Getting wrong result on FMUL-S with DYN-RDN mode

[zeeshanrafique23]

I am multiplying two numbers: rs1 = 0x00000000 and rs2 = 0x3a2b48ef.
I am getting the wrong result, the sign bit is high.

I am suspecting the error comes from this statement.
https://github.com/pulp-platform/fpnew/blob/0bfbeede0e01b2e44e41bb14c70a80efeffa1bbd/src/fpnew_rounding.sv#L68

@stmach @lucabertaccini

[zeeshanrafique23]

This issue is resolved by making changes in the module fpnew_rounding module.
Before:

  assign sign_o = (exact_zero_o && effective_subtraction_i)
                  ? (rnd_mode_i == fpnew_pkg::RDN)
                  : sign_i;

After:

assign sign_o = (exact_zero_o && effective_subtraction_i)
                  ? ((rnd_mode_i == fpnew_pkg::RDN) & (op_i != fpnew_pkg::MUL))
                  : sign_i;

The op_i is taken as an input to this module to restrict the sing bit 0 while multiplying any two numbers where one the operand in +zero.
https://github.com/pulp-platform/fpnew/blob/0fc3620978a500303ce94811eec7839e427dc995/src/fpnew_rounding.sv#L70