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ecp5: LUT packer

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Signed-off-by: David Shah <davey1576@gmail.com>
This commit is contained in:
David Shah 2018-07-17 15:44:36 +02:00
parent c0567c0d30
commit b52269bc19
3 changed files with 95 additions and 19 deletions
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12
ecp5/cells.cc
View File

@ -143,7 +143,7 @@ static void replace_port_safe(bool has_ff, CellInfo *ff, IdString ff_port, CellI
}
}
void ff_to_lc(Context *ctx, CellInfo *ff, CellInfo *lc, int index, bool driven_by_lut)
void ff_to_slice(Context *ctx, CellInfo *ff, CellInfo *lc, int index, bool driven_by_lut)
{
bool has_ff = lc->ports.at(ctx->id("Q0")).net != nullptr || lc->ports.at(ctx->id("Q1")).net != nullptr;
std::string reg = "REG" + std::to_string(index);
@ -165,4 +165,14 @@ void ff_to_lc(Context *ctx, CellInfo *ff, CellInfo *lc, int index, bool driven_b
}
}
void lut_to_slice(Context *ctx, CellInfo *lut, CellInfo *lc, int index)
{
lc->params[ctx->id("LUT" + std::to_string(index) + "_INITVAL")] = str_or_default(lc->params, ctx->id("INIT"), "0");
replace_port(lut, ctx->id("A"), lc, ctx->id("A" + std::to_string(index)));
replace_port(lut, ctx->id("B"), lc, ctx->id("B" + std::to_string(index)));
replace_port(lut, ctx->id("C"), lc, ctx->id("C" + std::to_string(index)));
replace_port(lut, ctx->id("D"), lc, ctx->id("D" + std::to_string(index)));
replace_port(lut, ctx->id("Z"), lc, ctx->id("F" + std::to_string(index)));
}
NEXTPNR_NAMESPACE_END

3
ecp5/cells.h
View File

@ -46,7 +46,8 @@ inline bool is_pfumx(const BaseCtx *ctx, const CellInfo *cell) { return cell->ty
inline bool is_l6mux(const BaseCtx *ctx, const CellInfo *cell) { return cell->type == ctx->id("L6MUX21"); }
void ff_to_lc(Context *ctx, CellInfo *ff, CellInfo *lc, int index, bool driven_by_lut);
void ff_to_slice(Context *ctx, CellInfo *ff, CellInfo *lc, int index, bool driven_by_lut);
void lut_to_slice(Context *ctx, CellInfo *lut, CellInfo *lc, int index);
NEXTPNR_NAMESPACE_END

