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Diffstat (limited to 'tests/simple/const_fold_func.v')
-rw-r--r-- | tests/simple/const_fold_func.v | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/tests/simple/const_fold_func.v b/tests/simple/const_fold_func.v new file mode 100644 index 000000000..ee2f12e06 --- /dev/null +++ b/tests/simple/const_fold_func.v @@ -0,0 +1,61 @@ +module top( + input wire [3:0] inp, + output wire [3:0] out1, out2, out3, out4, out5, + output reg [3:0] out6 +); + function automatic [3:0] flip; + input [3:0] inp; + flip = ~inp; + endfunction + + function automatic [3:0] help; + input [3:0] inp; + help = flip(inp); + endfunction + + // while loops are const-eval-only + function automatic [3:0] loop; + input [3:0] inp; + reg [3:0] val; + begin + val = inp; + loop = 1; + while (val != inp) begin + loop = loop * 2; + val = val + 1; + end + end + endfunction + + // not const-eval-only, despite calling a const-eval-only function + function automatic [3:0] help_mul; + input [3:0] inp; + help_mul = inp * loop(2); + endfunction + + // can be elaborated so long as exp is a constant + function automatic [3:0] pow_flip_a; + input [3:0] base, exp; + begin + pow_flip_a = 1; + if (exp > 0) + pow_flip_a = base * pow_flip_a(flip(base), exp - 1); + end + endfunction + + function automatic [3:0] pow_flip_b; + input [3:0] base, exp; + begin + out6[exp] = base & 1; + pow_flip_b = 1; + if (exp > 0) + pow_flip_b = base * pow_flip_b(flip(base), exp - 1); + end + endfunction + + assign out1 = flip(flip(inp)); + assign out2 = help(flip(inp)); + assign out3 = help_mul(inp); + assign out4 = pow_flip_a(flip(inp), 3); + assign out5 = pow_flip_b(2, 2); +endmodule |