intermediate changes

ref:cde9a383711a11544ce7e107a78147fb96cc4029

1 files changed, 123 insertions, 0 deletions

diff --git a/util/string/benchmark/ascii/main.cpp b/util/string/benchmark/ascii/main.cpp
new file mode 100644
index 00000000000..673047025d3
--- /dev/null
+++ b/util/string/benchmark/ascii/main.cpp
@@ -0,0 +1,123 @@
+#include <library/cpp/testing/benchmark/bench.h>
+
+#include <util/generic/xrange.h>
+#include <util/string/ascii.h>
+#include <util/generic/bitmap.h>
+#include <util/generic/singleton.h>
+
+namespace {
+    struct TUpperMap: public TBitMap<256> {
+        inline TUpperMap() noexcept {
+            for (unsigned i = 'A'; i <= 'Z'; ++i) {
+                Set((ui8)i);
+            }
+        }
+
+        inline char ToLower(char x) const noexcept {
+            return Get((ui8)x) ? x + ('a' - 'A') : x;
+        }
+    };
+
+    struct TToLowerLookup {
+        char Table[256];
+
+        TToLowerLookup() {
+            for (size_t i : xrange(256)) {
+                Table[i] = AsciiToLower(i);
+            }
+        }
+
+        char ToLower(char x) const noexcept {
+            return Table[(ui8)x];
+        }
+    };
+}
+
+static inline char FastAsciiToLower(char c) {
+    return (c >= 'A' && c <= 'Z') ? (c + ('a' - 'A')) : c;
+}
+
+static inline char FastAsciiToLower2(char c) {
+    return c + ('a' - 'A') * (int)(c >= 'A' && c <= 'Z');
+}
+
+Y_CPU_BENCHMARK(AsciiToLower, iface) {
+    for (const auto i : xrange(iface.Iterations())) {
+        Y_UNUSED(i);
+
+        for (int j = 0; j < 256; ++j) {
+            Y_DO_NOT_OPTIMIZE_AWAY(AsciiToLower(j));
+        }
+    }
+}
+
+Y_CPU_BENCHMARK(AsciiToLowerChar, iface) {
+    for (const auto i : xrange(iface.Iterations())) {
+        Y_UNUSED(i);
+
+        for (int j = 0; j < 256; ++j) {
+            Y_DO_NOT_OPTIMIZE_AWAY(AsciiToLower((char)j));
+        }
+    }
+}
+
+Y_CPU_BENCHMARK(FastAsciiToLower, iface) {
+    for (const auto i : xrange(iface.Iterations())) {
+        Y_UNUSED(i);
+
+        for (int j = 0; j < 256; ++j) {
+            Y_DO_NOT_OPTIMIZE_AWAY(FastAsciiToLower(j));
+        }
+    }
+}
+
+Y_CPU_BENCHMARK(FastAsciiToLower2, iface) {
+    for (const auto i : xrange(iface.Iterations())) {
+        Y_UNUSED(i);
+
+        for (int j = 0; j < 256; ++j) {
+            Y_DO_NOT_OPTIMIZE_AWAY(FastAsciiToLower2(j));
+        }
+    }
+}
+
+Y_CPU_BENCHMARK(BitMapAsciiToLower, iface) {
+    for (const auto i : xrange(iface.Iterations())) {
+        Y_UNUSED(i);
+
+        for (int j = 0; j < 256; ++j) {
+            Y_DO_NOT_OPTIMIZE_AWAY(Singleton<TUpperMap>()->ToLower(j));
+        }
+    }
+}
+
+Y_CPU_BENCHMARK(LookupAsciiToLower, iface) {
+    for (const auto i : xrange(iface.Iterations())) {
+        Y_UNUSED(i);
+
+        for (int j = 0; j < 256; ++j) {
+            Y_DO_NOT_OPTIMIZE_AWAY(Singleton<TToLowerLookup>()->ToLower(j));
+        }
+    }
+}
+
+Y_CPU_BENCHMARK(LookupAsciiToLowerNoSingleton, iface) {
+    TToLowerLookup lookup;
+    for (const auto i : xrange(iface.Iterations())) {
+        Y_UNUSED(i);
+
+        for (int j = 0; j < 256; ++j) {
+            Y_DO_NOT_OPTIMIZE_AWAY(lookup.ToLower(j));
+        }
+    }
+}
+
+Y_CPU_BENCHMARK(tolower, iface) {
+    for (const auto i : xrange(iface.Iterations())) {
+        Y_UNUSED(i);
+
+        for (int j = 0; j < 256; ++j) {
+            Y_DO_NOT_OPTIMIZE_AWAY(tolower(j));
+        }
+    }
+}