Accurate function prototypes for native calls from ARM simulator.

src/arm/simulator-arm.cc

Index: src/arm/simulator-arm.cc
diff --git a/src/arm/simulator-arm.cc b/src/arm/simulator-arm.cc
index 2551e14e4905932a4ad5bd853307bb6c941fac68..e3ef926ca0c0f88afc6c49bed1f55a02a27995a9 100644
--- a/src/arm/simulator-arm.cc
+++ b/src/arm/simulator-arm.cc
@@ -974,12 +974,14 @@ ReturnType Simulator::GetFromVFPRegister(int reg_index) {
 }
 
 
-// For use in calls that take two double values, constructed either
+// Runtime FP routines take up to two double arguments and zero
+// or one integer arguments. All are constructed here,
 // from r0-r3 or d0 and d1.
-void Simulator::GetFpArgs(double* x, double* y) {
+void Simulator::GetFpArgs(double* x, double* y, int32_t* z) {
   if (use_eabi_hardfloat()) {
     *x = vfp_registers_[0];
     *y = vfp_registers_[1];
+    *z = registers_[1];
   } else {
     // We use a char buffer to get around the strict-aliasing rules which
     // otherwise allow the compiler to optimize away the copy.
@@ -990,41 +992,9 @@ void Simulator::GetFpArgs(double* x, double* y) {
     // Registers 2 and 3 -> y.
     memcpy(buffer, registers_ + 2, sizeof(*y));
     memcpy(y, buffer, sizeof(*y));
-  }
-}
-
-// For use in calls that take one double value, constructed either
-// from r0 and r1 or d0.
-void Simulator::GetFpArgs(double* x) {
-  if (use_eabi_hardfloat()) {
-    *x = vfp_registers_[0];
-  } else {
-    // We use a char buffer to get around the strict-aliasing rules which
-    // otherwise allow the compiler to optimize away the copy.
-    char buffer[sizeof(*x)];
-    // Registers 0 and 1 -> x.
-    memcpy(buffer, registers_, sizeof(*x));
-    memcpy(x, buffer, sizeof(*x));
-  }
-}
-
-
-// For use in calls that take one double value constructed either
-// from r0 and r1 or d0 and one integer value.
-void Simulator::GetFpArgs(double* x, int32_t* y) {
-  if (use_eabi_hardfloat()) {
-    *x = vfp_registers_[0];
-    *y = registers_[1];
-  } else {
-    // We use a char buffer to get around the strict-aliasing rules which
-    // otherwise allow the compiler to optimize away the copy.
-    char buffer[sizeof(*x)];
-    // Registers 0 and 1 -> x.
-    memcpy(buffer, registers_, sizeof(*x));
-    memcpy(x, buffer, sizeof(*x));
-    // Register 2 -> y.
-    memcpy(buffer, registers_ + 2, sizeof(*y));
-    memcpy(y, buffer, sizeof(*y));
+    // Register 2 -> z.
+    memcpy(buffer, registers_ + 2, sizeof(*z));
+    memcpy(z, buffer, sizeof(*z));
   }
 }
 
@@ -1647,10 +1617,12 @@ typedef int64_t (*SimulatorRuntimeCall)(int32_t arg0,
                                         int32_t arg3,
                                         int32_t arg4,
                                         int32_t arg5);
-typedef double (*SimulatorRuntimeFPCall)(int32_t arg0,
-                                         int32_t arg1,
-                                         int32_t arg2,
-                                         int32_t arg3);
+
+// These prototypes handle the four types of FP calls.
+typedef int64_t (*SimulatorRuntimeCompareCall)(double darg0, double darg1);
+typedef double (*SimulatorRuntimeFPFPCall)(double darg0, double darg1);
+typedef double (*SimulatorRuntimeFPCall)(double darg0);
+typedef double (*SimulatorRuntimeFPIntCall)(double darg0, int32_t arg0);
 
