161,6 +163,27 @@ For the binary cells that output a logical value ({\tt \$logic\_and}, {\tt \$log
{\tt \$gt}), when the \B{Y\_WIDTH} parameter is greater than 1, the output is zero-extended,
and only the least significant bit varies.
+Division and modulo cells are available in two rounding modes. The original {\tt \$div} and {\tt \$mod}
+cells are based on truncating division, and correspond to the semantics of the verilog {\tt /} and
+{\tt \%} operators. The {\tt \$divfloor} and {\tt \$modfloor} cells represent flooring division and
+flooring modulo, the latter of which is also known as ``remainder'' in several languages. See
+table~\ref{tab:CellLib_divmod} for a side-by-side comparison between the different semantics.
+
+\begin{table}[h]
+\hfil
+\begin{tabular}{lr|rr|rr}
+\multirow{2}{*}{Division} & \multirow{2}{*}{Result} & \multicolumn{2}{c|}{Truncating} & \multicolumn{2}{c}{Flooring} \\
+ & & {\tt \$div} & {\tt \$mod} & {\tt \$divfloor} & {\tt \$modfloor} \\
+\hline
+{\tt -10 / 3} & {\tt -3.3} & {\tt -3} & {\tt -1} & {\tt -4} & {\tt 2} \\
+{\tt 10 / -3} & {\tt -3.3} & {\tt -3} & {\tt 1} & {\tt -4} & {\tt -2} \\
+{\tt -10 / -3} & {\tt 3.3} & {\tt 3} & {\tt -1} & {\tt 3} & {\tt -1} \\
+{\tt 10 / 3} & {\tt 3.3} & {\tt 3} & {\tt 1} & {\tt 3} & {\tt 1} \\
+\end{tabular}
+\caption{Comparison between different rounding modes for division and modulo cells.}
+\label{tab:CellLib_divmod}
+\end{table}
+
\subsection{Multiplexers}
Multiplexers are generated by the Verilog HDL frontend for {\tt
diff --git a/manual/PRESENTATION_Prog.tex b/manual/PRESENTATION_Prog.tex
index b85eda892..a9416f82a 100644
--- a/manual/PRESENTATION_Prog.tex
+++ b/manual/PRESENTATION_Prog.tex
@@ -307,7 +307,7 @@ cell name from the internal cell library:
\begin{lstlisting}[xleftmargin=1cm, basicstyle=\ttfamily\fontsize{6pt}{7pt}\selectfont]
$not $pos $neg $and $or $xor $xnor $reduce_and $reduce_or $reduce_xor $reduce_xnor
$reduce_bool $shl $shr $sshl $sshr $lt $le $eq $ne $eqx $nex $ge $gt $add $sub $mul $div $mod
-$pow $logic_not $logic_and $logic_or $mux $pmux $slice $concat $lut $assert $sr $dff
+$divfloor $modfloor $pow $logic_not $logic_and $logic_or $mux $pmux $slice $concat $lut $assert $sr $dff
$dffsr $adff $dlatch $dlatchsr $memrd $memwr $mem $fsm $_NOT_ $_AND_ $_OR_ $_XOR_ $_MUX_ $_SR_NN_
$_SR_NP_ $_SR_PN_ $_SR_PP_ $_DFF_N_ $_DFF_P_ $_DFF_NN0_ $_DFF_NN1_ $_DFF_NP0_ $_DFF_NP1_ $_DFF_PN0_
$_DFF_PN1_ $_DFF_PP0_ $_DFF_PP1_ $_DFFSR_NNN_ $_DFFSR_NNP_ $_DFFSR_NPN_ $_DFFSR_NPP_ $_DFFSR_PNN_
diff --git a/passes/cmds/stat.cc b/passes/cmds/stat.cc
index 6c4bc0e5b..30436d829 100644
--- a/passes/cmds/stat.cc
+++ b/passes/cmds/stat.cc
@@ -109,7 +109,7 @@ struct statdata_t
ID($lut), ID($and), ID($or), ID($xor), ID($xnor),
ID($shl), ID($shr), ID($sshl), ID($sshr), ID($shift), ID($shiftx),
ID($lt), ID($le), ID($eq), ID($ne), ID($eqx), ID($nex), ID($ge), ID($gt),
- ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($pow), ID($alu))) {
+ ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($divfloor), ID($modfloor), ID($pow), ID($alu))) {
int width_a = cell->hasPort(ID::A) ? GetSize(cell->getPort(ID::A)) : 0;
int width_b = cell->hasPort(ID::B) ? GetSize(cell->getPort(ID::B)) : 0;
int width_y = cell->hasPort(ID::Y) ? GetSize(cell->getPort(ID::Y)) : 0;
