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extract_reduce now only removes the head of the chain, relying on "clean" to delete upstream cells. Added "-allow-off-chain" flag, but it's currently ignored.

This commit is contained in:
Andrew Zonenberg 2017-09-15 10:52:09 -07:00
parent 5c4ea1366f
commit 3404934c9c
1 changed files with 19 additions and 9 deletions
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26
passes/techmap/extract_reduce.cc
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@ -37,7 +37,7 @@ struct ExtractReducePass : public Pass
{ {
// |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---| // |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
log("\n"); log("\n");
log(" extract_reduce [selection]\n"); log(" extract_reduce [options] [selection]\n");
log("\n"); log("\n");
log("converts gate chains into $reduce_* cells\n"); log("converts gate chains into $reduce_* cells\n");
log("\n"); log("\n");
@ -48,6 +48,11 @@ struct ExtractReducePass : public Pass
log("to map the design to only $_AND_ cells, run extract_reduce, map the remaining\n"); log("to map the design to only $_AND_ cells, run extract_reduce, map the remaining\n");
log("parts of the design to AND/OR/XOR cells, and run extract_reduce a second time.\n"); log("parts of the design to AND/OR/XOR cells, and run extract_reduce a second time.\n");
log("\n"); log("\n");
log(" -allow-off-chain\n");
log(" Allows matching of cells that have loads outside the chain. These cells\n");
log(" will be replicated and folded into the $reduce_* cell, but the original\n");
log(" cell will remain, driving its original loads.\n");
log("\n");
} }
virtual void execute(std::vector<std::string> args, RTLIL::Design *design) virtual void execute(std::vector<std::string> args, RTLIL::Design *design)
@ -56,12 +61,14 @@ struct ExtractReducePass : public Pass
log_push(); log_push();
size_t argidx; size_t argidx;
bool allow_off_chain = false;
for (argidx = 1; argidx < args.size(); argidx++) for (argidx = 1; argidx < args.size(); argidx++)
{ {
// if (args[argidx] == "-v") { if (args[argidx] == "-allow-off-chain")
// verbose = true; {
// continue; allow_off_chain = true;
// } continue;
}
break; break;
} }
extra_args(args, argidx, design); extra_args(args, argidx, design);
@ -102,6 +109,7 @@ struct ExtractReducePass : public Pass
// Actual logic starts here // Actual logic starts here
pool<Cell*> consumed_cells; pool<Cell*> consumed_cells;
pool<Cell*> head_cells;
for (auto cell : module->selected_cells()) for (auto cell : module->selected_cells())
{ {
if (consumed_cells.count(cell)) if (consumed_cells.count(cell))
@ -224,11 +232,13 @@ struct ExtractReducePass : public Pass
for (auto x : cur_supercell) for (auto x : cur_supercell)
consumed_cells.insert(x); consumed_cells.insert(x);
} head_cells.insert(head_cell);
} }
}
// Remove every cell that we've used up // Remove all of the head cells, since we supplant them.
for (auto cell : consumed_cells) // Do not remove the upstream cells since some might still be in use ("clean" will get rid of unused ones)
for (auto cell : head_cells)
module->remove(cell); module->remove(cell);
} }