src/oat/runtime/arm/context_arm.cc

/*
 * 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 "object.h"

namespace art {
namespace arm {

ArmContext::ArmContext() {
#ifndef NDEBUG
  // Initialize registers with easy to spot debug values
  for (int i = 0; i < 16; i++) {
    gprs_[i] = kBadGprBase + i;
  }
  for (int i = 0; i < 32; i++) {
    fprs_[i] = kBadFprBase + i;
  }
#endif
}

void ArmContext::FillCalleeSaves(const StackVisitor& fr) {
  Method* method = fr.GetMethod();
  uint32_t core_spills = method->GetCoreSpillMask();
  uint32_t fp_core_spills = method->GetFpSpillMask();
  size_t spill_count = __builtin_popcount(core_spills);
  size_t fp_spill_count = __builtin_popcount(fp_core_spills);
  size_t frame_size = method->GetFrameSizeInBytes();
  if (spill_count > 0) {
    // Lowest number spill is furthest away, walk registers and fill into context
    int j = 1;
    for (int i = 0; i < 16; i++) {
      if (((core_spills >> i) & 1) != 0) {
        gprs_[i] = fr.LoadCalleeSave(spill_count - j, frame_size);
        j++;
      }
    }
  }
  if (fp_spill_count > 0) {
    // Lowest number spill is furthest away, walk registers and fill into context
    int j = 1;
    for (int i = 0; i < 32; i++) {
      if (((fp_core_spills >> i) & 1) != 0) {
        fprs_[i] = fr.LoadCalleeSave(spill_count + fp_spill_count - j, frame_size);
        j++;
      }
    }
  }
}

void ArmContext::SmashCallerSaves() {
  gprs_[0] = 0; // This needs to be 0 because we want a null/zero return value.
  gprs_[1] = kBadGprBase + 1;
  gprs_[2] = kBadGprBase + 2;
  gprs_[3] = kBadGprBase + 3;
  gprs_[IP] = kBadGprBase + IP;
  gprs_[LR] = kBadGprBase + LR;
}

extern "C" void art_do_long_jump(uint32_t*, uint32_t*);

void ArmContext::DoLongJump() {
  art_do_long_jump(&gprs_[0], &fprs_[S0]);
}

}  // namespace arm
}  // namespace art