JIT root tables.
Implement root tables for the JIT. Each JIT compiled method
gets a table allocated before the stack maps.
The table gets visited through Runtime::SweepSystemWeaks.
Implement String roots for x86_64 as an example.
Test: test-art-host test-art-target
Change-Id: Id3d5bc67479e08b52dd4b253e970201203a0f0d2
diff --git a/compiler/optimizing/code_generator.cc b/compiler/optimizing/code_generator.cc
index 8b450e1..a5f248d 100644
--- a/compiler/optimizing/code_generator.cc
+++ b/compiler/optimizing/code_generator.cc
@@ -1375,4 +1375,30 @@
return klass->GetDisableIntrinsicFlagOffset().Uint32Value();
}
+void CodeGenerator::EmitJitRoots(uint8_t* code,
+ Handle<mirror::ObjectArray<mirror::Object>> roots,
+ const uint8_t* roots_data,
+ Handle<mirror::DexCache> outer_dex_cache) {
+ DCHECK_EQ(static_cast<size_t>(roots->GetLength()), GetNumberOfJitRoots());
+ StackHandleScope<1> hs(Thread::Current());
+ MutableHandle<mirror::DexCache> h_dex_cache(hs.NewHandle<mirror::DexCache>(nullptr));
+ ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+ size_t index = 0;
+ for (auto& entry : jit_string_roots_) {
+ const DexFile& entry_dex_file = *entry.first.dex_file;
+ // Avoid the expensive FindDexCache call by checking if the string is
+ // in the compiled method's dex file.
+ h_dex_cache.Assign(IsSameDexFile(*outer_dex_cache->GetDexFile(), entry_dex_file)
+ ? outer_dex_cache.Get()
+ : class_linker->FindDexCache(hs.Self(), entry_dex_file));
+ mirror::String* string = class_linker->LookupString(
+ entry_dex_file, entry.first.string_index, h_dex_cache);
+ DCHECK(string != nullptr) << "JIT roots require strings to have been loaded";
+ roots->Set(index, string);
+ entry.second = index;
+ ++index;
+ }
+ EmitJitRootPatches(code, roots_data);
+}
+
} // namespace art
diff --git a/compiler/optimizing/code_generator.h b/compiler/optimizing/code_generator.h
index a81f24e..212d571 100644
--- a/compiler/optimizing/code_generator.h
+++ b/compiler/optimizing/code_generator.h
@@ -31,6 +31,7 @@
#include "nodes.h"
#include "optimizing_compiler_stats.h"
#include "stack_map_stream.h"
+#include "string_reference.h"
#include "utils/label.h"
namespace art {
@@ -331,6 +332,17 @@
void BuildStackMaps(MemoryRegion region, const DexFile::CodeItem& code_item);
size_t ComputeStackMapsSize();
+ size_t GetNumberOfJitRoots() const {
+ return jit_string_roots_.size();
+ }
+
+ // Fills the `literals` array with literals collected during code generation.
+ // Also emits literal patches.
+ void EmitJitRoots(uint8_t* code,
+ Handle<mirror::ObjectArray<mirror::Object>> roots,
+ const uint8_t* roots_data,
+ Handle<mirror::DexCache> outer_dex_cache)
+ REQUIRES_SHARED(Locks::mutator_lock_);
bool IsLeafMethod() const {
return is_leaf_;
@@ -567,6 +579,8 @@
fpu_callee_save_mask_(fpu_callee_save_mask),
stack_map_stream_(graph->GetArena()),
block_order_(nullptr),
+ jit_string_roots_(StringReferenceValueComparator(),
+ graph->GetArena()->Adapter(kArenaAllocCodeGenerator)),
disasm_info_(nullptr),
stats_(stats),
graph_(graph),
@@ -633,6 +647,12 @@
return current_slow_path_;
}
+ // Emit the patches assocatied with JIT roots. Only applies to JIT compiled code.
+ virtual void EmitJitRootPatches(uint8_t* code ATTRIBUTE_UNUSED,
+ const uint8_t* roots_data ATTRIBUTE_UNUSED) {
+ DCHECK_EQ(jit_string_roots_.size(), 0u);
+ }
+
// Frame size required for this method.
uint32_t frame_size_;
uint32_t core_spill_mask_;
@@ -658,6 +678,11 @@
// The order to use for code generation.
const ArenaVector<HBasicBlock*>* block_order_;
+ // Maps a StringReference (dex_file, string_index) to the index in the literal table.
+ // Entries are intially added with a 0 index, and `EmitJitRoots` will compute all the
+ // indices.
