[sim] Consistent support for C calls with up to 9 args

src/arm64/simulator-arm64.cc

Index: src/arm64/simulator-arm64.cc
diff --git a/src/arm64/simulator-arm64.cc b/src/arm64/simulator-arm64.cc
index c8a26e44fda04e1126f4bbe7e1667a671661b6b2..59fa0fdbfc569c9ff49ce60d7dc5c97c709970f8 100644
--- a/src/arm64/simulator-arm64.cc
+++ b/src/arm64/simulator-arm64.cc
@@ -538,14 +538,11 @@ void Simulator::TearDown(base::CustomMatcherHashMap* i_cache,
 // uses the ObjectPair structure.
 // The simulator assumes all runtime calls return two 64-bits values. If they
 // don't, register x1 is clobbered. This is fine because x1 is caller-saved.
-typedef ObjectPair (*SimulatorRuntimeCall)(int64_t arg0,
-                                           int64_t arg1,
-                                           int64_t arg2,
-                                           int64_t arg3,
-                                           int64_t arg4,
-                                           int64_t arg5,
-                                           int64_t arg6,
-                                           int64_t arg7);
+typedef ObjectPair (*SimulatorRuntimeCall)(int64_t arg0, int64_t arg1,
+                                           int64_t arg2, int64_t arg3,
+                                           int64_t arg4, int64_t arg5,
+                                           int64_t arg6, int64_t arg7,
+                                           int64_t arg8);
 
 typedef ObjectTriple (*SimulatorRuntimeTripleCall)(int64_t arg0, int64_t arg1,
                                                    int64_t arg2, int64_t arg3,
@@ -587,6 +584,19 @@ void Simulator::DoRuntimeCall(Instruction* instr) {
     FATAL("ALIGNMENT EXCEPTION");
   }
 
+  int64_t* stack_pointer = reinterpret_cast<int64_t*>(sp());
+
+  const int64_t arg0 = xreg(0);
+  const int64_t arg1 = xreg(1);
+  const int64_t arg2 = xreg(2);
+  const int64_t arg3 = xreg(3);
+  const int64_t arg4 = xreg(4);
+  const int64_t arg5 = xreg(5);
+  const int64_t arg6 = xreg(6);
+  const int64_t arg7 = xreg(7);
+  const int64_t arg8 = stack_pointer[0];
+  STATIC_ASSERT(kMaxCParameters == 9);
+
   switch (redirection->type()) {
     default:
       TraceSim("Type: Unknown.\n");
@@ -604,15 +614,20 @@ void Simulator::DoRuntimeCall(Instruction* instr) {
       // We don't know how many arguments are being passed, but we can
       // pass 8 without touching the stack. They will be ignored by the
       // host function if they aren't used.
-      TraceSim("Arguments: "
-               "0x%016" PRIx64 ", 0x%016" PRIx64 ", "
-               "0x%016" PRIx64 ", 0x%016" PRIx64 ", "
-               "0x%016" PRIx64 ", 0x%016" PRIx64 ", "
-               "0x%016" PRIx64 ", 0x%016" PRIx64,
-               xreg(0), xreg(1), xreg(2), xreg(3),
-               xreg(4), xreg(5), xreg(6), xreg(7));
-      ObjectPair result = target(xreg(0), xreg(1), xreg(2), xreg(3),
-                                 xreg(4), xreg(5), xreg(6), xreg(7));
+      TraceSim(
+          "Arguments: "
+          "0x%016" PRIx64 ", 0x%016" PRIx64
+          ", "
+          "0x%016" PRIx64 ", 0x%016" PRIx64
+          ", "
+          "0x%016" PRIx64 ", 0x%016" PRIx64
+          ", "
+          "0x%016" PRIx64 ", 0x%016" PRIx64
+          ", "
+          "0x%016" PRIx64,
+          arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
+      ObjectPair result =
+          target(arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7, arg8);
       TraceSim("Returned: {%p, %p}\n", static_cast<void*>(result.x),
                static_cast<void*>(result.y));
 #ifdef DEBUG
@@ -634,16 +649,18 @@ void Simulator::DoRuntimeCall(Instruction* instr) {
       // host function if they aren't used.
       TraceSim(
           "Arguments: "
-          "0x%016" PRIx64 ", 0x%016" PRIx64 ", "
-          "0x%016" PRIx64 ", 0x%016" PRIx64 ", "
-          "0x%016" PRIx64 ", 0x%016" PRIx64 ", "
+          "0x%016" PRIx64 ", 0x%016" PRIx64
+          ", "
+          "0x%016" PRIx64 ", 0x%016" PRIx64
+          ", "
+          "0x%016" PRIx64 ", 0x%016" PRIx64
+          ", "
           "0x%016" PRIx64 ", 0x%016" PRIx64,
-          xreg(0), xreg(1), xreg(2), xreg(3), xreg(4), xreg(5), xreg(6),
-          xreg(7));
+          arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7);
       // Return location passed in x8.
       ObjectTriple* sim_result = reinterpret_cast<ObjectTriple*>(xreg(8));
-      ObjectTriple result = target(xreg(0), xreg(1), xreg(2), xreg(3), xreg(4),
-                                   xreg(5), xreg(6), xreg(7));
+      ObjectTriple result =
+          target(arg0, arg1, arg2, arg3, arg4, arg5, arg6, arg7);
       TraceSim("Returned: {%p, %p, %p}\n", static_cast<void*>(result.x),
                static_cast<void*>(result.y), static_cast<void*>(result.z));
 #ifdef DEBUG