blob: 05efb725cf450518e953f09f361c1c30dff2ba96 [file] [log] [blame]
// Copyright (c) 2014, 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 "vm/globals.h"
#if defined(TARGET_ARCH_ARM64)
#include "vm/runtime_entry.h"
#include "vm/simulator.h"
#include "vm/stub_code.h"
#include "vm/compiler/assembler/assembler.h"
#endif // !defined(DART_PRECOMPILED_RUNTIME)
namespace dart {
#define __ assembler->
uword RuntimeEntry::GetEntryPoint() const {
// Compute the effective address. When running under the simulator,
// this is a redirection address that forces the simulator to call
// into the runtime system.
uword entry = reinterpret_cast<uword>(function());
#if defined(USING_SIMULATOR)
// Redirection to leaf runtime calls supports a maximum of 4 arguments passed
// in registers (maximum 2 double arguments for leaf float runtime calls).
ASSERT(argument_count() >= 0);
ASSERT(!is_leaf() || (!is_float() && (argument_count() <= 4)) ||
(argument_count() <= 2));
Simulator::CallKind call_kind =
is_leaf() ? (is_float() ? Simulator::kLeafFloatRuntimeCall
: Simulator::kLeafRuntimeCall)
: Simulator::kRuntimeCall;
entry =
Simulator::RedirectExternalReference(entry, call_kind, argument_count());
return entry;
// Generate code to call into the stub which will call the runtime
// function. Input for the stub is as follows:
// SP : points to the arguments and return value array.
// R5 : address of the runtime function to call.
// R4 : number of arguments to the call.
void RuntimeEntry::CallInternal(const RuntimeEntry* runtime_entry,
compiler::Assembler* assembler,
intptr_t argument_count) {
if (runtime_entry->is_leaf()) {
ASSERT(argument_count == runtime_entry->argument_count());
// Since we are entering C++ code, we must restore the C stack pointer from
// the stack limit to an aligned value nearer to the top of the stack.
// We cache the Dart stack pointer and the stack limit in callee-saved
// registers, then align and call, restoring CSP and SP on return from the
// call.
// This sequence may occur in an intrinsic, so don't use registers an
// intrinsic must preserve.
COMPILE_ASSERT(kCallLeafRuntimeCalleeSaveScratch1 != CODE_REG);
COMPILE_ASSERT(kCallLeafRuntimeCalleeSaveScratch2 != CODE_REG);
COMPILE_ASSERT(kCallLeafRuntimeCalleeSaveScratch1 != ARGS_DESC_REG);
COMPILE_ASSERT(kCallLeafRuntimeCalleeSaveScratch2 != ARGS_DESC_REG);
__ mov(kCallLeafRuntimeCalleeSaveScratch1, CSP);
__ mov(kCallLeafRuntimeCalleeSaveScratch2, SP);
__ ReserveAlignedFrameSpace(0);
__ mov(CSP, SP);
__ ldr(TMP,
compiler::Address(THR, Thread::OffsetFromThread(runtime_entry)));
__ str(TMP, compiler::Address(THR, Thread::vm_tag_offset()));
__ blr(TMP);
__ LoadImmediate(TMP, VMTag::kDartTagId);
__ str(TMP, compiler::Address(THR, Thread::vm_tag_offset()));
__ mov(SP, kCallLeafRuntimeCalleeSaveScratch2);
__ mov(CSP, kCallLeafRuntimeCalleeSaveScratch1);
// These registers must be preserved by runtime functions, otherwise
// we'd need to restore them here.
} else {
// Argument count is not checked here, but in the runtime entry for a more
// informative error message.
__ ldr(R5, compiler::Address(THR, Thread::OffsetFromThread(runtime_entry)));
__ LoadImmediate(R4, argument_count);
__ BranchLinkToRuntime();
#endif // !defined(DART_PRECOMPILED_RUNTIME)
} // namespace dart
#endif // defined TARGET_ARCH_ARM64