Add ice40_wrapcarry pass, rename $__ICE40_FULL_ADDER -> CARRY_WRAPPER

6 files changed, 128 insertions, 10 deletions

diff --git a/passes/pmgen/Makefile.inc b/passes/pmgen/Makefile.inc
index 7911132db..c03606152 100644
--- a/passes/pmgen/Makefile.inc
+++ b/passes/pmgen/Makefile.inc
@@ -1,4 +1,5 @@
 OBJS += passes/pmgen/ice40_dsp.o
+OBJS += passes/pmgen/ice40_wrapcarry.o
 OBJS += passes/pmgen/peepopt.o
 
 # --------------------------------------
@@ -12,6 +13,15 @@ passes/pmgen/ice40_dsp_pm.h: passes/pmgen/pmgen.py passes/pmgen/ice40_dsp.pmg
 
 # --------------------------------------
 
+passes/pmgen/ice40_wrapcarry.o: passes/pmgen/ice40_wrapcarry_pm.h
+EXTRA_OBJS += passes/pmgen/ice40_wrapcarry_pm.h
+.SECONDARY: passes/pmgen/ice40_wrapcarry_pm.h
+
+passes/pmgen/ice40_wrapcarry_pm.h: passes/pmgen/pmgen.py passes/pmgen/ice40_wrapcarry.pmg
+	$(P) mkdir -p passes/pmgen && python3 $< -o $@ -p ice40_wrapcarry $(filter-out $<,$^)
+
+# --------------------------------------
+
 passes/pmgen/peepopt.o: passes/pmgen/peepopt_pm.h
 EXTRA_OBJS += passes/pmgen/peepopt_pm.h
 .SECONDARY: passes/pmgen/peepopt_pm.h
diff --git a/passes/pmgen/ice40_wrapcarry.cc b/passes/pmgen/ice40_wrapcarry.cc
new file mode 100644
index 000000000..69ef3cd82
--- /dev/null
+++ b/passes/pmgen/ice40_wrapcarry.cc
@@ -0,0 +1,90 @@
+/*
+ *  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
+
+#include "passes/pmgen/ice40_wrapcarry_pm.h"
+
+void create_ice40_wrapcarry(ice40_wrapcarry_pm &pm)
+{
+	auto &st = pm.st_ice40_wrapcarry;
+
+#if 0
+	log("\n");
+	log("carry: %s\n", log_id(st.carry, "--"));
+	log("lut:   %s\n", log_id(st.lut, "--"));
+#endif
+
+	log("  replacing SB_LUT + SB_CARRY with $__ICE40_CARRY_WRAPPER cell.\n");
+
+	Cell *cell = pm.module->addCell(NEW_ID, "$__ICE40_CARRY_WRAPPER");
+	pm.module->swap_names(cell, st.carry);
+
+	cell->setPort("\\A", st.carry->getPort("\\I0"));
+	cell->setPort("\\B", st.carry->getPort("\\I1"));
+	cell->setPort("\\CI", st.carry->getPort("\\CI"));
+	cell->setPort("\\CO", st.carry->getPort("\\CO"));
+
+	cell->setPort("\\I0", st.lut->getPort("\\I0"));
+	cell->setPort("\\I3", st.lut->getPort("\\I3"));
+	cell->setPort("\\O", st.lut->getPort("\\O"));
+	cell->setParam("\\LUT", st.lut->getParam("\\LUT_INIT"));
+
+	pm.autoremove(st.carry);
+	pm.autoremove(st.lut);
+}
+
+struct Ice40WrapCarryPass : public Pass {
+	Ice40WrapCarryPass() : Pass("ice40_wrapcarry", "iCE40: wrap carries") { }
+	void help() YS_OVERRIDE
+	{
+		//   |---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|---v---|
+		log("\n");
+		log("    ice40_wrapcarry [selection]\n");
+		log("\n");
+		log("Wrap manually instantiated SB_CARRY cells, along with their associated SB_LUTs,\n");
+		log("into an internal $__ICE40_CARRY_WRAPPER cell for preservation across technology\n");
+		log("mapping.");
+		log("\n");
+	}
+	void execute(std::vector<std::string> args, RTLIL::Design *design) YS_OVERRIDE
+	{
+		log_header(design, "Executing ICE40_WRAPCARRY pass (wrap carries).\n");
+
+		size_t argidx;
+		for (argidx = 1; argidx < args.size(); argidx++)
+		{
+			// if (args[argidx] == "-singleton") {
+			// 	singleton_mode = true;
+			// 	continue;
+			// }
+			break;
+		}
+		extra_args(args, argidx, design);
+
+		for (auto module : design->selected_modules())
+			ice40_wrapcarry_pm(module, module->selected_cells()).run_ice40_wrapcarry(create_ice40_wrapcarry);
+	}
+} Ice40WrapCarryPass;
+
+PRIVATE_NAMESPACE_END
diff --git a/passes/pmgen/ice40_wrapcarry.pmg b/passes/pmgen/ice40_wrapcarry.pmg
new file mode 100644
index 000000000..9e64c7467
--- /dev/null
+++ b/passes/pmgen/ice40_wrapcarry.pmg
@@ -0,0 +1,11 @@
+pattern ice40_wrapcarry
+
+match carry
+	select carry->type.in(\SB_CARRY)
+endmatch
+
+match lut
+	select lut->type.in(\SB_LUT4)
+	index <SigSpec> port(lut, \I1) === port(carry, \I0)
+	index <SigSpec> port(lut, \I2) === port(carry, \I1)
+endmatch
diff --git a/techlibs/ice40/arith_map.v b/techlibs/ice40/arith_map.v
index 65f28c585..26b24db9e 100644
--- a/techlibs/ice40/arith_map.v
+++ b/techlibs/ice40/arith_map.v
@@ -44,10 +44,18 @@ module _80_ice40_alu (A, B, CI, BI, X, Y, CO);
 
