fix(skip): fix RF updates for floating-point (#518)

src/test/csrc/difftest/difftest.cpp

@@ -557,13 +557,12 @@ int Difftest::do_instr_commit(int i) {
   }
 #endif
 
-  bool realWen = (dut->commit[i].rfwen && dut->commit[i].wdest != 0) || (dut->commit[i].fpwen);
-
   // MMIO accessing should not be a branch or jump, just +2/+4 to get the next pc
   // to skip the checking of an instruction, just copy the reg state to reference design
   if (dut->commit[i].skip || (DEBUG_MODE_SKIP(dut->commit[i].valid, dut->commit[i].pc, dut->commit[i].inst))) {
     // We use the physical register file to get wdata
-    proxy->skip_one(dut->commit[i].isRVC, realWen, dut->commit[i].wdest, get_commit_data(i));
+    proxy->skip_one(dut->commit[i].isRVC, (dut->commit[i].rfwen && dut->commit[i].wdest != 0), dut->commit[i].fpwen,
+                    dut->commit[i].vecwen, dut->commit[i].wdest, get_commit_data(i));
     return 0;
   }
 

src/test/csrc/difftest/refproxy.h

@@ -218,16 +218,26 @@ class RefProxy : public AbstractRefProxy {
   int compare(DiffTestState *dut);
   void display(DiffTestState *dut = nullptr);
 
-  inline void skip_one(bool isRVC, bool wen, uint32_t wdest, uint64_t wdata) {
+  inline void skip_one(bool isRVC, bool rfwen, bool fpwen, bool vecwen, uint32_t wdest, uint64_t wdata) {
+    bool wen = rfwen | fpwen;
     if (ref_skip_one) {
       ref_skip_one(isRVC, wen, wdest, wdata);
     } else {
       sync();
       pc += isRVC ? 2 : 4;
-      // TODO: what if skip with fpwen?
-      if (wen) {
+
+      if (rfwen)
         regs_int.value[wdest] = wdata;
-      }
+#ifdef CONFIG_DIFFTEST_ARCHFPREGSTATE
+      if (fpwen)
+        regs_fp.value[wdest] = wdata;
+#endif // CONFIG_DIFFTEST_ARCHFPREGSTATE
+#ifdef CONFIG_DIFFTEST_ARCHVECREGSTATE
+      // TODO: vec skip is not supported at this time.
+      if (vecwen)
+        assert(0);
+#endif // CONFIG_DIFFTEST_ARCHVECREGSTATE
+
       sync(true);
     }
   }