Adds support for ARM softfp calling convention.

runtime/vm/simulator_arm.cc

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 #include <math.h>  // for isnan.
 #include <setjmp.h>
 #include <stdlib.h>
 
 #include "vm/globals.h"
 #if defined(TARGET_ARCH_ARM)
@@ skipping 1509 matching lines @@
           NativeArguments arguments;
           ASSERT(sizeof(NativeArguments) == 4*kWordSize);
           arguments.isolate_ = reinterpret_cast<Isolate*>(get_register(R0));
           arguments.argc_tag_ = get_register(R1);
           arguments.argv_ = reinterpret_cast<RawObject*(*)[]>(get_register(R2));
           arguments.retval_ = reinterpret_cast<RawObject**>(get_register(R3));
           SimulatorRuntimeCall target =
               reinterpret_cast<SimulatorRuntimeCall>(external);
           target(arguments);
           set_register(R0, icount_);  // Zap result register from void function.
+          set_register(R1, icount_);
         } else if (redirection->call_kind() == kLeafRuntimeCall) {
           ASSERT((0 <= redirection->argument_count()) &&
                  (redirection->argument_count() <= 4));
           int32_t r0 = get_register(R0);
           int32_t r1 = get_register(R1);
           int32_t r2 = get_register(R2);
           int32_t r3 = get_register(R3);
           SimulatorLeafRuntimeCall target =
               reinterpret_cast<SimulatorLeafRuntimeCall>(external);
           r0 = target(r0, r1, r2, r3);
           set_register(R0, r0);  // Set returned result from function.
+          set_register(R1, icount_);  // Zap unused result register.
         } else if (redirection->call_kind() == kLeafFloatRuntimeCall) {
           ASSERT((0 <= redirection->argument_count()) &&
                  (redirection->argument_count() <= 2));
-          // We currently use 'hardfp' ('gnueabihf') rather than 'softfp'
-          // ('gnueabi') float ABI for leaf runtime calls, i.e. double values
-          // are passed and returned in vfp registers rather than in integer
-          // register pairs.
           SimulatorLeafFloatRuntimeCall target =
               reinterpret_cast<SimulatorLeafFloatRuntimeCall>(external);
+#if defined(ARM_FLOAT_ABI_HARD)
+          // If we're doing "hardfp", the double arguments are already in the
+          // floating point registers.
           double d0 = get_dregister(D0);
           double d1 = get_dregister(D1);
           d0 = target(d0, d1);
           set_dregister(D0, d0);
+#else
+          // If we're not doing "hardfp", we must be doing "soft" or "softfp",
+          // So take the double arguments from the integer registers.
+          uint32_t r0 = get_register(R0);
+          int32_t r1 = get_register(R1);
+          uint32_t r2 = get_register(R2);
+          int32_t r3 = get_register(R3);
+          int64_t a0 = Utils::LowHighTo64Bits(r0, r1);
+          int64_t a1 = Utils::LowHighTo64Bits(r2, r3);
+          double d0 = bit_cast<double, int64_t>(a0);
+          double d1 = bit_cast<double, int64_t>(a1);
+          d0 = target(d0, d1);
+          a0 = bit_cast<int64_t, double>(d0);
+          r0 = Utils::Low32Bits(a0);
+          r1 = Utils::High32Bits(a0);
+          set_register(R0, r0);
+          set_register(R1, r1);
+#endif
         } else if (redirection->call_kind() == kBootstrapNativeCall) {
           NativeArguments* arguments;
           arguments = reinterpret_cast<NativeArguments*>(get_register(R0));
           SimulatorBootstrapNativeCall target =
               reinterpret_cast<SimulatorBootstrapNativeCall>(external);
           target(arguments);
           set_register(R0, icount_);  // Zap result register from void function.
         } else {
           ASSERT(redirection->call_kind() == kNativeCall);
           NativeArguments* arguments;
           arguments = reinterpret_cast<NativeArguments*>(get_register(R0));
           uword target_func = get_register(R1);
           SimulatorNativeCall target =
               reinterpret_cast<SimulatorNativeCall>(external);
           target(arguments, target_func);
           set_register(R0, icount_);  // Zap result register from void function.
+          set_register(R1, icount_);
         }
         set_top_exit_frame_info(0);
 
         // Zap caller-saved registers, since the actual runtime call could have
         // used them.
-        set_register(R1, icount_);
         set_register(R2, icount_);
         set_register(R3, icount_);
         set_register(IP, icount_);
         set_register(LR, icount_);
         double zap_dvalue = static_cast<double>(icount_);
         // Do not zap D0, as it may contain a float result.
         for (int i = D1; i <= D7; i++) {
           set_dregister(static_cast<DRegister>(i), zap_dvalue);
         }
         // The above loop also zaps overlapping registers S2-S15.
@@ skipping 2119 matching lines @@
   set_register(kExceptionObjectReg, bit_cast<int32_t>(raw_exception));
   set_register(kStackTraceObjectReg, bit_cast<int32_t>(raw_stacktrace));
   buf->Longjmp();
 }
 
 }  // namespace dart
 
 #endif  // !defined(HOST_ARCH_ARM)
 
 #endif  // defined TARGET_ARCH_ARM