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| author | Eddie Hung <eddie@fpgeh.com> | 2019-08-22 08:22:23 -0700 |
|---|---|---|
| committer | Eddie Hung <eddie@fpgeh.com> | 2019-08-22 08:22:23 -0700 |
| commit | 379f33af5489850ef8e2e58ef12ff5b22da87711 (patch) | |
| tree | 75f9d114509ede495afc7d29850e838ef1e7e384 | |
| parent | 9e31f01b343a9b246430419e81da647e75bd1626 (diff) | |
| download | yosys-379f33af5489850ef8e2e58ef12ff5b22da87711.tar.gz yosys-379f33af5489850ef8e2e58ef12ff5b22da87711.tar.bz2 yosys-379f33af5489850ef8e2e58ef12ff5b22da87711.zip | |
Handle $shift and Y_WIDTH > 1 as per @cliffordwolf
| -rw-r--r-- | passes/opt/opt_expr.cc | 12 | ||||
| -rw-r--r-- | tests/opt/opt_expr.ys | 44 |
2 files changed, 51 insertions, 5 deletions
diff --git a/passes/opt/opt_expr.cc b/passes/opt/opt_expr.cc index aca15e5f2..c4da613ab 100644 --- a/passes/opt/opt_expr.cc +++ b/passes/opt/opt_expr.cc @@ -745,16 +745,20 @@ void replace_const_cells(RTLIL::Design *design, RTLIL::Module *module, bool cons } } - if (cell->type == ID($shiftx) && GetSize(cell->getPort(ID::Y)) == 1) { + if (cell->type.in(ID($shiftx), ID($shift))) { SigSpec sig_a = assign_map(cell->getPort(ID::A)); int width; + bool trim_x = true; + bool trim_0 = cell->type == ID($shift); for (width = GetSize(sig_a); width > 1; width--) { - if (sig_a[width-1] != State::Sx) - break; + if ((trim_x && sig_a[width-1] == State::Sx) || + (trim_0 && sig_a[width-1] == State::S0)) + continue; + break; } if (width < GetSize(sig_a)) { - cover("opt.opt_expr.trim_shiftx"); + cover_list("opt.opt_expr.xbit", "$shiftx", "$shift", cell->type.str()); sig_a.remove(width, GetSize(sig_a)-width); cell->setPort(ID::A, sig_a); cell->setParam(ID(A_WIDTH), width); diff --git a/tests/opt/opt_expr.ys b/tests/opt/opt_expr.ys index 4affc1ac8..02be20a62 100644 --- a/tests/opt/opt_expr.ys +++ b/tests/opt/opt_expr.ys @@ -226,7 +226,7 @@ select -assert-count 1 t:$alu r:A_WIDTH=8 r:B_WIDTH=8 r:Y_WIDTH=9 %i %i %i design -reset read_verilog -icells <<EOT -module opt_expr_shiftx(input [2:0] a, input [1:0] b, output y); +module opt_expr_shiftx_1bit(input [2:0] a, input [1:0] b, output y); \$shiftx #(.A_SIGNED(0), .B_SIGNED(0), .A_WIDTH(4), .B_WIDTH(2), .Y_WIDTH(1)) shiftx (.A({1'bx,a}), .B(b), .Y(y)); endmodule EOT @@ -235,3 +235,45 @@ check equiv_opt opt_expr design -load postopt select -assert-count 1 t:$shiftx r:A_WIDTH=3 %i + +########### + +design -reset +read_verilog -icells <<EOT +module opt_expr_shiftx_3bit(input [9:0] a, input [3:0] b, output [2:0] y); + \$shiftx #(.A_SIGNED(0), .B_SIGNED(0), .A_WIDTH(14), .B_WIDTH(4), .Y_WIDTH(3)) shiftx (.A({4'bxx00,a}), .B(b), .Y(y)); +endmodule +EOT +check + +equiv_opt opt_expr +design -load postopt +select -assert-count 1 t:$shiftx r:A_WIDTH=12 %i + +########### + +design -reset +read_verilog -icells <<EOT +module opt_expr_shift_1bit(input [2:0] a, input [1:0] b, output y); + \$shift #(.A_SIGNED(0), .B_SIGNED(0), .A_WIDTH(4), .B_WIDTH(2), .Y_WIDTH(1)) shift (.A({1'b0,a}), .B(b), .Y(y)); +endmodule +EOT +check + +equiv_opt opt_expr +design -load postopt +select -assert-count 1 t:$shift r:A_WIDTH=3 %i + +########### + +design -reset +read_verilog -icells <<EOT +module opt_expr_shift_3bit(input [9:0] a, input [3:0] b, output [2:0] y); + \$shift #(.A_SIGNED(0), .B_SIGNED(0), .A_WIDTH(14), .B_WIDTH(4), .Y_WIDTH(3)) shift (.A({4'b0x0x,a}), .B(b), .Y(y)); +endmodule +EOT +check + +equiv_opt opt_expr +design -load postopt +select -assert-count 1 t:$shift r:A_WIDTH=10 %i |