diff --git a/passes/memory/memory_share.cc b/passes/memory/memory_share.cc
index 477246687..e11958bd6 100644
--- a/passes/memory/memory_share.cc
+++ b/passes/memory/memory_share.cc
@@ -715,6 +715,8 @@ struct MemoryShareWorker
cone_ct.cell_types.erase(ID($mul));
cone_ct.cell_types.erase(ID($mod));
cone_ct.cell_types.erase(ID($div));
+ cone_ct.cell_types.erase(ID($modfloor));
+ cone_ct.cell_types.erase(ID($divfloor));
cone_ct.cell_types.erase(ID($pow));
cone_ct.cell_types.erase(ID($shl));
cone_ct.cell_types.erase(ID($shr));
diff --git a/passes/opt/opt_expr.cc b/passes/opt/opt_expr.cc
index 777a24777..e5b8bda95 100644
--- a/passes/opt/opt_expr.cc
+++ b/passes/opt/opt_expr.cc
@@ -864,7 +864,7 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons
skip_fine_alu:
if (cell->type.in(ID($reduce_xor), ID($reduce_xnor), ID($shift), ID($shiftx), ID($shl), ID($shr), ID($sshl), ID($sshr),
- ID($lt), ID($le), ID($ge), ID($gt), ID($neg), ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($pow)))
+ ID($lt), ID($le), ID($ge), ID($gt), ID($neg), ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($divfloor), ID($modfloor), ID($pow)))
{
RTLIL::SigSpec sig_a = assign_map(cell->getPort(ID::A));
RTLIL::SigSpec sig_b = cell->hasPort(ID::B) ? assign_map(cell->getPort(ID::B)) : RTLIL::SigSpec();
@@ -883,7 +883,7 @@ skip_fine_alu:
if (0) {
found_the_x_bit:
cover_list("opt.opt_expr.xbit", "$reduce_xor", "$reduce_xnor", "$shl", "$shr", "$sshl", "$sshr", "$shift", "$shiftx",
- "$lt", "$le", "$ge", "$gt", "$neg", "$add", "$sub", "$mul", "$div", "$mod", "$pow", cell->type.str());
+ "$lt", "$le", "$ge", "$gt", "$neg", "$add", "$sub", "$mul", "$div", "$mod", "$divfloor", "$modfloor", "$pow", cell->type.str());
if (cell->type.in(ID($reduce_xor), ID($reduce_xnor), ID($lt), ID($le), ID($ge), ID($gt)))
replace_cell(assign_map, module, cell, "x-bit in input", ID::Y, RTLIL::State::Sx);
else
@@ -1469,6 +1469,8 @@ skip_identity:
FOLD_2ARG_CELL(mul)
FOLD_2ARG_CELL(div)
FOLD_2ARG_CELL(mod)
+ FOLD_2ARG_CELL(divfloor)
+ FOLD_2ARG_CELL(modfloor)
FOLD_2ARG_CELL(pow)
FOLD_1ARG_CELL(pos)
@@ -1583,9 +1585,11 @@ skip_identity:
}
}
- if (!keepdc && cell->type.in(ID($div), ID($mod)))
+ if (!keepdc && cell->type.in(ID($div), ID($mod), ID($divfloor), ID($modfloor)))
{
+ bool a_signed = cell->parameters[ID::A_SIGNED].as_bool();
bool b_signed = cell->parameters[ID::B_SIGNED].as_bool();
+ SigSpec sig_a = assign_map(cell->getPort(ID::A));
SigSpec sig_b = assign_map(cell->getPort(ID::B));
SigSpec sig_y = assign_map(cell->getPort(ID::Y));
@@ -1610,11 +1614,13 @@ skip_identity:
for (int i = 1; i < (b_signed ? sig_b.size()-1 : sig_b.size()); i++)
if (b_val == (1 << i))
{
- if (cell->type == ID($div))
+ if (cell->type.in(ID($div), ID($divfloor)))
{
cover("opt.opt_expr.div_shift");
- log_debug("Replacing divide-by-%d cell `%s' in module `%s' with shift-by-%d.\n",
+ bool is_truncating = cell->type == ID($div);
+ log_debug("Replacing %s-divide-by-%d cell `%s' in module `%s' with shift-by-%d.\n",
+ is_truncating ? "truncating" : "flooring",
b_val, cell->name.c_str(), module->name.c_str(), i);
std::vector<RTLIL::SigBit> new_b = RTLIL::SigSpec(i, 6);
@@ -1622,17 +1628,35 @@ skip_identity:
while (GetSize(new_b) > 1 && new_b.back() == RTLIL::State::S0)
new_b.pop_back();
- cell->type = ID($shr);