+ ArenaSafeMap<StringReference, size_t, StringReferenceValueComparator> jit_string_roots_;
+
DisassemblyInformation* disasm_info_;
private:
diff --git a/compiler/optimizing/code_generator_arm.cc b/compiler/optimizing/code_generator_arm.cc
index 57823c9..90ec65b 100644
--- a/compiler/optimizing/code_generator_arm.cc
+++ b/compiler/optimizing/code_generator_arm.cc
@@ -5877,6 +5877,9 @@
case HLoadString::LoadKind::kBssEntry:
DCHECK(!Runtime::Current()->UseJitCompilation());
break;
+ case HLoadString::LoadKind::kJitTableAddress:
+ DCHECK(Runtime::Current()->UseJitCompilation());
+ return HLoadString::LoadKind::kDexCacheViaMethod;
case HLoadString::LoadKind::kDexCacheViaMethod:
break;
}
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index b411a43..1aafecd 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -4422,6 +4422,9 @@
break;
case HLoadString::LoadKind::kDexCacheViaMethod:
break;
+ case HLoadString::LoadKind::kJitTableAddress:
+ DCHECK(Runtime::Current()->UseJitCompilation());
+ return HLoadString::LoadKind::kDexCacheViaMethod;
}
return desired_string_load_kind;
}
diff --git a/compiler/optimizing/code_generator_mips.cc b/compiler/optimizing/code_generator_mips.cc
index 12b1ab9..eedd4d5 100644
--- a/compiler/optimizing/code_generator_mips.cc
+++ b/compiler/optimizing/code_generator_mips.cc
@@ -5204,6 +5204,11 @@
case HLoadString::LoadKind::kDexCacheViaMethod:
fallback_load = false;
break;
+ case HLoadString::LoadKind::kJitTableAddress:
+ DCHECK(Runtime::Current()->UseJitCompilation());
+ // TODO: implement.
+ fallback_load = true;
+ break;
}
if (fallback_load) {
desired_string_load_kind = HLoadString::LoadKind::kDexCacheViaMethod;
diff --git a/compiler/optimizing/code_generator_x86.cc b/compiler/optimizing/code_generator_x86.cc
index 2f946e4..9ac8276 100644
--- a/compiler/optimizing/code_generator_x86.cc
+++ b/compiler/optimizing/code_generator_x86.cc
@@ -6217,6 +6217,9 @@
break;
case HLoadString::LoadKind::kDexCacheViaMethod:
break;
+ case HLoadString::LoadKind::kJitTableAddress:
+ DCHECK(Runtime::Current()->UseJitCompilation());
+ return HLoadString::LoadKind::kDexCacheViaMethod;
}
return desired_string_load_kind;
}
diff --git a/compiler/optimizing/code_generator_x86_64.cc b/compiler/optimizing/code_generator_x86_64.cc
index 232c3b3..117a43d 100644
--- a/compiler/optimizing/code_generator_x86_64.cc
+++ b/compiler/optimizing/code_generator_x86_64.cc
@@ -1263,7 +1263,8 @@
simple_patches_(graph->GetArena()->Adapter(kArenaAllocCodeGenerator)),
string_patches_(graph->GetArena()->Adapter(kArenaAllocCodeGenerator)),
type_patches_(graph->GetArena()->Adapter(kArenaAllocCodeGenerator)),
- fixups_to_jump_tables_(graph->GetArena()->Adapter(kArenaAllocCodeGenerator)) {
+ fixups_to_jump_tables_(graph->GetArena()->Adapter(kArenaAllocCodeGenerator)),
+ jit_string_patches_(graph->GetArena()->Adapter(kArenaAllocCodeGenerator)) {
AddAllocatedRegister(Location::RegisterLocation(kFakeReturnRegister));
}
@@ -5632,6 +5633,9 @@
break;
case HLoadString::LoadKind::kDexCacheViaMethod:
break;
+ case HLoadString::LoadKind::kJitTableAddress:
+ DCHECK(Runtime::Current()->UseJitCompilation());
+ break;
}
return desired_string_load_kind;
}
@@ -5661,6 +5665,14 @@
}
}
+Label* CodeGeneratorX86_64::NewJitRootStringPatch(const DexFile& dex_file, uint32_t dex_index) {
+ jit_string_roots_.Overwrite(StringReference(&dex_file, dex_index), /* placeholder */ 0u);
+ // Add a patch entry and return the label.
