From 08778917dbd8ba026382694c57c1e8a02a473455 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Martin=20Povi=C5=A1er?= Date: Mon, 16 Dec 2024 12:56:44 +0100 Subject: [PATCH 1/4] wreduce: Optimize signedness when possible --- passes/opt/wreduce.cc | 51 +++++++++++++++++++++++++++++++++++++++ tests/various/wreduce2.ys | 22 +++++++++++++++++ 2 files changed, 73 insertions(+) create mode 100644 tests/various/wreduce2.ys diff --git a/passes/opt/wreduce.cc b/passes/opt/wreduce.cc index 02678d67680..9c0fcc7e1ea 100644 --- a/passes/opt/wreduce.cc +++ b/passes/opt/wreduce.cc @@ -263,6 +263,19 @@ struct WreduceWorker } } + int reduced_opsize(const SigSpec &inp, bool signed_) + { + int size = GetSize(inp); + if (signed_) { + while (size >= 2 && inp[size - 1] == inp[size - 2]) + size--; + } else { + while (size >= 1 && inp[size - 1] == State::S0) + size--; + } + return size; + } + void run_cell(Cell *cell) { bool did_something = false; @@ -295,6 +308,44 @@ struct WreduceWorker bool port_a_signed = false; bool port_b_signed = false; + // Under certain conditions we are free to choose the signedness of the operands + if (cell->type.in(ID($mul), ID($add), ID($sub)) && + max_port_a_size == GetSize(sig) && + max_port_b_size == GetSize(sig)) { + SigSpec sig_a = mi.sigmap(cell->getPort(ID::A)), sig_b = mi.sigmap(cell->getPort(ID::B)); + + // Remove top bits from sig_a and sig_b which are not visible on the output + sig_a.extend_u0(max_port_a_size); + sig_b.extend_u0(max_port_b_size); + + int signed_size, unsigned_size; + if (cell->type == ID($mul)) { + signed_size = reduced_opsize(sig_a, true) * reduced_opsize(sig_b, true); + unsigned_size = reduced_opsize(sig_a, false) * reduced_opsize(sig_b, false); + } else { + signed_size = max(reduced_opsize(sig_a, true), reduced_opsize(sig_b, true)); + unsigned_size = max(reduced_opsize(sig_a, false), reduced_opsize(sig_b, false)); + } + + if (!port_a_signed && !port_b_signed && signed_size < unsigned_size) { + log("Converting cell %s.%s (%s) from unsigned to signed.\n", + log_id(module), log_id(cell), log_id(cell->type)); + cell->setParam(ID::A_SIGNED, 1); + cell->setParam(ID::B_SIGNED, 1); + port_a_signed = true; + port_b_signed = true; + did_something = true; + } else if (port_a_signed && port_b_signed && unsigned_size < signed_size) { + log("Converting cell %s.%s (%s) from signed to unsigned.\n", + log_id(module), log_id(cell), log_id(cell->type)); + cell->setParam(ID::A_SIGNED, 0); + cell->setParam(ID::B_SIGNED, 0); + port_a_signed = false; + port_b_signed = false; + did_something = true; + } + } + if (max_port_a_size >= 0 && cell->type != ID($shiftx)) run_reduce_inport(cell, 'A', max_port_a_size, port_a_signed, did_something); diff --git a/tests/various/wreduce2.ys b/tests/various/wreduce2.ys new file mode 100644 index 00000000000..496aa97e90e --- /dev/null +++ b/tests/various/wreduce2.ys @@ -0,0 +1,22 @@ +read_verilog < Date: Fri, 3 Jan 2025 12:54:34 +0100 Subject: [PATCH 2/4] wreduce: Adjust naming and comments --- passes/opt/wreduce.cc | 17 +++++++++-------- 1 file changed, 9 insertions(+), 8 deletions(-) diff --git a/passes/opt/wreduce.cc b/passes/opt/wreduce.cc index 9c0fcc7e1ea..5b3b1edc827 100644 --- a/passes/opt/wreduce.cc +++ b/passes/opt/wreduce.cc @@ -308,7 +308,8 @@ struct WreduceWorker bool port_a_signed = false; bool port_b_signed = false; - // Under certain conditions we are free to choose the signedness of the operands + // For some operations if the output is no wider than either of the inputs + // we are free to choose the signedness of the operands if (cell->type.in(ID($mul), ID($add), ID($sub)) && max_port_a_size == GetSize(sig) && max_port_b_size == GetSize(sig)) { @@ -318,16 +319,16 @@ struct WreduceWorker sig_a.extend_u0(max_port_a_size); sig_b.extend_u0(max_port_b_size); - int signed_size, unsigned_size; + int signed_cost, unsigned_cost; if (cell->type == ID($mul)) { - signed_size = reduced_opsize(sig_a, true) * reduced_opsize(sig_b, true); - unsigned_size = reduced_opsize(sig_a, false) * reduced_opsize(sig_b, false); + signed_cost = reduced_opsize(sig_a, true) * reduced_opsize(sig_b, true); + unsigned_cost = reduced_opsize(sig_a, false) * reduced_opsize(sig_b, false); } else { - signed_size = max(reduced_opsize(sig_a, true), reduced_opsize(sig_b, true)); - unsigned_size = max(reduced_opsize(sig_a, false), reduced_opsize(sig_b, false)); + signed_cost = max(reduced_opsize(sig_a, true), reduced_opsize(sig_b, true)); + unsigned_cost = max(reduced_opsize(sig_a, false), reduced_opsize(sig_b, false)); } - if (!port_a_signed && !port_b_signed && signed_size < unsigned_size) { + if (!port_a_signed && !port_b_signed && signed_cost < unsigned_cost) { log("Converting cell %s.%s (%s) from unsigned to signed.\n", log_id(module), log_id(cell), log_id(cell->type)); cell->setParam(ID::A_SIGNED, 1); @@ -335,7 +336,7 @@ struct WreduceWorker port_a_signed = true; port_b_signed = true; did_something = true; - } else if (port_a_signed && port_b_signed && unsigned_size < signed_size) { + } else if (port_a_signed && port_b_signed && unsigned_cost < signed_cost) { log("Converting cell %s.%s (%s) from signed to unsigned.\n", log_id(module), log_id(cell), log_id(cell->type)); cell->setParam(ID::A_SIGNED, 0); From 9e039095e9fe25ef49a5993ab6b9699c008d8325 Mon Sep 17 00:00:00 2001 From: KrystalDelusion <93062060+KrystalDelusion@users.noreply.github.com> Date: Mon, 6 Jan 2025 11:08:00 +1300 Subject: [PATCH 3/4] Docs: Remove restructure note It's been almost a year since the restructure, so it's not recent anymore and doesn't need to link back to the old version. --- docs/source/index.rst | 11 ----------- 1 file changed, 11 deletions(-) diff --git a/docs/source/index.rst b/docs/source/index.rst index ab174242438..61dc114ef1f 100644 --- a/docs/source/index.rst +++ b/docs/source/index.rst @@ -7,17 +7,6 @@ see :doc:`/introduction`. For a quick guide on how to get started using Yosys, check out :doc:`/getting_started/index`. For the complete list of commands available, go to :ref:`commandindex`. -.. note:: - - This documentation recently went through a major restructure. If you're - looking for something from the previous version and can't find it here, - please `let us know`_. Documentation from before the restructure can still - be found by switching to `version 0.36`_ or earlier. Note that the previous - theme does not include a version switcher. - -.. _let us know: https://github.com/YosysHQ/yosys/issues/new/choose -.. _version 0.36: https://yosyshq.readthedocs.io/projects/yosys/en/0.36/ - .. todo:: look into command ref improvements - Search bar with live drop down suggestions for matching on title / From d37449605d1d66279f81cbe71dbf2e8ec4937215 Mon Sep 17 00:00:00 2001 From: "github-actions[bot]" <41898282+github-actions[bot]@users.noreply.github.com> Date: Tue, 7 Jan 2025 00:21:35 +0000 Subject: [PATCH 4/4] Bump version --- Makefile | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Makefile b/Makefile index 6f5fec6a299..c31fc26264e 100644 --- a/Makefile +++ b/Makefile @@ -153,7 +153,7 @@ ifeq ($(OS), Haiku) CXXFLAGS += -D_DEFAULT_SOURCE endif -YOSYS_VER := 0.48+51 +YOSYS_VER := 0.48+57 # Note: We arrange for .gitcommit to contain the (short) commit hash in # tarballs generated with git-archive(1) using .gitattributes. The git repo