Optimize ParseNumber()

3 files changed, 97 insertions, 73 deletions

diff --git a/include/rapidjson/reader.h b/include/rapidjson/reader.h
index 4aa98b18..0816b1f1 100644
--- a/include/rapidjson/reader.h
+++ b/include/rapidjson/reader.h
@@ -730,8 +730,8 @@ private:
         NumberStream(GenericReader& reader, InputStream& is) : is(is) { (void)reader;  }

         ~NumberStream() {}

 

-        Ch Peek() { return is.Peek(); }

-        Ch Take() { return is.Take(); }

+        RAPIDJSON_FORCEINLINE Ch Peek() const { return is.Peek(); }

+        RAPIDJSON_FORCEINLINE Ch Take() { return is.Take(); }

         size_t Tell() { return is.Tell(); }

         const char* Pop() { return 0; }

 

@@ -748,7 +748,7 @@ private:
         NumberStream(GenericReader& reader, InputStream& is) : NumberStream<InputStream, false>(reader, is), stackStream(reader.stack_) {}

         ~NumberStream() {}

 

-        Ch Take() {

+        RAPIDJSON_FORCEINLINE Ch Take() {

             stackStream.Put((char)Base::is.Peek());

             return Base::is.Take();

         }

@@ -869,28 +869,45 @@ private:
             s.Take();

 

             if (!useDouble) {

-                d = use64bit ? i64 : i;

-                useDouble = true;

-

+#if RAPIDJSON_64BIT

+                // Use i64 to store significand in 64-bit architecture

+                if (!use64bit)

+                    i64 = i;

+        

                 while (s.Peek() >= '0' && s.Peek() <= '9') {

-                    if (d >= 9007199254740991.0) {

-                        if (parseFlags & kParseFullPrecisionFlag)

+                    if (i64 > RAPIDJSON_UINT64_C2(0x1FFFFF, 0xFFFFFFFF)) { // 2^53 - 1 for fast path

+                        if (parseFlags & kParseFullPrecisionFlag) {

+                            while (s.Peek() >= '0' && s.Peek() <= '9')

+                                s.Take();

                             useStrtod = true;

+                            --expFrac;

+                        }

                         break;

                     }

                     else {

-                        d = d * 10.0 + static_cast<unsigned>(s.Take() - '0');

+                        i64 = i64 * 10 + static_cast<unsigned>(s.Take() - '0');

                         --expFrac;

                     }

                 }

+

+                if (!useStrtod)

+                    d = (double)i64;

+#else

+                // Use double to store significand in 32-bit architecture

+                d = use64bit ? (double)i64 : (double)i;

+#endif

+                useDouble = true;

             }

 

-            while (s.Peek() >= '0' && s.Peek() <= '9') {

-                //s.Take();

-                if (parseFlags & kParseFullPrecisionFlag)

+            if ((parseFlags & kParseFullPrecisionFlag) == 0 || !useStrtod) {

+                while (s.Peek() >= '0' && s.Peek() <= '9') {

+                    d = d * 10.0 + (s.Take() - '0');

+                    --expFrac;

+                }

+            }

+            else {

+                while (s.Peek() >= '0' && s.Peek() <= '9')

                     s.Take();

-                else

-                    d = d * 10 + (s.Take() - '0');

                 --expFrac;

             }

 

diff --git a/test/perftest/rapidjsontest.cpp b/test/perftest/rapidjsontest.cpp
index 6a451131..2321947c 100644
--- a/test/perftest/rapidjsontest.cpp
+++ b/test/perftest/rapidjsontest.cpp
@@ -96,6 +96,15 @@ TEST_F(RapidJson, SIMD_SUFFIX(ReaderParse_DummyHandler)) {
     }

 }

 

+TEST_F(RapidJson, SIMD_SUFFIX(ReaderParse_DummyHandler_FullPrecision)) {

+    for (size_t i = 0; i < kTrialCount; i++) {

+        StringStream s(json_);

+        BaseReaderHandler<> h;

+        Reader reader;

+        EXPECT_TRUE(reader.Parse<kParseFullPrecisionFlag>(s, h));