+ cell->type = ID($sshr);
cell->parameters[ID::B_WIDTH] = GetSize(new_b);
cell->parameters[ID::B_SIGNED] = false;
cell->setPort(ID::B, new_b);
+
+ // Truncating division is the same as flooring division, except when
+ // the result is negative and there is a remainder - then trunc = floor + 1
+ if (is_truncating && a_signed) {
+ Wire *flooring = module->addWire(NEW_ID, sig_y.size());
+ cell->setPort(ID::Y, flooring);
+
+ Wire *result_neg = module->addWire(NEW_ID);
+ module->addXor(NEW_ID, sig_a[sig_a.size()-1], sig_b[sig_b.size()-1], result_neg);
+ Wire *rem_nonzero = module->addWire(NEW_ID);
+ module->addReduceOr(NEW_ID, sig_a.extract(0, i), rem_nonzero);
+ Wire *should_add = module->addWire(NEW_ID);
+ module->addAnd(NEW_ID, result_neg, rem_nonzero, should_add);
+ module->addAdd(NEW_ID, flooring, should_add, sig_y);
+ }
+
cell->check();
}
- else
+ else if (cell->type.in(ID($mod), ID($modfloor)))
{
cover("opt.opt_expr.mod_mask");
- log_debug("Replacing modulo-by-%d cell `%s' in module `%s' with bitmask.\n",
+ bool is_truncating = cell->type == ID($mod);
+ log_debug("Replacing %s-modulo-by-%d cell `%s' in module `%s' with bitmask.\n",
+ is_truncating ? "truncating" : "flooring",
b_val, cell->name.c_str(), module->name.c_str());
std::vector<RTLIL::SigBit> new_b = RTLIL::SigSpec(State::S1, i);
@@ -1643,6 +1667,24 @@ skip_identity:
cell->type = ID($and);
cell->parameters[ID::B_WIDTH] = GetSize(new_b);
cell->setPort(ID::B, new_b);
+
+ // truncating modulo has the same masked bits as flooring modulo, but
+ // the sign bits are those of A (except when R=0)
+ if (is_truncating && a_signed) {
+ Wire *flooring = module->addWire(NEW_ID, sig_y.size());
+ cell->setPort(ID::Y, flooring);
+ SigSpec truncating = SigSpec(flooring).extract(0, i);
+
+ Wire *rem_nonzero = module->addWire(NEW_ID);
+ module->addReduceOr(NEW_ID, truncating, rem_nonzero);
+ SigSpec a_sign = sig_a[sig_a.size()-1];
+ Wire *extend_bit = module->addWire(NEW_ID);
+ module->addAnd(NEW_ID, a_sign, rem_nonzero, extend_bit);
+
+ truncating.append(extend_bit);
+ module->addPos(NEW_ID, truncating, sig_y, true);
+ }
+
cell->check();
}
diff --git a/passes/opt/opt_share.cc b/passes/opt/opt_share.cc
index 1f69c98f4..cbace7bac 100644
--- a/passes/opt/opt_share.cc
+++ b/passes/opt/opt_share.cc
@@ -103,7 +103,7 @@ bool cell_supported(RTLIL::Cell *cell)
if (sig_bi.is_fully_const() && sig_ci.is_fully_const() && sig_bi == sig_ci)
return true;
- } else if (cell->type.in(LOGICAL_OPS, SHIFT_OPS, BITWISE_OPS, RELATIONAL_OPS, ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($concat))) {
+ } else if (cell->type.in(LOGICAL_OPS, SHIFT_OPS, BITWISE_OPS, RELATIONAL_OPS, ID($add), ID($sub), ID($mul), ID($div), ID($mod), ID($divfloor), ID($modfloor), ID($concat))) {
return true;
}
@@ -130,7 +130,7 @@ bool mergeable(RTLIL::Cell *a, RTLIL::Cell *b)
RTLIL::IdString decode_port_semantics(RTLIL::Cell *cell, RTLIL::IdString port_name)
{
- if (cell->type.in(ID($lt), ID($le), ID($ge), ID($gt), ID($div), ID($mod), ID($concat), SHIFT_OPS) && port_name == ID::B)
+ if (cell->type.in(ID($lt), ID($le), ID($ge), ID($gt), ID($div), ID($mod), ID($divfloor), ID($modfloor), ID($concat), SHIFT_OPS) && port_name == ID::B)
return port_name;
return "";
diff --git a/passes/opt/share.cc b/passes/opt/share.cc
