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-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
4 files changed, 59 insertions, 13 deletions
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);
generated by cgit v1.2.3 (git 2.25.1) at 2025-02-03 03:55:41 +0000