fixup! abstract: -state MVP

This commit is contained in:
Emil J. Tywoniak 2025-02-03 18:31:33 +01:00
parent 083759676a
commit 6e99dbd351
2 changed files with 142 additions and 32 deletions

View File

@ -6,35 +6,79 @@ USING_YOSYS_NAMESPACE
PRIVATE_NAMESPACE_BEGIN
bool abstract_state(Module* mod, Cell* cell, Wire* enable, bool enable_pol) {
FfData ff(nullptr, cell);
if (ff.has_sr)
log_cmd_error("SR not supported\n");
// Normalize to simpler FF
ff.unmap_ce();
ff.unmap_srst();
if (ff.has_arst)
ff.arst_to_aload();
// Construct abstract value
auto anyseq = mod->Anyseq(NEW_ID, ff.width);
if (ff.has_aload) {
// aload := enable ? anyseq : aload
// ff.pol_aload = enable_pol;
Wire* abstracted_ad = mod->addWire(NEW_ID, ff.sig_ad.size());
SigSpec mux_a, mux_b;
if (enable_pol) {
mux_a = ff.sig_ad;
mux_b = anyseq;
} else {
mux_a = anyseq;
mux_b = ff.sig_ad;
}
(void)mod->addMux(NEW_ID,
mux_a,
mux_b,
enable,
abstracted_ad);
ff.sig_ad = abstracted_ad;
}
Wire* abstracted_d = mod->addWire(NEW_ID, ff.sig_d.size());
SigSpec mux_a, mux_b;
if (enable_pol) {
mux_a = ff.sig_d;
mux_b = anyseq;
} else {
mux_a = anyseq;
mux_b = ff.sig_d;
}
(void)mod->addMux(NEW_ID,
mux_a,
mux_b,
enable,
abstracted_d);
ff.sig_d = abstracted_d;
(void)ff.emit();
return true;
}
bool abstract_value(Module* mod, Wire* wire, Wire* enable, bool enable_pol) {
// (void)mod->addMux(NEW_ID,
// mux_a,
// mux_b,
// enable,
// abstracted);
// cell->setPort(ID::D, SigSpec(abstracted));
return false;
}
bool abstract_init(Module* mod, Cell* cell) {
CellTypes ct;
ct.setup_internals_ff();
if (!ct.cell_types.count(cell->type))
return false;
FfData ff(nullptr, cell);
// Doesn't matter if there was an enable signal already
// we discard it and mux with symbolic value
ff.has_ce = false;
Wire* inp = cell->getPort(ID::D).as_wire();
cell = ff.emit();
// TODO figure out memory cells?
Wire* abstracted = mod->addWire(NEW_ID, inp->width);
SigSpec mux_a, mux_b;
if (enable_pol) {
mux_a = inp;
mux_b = mod->Anyseq(NEW_ID, inp->width);
} else {
mux_a = mod->Anyseq(NEW_ID, inp->width);
mux_b = inp;
}
(void)mod->addMux(NEW_ID,
mux_a,
mux_b,
enable,
abstracted);
cell->setPort(ID::D, SigSpec(abstracted));
cell->unsetParam(ID::init);
return true;
}
struct AbstractPass : public Pass {
AbstractPass() : Pass("abstract", "extract clock gating out of flip flops") { }
void help() override {
@ -84,31 +128,41 @@ struct AbstractPass : public Pass {
}
extra_args(args, argidx, design);
unsigned int changed_cells = 0;
unsigned int changed = 0;
if ((mode == State) || (mode == Value)) {
if (!enable_name.length())
log_cmd_error("Unspecified enable wire\n");
CellTypes ct;
if (mode == State)
ct.setup_internals_ff();
for (auto mod : design->selected_modules()) {
log("module %s\n", mod->name.c_str());
log_debug("module %s\n", mod->name.c_str());
Wire *enable_wire = mod->wire("\\" + enable_name);
if (!enable_wire)
log_cmd_error("Enable wire %s not found in module %s\n", enable_name.c_str(), mod->name.c_str());
if (mode == State) {
for (auto cell : mod->selected_cells()) {
log("cell %s\n", cell->name.c_str());
changed_cells += abstract_state(mod, cell, enable_wire, enable_pol);
}
for (auto cell : mod->selected_cells())
if (ct.cell_types.count(cell->type))
changed += abstract_state(mod, cell, enable_wire, enable_pol);
} else {
// Value
for (auto wire : mod->selected_wires()) {
changed += abstract_value(mod, wire, enable_wire, enable_pol);
}
log_cmd_error("Unsupported (TODO)\n");
}
}
log("Abstracted %d cells.\n", changed);
} else if (mode == Initial) {
log_cmd_error("Unsupported\n");
for (auto mod : design->selected_modules()) {
for (auto cell : mod->selected_cells()) {
changed += abstract_init(mod, cell);
}
}
log("Abstracted %d wires.\n", changed);
} else {
log_cmd_error("No mode selected, see help message\n");
}
log("Abstracted %d cell(s).\n", changed_cells);
}
} AbstractPass;

View File

@ -11,14 +11,14 @@ endmodule
EOT
proc
# dump
# show -prefix before_base
abstract -state -enablen magic
check
# show -prefix after_base
# dump
design -reset
read_verilog <<EOT
module half_clock_en (CLK, E, Q);
input CLK;
input E;
@ -28,14 +28,70 @@ module half_clock_en (CLK, E, Q);
if (E)
Q <= ~Q;
endmodule
EOT
proc
opt_expr
opt_dff
# show
# dump
# show -prefix before_en
abstract -state -enablen magic
check
# show -prefix after_en
design -reset
read_verilog <<EOT
module half_clock (CLK, Q);
input CLK;
output reg Q = 1'b1;
always @(posedge CLK)
Q <= ~Q;
endmodule
EOT
proc
opt_expr
opt_dff
dump
abstract -init
check
dump
design -reset
read_verilog <<EOT
module this_adff (CLK, ARST, D, Q, magic);
parameter WIDTH = 2;
parameter CLK_POLARITY = 1'b1;
parameter ARST_POLARITY = 1'b1;
parameter ARST_VALUE = 0;
input CLK, ARST, magic;
input [WIDTH-1:0] D;
output reg [WIDTH-1:0] Q;
wire pos_clk = CLK == CLK_POLARITY;
wire pos_arst = ARST == ARST_POLARITY;
always @(posedge pos_clk, posedge pos_arst) begin
if (pos_arst)
Q <= ARST_VALUE;
else
Q <= D;
end
endmodule
EOT
proc
opt_expr
opt_dff
# show
# dump
show -prefix before_a
abstract -state -enablen magic
check
show -prefix after_a
# opt_clean
# show