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      1 /*
      2  * Copyright (C) 2011 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 
     17 #include "assembler.h"
     18 
     19 #include <algorithm>
     20 #include <vector>
     21 
     22 #ifdef ART_ENABLE_CODEGEN_arm
     23 #include "arm/assembler_thumb2.h"
     24 #endif
     25 #ifdef ART_ENABLE_CODEGEN_arm64
     26 #include "arm64/assembler_arm64.h"
     27 #endif
     28 #ifdef ART_ENABLE_CODEGEN_mips
     29 #include "mips/assembler_mips.h"
     30 #endif
     31 #ifdef ART_ENABLE_CODEGEN_mips64
     32 #include "mips64/assembler_mips64.h"
     33 #endif
     34 #ifdef ART_ENABLE_CODEGEN_x86
     35 #include "x86/assembler_x86.h"
     36 #endif
     37 #ifdef ART_ENABLE_CODEGEN_x86_64
     38 #include "x86_64/assembler_x86_64.h"
     39 #endif
     40 #include "base/casts.h"
     41 #include "globals.h"
     42 #include "memory_region.h"
     43 
     44 namespace art {
     45 
     46 AssemblerBuffer::AssemblerBuffer(ArenaAllocator* arena)
     47     : arena_(arena) {
     48   static const size_t kInitialBufferCapacity = 4 * KB;
     49   contents_ = arena_->AllocArray<uint8_t>(kInitialBufferCapacity, kArenaAllocAssembler);
     50   cursor_ = contents_;
     51   limit_ = ComputeLimit(contents_, kInitialBufferCapacity);
     52   fixup_ = nullptr;
     53   slow_path_ = nullptr;
     54 #ifndef NDEBUG
     55   has_ensured_capacity_ = false;
     56   fixups_processed_ = false;
     57 #endif
     58 
     59   // Verify internal state.
     60   CHECK_EQ(Capacity(), kInitialBufferCapacity);
     61   CHECK_EQ(Size(), 0U);
     62 }
     63 
     64 
     65 AssemblerBuffer::~AssemblerBuffer() {
     66   if (arena_->IsRunningOnMemoryTool()) {
     67     arena_->MakeInaccessible(contents_, Capacity());
     68   }
     69 }
     70 
     71 
     72 void AssemblerBuffer::ProcessFixups(const MemoryRegion& region) {
     73   AssemblerFixup* fixup = fixup_;
     74   while (fixup != nullptr) {
     75     fixup->Process(region, fixup->position());
     76     fixup = fixup->previous();
     77   }
     78 }
     79 
     80 
     81 void AssemblerBuffer::FinalizeInstructions(const MemoryRegion& instructions) {
     82   // Copy the instructions from the buffer.
     83   MemoryRegion from(reinterpret_cast<void*>(contents()), Size());
     84   instructions.CopyFrom(0, from);
     85   // Process fixups in the instructions.
     86   ProcessFixups(instructions);
     87 #ifndef NDEBUG
     88   fixups_processed_ = true;
     89 #endif
     90 }
     91 
     92 
     93 void AssemblerBuffer::ExtendCapacity(size_t min_capacity) {
     94   size_t old_size = Size();
     95   size_t old_capacity = Capacity();
     96   DCHECK_GT(min_capacity, old_capacity);
     97   size_t new_capacity = std::min(old_capacity * 2, old_capacity + 1 * MB);
     98   new_capacity = std::max(new_capacity, min_capacity);
     99 
    100   // Allocate the new data area and copy contents of the old one to it.
    101   contents_ = reinterpret_cast<uint8_t*>(
    102       arena_->Realloc(contents_, old_capacity, new_capacity, kArenaAllocAssembler));
    103 
    104   // Update the cursor and recompute the limit.
    105   cursor_ = contents_ + old_size;
    106   limit_ = ComputeLimit(contents_, new_capacity);
    107 
    108   // Verify internal state.
    109   CHECK_EQ(Capacity(), new_capacity);
    110   CHECK_EQ(Size(), old_size);
    111 }
    112 
    113 void DebugFrameOpCodeWriterForAssembler::ImplicitlyAdvancePC() {
    114   uint32_t pc = dchecked_integral_cast<uint32_t>(assembler_->CodeSize());
    115   if (delay_emitting_advance_pc_) {
    116     uint32_t stream_pos = dchecked_integral_cast<uint32_t>(opcodes_.size());
    117     delayed_advance_pcs_.push_back(DelayedAdvancePC {stream_pos, pc});
    118   } else {
    119     AdvancePC(pc);
    120   }
    121 }
    122 
    123 }  // namespace art
    124