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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 "context_arm.h"
#include "base/bit_utils.h"
#include "base/bit_utils_iterator.h"
#include "quick/quick_method_frame_info.h"
#include "thread-current-inl.h"
namespace art {
namespace arm {
static constexpr uint32_t gZero = 0;
void ArmContext::Reset() {
std::fill_n(gprs_, arraysize(gprs_), nullptr);
std::fill_n(fprs_, arraysize(fprs_), nullptr);
gprs_[SP] = &sp_;
gprs_[PC] = &pc_;
gprs_[R0] = &arg0_;
// Initialize registers with easy to spot debug values.
sp_ = ArmContext::kBadGprBase + SP;
pc_ = ArmContext::kBadGprBase + PC;
arg0_ = 0;
}
void ArmContext::FillCalleeSaves(uint8_t* frame, const QuickMethodFrameInfo& frame_info) {
int spill_pos = 0;
// Core registers come first, from the highest down to the lowest.
uint32_t core_regs = frame_info.CoreSpillMask();
DCHECK_EQ(0u, core_regs & (static_cast<uint32_t>(-1) << kNumberOfCoreRegisters));
for (uint32_t core_reg : HighToLowBits(core_regs)) {
gprs_[core_reg] = CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes());
++spill_pos;
}
DCHECK_EQ(spill_pos, POPCOUNT(frame_info.CoreSpillMask()));
// FP registers come second, from the highest down to the lowest.
for (uint32_t fp_reg : HighToLowBits(frame_info.FpSpillMask())) {
fprs_[fp_reg] = CalleeSaveAddress(frame, spill_pos, frame_info.FrameSizeInBytes());
++spill_pos;
}
DCHECK_EQ(spill_pos, POPCOUNT(frame_info.CoreSpillMask()) + POPCOUNT(frame_info.FpSpillMask()));
}
void ArmContext::SetGPR(uint32_t reg, uintptr_t value) {
DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfCoreRegisters));
DCHECK(IsAccessibleGPR(reg));
DCHECK_NE(gprs_[reg], &gZero); // Can't overwrite this static value since they are never reset.
*gprs_[reg] = value;
}
void ArmContext::SetFPR(uint32_t reg, uintptr_t value) {
DCHECK_LT(reg, static_cast<uint32_t>(kNumberOfSRegisters));
DCHECK(IsAccessibleFPR(reg));
DCHECK_NE(fprs_[reg], &gZero); // Can't overwrite this static value since they are never reset.
*fprs_[reg] = value;
}
void ArmContext::SmashCallerSaves() {
// This needs to be 0 because we want a null/zero return value.
gprs_[R0] = const_cast<uint32_t*>(&gZero);
gprs_[R1] = const_cast<uint32_t*>(&gZero);
gprs_[R2] = nullptr;
gprs_[R3] = nullptr;
fprs_[S0] = nullptr;
fprs_[S1] = nullptr;
fprs_[S2] = nullptr;
fprs_[S3] = nullptr;
fprs_[S4] = nullptr;
fprs_[S5] = nullptr;
fprs_[S6] = nullptr;
fprs_[S7] = nullptr;
fprs_[S8] = nullptr;
fprs_[S9] = nullptr;
fprs_[S10] = nullptr;
fprs_[S11] = nullptr;
fprs_[S12] = nullptr;
fprs_[S13] = nullptr;
fprs_[S14] = nullptr;
fprs_[S15] = nullptr;
}
extern "C" NO_RETURN void art_quick_do_long_jump(uint32_t*, uint32_t*);
void ArmContext::DoLongJump() {
uintptr_t gprs[kNumberOfCoreRegisters];
uint32_t fprs[kNumberOfSRegisters];
for (size_t i = 0; i < kNumberOfCoreRegisters; ++i) {
gprs[i] = gprs_[i] != nullptr ? *gprs_[i] : ArmContext::kBadGprBase + i;
}
for (size_t i = 0; i < kNumberOfSRegisters; ++i) {
fprs[i] = fprs_[i] != nullptr ? *fprs_[i] : ArmContext::kBadFprBase + i;
}
// Ensure the Thread Register contains the address of the current thread.
DCHECK_EQ(reinterpret_cast<uintptr_t>(Thread::Current()), gprs[TR]);
// The Marking Register will be updated by art_quick_do_long_jump.
art_quick_do_long_jump(gprs, fprs);
}
} // namespace arm
} // namespace art