Import initial pmux2shiftx from eddieh

Signed-off-by: Clifford Wolf <clifford@clifford.at>

diff --git a/passes/opt/Makefile.inc b/passes/opt/Makefile.inc
index c3e0a2a40204b70ef7134455eb40670822bf916c..337fee9e43f02d3f0f65f41f93347f565ed516ce 100644 (file)
--- a/passes/opt/Makefile.inc
+++ b/passes/opt/Makefile.inc
@@ -13,5 +13,6 @@ OBJS += passes/opt/wreduce.o
 OBJS += passes/opt/opt_demorgan.o
 OBJS += passes/opt/rmports.o
 OBJS += passes/opt/opt_lut.o
+OBJS += passes/opt/pmux2shiftx.o
 endif
 

diff --git a/passes/opt/pmux2shiftx.cc b/passes/opt/pmux2shiftx.cc
new file mode 100644 (file)
index 0000000..6ffc27a
--- /dev/null
+++ b/passes/opt/pmux2shiftx.cc
@@ -0,0 +1,81 @@
+/*
+ *  yosys -- Yosys Open SYnthesis Suite
+ *
+ *  Copyright (C) 2012  Clifford Wolf <clifford@clifford.at>
+ *
+ *  Permission to use, copy, modify, and/or distribute this software for any
+ *  purpose with or without fee is hereby granted, provided that the above
+ *  copyright notice and this permission notice appear in all copies.
+ *
+ *  THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ *  WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ *  MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ *  ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ *  WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ *  ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ *  OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ *
+ */
+
+#include "kernel/yosys.h"
+#include "kernel/sigtools.h"
+
+USING_YOSYS_NAMESPACE
+PRIVATE_NAMESPACE_BEGIN
+
+struct Pmux2ShiftxPass : public Pass {
+       Pmux2ShiftxPass() : Pass("pmux2shiftx", "transform $pmux cells to $shiftx cells") { }
+       void help() YS_OVERRIDE
+       {
+               //   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+               log("\n");
+               log("    pmux2shiftx [selection]\n");
+               log("\n");
+               log("This pass transforms $pmux cells to $shiftx cells.\n");
+               log("\n");
+       }
+       void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
+       {
+               log_header(design, "Executing PMUX2SHIFTX pass.\n");
+
+               size_t argidx;
+               for (argidx = 1; argidx < args.size(); argidx++) {
+                       break;
+               }
+               extra_args(args, argidx, design);
+
+               for (auto module : design->selected_modules())
+               for (auto cell : module->selected_cells())
+               {
+                       if (cell->type != "$pmux")
+                               continue;
+
+                       // Create a new encoder, out of a $pmux, that takes
+                       // the existing pmux's 'S' input and transforms it
+                       // back into a binary value
+                       RTLIL::SigSpec shiftx_a;
+                       RTLIL::SigSpec pmux_s;
+
+                       int s_width = cell->getParam("\\S_WIDTH").as_int();
+                       if (!cell->getPort("\\A").is_fully_undef()) {
+                               ++s_width;
+                               shiftx_a.append(cell->getPort("\\A"));
+                               pmux_s.append(module->Not(NEW_ID, module->ReduceOr(NEW_ID, cell->getPort("\\S"))));
+                       }
+                       const int clog2width = ceil(log2(s_width));
+
+                       RTLIL::SigSpec pmux_b;
+                       for (int i = s_width-1; i >= 0; i--)
+                               pmux_b.append(RTLIL::Const(i, clog2width));
+                       shiftx_a.append(cell->getPort("\\B"));
+                       pmux_s.append(cell->getPort("\\S"));
+
+                       RTLIL::SigSpec pmux_y = module->addWire(NEW_ID, clog2width);
+                       module->addPmux(NEW_ID, RTLIL::Const(RTLIL::Sx, clog2width), pmux_b, pmux_s, pmux_y);
+                       module->addShiftx(NEW_ID, shiftx_a, pmux_y, cell->getPort("\\Y"));
+                       module->remove(cell);
+               }
+       }
+} Pmux2ShiftxPass;
+
+PRIVATE_NAMESPACE_END