Performance optimizations for base/numerics absolute value and multiply

base/numerics/safe_numerics_unittest.cc

 // Copyright 2013 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include <stddef.h>
 #include <stdint.h>
 
 #include <limits>
 #include <type_traits>
 
@@ skipping 88 matching lines @@
 
 // Helper macros to wrap displaying the conversion types and line numbers.
 #define TEST_EXPECTED_VALIDITY(expected, actual)                           \
   EXPECT_EQ(expected, (actual).template Cast<Dst>().IsValid())             \
       << "Result test: Value " << GetNumericValueForTest(actual) << " as " \
       << dst << " on line " << line
 
 #define TEST_EXPECTED_SUCCESS(actual) TEST_EXPECTED_VALIDITY(true, actual)
 #define TEST_EXPECTED_FAILURE(actual) TEST_EXPECTED_VALIDITY(false, actual)
 
-#define TEST_EXPECTED_VALUE(expected, actual)                              \
-  EXPECT_EQ(static_cast<Dst>(expected),                                    \
-            ((actual)                                                      \
-                 .template Cast<Dst>()                                     \
-                 .template ValueOrDie<Dst, LogOnFailure>()))               \
-      << "Result test: Value " << GetNumericValueForTest(actual) << " as " \
+// We have to handle promotions, so infer the underlying type below from actual.
+#define TEST_EXPECTED_VALUE(expected, actual)                               \
+  EXPECT_EQ(static_cast<typename std::decay<decltype(actual)>::type::type>( \
+                expected),                                                  \
+            ((actual)                                                       \
+                 .template ValueOrDie<                                      \
+                     typename std::decay<decltype(actual)>::type::type,     \
+                     LogOnFailure>()))                                      \
+      << "Result test: Value " << GetNumericValueForTest(actual) << " as "  \
       << dst << " on line " << line
 
 // Test the simple pointer arithmetic overrides.
 template <typename Dst>
 void TestStrictPointerMath() {
   Dst dummy_value = 0;
   Dst* dummy_ptr = &dummy_value;
   static const Dst kDummyOffset = 2;  // Don't want to go too far.
   EXPECT_EQ(dummy_ptr + kDummyOffset,
             dummy_ptr + StrictNumeric<Dst>(kDummyOffset));
@@ skipping 11 matching lines @@
 static void TestSpecializedArithmetic(
     const char* dst,
     int line,
     typename std::enable_if<numeric_limits<Dst>::is_integer &&
                                 numeric_limits<Dst>::is_signed,
                             int>::type = 0) {
   using DstLimits = numeric_limits<Dst>;
   TEST_EXPECTED_FAILURE(-CheckedNumeric<Dst>(DstLimits::lowest()));
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::lowest()).Abs());
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(-1).Abs());
+  TEST_EXPECTED_VALUE(DstLimits::max(),
+                      MakeCheckedNum(-DstLimits::max()).Abs());
 
   TEST_EXPECTED_SUCCESS(CheckedNumeric<Dst>(DstLimits::max()) + -1);
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::lowest()) + -1);
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::lowest()) +
                         DstLimits::lowest());
 
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::lowest()) - 1);
   TEST_EXPECTED_SUCCESS(CheckedNumeric<Dst>(DstLimits::lowest()) - -1);
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::max()) -
                         DstLimits::lowest());
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::lowest()) -
                         DstLimits::max());
 
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::lowest()) * 2);
 
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::lowest()) / -1);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(-1) / 2);
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::lowest()) * -1);
+  TEST_EXPECTED_VALUE(DstLimits::lowest(),
+                      MakeCheckedNum(DstLimits::lowest()).UnsignedAbs());
+  TEST_EXPECTED_VALUE(DstLimits::max(),
+                      MakeCheckedNum(DstLimits::max()).UnsignedAbs());
+  TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(0).UnsignedAbs());
+  TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1).UnsignedAbs());
+  TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(-1).UnsignedAbs());
 
   // Modulus is legal only for integers.
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() % 1);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
   TEST_EXPECTED_VALUE(-1, CheckedNumeric<Dst>(-1) % 2);
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(-1) % -2);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::lowest()) % 2);
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(DstLimits::max()) % 2);
   // Test all the different modulus combinations.
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % CheckedNumeric<Dst>(1));
@@ skipping 40 matching lines @@
   TEST_EXPECTED_SUCCESS(CheckedNumeric<Dst>(DstLimits::lowest()).Abs());
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::lowest()) + -1);
   TEST_EXPECTED_FAILURE(CheckedNumeric<Dst>(DstLimits::lowest()) - 1);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::lowest()) * 2);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) / 2);
   TEST_EXPECTED_SUCCESS(CheckedNumeric<Dst>(DstLimits::lowest()).UnsignedAbs());
   TEST_EXPECTED_SUCCESS(
       CheckedNumeric<typename std::make_signed<Dst>::type>(
           std::numeric_limits<typename std::make_signed<Dst>::type>::lowest())
           .UnsignedAbs());
+  TEST_EXPECTED_VALUE(DstLimits::lowest(),
+                      MakeCheckedNum(DstLimits::lowest()).UnsignedAbs());
+  TEST_EXPECTED_VALUE(DstLimits::max(),
+                      MakeCheckedNum(DstLimits::max()).UnsignedAbs());
+  TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(0).UnsignedAbs());
+  TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1).UnsignedAbs());
 
   // Modulus is legal only for integers.
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>() % 1);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % 1);
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(1) % 2);
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(DstLimits::lowest()) % 2);
   TEST_EXPECTED_VALUE(1, CheckedNumeric<Dst>(DstLimits::max()) % 2);
   // Test all the different modulus combinations.
   TEST_EXPECTED_VALUE(0, CheckedNumeric<Dst>(1) % CheckedNumeric<Dst>(1));
   TEST_EXPECTED_VALUE(0, 1 % CheckedNumeric<Dst>(1));
@@ skipping 804 matching lines @@
   EXPECT_EQ(static_cast<decltype(d)::type>(-.5), d);
   auto e = CheckMod(MakeCheckedNum(20), 3).ValueOrDie();
   EXPECT_EQ(static_cast<decltype(e)::type>(2), e);
   auto f = CheckLsh(1, MakeCheckedNum(2)).ValueOrDie();
   EXPECT_EQ(static_cast<decltype(f)::type>(4), f);
   auto g = CheckRsh(4, MakeCheckedNum(2)).ValueOrDie();
   EXPECT_EQ(static_cast<decltype(g)::type>(1), g);
   auto h = CheckRsh(CheckAdd(1, 1, 1, 1), CheckSub(4, 2)).ValueOrDie();
   EXPECT_EQ(static_cast<decltype(h)::type>(1), h);
 }