Merge pull request #2 from alainmarcel/new_peepopts

Fix code review issue

passes/pmgen/peepopt_muldiv_c.pmg

@@ -34,6 +34,7 @@ match div
 	// Check that b_const and c_const is constant
 	filter b_const.is_fully_const()
 	filter port(div, \B).is_fully_const()
+	index <SigSpec> remove_bottom_padding(port(div, \A)) === mul_y
 endmatch
 
 code

passes/pmgen/pmgen.py

@@ -429,6 +429,13 @@ def process_pmgfile(f, filename):
     print("  }", file=f)
     print("", file=f)
 
+    print("  SigSpec remove_bottom_padding(SigSpec sig) {", file=f)
+    print("    int i = 0;", file=f)
+    print("    for (; i < sig.size() - 1 && sig[i] == State::S0; i++) {} ", file=f)
+    print("    return sig.extract(i, sig.size() - i);", file=f)
+    print("  }", file=f)
+    print("", file=f)
+
     print("  void blacklist(Cell *cell) {", file=f)
     print("    if (cell != nullptr && blacklist_cells.insert(cell).second) {", file=f)
     print("      auto ptr = rollback_cache.find(cell);", file=f)

tests/peepopt/multdiv_c.ys

@@ -0,0 +1,38 @@
+log -header "Test simple positive case"
+log -push
+design -reset
+read_verilog <<EOF
+module muldiv_const_ok (
+  input wire  [31:0] a,
+  output wire  [63:0] y
+);
+  assign y = (a * 5140) / (257 * 2);
+endmodule
+EOF
+check -assert
+equiv_opt -assert peepopt ;;;
+design -load postopt
+select -assert-any t:$mul  # assert mult
+
+log -pop
+log -header "Test negative case where div is kept"
+log -push
+design -reset
+read_verilog <<EOF
+module muldiv_const_ko (
+  input wire signed [31:0] a,
+  output wire signed [63:0] y,
+  output wire probe
+);
+   wire [44:0] tmp = (a * 5140);
+   assign probe = tmp[44];
+
+  assign y = tmp[43:0] / (257 * 2);
+endmodule
+EOF
+check -assert
+equiv_opt -assert peepopt ;;;
+design -load postopt
+select -assert-any t:$div  # assert div
+
+log -pop