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/*
* Copyright (C) 2011 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include "compiled_method.h"
#include "compiler.h"
#include "oat/utils/assembler.h"
#include "oat/utils/x86/assembler_x86.h"
#include "object.h"
namespace art {
namespace x86 {
// Creates a function which invokes a managed method with an array of
// arguments.
//
// Immediately after the call on X86, the environment looks like this:
//
// [SP+0 ] = Return address
// [SP+4 ] = method pointer
// [SP+8 ] = receiver pointer or NULL for static methods
// [SP+12] = (managed) thread pointer
// [SP+16] = argument array or NULL for no argument methods
// [SP+20] = JValue* result or NULL for void returns
//
// As the JNI call has already transitioned the thread into the
// "running" state the remaining responsibilities of this routine are
// to save the native registers and set up the managed registers. On
// return, the return value must be store into the result JValue.
CompiledInvokeStub* CreateInvokeStub(bool is_static, const char* shorty, uint32_t shorty_len) {
UniquePtr<X86Assembler> assembler(down_cast<X86Assembler*>(Assembler::Create(kX86)));
#define __ assembler->
size_t num_arg_array_bytes = NumArgArrayBytes(shorty, shorty_len);
// Size of frame = return address + saved EBX + Method* + possible receiver + arg array size
// Note, space is left in the frame to flush arguments in registers back to out locations.
size_t frame_size = 3 * kPointerSize + (is_static ? 0 : kPointerSize) + num_arg_array_bytes;
size_t pad_size = RoundUp(frame_size, kStackAlignment) - frame_size;
Register rMethod = EAX;
__ movl(rMethod, Address(ESP, 4)); // EAX = method
Register rReceiver = ECX;
if (!is_static) {
__ movl(rReceiver, Address(ESP, 8)); // ECX = receiver
}
// Save EBX
__ pushl(EBX);
Register rArgArray = EBX;
__ movl(rArgArray, Address(ESP, 20)); // EBX = arg array
// TODO: optimize the frame set up to avoid excessive SP math
// Push padding
if (pad_size != 0) {
__ subl(ESP, Immediate(pad_size));
}
// Push/copy arguments.
size_t arg_count = (shorty_len - 1);
size_t dst_offset = num_arg_array_bytes;
size_t src_offset = arg_count * sizeof(JValue);
for (size_t i = shorty_len - 1; i > 0; --i) {
switch (shorty[i]) {
case 'D':
case 'J':
// Move both pointers 64 bits.
dst_offset -= kPointerSize;
src_offset -= sizeof(JValue) / 2;
__ pushl(Address(rArgArray, src_offset));
dst_offset -= kPointerSize;
src_offset -= sizeof(JValue) / 2;
__ pushl(Address(rArgArray, src_offset));
break;
default:
// Move the source pointer sizeof(JValue) and the destination pointer 32 bits.
dst_offset -= kPointerSize;
src_offset -= sizeof(JValue);
__ pushl(Address(rArgArray, src_offset));
break;
}
}
// Backing space for receiver.
if (!is_static) {
__ pushl(Immediate(0));
}
// Push 0 as NULL Method* thereby terminating managed stack crawls.
__ pushl(Immediate(0));
if (!is_static) {
if (shorty_len > 1) {
// Receiver already in ECX, pass remaining 2 args in EDX and EBX.
__ movl(EDX, Address(rArgArray, 0));
if (shorty[1] == 'D' || shorty[1] == 'J') {
__ movl(EBX, Address(rArgArray, sizeof(JValue) / 2));
} else if (shorty_len > 2) {
__ movl(EBX, Address(rArgArray, sizeof(JValue)));
}
}
} else {
if (shorty_len > 1) {
// Pass remaining 3 args in ECX, EDX and EBX.
__ movl(ECX, Address(rArgArray, 0));
if (shorty[1] == 'D' || shorty[1] == 'J') {
__ movl(EDX, Address(rArgArray, sizeof(JValue) / 2));
if (shorty_len > 2) {
__ movl(EBX, Address(rArgArray, sizeof(JValue)));
}
} else if (shorty_len > 2) {
__ movl(EDX, Address(rArgArray, sizeof(JValue)));
if (shorty[2] == 'D' || shorty[2] == 'J') {
__ movl(EBX, Address(rArgArray, sizeof(JValue) + (sizeof(JValue) / 2)));
} else {
__ movl(EBX, Address(rArgArray, sizeof(JValue) + sizeof(JValue)));
}
}
}
}
__ call(Address(EAX, AbstractMethod::GetCodeOffset())); // Call code off of method
// Pop arguments up to EBX and the return address.
__ addl(ESP, Immediate(frame_size + pad_size - (2 * kPointerSize)));
// Restore EBX.
__ popl(EBX);
char ch = shorty[0];
if (ch != 'V') {
// Load the result JValue pointer.
__ movl(ECX, Address(ESP, 20));
switch (ch) {
case 'D':
__ movsd(Address(ECX, 0), XMM0);
break;
case 'F':
__ movss(Address(ECX, 0), XMM0);
break;
case 'J':
__ movl(Address(ECX, 0), EAX);
__ movl(Address(ECX, 4), EDX);
break;
default:
__ movl(Address(ECX, 0), EAX);
break;
}
}
__ ret();
// TODO: store native_entry in the stub table
std::vector<uint8_t> code(assembler->CodeSize());
MemoryRegion region(&code[0], code.size());
assembler->FinalizeInstructions(region);
return new CompiledInvokeStub(kX86, code);
#undef __
}
} // namespace x86
} // namespace art
extern "C" art::CompiledInvokeStub* ArtCreateInvokeStub(art::Compiler& /*compiler*/, bool is_static,
const char* shorty, uint32_t shorty_len) {
return art::x86::CreateInvokeStub(is_static, shorty, shorty_len);
}
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