 	genvar i;
 	generate for (i = 0; i < Y_WIDTH; i = i + 1) begin:slice
-		\$__ICE40_FULL_ADDER carry (
+		\$__ICE40_CARRY_WRAPPER #(
+			//    A[0]: 1010 1010 1010 1010
+			//    A[1]: 1100 1100 1100 1100
+			//    A[2]: 1111 0000 1111 0000
+			//    A[3]: 1111 1111 0000 0000
+			.LUT(16'b 0110_1001_1001_0110)
+		) fadd (
 			.A(AA[i]),
 			.B(BB[i]),
 			.CI(C[i]),
+			.I0(1'b0),
+			.I3(C[i]),
 			.CO(CO[i]),
 			.O(Y[i])
 		);
diff --git a/techlibs/ice40/cells_map.v b/techlibs/ice40/cells_map.v
index 511b7f6c6..0c10c9ac4 100644
--- a/techlibs/ice40/cells_map.v
+++ b/techlibs/ice40/cells_map.v
@@ -63,7 +63,8 @@ endmodule
 `endif
 
 `ifndef NO_ADDER
-module \$__ICE40_FULL_ADDER (output CO, O, input A, B, CI);
+module \$__ICE40_CARRY_WRAPPER (output CO, O, input A, B, CI, I0, I3);
+  parameter LUT = 0;
   SB_CARRY carry (
     .I0(A),
     .I1(B),
@@ -72,13 +73,9 @@ module \$__ICE40_FULL_ADDER (output CO, O, input A, B, CI);
   );
   \$lut #(
     .WIDTH(4),
-    //    A[0]: 1010 1010 1010 1010
-    //    A[1]: 1100 1100 1100 1100
-    //    A[2]: 1111 0000 1111 0000
-    //    A[3]: 1111 1111 0000 0000
-    .LUT(16'b 0110_1001_1001_0110)
-  ) adder (
-    .A({CI,B,A,1'b0}),
+    .LUT(LUT)
+  ) lut (
+    .A({I3,B,A,I0}),
     .Y(O)
   );
 endmodule
diff --git a/techlibs/ice40/synth_ice40.cc b/techlibs/ice40/synth_ice40.cc
index 93d5dcbd4..8f4a0f377 100644
--- a/techlibs/ice40/synth_ice40.cc
+++ b/techlibs/ice40/synth_ice40.cc
@@ -293,8 +293,10 @@ struct SynthIce40Pass : public ScriptPass
 		{
 			if (nocarry)
 				run("techmap");
-			else
+			else {
+				run("ice40_wrapcarry");
 				run("techmap -map +/techmap.v -map +/ice40/arith_map.v");
+			}
 			if (retime || help_mode)
 				run(abc + " -dff", "(only if -retime)");
 			run("ice40_opt");