From 9ef078848a5b121336b83043c565ce47433eb2d8 Mon Sep 17 00:00:00 2001
From: whitequark <whitequark@whitequark.org>
Date: Wed, 5 Dec 2018 04:50:38 +0000
Subject: [PATCH] gate2lut: new techlib, for converting Yosys gates to FPGA
 LUTs.

---
 techlibs/common/Makefile.inc |  1 +
 techlibs/common/gate2lut.v   | 87 ++++++++++++++++++++++++++++++++++++
 tests/lut/.gitignore         |  1 +
 tests/lut/check_map.ys       | 13 ++++++
 tests/lut/map_and.v          |  5 +++
 tests/lut/map_mux.v          |  5 +++
 tests/lut/map_not.v          |  5 +++
 tests/lut/map_or.v           |  5 +++
 tests/lut/map_xor.v          |  5 +++
 tests/lut/run-test.sh        |  6 +++
 10 files changed, 133 insertions(+)
 create mode 100644 techlibs/common/gate2lut.v
 create mode 100644 tests/lut/.gitignore
 create mode 100644 tests/lut/check_map.ys
 create mode 100644 tests/lut/map_and.v
 create mode 100644 tests/lut/map_mux.v
 create mode 100644 tests/lut/map_not.v
 create mode 100644 tests/lut/map_or.v
 create mode 100644 tests/lut/map_xor.v
 create mode 100644 tests/lut/run-test.sh

diff --git a/techlibs/common/Makefile.inc b/techlibs/common/Makefile.inc
index ab961ac0b..70074f653 100644
--- a/techlibs/common/Makefile.inc
+++ b/techlibs/common/Makefile.inc
@@ -25,5 +25,6 @@ $(eval $(call add_share_file,share,techlibs/common/techmap.v))
 $(eval $(call add_share_file,share,techlibs/common/pmux2mux.v))
 $(eval $(call add_share_file,share,techlibs/common/adff2dff.v))
 $(eval $(call add_share_file,share,techlibs/common/dff2ff.v))
+$(eval $(call add_share_file,share,techlibs/common/gate2lut.v))
 $(eval $(call add_share_file,share,techlibs/common/cells.lib))
 
diff --git a/techlibs/common/gate2lut.v b/techlibs/common/gate2lut.v
new file mode 100644
index 000000000..99c123f4a
--- /dev/null
+++ b/techlibs/common/gate2lut.v
@@ -0,0 +1,87 @@
+(* techmap_celltype = "$_NOT_" *)
+module _90_lut_not (A, Y);
+    input A;
+    output Y;
+
+    wire [`LUT_WIDTH-1:0] AA;
+    assign AA = {A};
+
+    \$lut #(
+        .WIDTH(`LUT_WIDTH),
+        .LUT(4'b01)
+    ) lut (
+        .A(AA),
+        .Y(Y)
+    );
+endmodule
+
+(* techmap_celltype = "$_OR_" *)
+module _90_lut_or (A, B, Y);
+    input A, B;
+    output Y;
+
+    wire [`LUT_WIDTH-1:0] AA;
+    assign AA = {B, A};
+
+    \$lut #(
+        .WIDTH(`LUT_WIDTH),
+        .LUT(4'b1110)
+    ) lut (
+        .A(AA),
+        .Y(Y)
+    );
+endmodule
+
+(* techmap_celltype = "$_AND_" *)
+module _90_lut_and (A, B, Y);
+    input A, B;
+    output Y;
+
+    wire [`LUT_WIDTH-1:0] AA;
+    assign AA = {B, A};
+
+    \$lut #(
+        .WIDTH(`LUT_WIDTH),
+        .LUT(4'b1000)
+    ) lut (
+        .A(AA),
+        .Y(Y)
+    );
+endmodule
+
+(* techmap_celltype = "$_XOR_" *)
+module _90_lut_xor (A, B, Y);
+    input A, B;
+    output Y;
+
+    wire [`LUT_WIDTH-1:0] AA;
+    assign AA = {B, A};
+
+    \$lut #(
+        .WIDTH(`LUT_WIDTH),
+        .LUT(4'b0110)
+    ) lut (
+        .A(AA),
+        .Y(Y)
+    );
+endmodule
+
+(* techmap_celltype = "$_MUX_" *)
+module _90_lut_mux (A, B, S, Y);
+    input A, B, S;
+    output Y;
+
+    wire [`LUT_WIDTH-1:0] AA;
+    assign AA = {S, B, A};
+
+    \$lut #(
+        .WIDTH(`LUT_WIDTH),
+        //     A 1010 1010
+        //     B 1100 1100
+        //     S 1111 0000
+        .LUT(8'b_1100_1010)
+    ) lut (
+        .A(AA),
+        .Y(Y)
+    );
+endmodule
diff --git a/tests/lut/.gitignore b/tests/lut/.gitignore
new file mode 100644
index 000000000..397b4a762
--- /dev/null
+++ b/tests/lut/.gitignore
@@ -0,0 +1 @@
+*.log
diff --git a/tests/lut/check_map.ys b/tests/lut/check_map.ys
new file mode 100644
index 000000000..6d659891f
--- /dev/null
+++ b/tests/lut/check_map.ys
@@ -0,0 +1,13 @@
+design -save preopt
+
+simplemap
+techmap -map +/gate2lut.v -D LUT_WIDTH=4
+select -assert-count 1 t:$lut
+design -stash postopt
+
+design -copy-from preopt -as preopt top
+design -copy-from postopt -as postopt top
+equiv_make preopt postopt equiv
+prep -flatten -top equiv
+equiv_induct
+equiv_status -assert
diff --git a/tests/lut/map_and.v b/tests/lut/map_and.v
new file mode 100644
index 000000000..68ae33fd6
--- /dev/null
+++ b/tests/lut/map_and.v
@@ -0,0 +1,5 @@
+module top(...);
+    input a, b;
+    output y;
+    assign y = a&b;
+endmodule
diff --git a/tests/lut/map_mux.v b/tests/lut/map_mux.v
new file mode 100644
index 000000000..ccecf3023
--- /dev/null
+++ b/tests/lut/map_mux.v
@@ -0,0 +1,5 @@
+module top(...);
+    input a, b, s;
+    output y;
+    assign y = s?a:b;
+endmodule
diff --git a/tests/lut/map_not.v b/tests/lut/map_not.v
new file mode 100644
index 000000000..385997414
--- /dev/null
+++ b/tests/lut/map_not.v
@@ -0,0 +1,5 @@
+module top(...);
+    input a;
+    output y;
+    assign y = ~a;
+endmodule
diff --git a/tests/lut/map_or.v b/tests/lut/map_or.v
new file mode 100644
index 000000000..8b8c55188
--- /dev/null
+++ b/tests/lut/map_or.v
@@ -0,0 +1,5 @@
+module top(...);
+    input a, b;
+    output y;
+    assign y = a|b;
+endmodule
diff --git a/tests/lut/map_xor.v b/tests/lut/map_xor.v
new file mode 100644
index 000000000..708a05789
--- /dev/null
+++ b/tests/lut/map_xor.v
@@ -0,0 +1,5 @@
+module top(...);
+    input a, b;
+    output y;
+    assign y = a^b;
+endmodule
diff --git a/tests/lut/run-test.sh b/tests/lut/run-test.sh
new file mode 100644
index 000000000..207417fa6
--- /dev/null
+++ b/tests/lut/run-test.sh
@@ -0,0 +1,6 @@
+#!/bin/bash
+set -e
+for x in *.v; do
+  echo "Running $x.."
+  ../../yosys -q -s check_map.ys -l ${x%.v}.log $x
+done