index 2839507b0..988253edf 100644
--- a/passes/opt/share.cc
+++ b/passes/opt/share.cc
@@ -376,7 +376,7 @@ struct ShareWorker
continue;
}
- if (cell->type.in(ID($mul), ID($div), ID($mod))) {
+ if (cell->type.in(ID($mul), ID($div), ID($mod), ID($divfloor), ID($modfloor))) {
if (config.opt_aggressive || cell->parameters.at(ID::Y_WIDTH).as_int() >= 4)
shareable_cells.insert(cell);
continue;
@@ -1133,6 +1133,8 @@ struct ShareWorker
cone_ct.cell_types.erase(ID($mul));
cone_ct.cell_types.erase(ID($mod));
cone_ct.cell_types.erase(ID($div));
+ cone_ct.cell_types.erase(ID($modfloor));
+ cone_ct.cell_types.erase(ID($divfloor));
cone_ct.cell_types.erase(ID($pow));
cone_ct.cell_types.erase(ID($shl));
cone_ct.cell_types.erase(ID($shr));
@@ -1512,6 +1514,8 @@ struct SharePass : public Pass {
config.generic_bin_ops.insert(ID($sub));
config.generic_bin_ops.insert(ID($div));
config.generic_bin_ops.insert(ID($mod));
+ config.generic_bin_ops.insert(ID($divfloor));
+ config.generic_bin_ops.insert(ID($modfloor));
// config.generic_bin_ops.insert(ID($pow));
config.generic_uni_ops.insert(ID($logic_not));
diff --git a/passes/opt/wreduce.cc b/passes/opt/wreduce.cc
index 195400bf0..f60f2f8a8 100644
--- a/passes/opt/wreduce.cc
+++ b/passes/opt/wreduce.cc
@@ -37,7 +37,7 @@ struct WreduceConfig
ID($and), ID($or), ID($xor), ID($xnor),
ID($shl), ID($shr), ID($sshl), ID($sshr), ID($shift), ID($shiftx),
ID($lt), ID($le), ID($eq), ID($ne), ID($eqx), ID($nex), ID($ge), ID($gt),
- ID($add), ID($sub), ID($mul), // ID($div), ID($mod), ID($pow),
+ ID($add), ID($sub), ID($mul), // ID($div), ID($mod), ID($divfloor), ID($modfloor), ID($pow),
ID($mux), ID($pmux),
ID($dff), ID($adff)
});
@@ -545,7 +545,7 @@ struct WreducePass : public Pass {
}
}
- if (c->type.in(ID($div), ID($mod), ID($pow)))
+ if (c->type.in(ID($div), ID($mod), ID($divfloor), ID($modfloor), ID($pow)))
{
SigSpec A = c->getPort(ID::A);
int original_a_width = GetSize(A);
diff --git a/passes/tests/test_cell.cc b/passes/tests/test_cell.cc
index cdbe922b2..c6801007d 100644
--- a/passes/tests/test_cell.cc
+++ b/passes/tests/test_cell.cc
@@ -264,7 +264,7 @@ static void create_gold_module(RTLIL::Design *design, RTLIL::IdString cell_type,
cell->setPort(ID::Y, wire);
}
- if (muxdiv && cell_type.in(ID($div), ID($mod))) {
+ if (muxdiv && cell_type.in(ID($div), ID($mod), ID($divfloor), ID($modfloor))) {
auto b_not_zero = module->ReduceBool(NEW_ID, cell->getPort(ID::B));
auto div_out = module->addWire(NEW_ID, GetSize(cell->getPort(ID::Y)));
module->addMux(NEW_ID, RTLIL::SigSpec(0, GetSize(div_out)), div_out, b_not_zero, cell->getPort(ID::Y));
@@ -839,6 +839,8 @@ struct TestCellPass : public Pass {
cell_types[ID($mul)] = "ABSY";
cell_types[ID($div)] = "ABSY";
cell_types[ID($mod)] = "ABSY";
+ cell_types[ID($divfloor)] = "ABSY";
+ cell_types[ID($modfloor)] = "ABSY";
// cell_types[ID($pow)] = "ABsY";
cell_types[ID($logic_not)] = "ASY";
diff --git a/techlibs/common/simlib.v b/techlibs/common/simlib.v
index 2cdddeabb..125b8e013 100644
--- a/techlibs/common/simlib.v
+++ b/techlibs/common/simlib.v
@@ -997,6 +997,12 @@ endmodule
// --------------------------------------------------------
+// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+//-
+//- $div (A, B, Y)
+//-
+//- Division with truncated result (rounded towards 0).
