src/cpu/x86/vm/sharedRuntime_x86_64.cpp

@@ -516,10 +516,91 @@
   }
 
   return round_to(stk_args, 2);
 }
 
+// Same as java_calling_convention() but for multiple return
+// values. There's no way to store them on the stack so if we don't
+// have enough registers, multiple values can't be returned.
+const uint SharedRuntime::java_return_convention_max_int = Argument::n_int_register_parameters_j+1;
+const uint SharedRuntime::java_return_convention_max_float = Argument::n_float_register_parameters_j;
+int SharedRuntime::java_return_convention(const BasicType *sig_bt,
+                                          VMRegPair *regs,
+                                          int total_args_passed) {
+  // Create the mapping between argument positions and
+  // registers.
+  static const Register INT_ArgReg[java_return_convention_max_int] = {
+    rax, j_rarg5, j_rarg4, j_rarg3, j_rarg2, j_rarg1, j_rarg0
+  };
+  static const XMMRegister FP_ArgReg[java_return_convention_max_float] = {
+    j_farg0, j_farg1, j_farg2, j_farg3,
+    j_farg4, j_farg5, j_farg6, j_farg7
+  };
+
+
+  uint int_args = 0;
+  uint fp_args = 0;
+
+  for (int i = 0; i < total_args_passed; i++) {
+    switch (sig_bt[i]) {
+    case T_BOOLEAN:
+    case T_CHAR:
+    case T_BYTE:
+    case T_SHORT:
+    case T_INT:
+      if (int_args < Argument::n_int_register_parameters_j+1) {
+        regs[i].set1(INT_ArgReg[int_args]->as_VMReg());
+        int_args++;
+      } else {
+        return -1;
+      }
+      break;
+    case T_VOID:
+      // halves of T_LONG or T_DOUBLE
+      assert(i != 0 && (sig_bt[i - 1] == T_LONG || sig_bt[i - 1] == T_DOUBLE), "expecting half");
+      regs[i].set_bad();
+      break;
+    case T_LONG:
+      assert(sig_bt[i + 1] == T_VOID, "expecting half");
+      // fall through
+    case T_OBJECT:
+    case T_ARRAY:
+    case T_ADDRESS:
+    case T_METADATA:
+      if (int_args < Argument::n_int_register_parameters_j+1) {
+        regs[i].set2(INT_ArgReg[int_args]->as_VMReg());
+        int_args++;
+      } else {
+        return -1;
+      }
+      break;
+    case T_FLOAT:
+      if (fp_args < Argument::n_float_register_parameters_j) {
+        regs[i].set1(FP_ArgReg[fp_args]->as_VMReg());
+        fp_args++;
+      } else {
+        return -1;
+      }
+      break;
+    case T_DOUBLE:
+      assert(sig_bt[i + 1] == T_VOID, "expecting half");
+      if (fp_args < Argument::n_float_register_parameters_j) {
+        regs[i].set2(FP_ArgReg[fp_args]->as_VMReg());
+        fp_args++;
+      } else {
+        return -1;
+      }
+      break;
+    default:
+      ShouldNotReachHere();
+      break;
+    }
+  }
+
+  return int_args + fp_args;
+}
+
 // Patch the callers callsite with entry to compiled code if it exists.
 static void patch_callers_callsite(MacroAssembler *masm) {
   Label L;
   __ cmpptr(Address(rbx, in_bytes(Method::code_offset())), (int32_t)NULL_WORD);
   __ jcc(Assembler::equal, L);