[aarch64-port-dev ] Simulator: support buffered memory

[Andrew Haley]

This adds support for buffered memory to the simulator.  You'll
need to rebuild HotSpot.

Andrew.


comparing with http://hg.code.sf.net/p/smallaarch64sim/code
searching for changes
changeset:   201:cfb5b9b2a78d
tag:         tip
user:        aph
date:        Fri Jul 19 12:35:09 2013 +0100
summary:     Buffered memory support

diff -r 810fe3c0aba0 -r cfb5b9b2a78d simgdbinit
--- a/simgdbinit	Thu Jul 04 18:20:11 2013 +0100
+++ b/simgdbinit	Fri Jul 19 12:35:09 2013 +0100
@@ -105,6 +105,14 @@
 # commands from now on are documneted using the gdb document command
 # which makes the documenation available from gdb itself.

+define simstop
+  call 'AArch64Simulator::stopped'++
+end
+
+define simstart
+  call 'AArch64Simulator::stopped'--
+end
+
 define simstep
   if $argc == 0
     set 'AArch64Simulator::current'()->debugState.stepCount = 1
@@ -878,7 +886,9 @@


 define simpf
+    simstop
     call pf('AArch64Simulator::current'()->cpuState.gr[31].value.u64, 'AArch64Simulator::current'()->cpuState.gr[rfp].value.u64, 'AArch64Simulator::current'()->cpuState.pc, 'AArch64Simulator::current'()->cpuState.gr[22].value.u64, 'AArch64Simulator::current'()->cpuState.gr[28].value.u64)
+    simstart
 end

 document simpf
diff -r 810fe3c0aba0 -r cfb5b9b2a78d simulator.cpp
--- a/simulator.cpp	Thu Jul 04 18:20:11 2013 +0100
+++ b/simulator.cpp	Fri Jul 19 12:35:09 2013 +0100
@@ -71,9 +71,7 @@
   "ERROR_EXCEPTION"
 };

-int AArch64Simulator::useCache = 0;
-
-AArch64Simulator::AArch64Simulator() : memory((useCache ? (Memory *)new CacheMemory(&debugState) : (Memory *)new DirectMemory()))
+AArch64Simulator::AArch64Simulator(bool useCache) : memory((useCache ? (Memory *)new CacheMemory(&debugState) : (Memory *)new DirectMemory()))
 {
   // set up callbacks into JVM
   initCallbacks();
@@ -179,10 +177,10 @@
 static __thread AArch64Simulator *sim = 0;
 static __thread u_int64_t stack = 0;

-AArch64Simulator *AArch64Simulator::current()
+AArch64Simulator *AArch64Simulator::get_current(bool buffered)
 {
   if (sim == 0) {
-    sim = new AArch64Simulator();
+    sim = new AArch64Simulator(buffered);
   } else {
     assert(sim->debugState.tid == syscall(__NR_gettid));
   }
@@ -192,6 +190,11 @@
   return sim;
 }

+AArch64Simulator *AArch64Simulator::current()
+{
+  return get_current(false);
+}
+
 extern "C" void stop();
 extern "C" void start();

@@ -294,7 +297,7 @@
   return;
 }

-bool AArch64Simulator::stopped;
+int AArch64Simulator::stopped;

 extern "C" void stop() { AArch64Simulator::stopped = true; }
 extern "C" void start() { AArch64Simulator::stopped = false; }
@@ -3757,8 +3760,29 @@

 // data synchronization barrier

+enum barrier {OSHLD = 0b0001, OSHST, OSH, NSHLD=0b0101, NSHST, NSH,
+	      ISHLD = 0b1001, ISHST, ISH, LD=0b1101, ST, SY};
+
 void AArch64Simulator::dsb()
 {
+  barrier kind = (barrier)uimm(instr, 11, 8);
+  switch (kind) {
+  case ST:
+    memory->flush_all(false);
+    asm("sfence");
+    break;
+  case LD:
+    memory->flush_all(true);
+    asm("lfence");
+    break;
+  case SY:
+    memory->flush_all(true);
+    asm("mfence");
+    break;
+  default:
+    abort();
+    break;
+  }
 }

 // data memory barrier
diff -r 810fe3c0aba0 -r cfb5b9b2a78d simulator.hpp
--- a/simulator.hpp	Thu Jul 04 18:20:11 2013 +0100
+++ b/simulator.hpp	Fri Jul 19 12:35:09 2013 +0100
@@ -104,15 +104,14 @@
   // allow memory to be supplied at create so we can support
   // alternative memory models

-  AArch64Simulator();
+  AArch64Simulator(bool useCache = true);
   AArch64Simulator(Memory *m);

   void initCallbacks();

-  // configure use of memory
-  static int useCache;
   // retrieve the simulator associated with the current thread

+  static AArch64Simulator *get_current(bool useCache);
   static AArch64Simulator *current();

   // retrieve the alternative stack on which we should
@@ -294,7 +293,7 @@
     return errorCodeText[errorCode];
   }

-  static bool stopped;
+  static int stopped;

   // used by exception handler