+    }

+}

+

 TEST_F(RapidJson, SIMD_SUFFIX(ReaderParseIterative_DummyHandler)) {

     for (size_t i = 0; i < kTrialCount; i++) {

         StringStream s(json_);

diff --git a/test/unittest/readertest.cpp b/test/unittest/readertest.cpp
index a82aacfa..bbd33d97 100644
--- a/test/unittest/readertest.cpp
+++ b/test/unittest/readertest.cpp
@@ -184,7 +184,7 @@ static void TestParseDouble() {
         StringStream s(str); \

         ParseDoubleHandler h; \

         Reader reader; \

-        reader.Parse<fullPrecision ? kParseFullPrecisionFlag : 0>(s, h); \

+        ASSERT_EQ(kParseErrorNone, reader.Parse<fullPrecision ? kParseFullPrecisionFlag : 0>(s, h).Code()); \

         EXPECT_EQ(1u, h.step_); \

         if (fullPrecision) { \

             EXPECT_EQ(x, h.actual_); \

@@ -195,67 +195,65 @@ static void TestParseDouble() {
             EXPECT_DOUBLE_EQ(x, h.actual_); \

     }

 

-TEST_DOUBLE(fullPrecision, "0.0", 0.0);

-TEST_DOUBLE(fullPrecision, "1.0", 1.0);

-TEST_DOUBLE(fullPrecision, "-1.0", -1.0);

-TEST_DOUBLE(fullPrecision, "1.5", 1.5);

-TEST_DOUBLE(fullPrecision, "-1.5", -1.5);

-TEST_DOUBLE(fullPrecision, "3.1416", 3.1416);

-TEST_DOUBLE(fullPrecision, "1E10", 1E10);

-TEST_DOUBLE(fullPrecision, "1e10", 1e10);

-TEST_DOUBLE(fullPrecision, "1E+10", 1E+10);

-TEST_DOUBLE(fullPrecision, "1E-10", 1E-10);

-TEST_DOUBLE(fullPrecision, "-1E10", -1E10);

-TEST_DOUBLE(fullPrecision, "-1e10", -1e10);

-TEST_DOUBLE(fullPrecision, "-1E+10", -1E+10);

-TEST_DOUBLE(fullPrecision, "-1E-10", -1E-10);

-TEST_DOUBLE(fullPrecision, "1.234E+10", 1.234E+10);

-TEST_DOUBLE(fullPrecision, "1.234E-10", 1.234E-10);

-TEST_DOUBLE(fullPrecision, "1.79769e+308", 1.79769e+308);

-TEST_DOUBLE(fullPrecision, "2.22507e-308", 2.22507e-308);

-TEST_DOUBLE(fullPrecision, "-1.79769e+308", -1.79769e+308);

-TEST_DOUBLE(fullPrecision, "-2.22507e-308", -2.22507e-308);

-TEST_DOUBLE(fullPrecision, "4.9406564584124654e-324", 4.9406564584124654e-324); // minimum denormal

-TEST_DOUBLE(fullPrecision, "1e-10000", 0.0);                                   // must underflow

-TEST_DOUBLE(fullPrecision, "18446744073709551616", 18446744073709551616.0);    // 2^64 (max of uint64_t + 1, force to use double)

-TEST_DOUBLE(fullPrecision, "-9223372036854775809", -9223372036854775809.0);    // -2^63 - 1(min of int64_t + 1, force to use double)

-TEST_DOUBLE(fullPrecision, "0.9868011474609375", 0.9868011474609375);          // https://github.com/miloyip/rapidjson/issues/120

-TEST_DOUBLE(fullPrecision, "123e34", 123e34);                                  // Fast Path Cases In Disguise

-

-{

-    char n1e308[310];   // '1' followed by 308 '0'

-    n1e308[0] = '1';

-    for (int i = 1; i < 309; i++)

-        n1e308[i] = '0';

-    n1e308[309] = '\0';

-    TEST_DOUBLE(fullPrecision, n1e308, 1E308);

-}

+    TEST_DOUBLE(fullPrecision, "0.0", 0.0);

+    TEST_DOUBLE(fullPrecision, "1.0", 1.0);

+    TEST_DOUBLE(fullPrecision, "-1.0", -1.0);

+    TEST_DOUBLE(fullPrecision, "1.5", 1.5);

