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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 "calling_convention_arm.h"
#include "logging.h"
#include "managed_register_arm.h"
namespace art {
namespace arm {
// Calling convention
ManagedRegister ArmManagedRuntimeCallingConvention::InterproceduralScratchRegister() {
return ArmManagedRegister::FromCoreRegister(IP); // R12
}
ManagedRegister ArmJniCallingConvention::InterproceduralScratchRegister() {
return ArmManagedRegister::FromCoreRegister(IP); // R12
}
static ManagedRegister ReturnRegisterForShorty(const char* shorty) {
if (shorty[0] == 'F') {
return ArmManagedRegister::FromCoreRegister(R0);
} else if (shorty[0] == 'D') {
return ArmManagedRegister::FromRegisterPair(R0_R1);
} else if (shorty[0] == 'J') {
return ArmManagedRegister::FromRegisterPair(R0_R1);
} else if (shorty[0] == 'V') {
return ArmManagedRegister::NoRegister();
} else {
return ArmManagedRegister::FromCoreRegister(R0);
}
}
ManagedRegister ArmManagedRuntimeCallingConvention::ReturnRegister() {
return ReturnRegisterForShorty(GetShorty());
}
ManagedRegister ArmJniCallingConvention::ReturnRegister() {
return ReturnRegisterForShorty(GetShorty());
}
// Managed runtime calling convention
ManagedRegister ArmManagedRuntimeCallingConvention::MethodRegister() {
return ArmManagedRegister::FromCoreRegister(R0);
}
bool ArmManagedRuntimeCallingConvention::IsCurrentParamInRegister() {
return itr_slots_ < 3;
}
bool ArmManagedRuntimeCallingConvention::IsCurrentParamOnStack() {
if (itr_slots_ < 2) {
return false;
} else if (itr_slots_ > 2) {
return true;
} else {
// handle funny case of a long/double straddling registers and the stack
return IsParamALongOrDouble(itr_args_);
}
}
static const Register kManagedArgumentRegisters[] = {
R1, R2, R3
};
ManagedRegister ArmManagedRuntimeCallingConvention::CurrentParamRegister() {
CHECK(IsCurrentParamInRegister());
if (IsParamALongOrDouble(itr_args_)) {
if (itr_slots_ == 0) {
return ArmManagedRegister::FromRegisterPair(R1_R2);
} else if (itr_slots_ == 1) {
return ArmManagedRegister::FromRegisterPair(R2_R3);
} else {
// This is a long/double split between registers and the stack
return ArmManagedRegister::FromCoreRegister(
kManagedArgumentRegisters[itr_slots_]);
}
} else {
return
ArmManagedRegister::FromCoreRegister(kManagedArgumentRegisters[itr_slots_]);
}
}
FrameOffset ArmManagedRuntimeCallingConvention::CurrentParamStackOffset() {
CHECK(IsCurrentParamOnStack());
FrameOffset result =
FrameOffset(displacement_.Int32Value() + // displacement
kPointerSize + // Method*
(itr_slots_ * kPointerSize)); // offset into in args
if (itr_slots_ == 2) {
// the odd spanning case, bump the offset to skip the first half of the
// input which is in a register
CHECK(IsCurrentParamInRegister());
result = FrameOffset(result.Int32Value() + 4);
}
return result;
}
// JNI calling convention
ArmJniCallingConvention::ArmJniCallingConvention(bool is_static, bool is_synchronized,
const char* shorty)
: JniCallingConvention(is_static, is_synchronized, shorty) {
// Compute padding to ensure longs and doubles are not split in AAPCS. Ignore the 'this' jobject
// or jclass for static methods and the JNIEnv. We start at the aligned register r2.
