pseudo inst: Add rpns (read processor nanoseconds) instruction.

This instruction basically returns the number of nanoseconds that the CPU
has been running.

src/arch/alpha/isa/decoder.isa

@@ -806,6 +806,9 @@ decode OPCODE default Unknown::unknown() {
             0x04: quiesceTime({{
                 R0 = PseudoInst::quiesceTime(xc->tcBase());
             }}, IsNonSpeculative, IsUnverifiable);
+            0x07: rpns({{
+                R0 = PseudoInst::rpns(xc->tcBase());
+            }}, IsNonSpeculative, IsUnverifiable);
             0x10: deprecated_ivlb({{
                 warn_once("Obsolete M5 ivlb instruction encountered.\n");
             }});

src/sim/pseudo_inst.cc

@@ -125,6 +125,12 @@ quiesceTime(ThreadContext *tc)
     return (tc->readLastActivate() - tc->readLastSuspend()) / Clock::Int::ns;
 }
 
+uint64_t
+rpns(ThreadContext *tc)
+{
+    return curTick / Clock::Int::ns;
+}
+
 void
 m5exit(ThreadContext *tc, Tick delay)
 {

src/sim/pseudo_inst.hh

@@ -47,6 +47,7 @@ void quiesce(ThreadContext *tc);
 void quiesceNs(ThreadContext *tc, uint64_t ns);
 void quiesceCycles(ThreadContext *tc, uint64_t cycles);
 uint64_t quiesceTime(ThreadContext *tc);
+uint64_t rpns(ThreadContext *tc);
 void m5exit(ThreadContext *tc, Tick delay);
 void loadsymbol(ThreadContext *xc);
 void resetstats(ThreadContext *tc, Tick delay, Tick period);

util/m5/m5op.h

@@ -39,6 +39,7 @@ void quiesce(void);
 void quiesceNs(uint64_t ns);
 void quiesceCycle(uint64_t cycles);
 uint64_t quiesceTime(void);
+uint64_t rpns();
 
 void m5_exit(uint64_t ns_delay);
 uint64_t m5_initparam(void);

util/m5/m5op_alpha.S

@@ -59,6 +59,7 @@ func:
 #define QUIESCENS(r1) INST(m5_op, r1, 0, quiescens_func)
 #define QUIESCECYC(r1) INST(m5_op, r1, 0, quiescecycle_func)
 #define QUIESCETIME INST(m5_op, 0, 0, quiescetime_func)
+#define RPNS INST(m5_op, 0, 0, rpns_func)
 #define M5EXIT(reg) INST(m5_op, reg, 0, exit_func)
 #define INITPARAM(reg) INST(m5_op, reg, 0, initparam_func)
 #define LOADSYMBOL(reg) INST(m5_op, reg, 0, loadsymbol_func)
@@ -79,6 +80,7 @@ SIMPLE_OP(quiesce, QUIESCE)
 SIMPLE_OP(quiesceNs, QUIESCENS(16))
 SIMPLE_OP(quiesceCycle, QUIESCECYC(16))
 SIMPLE_OP(quiesceTime, QUIESCETIME)
+SIMPLE_OP(rpns, RPNS)
 SIMPLE_OP(m5_exit, M5EXIT(16))
 SIMPLE_OP(m5_initparam, INITPARAM(0))
 SIMPLE_OP(m5_loadsymbol, LOADSYMBOL(0))

util/m5/m5ops.h

@@ -34,6 +34,7 @@
 #define quiescens_func          0x02
 #define quiescecycle_func       0x03
 #define quiescetime_func        0x04
+#define rpns_func               0x07
 #define deprecated1_func        0x10 // obsolete ivlb
 #define deprecated2_func        0x11 // obsolete ivle
 #define deprecated3_func        0x20 // deprecated exit function