From d0dde3c3533d2335293a94146bb089a90e50259e Mon Sep 17 00:00:00 2001 From: Victor Chang Date: Wed, 29 Jan 2025 15:26:44 +0000 Subject: Add benchmarks for LocaleDataLookup on aosp_cf_x86_64_phone-userdebug, the benchmark result is libandroidfw_benchmarks#BM_LocaleDataLookupIsLocaleRepresentative: PASSED (0ms) cpu_time_ns: 55.07607273354898 real_time_ns: 55.19976479889459 libandroidfw_benchmarks#BM_LocaleDataLookupLikelyScript: PASSED (0ms) cpu_time_ns: 87.99205759931041 real_time_ns: 88.19010674954154 With the unordered_set and unordered_map, the result is libandroidfw_benchmarks#BM_LocaleDataLookupIsLocaleRepresentative: PASSED (0ms) cpu_time_ns: 113.01179143336402 real_time_ns: 113.3695957412614 libandroidfw_benchmarks#BM_LocaleDataLookupLikelyScript: PASSED (1ms) cpu_time_ns: 109.63471229710265 real_time_ns: 109.91545630537807 With std::binary_search, the result is libandroidfw_benchmarks#BM_LocaleDataLookupIsLocaleRepresentative: PASSED (0ms) cpu_time_ns: 123.82590108826805 real_time_ns: 123.98891085230711 Let's keep the current implementation, and add a TODO about the disk size. Bug: 383096413 Test: atest libandroidfw_benchmarks Change-Id: Iaa5f1ab5ac4dcc6bbdd3c4b66fe129c61d75c1d1 --- libs/androidfw/LocaleDataLookup.cpp | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'libs/androidfw/LocaleDataLookup.cpp') diff --git a/libs/androidfw/LocaleDataLookup.cpp b/libs/androidfw/LocaleDataLookup.cpp index 6e751a77f355..ea9e9a2d4280 100644 --- a/libs/androidfw/LocaleDataLookup.cpp +++ b/libs/androidfw/LocaleDataLookup.cpp @@ -7518,6 +7518,13 @@ const char* lookupLikelyScript(uint32_t packed_lang_region) { } } +/* + * TODO: Consider turning the below switch statement into binary search + * to save the disk space when the table is larger in the future. + * Disassembled code shows that the jump table emitted by clang can be + * 4x larger than the data in disk size, but it depends on the optimization option. + * However, a switch statement will benefit from the future of compiler improvement. + */ bool isLocaleRepresentative(uint32_t language_and_region, const char* script) { const uint64_t packed_locale = ((static_cast(language_and_region)) << 32u) | -- cgit v1.2.3-59-g8ed1b