+//-
module \$div (A, B, Y);
parameter A_SIGNED = 0;
@@ -1021,6 +1027,14 @@ endmodule
// --------------------------------------------------------
+// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+//-
+//- $mod (A, B, Y)
+//-
+//- Modulo/remainder of division with truncated result (rounded towards 0).
+//-
+//- Invariant: $div(A, B) * B + $mod(A, B) == A
+//-
module \$mod (A, B, Y);
parameter A_SIGNED = 0;
@@ -1044,6 +1058,83 @@ endgenerate
endmodule
// --------------------------------------------------------
+
+// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+//-
+//- $divfloor (A, B, Y)
+//-
+//- Division with floored result (rounded towards negative infinity).
+//-
+module \$divfloor (A, B, Y);
+
+parameter A_SIGNED = 0;
+parameter B_SIGNED = 0;
+parameter A_WIDTH = 0;
+parameter B_WIDTH = 0;
+parameter Y_WIDTH = 0;
+
+input [A_WIDTH-1:0] A;
+input [B_WIDTH-1:0] B;
+output [Y_WIDTH-1:0] Y;
+
+generate
+ if (A_SIGNED && B_SIGNED) begin:BLOCK1
+ localparam WIDTH =
+ A_WIDTH >= B_WIDTH && A_WIDTH >= Y_WIDTH ? A_WIDTH :
+ B_WIDTH >= A_WIDTH && B_WIDTH >= Y_WIDTH ? B_WIDTH : Y_WIDTH;
+ wire [WIDTH:0] A_buf, B_buf, N_buf;
+ assign A_buf = $signed(A);
+ assign B_buf = $signed(B);
+ assign N_buf = (A[A_WIDTH-1] == B[B_WIDTH-1]) || A == 0 ? A_buf : $signed(A_buf - (B[B_WIDTH-1] ? B_buf+1 : B_buf-1));
+ assign Y = $signed(N_buf) / $signed(B_buf);
+ end else begin:BLOCK2
+ assign Y = A / B;
+ end
+endgenerate
+
+endmodule
+
+// --------------------------------------------------------
+
+// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+//-
+//- $modfloor (A, B, Y)
+//-
+//- Modulo/remainder of division with floored result (rounded towards negative infinity).
+//-
+//- Invariant: $divfloor(A, B) * B + $modfloor(A, B) == A
+//-
+module \$modfloor (A, B, Y);
+
+parameter A_SIGNED = 0;
+parameter B_SIGNED = 0;
+parameter A_WIDTH = 0;
+parameter B_WIDTH = 0;
+parameter Y_WIDTH = 0;
+
+input [A_WIDTH-1:0] A;
+input [B_WIDTH-1:0] B;
+output [Y_WIDTH-1:0] Y;
+
+generate
+ if (A_SIGNED && B_SIGNED) begin:BLOCK1
+ localparam WIDTH = B_WIDTH >= Y_WIDTH ? B_WIDTH : Y_WIDTH;
+ wire [WIDTH-1:0] B_buf, Y_trunc;
+ assign B_buf = $signed(B);
+ assign Y_trunc = $signed(A) % $signed(B);
+ // flooring mod is the same as truncating mod for positive division results (A and B have
+ // the same sign), as well as when there's no remainder.