+ jit_string_patches_.emplace_back(dex_file, dex_index);
+ PatchInfo<Label>* info = &jit_string_patches_.back();
+ return &info->label;
+}
+
void InstructionCodeGeneratorX86_64::VisitLoadString(HLoadString* load) {
LocationSummary* locations = load->GetLocations();
Location out_loc = locations->Out();
@@ -5692,6 +5704,15 @@
__ Bind(slow_path->GetExitLabel());
return;
}
+ case HLoadString::LoadKind::kJitTableAddress: {
+ Address address = Address::Absolute(CodeGeneratorX86_64::kDummy32BitOffset,
+ /* no_rip */ true);
+ Label* fixup_label =
+ codegen_->NewJitRootStringPatch(load->GetDexFile(), load->GetStringIndex());
+ // /* GcRoot<mirror::String> */ out = *address
+ GenerateGcRootFieldLoad(load, out_loc, address, fixup_label, kEmitCompilerReadBarrier);
+ return;
+ }
default:
break;
}
@@ -7129,6 +7150,20 @@
}
}
+void CodeGeneratorX86_64::EmitJitRootPatches(uint8_t* code, const uint8_t* roots_data) {
+ for (const PatchInfo<Label>& info : jit_string_patches_) {
+ const auto& it = jit_string_roots_.find(StringReference(&info.dex_file, info.index));
+ DCHECK(it != jit_string_roots_.end());
+ size_t index_in_table = it->second;
+ uint32_t code_offset = info.label.Position() - kLabelPositionToLiteralOffsetAdjustment;
+ uintptr_t address =
+ reinterpret_cast<uintptr_t>(roots_data) + index_in_table * sizeof(GcRoot<mirror::Object>);
+ typedef __attribute__((__aligned__(1))) uint32_t unaligned_uint32_t;
+ reinterpret_cast<unaligned_uint32_t*>(code + code_offset)[0] =
+ dchecked_integral_cast<uint32_t>(address);
+ }
+}
+
#undef __
} // namespace x86_64
diff --git a/compiler/optimizing/code_generator_x86_64.h b/compiler/optimizing/code_generator_x86_64.h
index 5a6dc54..bc78b8c 100644
--- a/compiler/optimizing/code_generator_x86_64.h
+++ b/compiler/optimizing/code_generator_x86_64.h
@@ -411,11 +411,14 @@
void RecordTypePatch(HLoadClass* load_class);
Label* NewStringBssEntryPatch(HLoadString* load_string);
Label* NewPcRelativeDexCacheArrayPatch(const DexFile& dex_file, uint32_t element_offset);
+ Label* NewJitRootStringPatch(const DexFile& dex_file, uint32_t dex_index);
void MoveFromReturnRegister(Location trg, Primitive::Type type) OVERRIDE;
void EmitLinkerPatches(ArenaVector<LinkerPatch>* linker_patches) OVERRIDE;
+ void EmitJitRootPatches(uint8_t* code, const uint8_t* roots_data) OVERRIDE;
+
const X86_64InstructionSetFeatures& GetInstructionSetFeatures() const {
return isa_features_;
}
@@ -601,6 +604,9 @@
// Fixups for jump tables need to be handled specially.
ArenaVector<JumpTableRIPFixup*> fixups_to_jump_tables_;
+ // Patches for string literals in JIT compiled code.
+ ArenaDeque<PatchInfo<Label>> jit_string_patches_;
+
DISALLOW_COPY_AND_ASSIGN(CodeGeneratorX86_64);
};
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index ce2edde..a946e31 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -5692,7 +5692,10 @@
// all other types are unavailable.
kDexCacheViaMethod,
- kLast = kDexCacheViaMethod
+ // Load from the root table associated with the JIT compiled method.
+ kJitTableAddress,
+
+ kLast = kJitTableAddress,
};
HLoadString(HCurrentMethod* current_method,
@@ -5750,7 +5753,8 @@
LoadKind load_kind = GetLoadKind();
if (load_kind == LoadKind::kBootImageLinkTimeAddress ||
load_kind == LoadKind::kBootImageLinkTimePcRelative ||
- load_kind == LoadKind::kBootImageAddress) {
+ load_kind == LoadKind::kBootImageAddress ||
+ load_kind == LoadKind::kJitTableAddress) {
return false;
}
return !IsInDexCache();
@@ -5803,7 +5807,8 @@
return load_kind == LoadKind::kBootImageLinkTimeAddress ||
load_kind == LoadKind::kBootImageLinkTimePcRelative ||
load_kind == LoadKind::kBssEntry ||
- load_kind == LoadKind::kDexCacheViaMethod;
+ load_kind == LoadKind::kDexCacheViaMethod ||
+ load_kind == LoadKind::kJitTableAddress;
}
static bool HasAddress(LoadKind load_kind) {
diff --git a/compiler/optimizing/optimizing_compiler.cc b/compiler/optimizing/optimizing_compiler.cc
index a484760..85f6871 100644
--- a/compiler/optimizing/optimizing_compiler.cc
+++ b/compiler/optimizing/optimizing_compiler.cc
@@ -117,6 +117,7 @@
size_t GetSize() const { return size_; }
const ArenaVector<uint8_t>& GetMemory() const { return memory_; }
+ uint8_t* GetData() { return memory_.data(); }
private:
ArenaVector<uint8_t> memory_;
@@ -1126,7 +1127,7 @@
jit::JitCodeCache* code_cache,
ArtMethod* method,
bool osr) {
- StackHandleScope<2> hs(self);
+ StackHandleScope<3> hs(self);
Handle<mirror::ClassLoader> class_loader(hs.NewHandle(
method->GetDeclaringClass()->GetClassLoader()));
Handle<mirror::DexCache> dex_cache(hs.NewHandle(method->GetDexCache()));
@@ -1172,22 +1173,43 @@
}
size_t stack_map_size = codegen->ComputeStackMapsSize();
- uint8_t* stack_map_data = code_cache->ReserveData(self, stack_map_size, method);
- if (stack_map_data == nullptr) {
+ size_t number_of_roots = codegen->GetNumberOfJitRoots();
+ ClassLinker* class_linker = Runtime::Current()->GetClassLinker();
+ // We allocate an object array to ensure the JIT roots that we will collect in EmitJitRoots
+ // will be visible by the GC between EmitLiterals and CommitCode. Once CommitCode is
+ // executed, this array is not needed.
