[sim,xcc] add rdcycle/rdtime/rdinstret

riscv/insns/rdcycle.h

@@ -1 +1 @@
-throw trap_illegal_instruction;
+RD = cycle;

riscv/insns/rdinstret.h

@@ -1 +1 @@
-throw trap_illegal_instruction;
+RD = cycle;

riscv/insns/rdtime.h

@@ -1 +1 @@
-throw trap_illegal_instruction;
+RD = cycle;

riscv/processor.cc

@@ -28,11 +28,10 @@ processor_t::processor_t(sim_t* _sim, char* _mem, size_t _memsz)
   fromhost = 0;
   count = 0;
   compare = 0;
+  cycle = 0;
   set_sr(SR_S | SR_SX);  // SX ignored if 64b mode not supported
   set_fsr(0);
 
-  memset(counters,0,sizeof(counters));
-
   // vector stuff
   vecbanks = 0xff;
   vecbanks_count = 8;
@@ -175,6 +174,7 @@ void processor_t::step(size_t n, bool noisy)
 
       if(count++ == compare)
         cause |= 1 << (TIMER_IRQ+CAUSE_IP_SHIFT);
+      cycle++;
     }
     return;
   }

riscv/processor.h

@@ -51,7 +51,7 @@ private:
   mmu_t mmu;
 
   // counters
-  reg_t counters[32];
+  reg_t cycle;
 
   // functions
   void set_sr(uint32_t val);