99
ecp5/pack.cc
View File

@ -55,6 +55,7 @@ class Ecp5Packer
// Find FFs associated with LUTs, or LUT expansion muxes
void find_lutff_pairs()
{
log_info("Finding LUTFF pairs...\n");
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
if (is_lut(ctx, ci) || is_pfumx(ctx, ci) || is_l6mux(ctx, ci)) {
@ -108,8 +109,9 @@ class Ecp5Packer
}
// Find "closely connected" LUTs and pair them together
void pair_luts(std::unordered_map<IdString, IdString> &lutPairs)
void pair_luts()
{
log_info("Finding LUT-LUT pairs...\n");
std::unordered_set<IdString> procdLuts;
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
@ -240,22 +242,25 @@ class Ecp5Packer
NetInfo *f1 = ci->ports.at(ctx->id("ALUT")).net;
if (f1 == nullptr)
log_error("PFUMX '%s' has disconnected port 'ALUT'\n", ci->name.c_str(ctx));
CellInfo *lc0 = net_driven_by(ctx, f0, is_lut, ctx->id("Z"));
CellInfo *lc1 = net_driven_by(ctx, f1, is_lut, ctx->id("Z"));
if (lc0 == nullptr)
CellInfo *lut0 = net_driven_by(ctx, f0, is_lut, ctx->id("Z"));
CellInfo *lut1 = net_driven_by(ctx, f1, is_lut, ctx->id("Z"));
if (lut0 == nullptr)
log_error("PFUMX '%s' has BLUT driven by cell other than a LUT\n", ci->name.c_str(ctx));
if (lc1 == nullptr)
if (lut1 == nullptr)
log_error("PFUMX '%s' has ALUT driven by cell other than a LUT\n", ci->name.c_str(ctx));
replace_port(lc0, ctx->id("A"), packed.get(), ctx->id("A0"));
replace_port(lc0, ctx->id("B"), packed.get(), ctx->id("B0"));
replace_port(lc0, ctx->id("C"), packed.get(), ctx->id("C0"));
replace_port(lc0, ctx->id("D"), packed.get(), ctx->id("D0"));
replace_port(lc1, ctx->id("A"), packed.get(), ctx->id("A1"));
replace_port(lc1, ctx->id("B"), packed.get(), ctx->id("B1"));
replace_port(lc1, ctx->id("C"), packed.get(), ctx->id("C1"));
replace_port(lc1, ctx->id("D"), packed.get(), ctx->id("D1"));
replace_port(lut0, ctx->id("A"), packed.get(), ctx->id("A0"));
replace_port(lut0, ctx->id("B"), packed.get(), ctx->id("B0"));
replace_port(lut0, ctx->id("C"), packed.get(), ctx->id("C0"));
replace_port(lut0, ctx->id("D"), packed.get(), ctx->id("D0"));
replace_port(lut1, ctx->id("A"), packed.get(), ctx->id("A1"));
replace_port(lut1, ctx->id("B"), packed.get(), ctx->id("B1"));
replace_port(lut1, ctx->id("C"), packed.get(), ctx->id("C1"));
replace_port(lut1, ctx->id("D"), packed.get(), ctx->id("D1"));
replace_port(ci, ctx->id("C0"), packed.get(), ctx->id("M0"));
replace_port(ci, ctx->id("Z"), packed.get(), ctx->id("OFX0"));
packed->params[ctx->id("LUT0_INITVAL")] = str_or_default(lut0->params, ctx->id("INIT"), "0");
packed->params[ctx->id("LUT1_INITVAL")] = str_or_default(lut1->params, ctx->id("INIT"), "0");
ctx->nets.erase(f0->name);
ctx->nets.erase(f1->name);
sliceUsage[packed->name].lut0_used = true;
@ -264,14 +269,70 @@ class Ecp5Packer
if (lutffPairs.find(ci->name) != lutffPairs.end()) {
CellInfo *ff = ctx->cells.at(lutffPairs[ci->name]).get();
ff_to_lc(ctx, ff, packed.get(), 0, true);
ff_to_slice(ctx, ff, packed.get(), 0, true);
packed_cells.insert(ff->name);
sliceUsage[packed->name].ff0_used = true;
}
new_cells.push_back(std::move(packed));
packed_cells.insert(lc0->name);
packed_cells.insert(lc1->name);
packed_cells.insert(lut0->name);
packed_cells.insert(lut1->name);
packed_cells.insert(ci->name);
}
}
flush_cells();
}
// Pack LUTs that have been paired together
void pack_lut_pairs()
{
log_info("Packing paired LUTs into a SLICE...\n");
for (auto pair : lutPairs) {
CellInfo *lut0 = ctx->cells.at(pair.first).get();
CellInfo *lut1 = ctx->cells.at(pair.second).get();
std::unique_ptr<CellInfo> slice =
create_ecp5_cell(ctx, ctx->id("TRELLIS_SLICE"), lut0->name.str(ctx) + "_SLICE");
lut_to_slice(ctx, lut0, slice.get(), 0);
lut_to_slice(ctx, lut1, slice.get(), 1);
auto ff0 = lutffPairs.find(lut0->name), ff1 = lutffPairs.find(lut1->name);
if (ff0 != lutffPairs.end()) {
ff_to_slice(ctx, ctx->cells.at(ff0->second).get(), slice.get(), 0, true);
packed_cells.insert(ff0->second);
}
if (ff1 != lutffPairs.end()) {
ff_to_slice(ctx, ctx->cells.at(ff1->second).get(), slice.get(), 1, true);
packed_cells.insert(ff1->second);
}
new_cells.push_back(std::move(slice));
packed_cells.insert(lut0->name);
packed_cells.insert(lut1->name);
}
flush_cells();
}
// Pack single LUTs that weren't paired into their own slice,
// with an optional FF also
void pack_remaining_luts()
{
log_info("Unpaired LUTs into a SLICE...\n");
for (auto cell : sorted(ctx->cells)) {
CellInfo *ci = cell.second;
if (is_lut(ctx, ci)) {
std::unique_ptr<CellInfo> slice =
create_ecp5_cell(ctx, ctx->id("TRELLIS_SLICE"), ci->name.str(ctx) + "_SLICE");
lut_to_slice(ctx, ci, slice.get(), 0);
auto ff = lutffPairs.find(ci->name);
if (ff != lutffPairs.end()) {
ff_to_slice(ctx, ctx->cells.at(ff->second).get(), slice.get(), 0, true);
packed_cells.insert(ff->second);
}
new_cells.push_back(std::move(slice));
packed_cells.insert(ci->name);
}
}
@ -282,7 +343,11 @@ class Ecp5Packer
void pack()
{
pack_io();
find_lutff_pairs();
pack_lut5s();
pair_luts();
pack_lut_pairs();
pack_remaining_luts();
}
private:
@ -302,8 +367,8 @@ class Ecp5Packer
std::unordered_map<IdString, SliceUsage> sliceUsage;
std::unordered_map<IdString, IdString> lutffPairs;
std::unordered_map<IdString, IdString> fflutPairs;
std::unordered_map<IdString, IdString> lutPairs;
};
// Main pack function
bool Arch::pack()
{