From 552a13415573da19eafa46e1ac00fb0eb68f2b23 Mon Sep 17 00:00:00 2001 From: Vladimir Marko Date: Tue, 31 Oct 2017 10:56:47 +0000 Subject: ART: Optimize StringBuilder append pattern. Recognize appending with StringBuilder and replace the entire expression with a runtime call that perfoms the append in a more efficient manner. For now, require the entire pattern to be in a single block and be very strict about the StringBuilder environment uses. Also, do not accept StringBuilder/char[]/Object/float/double arguments as they throw non-OOME exceptions and/or require a call from the entrypoint back to a helper function in Java; these shall be implemented later. Boot image size for aosp_taimen-userdebug: - before: arm/boot*.oat: 19653872 arm64/boot*.oat: 23292784 oat/arm64/services.odex: 22408664 - after: arm/boot*.oat: 19432184 (-216KiB) arm64/boot*.oat: 22992488 (-293KiB) oat/arm64/services.odex: 22376776 (-31KiB) Note that const-string in compiled boot image methods cannot throw, but for apps it can and therefore its environment can prevent the optimization for apps. We could implement either a simple carve-out for const-string or generic environment pruning to allow this pattern to be applied more often. Results for the new StringBuilderAppendBenchmark on taimen: timeAppendLongStrings: ~700ns -> ~200ns timeAppendStringAndInt: ~220ns -> ~140ns timeAppendStrings: ~200ns -> 130ns Bug: 19575890 Test: 697-checker-string-append Test: m test-art-host-gtest Test: testrunner.py --host --optimizing Test: aosp_taimen-userdebug boots. Test: run-gtests.sh Test: testrunner.py --target --optimizing Test: vogar --benchmark art/benchmark/stringbuilder-append/src/StringBuilderAppendBenchmark.java Change-Id: I51789bf299f5219f68ada4c077b6a1d3fe083964 --- compiler/optimizing/code_generator_mips.cc | 9 +++++++++ 1 file changed, 9 insertions(+) (limited to 'compiler/optimizing/code_generator_mips.cc') diff --git a/compiler/optimizing/code_generator_mips.cc b/compiler/optimizing/code_generator_mips.cc index 72334afa40..b3bce78940 100644 --- a/compiler/optimizing/code_generator_mips.cc +++ b/compiler/optimizing/code_generator_mips.cc @@ -9529,6 +9529,15 @@ void InstructionCodeGeneratorMIPS::VisitStaticFieldSet(HStaticFieldSet* instruct instruction->GetValueCanBeNull()); } +void LocationsBuilderMIPS::VisitStringBuilderAppend(HStringBuilderAppend* instruction) { + codegen_->CreateStringBuilderAppendLocations(instruction, Location::RegisterLocation(V0)); +} + +void InstructionCodeGeneratorMIPS::VisitStringBuilderAppend(HStringBuilderAppend* instruction) { + __ LoadConst32(A0, instruction->GetFormat()->GetValue()); + codegen_->InvokeRuntime(kQuickStringBuilderAppend, instruction, instruction->GetDexPc()); +} + void LocationsBuilderMIPS::VisitUnresolvedInstanceFieldGet( HUnresolvedInstanceFieldGet* instruction) { FieldAccessCallingConventionMIPS calling_convention; -- cgit v1.2.3