 // This signature supports direct call in to API function native callback
 // (refer to InvocationCallback in v8.h).
@@ -1716,27 +1688,27 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
       intptr_t external =
           reinterpret_cast<intptr_t>(redirection->external_function());
       if (fp_call) {
+        double dval0, dval1;  // one or two double parameters
+        int32_t ival;         // zero or one integer parameters
+        int64_t iresult = 0;  // integer return value
+        double dresult = 0;   // double return value
+        GetFpArgs(&dval0, &dval1, &ival);
         if (::v8::internal::FLAG_trace_sim || !stack_aligned) {
-          SimulatorRuntimeFPCall target =
-              reinterpret_cast<SimulatorRuntimeFPCall>(external);
-          double dval0, dval1;
-          int32_t ival;
+          SimulatorRuntimeCall generic_target =
+            reinterpret_cast<SimulatorRuntimeCall>(external);
           switch (redirection->type()) {
           case ExternalReference::BUILTIN_FP_FP_CALL:
           case ExternalReference::BUILTIN_COMPARE_CALL:
-            GetFpArgs(&dval0, &dval1);
             PrintF("Call to host function at %p with args %f, %f",
-                FUNCTION_ADDR(target), dval0, dval1);
+                   FUNCTION_ADDR(generic_target), dval0, dval1);
             break;
           case ExternalReference::BUILTIN_FP_CALL:
-            GetFpArgs(&dval0);
             PrintF("Call to host function at %p with arg %f",
-                FUNCTION_ADDR(target), dval0);
+                FUNCTION_ADDR(generic_target), dval0);
             break;
           case ExternalReference::BUILTIN_FP_INT_CALL:
-            GetFpArgs(&dval0, &ival);
             PrintF("Call to host function at %p with args %f, %d",
-                FUNCTION_ADDR(target), dval0, ival);
+                   FUNCTION_ADDR(generic_target), dval0, ival);
             break;
           default:
             UNREACHABLE();
@@ -1748,22 +1720,54 @@ void Simulator::SoftwareInterrupt(Instruction* instr) {
           PrintF("\n");
         }
         CHECK(stack_aligned);
-        if (redirection->type() != ExternalReference::BUILTIN_COMPARE_CALL) {
+        switch (redirection->type()) {
+        case ExternalReference::BUILTIN_COMPARE_CALL: {
+          SimulatorRuntimeCompareCall target =
+            reinterpret_cast<SimulatorRuntimeCompareCall>(external);
+          iresult = target(dval0, dval1);
+          set_register(r0, static_cast<int32_t>(iresult));
+          set_register(r1, static_cast<int32_t>(iresult >> 32));
+          break;
+        }
+        case ExternalReference::BUILTIN_FP_FP_CALL: {
+          SimulatorRuntimeFPFPCall target =
+            reinterpret_cast<SimulatorRuntimeFPFPCall>(external);
+          dresult = target(dval0, dval1);
+          SetFpResult(dresult);
+          break;
+        }
+        case ExternalReference::BUILTIN_FP_CALL: {
           SimulatorRuntimeFPCall target =
-              reinterpret_cast<SimulatorRuntimeFPCall>(external);
-          double result = target(arg0, arg1, arg2, arg3);
-          SetFpResult(result);
-        } else {
-          SimulatorRuntimeCall target =
-              reinterpret_cast<SimulatorRuntimeCall>(external);
-          int64_t result = target(arg0, arg1, arg2, arg3, arg4, arg5);
-          int32_t lo_res = static_cast<int32_t>(result);
-          int32_t hi_res = static_cast<int32_t>(result >> 32);
-          if (::v8::internal::FLAG_trace_sim) {
-            PrintF("Returned %08x\n", lo_res);
+            reinterpret_cast<SimulatorRuntimeFPCall>(external);
+          dresult = target(dval0);
+          SetFpResult(dresult);
+          break;
+        }
+        case ExternalReference::BUILTIN_FP_INT_CALL: {
+          SimulatorRuntimeFPIntCall target =
+            reinterpret_cast<SimulatorRuntimeFPIntCall>(external);
+          dresult = target(dval0, ival);
+          SetFpResult(dresult);
+          break;
+        }
+        default:
+          UNREACHABLE();
+          break;
+        }
+        if (::v8::internal::FLAG_trace_sim || !stack_aligned) {
+          switch (redirection->type()) {
+          case ExternalReference::BUILTIN_COMPARE_CALL:
+            PrintF("Returned %08x\n", static_cast<int32_t>(iresult));
+            break;
+          case ExternalReference::BUILTIN_FP_FP_CALL:
+          case ExternalReference::BUILTIN_FP_CALL:
+          case ExternalReference::BUILTIN_FP_INT_CALL:
+            PrintF("Returned %f\n", dresult);
+            break;
+          default:
+            UNREACHABLE();
+            break;
           }
-          set_register(r0, lo_res);
-          set_register(r1, hi_res);
         }
       } else if (redirection->type() == ExternalReference::DIRECT_API_CALL) {
         SimulatorRuntimeDirectApiCall target =