Fix FCSR accesses under Zfinx

Author: aswaterman

riscv/csrs.cc

@@ -1410,8 +1410,9 @@ float_csr_t::float_csr_t(processor_t* const proc, const reg_t addr, const reg_t
 
 void float_csr_t::verify_permissions(insn_t insn, bool write) const {
   masked_csr_t::verify_permissions(insn, write);
-  require(STATE.sstatus->enabled(SSTATUS_FS));
-  if (!proc->extension_enabled('F') && !proc->extension_enabled(EXT_ZFINX))
+
+  if (!((proc->extension_enabled('F') && STATE.sstatus->enabled(SSTATUS_FS))
+        || proc->extension_enabled(EXT_ZFINX)))
     throw trap_illegal_instruction(insn.bits());
 
   if (proc->extension_enabled(EXT_SMSTATEEN) && proc->extension_enabled(EXT_ZFINX)) {
@@ -1431,7 +1432,8 @@ void float_csr_t::verify_permissions(insn_t insn, bool write) const {
 }
 
 bool float_csr_t::unlogged_write(const reg_t val) noexcept {
-  dirty_fp_state;
+  if (!proc->extension_enabled(EXT_ZFINX))
+    dirty_fp_state;
   return masked_csr_t::unlogged_write(val);
 }