Keep resolved String in HLoadString.
For the following reasons:
- Avoids needing to do a lookup again in CodeGenerator::EmitJitRoots.
- Fixes races where we the string was GC'ed before CodeGenerator::EmitJitRoots.
- Makes it possible to do GVN on the same string but defined in different
dex files.
Test: test-art-host, test-art-target
Change-Id: If2b5d3079f7555427b1b96ab04546b3373fcf921
diff --git a/compiler/optimizing/code_generator.cc b/compiler/optimizing/code_generator.cc
index 402eeee..f00648f 100644
--- a/compiler/optimizing/code_generator.cc
+++ b/compiler/optimizing/code_generator.cc
@@ -1378,28 +1378,21 @@
void CodeGenerator::EmitJitRoots(uint8_t* code,
Handle<mirror::ObjectArray<mirror::Object>> roots,
- const uint8_t* roots_data,
- Handle<mirror::DexCache> outer_dex_cache) {
+ const uint8_t* roots_data) {
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";
+ // Update the `roots` with the string, and replace the address temporarily
+ // stored to the index in the table.
+ uint64_t address = entry.second;
+ roots->Set(index, reinterpret_cast<StackReference<mirror::String>*>(address)->AsMirrorPtr());
+ DCHECK(roots->Get(index) != nullptr);
+ entry.second = index;
// Ensure the string is strongly interned. This is a requirement on how the JIT
// handles strings. b/32995596
- class_linker->GetInternTable()->InternStrong(string);
- roots->Set(index, string);
- entry.second = index;
+ class_linker->GetInternTable()->InternStrong(
+ reinterpret_cast<mirror::String*>(roots->Get(index)));
++index;
}
for (auto& entry : jit_class_roots_) {
@@ -1407,6 +1400,7 @@
// stored to the index in the table.
uint64_t address = entry.second;
roots->Set(index, reinterpret_cast<StackReference<mirror::Class>*>(address)->AsMirrorPtr());
+ DCHECK(roots->Get(index) != nullptr);
entry.second = index;
++index;
}