fixes cause CSR handling

src/iss/arch/riscv_hart_m_p.h

@@ -959,14 +959,13 @@ template <typename BASE, features_e FEAT> iss::status riscv_hart_m_p<BASE, FEAT>
 }
 
 template <typename BASE, features_e FEAT> iss::status riscv_hart_m_p<BASE, FEAT>::read_cause(unsigned addr, reg_t &val) {
-    auto res = csr[addr];
     if((FEAT & features_e::FEAT_CLIC) && (csr[mtvec]&0x3)==3) {
         val = csr[addr] & ((1UL<<(traits<BASE>::XLEN-1)) | (mcause_max_irq-1) | (0xfUL<<16));
         val |= clic_mprev_lvl<<16;
         val |= state.mstatus.MPIE<<27;
         val |= state.mstatus.MPP<<28;
     } else
-        val = csr[addr]; // & ((1UL<<(traits<BASE>::XLEN-1)) | (mcause_max_irq-1));
+        val = csr[addr] & ((1UL<<(traits<BASE>::XLEN-1)) | (mcause_max_irq-1));
     return iss::Ok;
 }
 

src/iss/arch/riscv_hart_mu_p.h

@@ -1149,7 +1149,7 @@ template <typename BASE, features_e FEAT> iss::status riscv_hart_mu_p<BASE, FEAT
             break;
         }
     } else
-        val = csr[addr];// & ((1UL<<(traits<BASE>::XLEN-1)) | (mcause_max_irq-1));
+        val = csr[addr] & ((1UL<<(traits<BASE>::XLEN-1)) | (mcause_max_irq-1));
     return iss::Ok;
 }