Merge pull request #1213 from YosysHQ/eddie/wreduce_add

wreduce/opt_expr: improve width reduction for $add and $sub cells

2 files changed, 196 insertions, 0 deletions

diff --git a/tests/various/opt_expr.ys b/tests/various/opt_expr.ys
new file mode 100644
index 000000000..0c61ac881
--- /dev/null
+++ b/tests/various/opt_expr.ys
@@ -0,0 +1,148 @@
+
+read_verilog <<EOT
+module opt_expr_add_test(input [3:0] i, input [7:0] j, output [8:0] o);
+    assign o = (i << 4) + j;
+endmodule
+EOT
+
+hierarchy -auto-top
+proc
+design -save gold
+
+opt_expr -fine
+wreduce
+
+select -assert-count 1 t:$add r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+design -stash gate
+
+design -import gold -as gold
+design -import gate -as gate
+
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter
+
+##########
+
+read_verilog <<EOT
+module opt_expr_add_signed_test(input signed [3:0] i, input signed [7:0] j, output signed [8:0] o);
+    assign o = (i << 4) + j;
+endmodule
+EOT
+
+hierarchy -auto-top
+proc
+design -save gold
+
+opt_expr -fine
+wreduce
+
+select -assert-count 1 t:$add r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+design -stash gate
+
+design -import gold -as gold
+design -import gate -as gate
+
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter
+
+##########
+
+read_verilog <<EOT
+module opt_expr_sub_test1(input [3:0] i, input [7:0] j, output [8:0] o);
+    assign o = j - (i << 4);
+endmodule
+EOT
+
+hierarchy -auto-top
+proc
+design -save gold
+
+opt_expr -fine
+wreduce
+
+select -assert-count 1 t:$sub r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+design -stash gate
+
+design -import gold -as gold
+design -import gate -as gate
+
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter
+
+##########
+
+read_verilog <<EOT
+module opt_expr_sub_signed_test1(input signed [3:0] i, input signed [7:0] j, output signed [8:0] o);
+    assign o = j - (i << 4);
+endmodule
+EOT
+
+hierarchy -auto-top
+proc
+design -save gold
+
+opt_expr -fine
+wreduce
+
+select -assert-count 1 t:$sub r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+design -stash gate
+
+design -import gold -as gold
+design -import gate -as gate
+
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter
+
+##########
+
+read_verilog <<EOT
+module opt_expr_sub_test2(input [3:0] i, input [7:0] j, output [8:0] o);
+    assign o = (i << 4) - j;
+endmodule
+EOT
+
+hierarchy -auto-top
+proc
+design -save gold
+
+opt_expr -fine
+wreduce
+
+select -assert-count 1 t:$sub r:A_WIDTH=8 r:B_WIDTH=8 r:Y_WIDTH=9 %i %i %i
+
+design -stash gate
+
+design -import gold -as gold
+design -import gate -as gate
+
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter
+
+##########
+
+read_verilog <<EOT
+module opt_expr_sub_test4(input [3:0] i, output [8:0] o);
+    assign o = 5'b00010 - i;
+endmodule
+EOT
+
+hierarchy -auto-top
+proc
+design -save gold
+
+opt_expr -fine
+wreduce
+
+select -assert-count 1 t:$sub r:A_WIDTH=2 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+design -stash gate
+
+design -import gold -as gold
+design -import gate -as gate
+
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter
diff --git a/tests/various/wreduce.ys b/tests/various/wreduce.ys
new file mode 100644
index 000000000..4257292f5
--- /dev/null
+++ b/tests/various/wreduce.ys
@@ -0,0 +1,48 @@
+read_verilog <<EOT
+module wreduce_sub_test(input [3:0] i, input [7:0] j, output [8:0] o);
+    assign o = (j >> 4) - i;
+endmodule
+EOT
+
+hierarchy -auto-top
+proc
+design -save gold
+
+opt_expr
+wreduce
+
+select -assert-count 1 t:$sub r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+design -stash gate
+
+design -import gold -as gold
+design -import gate -as gate
+
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter
+
+##########
+
+read_verilog <<EOT
+module wreduce_sub_signed_test(input signed [3:0] i, input signed [7:0] j, output signed [8:0] o);
+    assign o = (j >>> 4) - i;
+endmodule
+EOT
+
+hierarchy -auto-top
+proc
+design -save gold
+
+opt_expr
+wreduce
+
+dump
+select -assert-count 1 t:$sub r:A_WIDTH=4 r:B_WIDTH=4 r:Y_WIDTH=5 %i %i %i
+
+design -stash gate
+
+design -import gold -as gold
+design -import gate -as gate
+
+miter -equiv -flatten -make_assert -make_outputs gold gate miter
+sat -verify -prove-asserts -show-ports miter