+ Handle<mirror::ObjectArray<mirror::Object>> roots(
+ hs.NewHandle(mirror::ObjectArray<mirror::Object>::Alloc(
+ self, class_linker->GetClassRoot(ClassLinker::kObjectArrayClass), number_of_roots)));
+ if (roots.Get() == nullptr) {
+ // Out of memory, just clear the exception to avoid any Java exception uncaught problems.
+ DCHECK(self->IsExceptionPending());
+ self->ClearException();
+ return false;
+ }
+ uint8_t* stack_map_data = nullptr;
+ uint8_t* roots_data = nullptr;
+ code_cache->ReserveData(
+ self, stack_map_size, number_of_roots, method, &stack_map_data, &roots_data);
+ if (stack_map_data == nullptr || roots_data == nullptr) {
return false;
}
MaybeRecordStat(MethodCompilationStat::kCompiled);
codegen->BuildStackMaps(MemoryRegion(stack_map_data, stack_map_size), *code_item);
+ codegen->EmitJitRoots(code_allocator.GetData(), roots, roots_data, dex_cache);
+
const void* code = code_cache->CommitCode(
self,
method,
stack_map_data,
+ roots_data,
codegen->HasEmptyFrame() ? 0 : codegen->GetFrameSize(),
codegen->GetCoreSpillMask(),
codegen->GetFpuSpillMask(),
code_allocator.GetMemory().data(),
code_allocator.GetSize(),
- osr);
+ osr,
+ roots);
if (code == nullptr) {
code_cache->ClearData(self, stack_map_data);
diff --git a/compiler/optimizing/sharpening.cc b/compiler/optimizing/sharpening.cc
index fd1db59..13e4494 100644
--- a/compiler/optimizing/sharpening.cc
+++ b/compiler/optimizing/sharpening.cc
@@ -281,7 +281,8 @@
: hs.NewHandle(class_linker->FindDexCache(soa.Self(), dex_file));
if (codegen_->GetCompilerOptions().IsBootImage()) {
- // Compiling boot image. Resolve the string and allocate it if needed.
+ // Compiling boot image. Resolve the string and allocate it if needed, to ensure
+ // the string will be added to the boot image.
DCHECK(!runtime->UseJitCompilation());
mirror::String* string = class_linker->ResolveString(dex_file, string_index, dex_cache);
CHECK(string != nullptr);
@@ -297,10 +298,14 @@
} else if (runtime->UseJitCompilation()) {
// TODO: Make sure we don't set the "compile PIC" flag for JIT as that's bogus.
// DCHECK(!codegen_->GetCompilerOptions().GetCompilePic());
- mirror::String* string = dex_cache->GetResolvedString(string_index);
- if (string != nullptr && runtime->GetHeap()->ObjectIsInBootImageSpace(string)) {
- desired_load_kind = HLoadString::LoadKind::kBootImageAddress;
- address = reinterpret_cast64<uint64_t>(string);
+ mirror::String* string = class_linker->LookupString(dex_file, string_index, dex_cache);
+ if (string != nullptr) {
+ if (runtime->GetHeap()->ObjectIsInBootImageSpace(string)) {
+ desired_load_kind = HLoadString::LoadKind::kBootImageAddress;
+ address = reinterpret_cast64<uint64_t>(string);
+ } else {
+ desired_load_kind = HLoadString::LoadKind::kJitTableAddress;
+ }
}
} else {
// AOT app compilation. Try to lookup the string without allocating if not found.
@@ -322,6 +327,7 @@
case HLoadString::LoadKind::kBootImageLinkTimePcRelative:
case HLoadString::LoadKind::kBssEntry:
case HLoadString::LoadKind::kDexCacheViaMethod:
+ case HLoadString::LoadKind::kJitTableAddress:
load_string->SetLoadKindWithStringReference(load_kind, dex_file, string_index);
break;
case HLoadString::LoadKind::kBootImageAddress: