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authorClifford Wolf <clifford@clifford.at>2013-12-21 08:42:37 +0100
committerClifford Wolf <clifford@clifford.at>2013-12-21 08:42:37 +0100
commit8856cec308932d224da2061ca59d0eacf90f4793 (patch)
tree9290369a9a6bbe520f1188736cdbb0bf58351ea2 /passes
parent1fb29050e57b99822db3b111647a87491f935ee9 (diff)
Now prefer smallest cells in dfflibmap
Diffstat (limited to 'passes')
-rw-r--r--passes/techmap/dfflibmap.cc24
1 files changed, 22 insertions, 2 deletions
diff --git a/passes/techmap/dfflibmap.cc b/passes/techmap/dfflibmap.cc
index 765a606c..6fbd5210 100644
--- a/passes/techmap/dfflibmap.cc
+++ b/passes/techmap/dfflibmap.cc
@@ -106,6 +106,7 @@ static void find_cell(LibertyAst *ast, std::string cell_type, bool clkpol, bool
LibertyAst *best_cell = NULL;
std::map<std::string, char> best_cell_ports;
int best_cell_pins = 0;
+ float best_cell_area = 0;
if (ast->id != "library")
log_error("Format error in liberty file.\n");
@@ -141,6 +142,11 @@ static void find_cell(LibertyAst *ast, std::string cell_type, bool clkpol, bool
this_cell_ports[cell_rst_pin] = 'R';
this_cell_ports[cell_next_pin] = 'D';
+ float area = 0;
+ LibertyAst *ar = cell->find("area");
+ if (ar != NULL && !ar->value.empty())
+ area = atof(ar->value.c_str());
+
int num_pins = 0;
bool found_output = false;
for (auto pin : cell->children)
@@ -174,14 +180,18 @@ static void find_cell(LibertyAst *ast, std::string cell_type, bool clkpol, bool
if (!found_output || (best_cell != NULL && num_pins > best_cell_pins))
continue;
+ if (best_cell != NULL && num_pins == best_cell_pins && area > best_cell_area)
+ continue;
+
best_cell = cell;
best_cell_pins = num_pins;
+ best_cell_area = area;
best_cell_ports.swap(this_cell_ports);
continue_cell_loop:;
}
if (best_cell != NULL) {
- log(" cell %s is a direct match for cell type %s.\n", best_cell->args[0].c_str(), cell_type.substr(1).c_str());
+ log(" cell %s (pins=%d, area=%.2f) is a direct match for cell type %s.\n", best_cell->args[0].c_str(), best_cell_pins, best_cell_area, cell_type.substr(1).c_str());
cell_mappings[cell_type].cell_name = best_cell->args[0];
cell_mappings[cell_type].ports = best_cell_ports;
}
@@ -192,6 +202,7 @@ static void find_cell_sr(LibertyAst *ast, std::string cell_type, bool clkpol, bo
LibertyAst *best_cell = NULL;
std::map<std::string, char> best_cell_ports;
int best_cell_pins = 0;
+ float best_cell_area = 0;
if (ast->id != "library")
log_error("Format error in liberty file.\n");
@@ -223,6 +234,11 @@ static void find_cell_sr(LibertyAst *ast, std::string cell_type, bool clkpol, bo
this_cell_ports[cell_clr_pin] = 'R';
this_cell_ports[cell_next_pin] = 'D';
+ float area = 0;
+ LibertyAst *ar = cell->find("area");
+ if (ar != NULL && !ar->value.empty())
+ area = atof(ar->value.c_str());
+
int num_pins = 0;
bool found_output = false;
for (auto pin : cell->children)
@@ -256,14 +272,18 @@ static void find_cell_sr(LibertyAst *ast, std::string cell_type, bool clkpol, bo
if (!found_output || (best_cell != NULL && num_pins > best_cell_pins))
continue;
+ if (best_cell != NULL && num_pins == best_cell_pins && area > best_cell_area)
+ continue;
+
best_cell = cell;
best_cell_pins = num_pins;
+ best_cell_area = area;
best_cell_ports.swap(this_cell_ports);
continue_cell_loop:;
}
if (best_cell != NULL) {
- log(" cell %s is a direct match for cell type %s.\n", best_cell->args[0].c_str(), cell_type.substr(1).c_str());
+ log(" cell %s (pins=%d, area=%.2f) is a direct match for cell type %s.\n", best_cell->args[0].c_str(), best_cell_pins, best_cell_area, cell_type.substr(1).c_str());
cell_mappings[cell_type].cell_name = best_cell->args[0];
cell_mappings[cell_type].ports = best_cell_ports;
}