system verilog - The best way to convert a real valued number to an integer value larger than 32 bits? -

are there system functions support more 32 bits in system verilog? want convert real-valued quantity integral value contains more 32 bits. $rtoi() system function precisely want values can represented in 32 bits or less. there built-in this, or need write own?

for concrete example, able following:

logic [41:0] test_value;  initial begin     test_value = $rtoi($pow(2.0, 39.5)); end 

where, instead of $rtoi(), use unknown sought after system function. given correct function, expect result in test_value being initialized bit sequence 42'b1011010100000100111100110011001111111001 or possibly 42'b1011010100000100111100110011001111111010 if rounding supported.

i can write own function, avoid reinventing wheel unless there no wheel.

a implicit cast real integral gives want rounding

test_value = 2.0**39.5; 

or can use explicit cast

typedef logic [41:0] uint42_t;  test_value = uint42_t'(2.0**39.5);