size_t padding = 0;
for (size_t cur_arg = IsStatic() ? 0 : 1, cur_reg = 2; cur_arg < NumArgs(); cur_arg++) {
if (IsParamALongOrDouble(cur_arg)) {
if ((cur_reg & 1) != 0) {
padding += 4;
cur_reg++; // additional bump to ensure alignment
}
cur_reg++; // additional bump to skip extra long word
}
cur_reg++; // bump the iterator for every argument
}
padding_ = padding;
callee_save_regs_.push_back(ArmManagedRegister::FromCoreRegister(R5));
callee_save_regs_.push_back(ArmManagedRegister::FromCoreRegister(R6));
callee_save_regs_.push_back(ArmManagedRegister::FromCoreRegister(R7));
callee_save_regs_.push_back(ArmManagedRegister::FromCoreRegister(R8));
callee_save_regs_.push_back(ArmManagedRegister::FromCoreRegister(R10));
callee_save_regs_.push_back(ArmManagedRegister::FromCoreRegister(R11));
}
uint32_t ArmJniCallingConvention::CoreSpillMask() const {
// Compute spill mask to agree with callee saves initialized in the constructor
uint32_t result = 0;
result = 1 << R5 | 1 << R6 | 1 << R7 | 1 << R8 | 1 << R10 | 1 << R11 | 1 << LR;
return result;
}
ManagedRegister ArmJniCallingConvention::ReturnScratchRegister() const {
return ArmManagedRegister::FromCoreRegister(R2);
}
size_t ArmJniCallingConvention::FrameSize() {
// Method*, LR and callee save area size, local reference segment state
size_t frame_data_size = (3 + CalleeSaveRegisters().size()) * kPointerSize;
// References plus 2 words for SIRT header
size_t sirt_size = (ReferenceCount() + 2) * kPointerSize;
// Plus return value spill area size
return RoundUp(frame_data_size + sirt_size + SizeOfReturnValue(), kStackAlignment);
}
size_t ArmJniCallingConvention::OutArgSize() {
return RoundUp(NumberOfOutgoingStackArgs() * kPointerSize + padding_,
kStackAlignment);
}
// Will reg be crushed by an outgoing argument?
bool ArmJniCallingConvention::IsMethodRegisterClobberedPreCall() {
return true; // The method register R0 is always clobbered by the JNIEnv
}
// JniCallingConvention ABI follows AAPCS where longs and doubles must occur
// in even register numbers and stack slots
void ArmJniCallingConvention::Next() {
JniCallingConvention::Next();
size_t arg_pos = itr_args_ - NumberOfExtraArgumentsForJni();
if ((itr_args_ >= 2) &&
(arg_pos < NumArgs()) &&
IsParamALongOrDouble(arg_pos)) {
// itr_slots_ needs to be an even number, according to AAPCS.
if ((itr_slots_ & 0x1u) != 0) {
itr_slots_++;
}
}
}
bool ArmJniCallingConvention::IsCurrentParamInRegister() {
return itr_slots_ < 4;
}
bool ArmJniCallingConvention::IsCurrentParamOnStack() {
return !IsCurrentParamInRegister();
}
static const Register kJniArgumentRegisters[] = {
R0, R1, R2, R3
};
ManagedRegister ArmJniCallingConvention::CurrentParamRegister() {
CHECK_LT(itr_slots_, 4u);
int arg_pos = itr_args_ - NumberOfExtraArgumentsForJni();
if ((itr_args_ >= 2) && IsParamALongOrDouble(arg_pos)) {
CHECK_EQ(itr_slots_, 2u);
return ArmManagedRegister::FromRegisterPair(R2_R3);
} else {
return
ArmManagedRegister::FromCoreRegister(kJniArgumentRegisters[itr_slots_]);
}
}
FrameOffset ArmJniCallingConvention::CurrentParamStackOffset() {
CHECK_GE(itr_slots_, 4u);
size_t offset = displacement_.Int32Value() - OutArgSize() + ((itr_slots_ - 4) * kPointerSize);
CHECK_LT(offset, OutArgSize());
return FrameOffset(offset);
}
size_t ArmJniCallingConvention::NumberOfOutgoingStackArgs() {
size_t static_args = IsStatic() ? 1 : 0; // count jclass
// regular argument parameters and this
size_t param_args = NumArgs() + NumLongOrDoubleArgs();
// count JNIEnv* less arguments in registers
return static_args + param_args + 1 - 4;
}
} // namespace arm
} // namespace art