+    TEST_DOUBLE(fullPrecision, "-1.5", -1.5);

+    TEST_DOUBLE(fullPrecision, "3.1416", 3.1416);

+    TEST_DOUBLE(fullPrecision, "1E10", 1E10);

+    TEST_DOUBLE(fullPrecision, "1e10", 1e10);

+    TEST_DOUBLE(fullPrecision, "1E+10", 1E+10);

+    TEST_DOUBLE(fullPrecision, "1E-10", 1E-10);

+    TEST_DOUBLE(fullPrecision, "-1E10", -1E10);

+    TEST_DOUBLE(fullPrecision, "-1e10", -1e10);

+    TEST_DOUBLE(fullPrecision, "-1E+10", -1E+10);

+    TEST_DOUBLE(fullPrecision, "-1E-10", -1E-10);

+    TEST_DOUBLE(fullPrecision, "1.234E+10", 1.234E+10);

+    TEST_DOUBLE(fullPrecision, "1.234E-10", 1.234E-10);

+    TEST_DOUBLE(fullPrecision, "1.79769e+308", 1.79769e+308);

+    TEST_DOUBLE(fullPrecision, "2.22507e-308", 2.22507e-308);

+    TEST_DOUBLE(fullPrecision, "-1.79769e+308", -1.79769e+308);

+    TEST_DOUBLE(fullPrecision, "-2.22507e-308", -2.22507e-308);

+    TEST_DOUBLE(fullPrecision, "4.9406564584124654e-324", 4.9406564584124654e-324); // minimum denormal

+    TEST_DOUBLE(fullPrecision, "1e-10000", 0.0);                                   // must underflow

+    TEST_DOUBLE(fullPrecision, "18446744073709551616", 18446744073709551616.0);    // 2^64 (max of uint64_t + 1, force to use double)

+    TEST_DOUBLE(fullPrecision, "-9223372036854775809", -9223372036854775809.0);    // -2^63 - 1(min of int64_t + 1, force to use double)

+    TEST_DOUBLE(fullPrecision, "0.9868011474609375", 0.9868011474609375);          // https://github.com/miloyip/rapidjson/issues/120

+    TEST_DOUBLE(fullPrecision, "123e34", 123e34);                                  // Fast Path Cases In Disguise

+    TEST_DOUBLE(fullPrecision, "45913141877270640000.0", 45913141877270640000.0);

 

-// Random test for double

-{

-    union {

-        double d;

-        uint64_t u;

-    }u;

-    Random r;

-

-    for (unsigned i = 0; i < 100000; i++) {

-        do {

-            // Need to call r() in two statements for cross-platform coherent sequence.

-            u.u = uint64_t(r()) << 32;

-            u.u |= uint64_t(r());

-        } while (std::isnan(u.d) || std::isinf(u.d)

-#ifdef _MSC_VER

-            // VC's strtod() has problem with denormal numbers

-            || !std::isnormal(u.d)

-#endif

-            );

+    {

+        char n1e308[310];   // '1' followed by 308 '0'

+        n1e308[0] = '1';

+        for (int i = 1; i < 309; i++)

+            n1e308[i] = '0';

+        n1e308[309] = '\0';

+        TEST_DOUBLE(fullPrecision, n1e308, 1E308);

+    }

 

-        char buffer[32];

-        *internal::dtoa(u.d, buffer) = '\0';

-        TEST_DOUBLE(fullPrecision, buffer, u.d);

+#if 1

+    // Random test for double

+    {

+        union {

+            double d;

+            uint64_t u;

+        }u;

+        Random r;

+

+        for (unsigned i = 0; i < 100000; i++) {

+            do {

+                // Need to call r() in two statements for cross-platform coherent sequence.

+                u.u = uint64_t(r()) << 32;

+                u.u |= uint64_t(r());

+            } while (std::isnan(u.d) || std::isinf(u.d) || !std::isnormal(u.d));

+

+            char buffer[32];

+            *internal::dtoa(u.d, buffer) = '\0';

+            TEST_DOUBLE(fullPrecision, buffer, u.d);

+        }

     }

-}

+#endif

 

 #undef TEST_DOUBLE

 }