Use mmapped boot image class table for PIC app HLoadClass.
Implement new HLoadClass load kind for boot image classes
referenced by PIC-compiled apps (i.e. prebuilts) that uses
PC-relative load from a boot image ClassTable mmapped into
the apps .bss. This reduces the size of the PIC prebuilts
that reference boot image classes compared to the kBssEntry
as we can completely avoid the slow path and stack map
unless we need to do the class initialization check.
Prebuilt services.odex for aosp_angler-userdebug (arm64):
- before: 20312800
- after: 19775352 (-525KiB)
Test: m test-art-host-gtest
Test: testrunner.py --host
Test: testrunner.py --host --pictest
Test: testrunner.py --target on Nexus 6P.
Test: testrunner.py --target --pictest on Nexus 6P.
Test: Nexus 6P boots.
Bug: 31951624
Change-Id: I13adb19a1fa7d095a72a41f09daa6101876e77a8
diff --git a/compiler/optimizing/code_generator_arm64.cc b/compiler/optimizing/code_generator_arm64.cc
index 1b62868..19e5d06 100644
--- a/compiler/optimizing/code_generator_arm64.cc
+++ b/compiler/optimizing/code_generator_arm64.cc
@@ -21,6 +21,7 @@
#include "art_method.h"
#include "base/bit_utils.h"
#include "base/bit_utils_iterator.h"
+#include "class_table.h"
#include "code_generator_utils.h"
#include "compiled_method.h"
#include "entrypoints/quick/quick_entrypoints.h"
@@ -4784,7 +4785,8 @@
linker_patches);
} else {
DCHECK(pc_relative_method_patches_.empty());
- DCHECK(pc_relative_type_patches_.empty());
+ EmitPcRelativeLinkerPatches<LinkerPatch::TypeClassTablePatch>(pc_relative_type_patches_,
+ linker_patches);
EmitPcRelativeLinkerPatches<LinkerPatch::StringInternTablePatch>(pc_relative_string_patches_,
linker_patches);
}
@@ -4861,6 +4863,7 @@
case HLoadClass::LoadKind::kReferrersClass:
break;
case HLoadClass::LoadKind::kBootImageLinkTimePcRelative:
+ case HLoadClass::LoadKind::kBootImageClassTable:
case HLoadClass::LoadKind::kBssEntry:
DCHECK(!Runtime::Current()->UseJitCompilation());
break;
@@ -4972,6 +4975,25 @@
__ Ldr(out.W(), codegen_->DeduplicateBootImageAddressLiteral(address));
break;
}
+ case HLoadClass::LoadKind::kBootImageClassTable: {
+ DCHECK(!codegen_->GetCompilerOptions().IsBootImage());
+ // Add ADRP with its PC-relative type patch.
+ const DexFile& dex_file = cls->GetDexFile();
+ dex::TypeIndex type_index = cls->GetTypeIndex();
+ vixl::aarch64::Label* adrp_label = codegen_->NewPcRelativeTypePatch(dex_file, type_index);
+ codegen_->EmitAdrpPlaceholder(adrp_label, out.X());
+ // Add LDR with its PC-relative type patch.
+ vixl::aarch64::Label* ldr_label =
+ codegen_->NewPcRelativeTypePatch(dex_file, type_index, adrp_label);
+ codegen_->EmitLdrOffsetPlaceholder(ldr_label, out.W(), out.X());
+ // Extract the reference from the slot data, i.e. clear the hash bits.
+ int32_t masked_hash = ClassTable::TableSlot::MaskHash(
+ ComputeModifiedUtf8Hash(dex_file.StringByTypeIdx(type_index)));
+ if (masked_hash != 0) {
+ __ Sub(out.W(), out.W(), Operand(masked_hash));
+ }
+ break;
+ }
case HLoadClass::LoadKind::kBssEntry: {
// Add ADRP with its PC-relative Class .bss entry patch.
const DexFile& dex_file = cls->GetDexFile();