+ // For all other cases, they behave as `floor - trunc = B`
+ assign Y = (A[A_WIDTH-1] == B[B_WIDTH-1]) || Y_trunc == 0 ? Y_trunc : $signed(B_buf) + $signed(Y_trunc);
+ end else begin:BLOCK2
+ // no difference between truncating and flooring for unsigned
+ assign Y = A % B;
+ end
+endgenerate
+
+endmodule
+
+// --------------------------------------------------------
`ifndef SIMLIB_NOPOW
module \$pow (A, B, Y);
diff --git a/techlibs/common/techmap.v b/techlibs/common/techmap.v
index c1efc378b..eafe8d4da 100644
--- a/techlibs/common/techmap.v
+++ b/techlibs/common/techmap.v
@@ -364,7 +364,8 @@ module \$__div_mod_u (A, B, Y, R);
end endgenerate
endmodule
-module \$__div_mod (A, B, Y, R);
+// truncating signed division/modulo
+module \$__div_mod_trunc (A, B, Y, R);
parameter A_SIGNED = 0;
parameter B_SIGNED = 0;
parameter A_WIDTH = 1;
@@ -420,7 +421,7 @@ module _90_div (A, B, Y);
(* force_downto *)
output [Y_WIDTH-1:0] Y;
- \$__div_mod #(
+ \$__div_mod_trunc #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
@@ -448,7 +449,107 @@ module _90_mod (A, B, Y);
(* force_downto *)
output [Y_WIDTH-1:0] Y;
- \$__div_mod #(
+ \$__div_mod_trunc #(
+ .A_SIGNED(A_SIGNED),
+ .B_SIGNED(B_SIGNED),
+ .A_WIDTH(A_WIDTH),
+ .B_WIDTH(B_WIDTH),
+ .Y_WIDTH(Y_WIDTH)
+ ) div_mod (
+ .A(A),
+ .B(B),
+ .R(Y)
+ );
+endmodule
+
+// flooring signed division/modulo
+module \$__div_mod_floor (A, B, Y, R);
+ parameter A_SIGNED = 0;
+ parameter B_SIGNED = 0;
+ parameter A_WIDTH = 1;
+ parameter B_WIDTH = 1;
+ parameter Y_WIDTH = 1;
+
+ localparam WIDTH =
+ A_WIDTH >= B_WIDTH && A_WIDTH >= Y_WIDTH ? A_WIDTH :
+ B_WIDTH >= A_WIDTH && B_WIDTH >= Y_WIDTH ? B_WIDTH : Y_WIDTH;
+
+ input [A_WIDTH-1:0] A;
+ input [B_WIDTH-1:0] B;
+ output [Y_WIDTH-1:0] Y, R;
+
+ wire [WIDTH-1:0] A_buf, B_buf;
+ \$pos #(.A_SIGNED(A_SIGNED), .A_WIDTH(A_WIDTH), .Y_WIDTH(WIDTH)) A_conv (.A(A), .Y(A_buf));
+ \$pos #(.A_SIGNED(B_SIGNED), .A_WIDTH(B_WIDTH), .Y_WIDTH(WIDTH)) B_conv (.A(B), .Y(B_buf));
+
+ wire [WIDTH-1:0] A_buf_u, B_buf_u, Y_u, R_u, R_s;
+ assign A_buf_u = A_SIGNED && A_buf[WIDTH-1] ? -A_buf : A_buf;
+ assign B_buf_u = B_SIGNED && B_buf[WIDTH-1] ? -B_buf : B_buf;
+
+ \$__div_mod_u #(
+ .WIDTH(WIDTH)
+ ) div_mod_u (
+ .A(A_buf_u),
+ .B(B_buf_u),
+ .Y(Y_u),
+ .R(R_u)
+ );
+
+ // For negative results, if there was a remainder, subtract one to turn
+ // the round towards 0 into a round towards -inf
+ assign Y = A_SIGNED && B_SIGNED && (A_buf[WIDTH-1] != B_buf[WIDTH-1]) ? (R_u == 0 ? -Y_u : -Y_u-1) : Y_u;
+
+ // truncating modulo
+ assign R_s = A_SIGNED && B_SIGNED && A_buf[WIDTH-1] ? -R_u : R_u;
+ // Flooring modulo differs from truncating modulo only if it is nonzero and
+ // A and B have different signs - then `floor - trunc = B`
+ assign R = (R_s != 0) && A_SIGNED && B_SIGNED && (A_buf[WIDTH-1] != B_buf[WIDTH-1]) ? $signed(B_buf) + $signed(R_s) : R_s;
+endmodule
+
+(* techmap_celltype = "$divfloor" *)
+module _90_divfloor (A, B, Y);
+ parameter A_SIGNED = 0;
+ parameter B_SIGNED = 0;
+ parameter A_WIDTH = 1;
+ parameter B_WIDTH = 1;
+ parameter Y_WIDTH = 1;
+
+ (* force_downto *)
+ input [A_WIDTH-1:0] A;
+ (* force_downto *)
+ input [B_WIDTH-1:0] B;
+ (* force_downto *)
+ output [Y_WIDTH-1:0] Y;
+
+ \$__div_mod_floor #(
+ .A_SIGNED(A_SIGNED),
+ .B_SIGNED(B_SIGNED),
+ .A_WIDTH(A_WIDTH),
+ .B_WIDTH(B_WIDTH),
+ .Y_WIDTH(Y_WIDTH)
+ ) div_mod (
+ .A(A),
+ .B(B),
+ .Y(Y)
+ );
+endmodule
+
+(* techmap_celltype = "$modfloor" *)
+module _90_modfloor (A, B, Y);
+ parameter A_SIGNED = 0;
+ parameter B_SIGNED = 0;
+ parameter A_WIDTH = 1;
+ parameter B_WIDTH = 1;
+ parameter Y_WIDTH = 1;
+
+ (* force_downto *)
+ input [A_WIDTH-1:0] A;
+ (* force_downto *)
+ input [B_WIDTH-1:0] B;
+ (* force_downto *)
+ output [Y_WIDTH-1:0] Y;
+
+ \$__div_mod_floor #(
.A_SIGNED(A_SIGNED),
.B_SIGNED(B_SIGNED),
.A_WIDTH(A_WIDTH),
diff --git a/tests/simple/constmuldivmod.v b/tests/simple/constmuldivmod.v
index d1d8be862..5dd8f9295 100644
--- a/tests/simple/constmuldivmod.v
+++ b/tests/simple/constmuldivmod.v
@@ -1,4 +1,4 @@
-module constmuldivmod(input [7:0] A, input [2:0] mode, output reg [7:0] Y);
+module constmuldivmod(input [7:0] A, input [5:0] mode, output reg [7:0] Y);
always @* begin
case (mode)
0: Y = A / 8'd0;
@@ -21,6 +21,46 @@ module constmuldivmod(input [7:0] A, input [2:0] mode, output reg [7:0] Y);
13: Y = A % 8'd8;
14: Y = A * 8'd8;
+ 15: Y = $signed(A) / $signed(8'd0);
+ 16: Y = $signed(A) % $signed(8'd0);
+ 17: Y = $signed(A) * $signed(8'd0);
+
+ 18: Y = $signed(A) / $signed(8'd1);
+ 19: Y = $signed(A) % $signed(8'd1);
+ 20: Y = $signed(A) * $signed(8'd1);
+
+ 21: Y = $signed(A) / $signed(8'd2);
+ 22: Y = $signed(A) % $signed(8'd2);
+ 23: Y = $signed(A) * $signed(8'd2);
+
+ 24: Y = $signed(A) / $signed(8'd4);
+ 25: Y = $signed(A) % $signed(8'd4);
+ 26: Y = $signed(A) * $signed(8'd4);
+
+ 27: Y = $signed(A) / $signed(8'd8);
+ 28: Y = $signed(A) % $signed(8'd8);
+ 29: Y = $signed(A) * $signed(8'd8);
+
+ 30: Y = $signed(A) / $signed(-8'd0);
+ 31: Y = $signed(A) % $signed(-8'd0);
+ 32: Y = $signed(A) * $signed(-8'd0);
+
+ 33: Y = $signed(A) / $signed(-8'd1);
+ 34: Y = $signed(A) % $signed(-8'd1);
+ 35: Y = $signed(A) * $signed(-8'd1);
+
+ 36: Y = $signed(A) / $signed(-8'd2);
+ 37: Y = $signed(A) % $signed(-8'd2);
+ 38: Y = $signed(A) * $signed(-8'd2);
+
+ 39: Y = $signed(A) / $signed(-8'd4);
+ 40: Y = $signed(A) % $signed(-8'd4);
+ 41: Y = $signed(A) * $signed(-8'd4);
+
+ 42: Y = $signed(A) / $signed(-8'd8);
+ 43: Y = $signed(A) % $signed(-8'd8);
+ 44: Y = $signed(A) * $signed(-8'd8);
+
default: Y = 8'd16 * A;
endcase
end
generated by cgit v1.2.3 (git 2.25.1) at 2025-03-30 11:22:11 +0000