while (I != IE && I->Value < J->Value)
++I;
if (I != IE && I->Value == J->Value) {
- I->Count = SaturatingAdd(I->Count, J->Count);
+ I->Count += J->Count;
++I;
continue;
}
/// Sample counts accumulate using saturating arithmetic, to avoid wrapping
/// around unsigned integers.
void addSamples(uint64_t S) {
- NumSamples = SaturatingAdd(NumSamples, S);
+ if (NumSamples <= std::numeric_limits<uint64_t>::max() - S)
+ NumSamples += S;
+ else
+ NumSamples = std::numeric_limits<uint64_t>::max();
}
/// Add called function \p F with samples \p S.
/// around unsigned integers.
void addCalledTarget(StringRef F, uint64_t S) {
uint64_t &TargetSamples = CallTargets[F];
- TargetSamples = SaturatingAdd(TargetSamples, S);
+ if (TargetSamples <= std::numeric_limits<uint64_t>::max() - S)
+ TargetSamples += S;
+ else
+ TargetSamples = std::numeric_limits<uint64_t>::max();
}
/// Return true if this sample record contains function calls.
return int64_t(X << (64 - B)) >> (64 - B);
}
-/// \brief Add two unsigned integers, X and Y, of type T.
-/// Clamp the result to the maximum representable value of T on overflow.
-template <typename T>
-typename std::enable_if<std::is_unsigned<T>::value, T>::type
-SaturatingAdd(T X, T Y) {
- // Hacker's Delight, p. 29
- T Z = X + Y;
- if (Z < X || Z < Y)
- return std::numeric_limits<T>::max();
- else
- return Z;
-}
-
-/// \brief Multiply two unsigned integers, X and Y, of type T.
-/// Clamp the result to the maximum representable value of T on overflow.
-template <typename T>
-typename std::enable_if<std::is_unsigned<T>::value, T>::type
-SaturatingMultiply(T X, T Y) {
- // Hacker's Delight, p. 30
- T Z = X * Y;
- if (Y != 0 && Z / Y != X)
- return std::numeric_limits<T>::max();
- else
- return Z;
-}
-
extern const float huge_valf;
} // End llvm namespace
ASSERT_EQ(2U, VD_4[2].Count);
}
-TEST_F(InstrProfTest, get_icall_data_merge1_saturation) {
- const uint64_t Max = std::numeric_limits<uint64_t>::max();
-
- InstrProfRecord Record1("caller", 0x1234, {1});
- InstrProfRecord Record2("caller", 0x1234, {1});
- InstrProfRecord Record3("callee1", 0x1235, {3, 4});
-
- Record1.reserveSites(IPVK_IndirectCallTarget, 1);
- InstrProfValueData VD1[] = {{(uint64_t) "callee1", 1}};
- Record1.addValueData(IPVK_IndirectCallTarget, 0, VD1, 1, nullptr);
-
- Record2.reserveSites(IPVK_IndirectCallTarget, 1);
- InstrProfValueData VD2[] = {{(uint64_t) "callee1", Max}};
- Record2.addValueData(IPVK_IndirectCallTarget, 0, VD2, 1, nullptr);
-
- Writer.addRecord(std::move(Record1));
- Writer.addRecord(std::move(Record2));
- Writer.addRecord(std::move(Record3));
-
- auto Profile = Writer.writeBuffer();
- readProfile(std::move(Profile));
-
- // Verify saturation of counts.
- ErrorOr<InstrProfRecord> R = Reader->getInstrProfRecord("caller", 0x1234);
- ASSERT_TRUE(NoError(R.getError()));
- ASSERT_EQ(1U, R.get().getNumValueSites(IPVK_IndirectCallTarget));
- std::unique_ptr<InstrProfValueData[]> VD =
- R.get().getValueForSite(IPVK_IndirectCallTarget, 0);
- ASSERT_EQ(StringRef("callee1"), StringRef((const char *)VD[0].Value, 7));
- ASSERT_EQ(Max, VD[0].Count);
-}
-
TEST_F(InstrProfTest, get_max_function_count) {
InstrProfRecord Record1("foo", 0x1234, {1ULL << 31, 2});
InstrProfRecord Record2("bar", 0, {1ULL << 63});
EXPECT_EQ(552u, RoundUpToAlignment(321, 255, 42));
}
-template<typename T>
-void SaturatingAddTestHelper()
-{
- const T Max = std::numeric_limits<T>::max();
- EXPECT_EQ(T(3), SaturatingAdd(T(1), T(2)));
- EXPECT_EQ(Max, SaturatingAdd(Max, T(1)));
- EXPECT_EQ(Max, SaturatingAdd(T(1), Max));
- EXPECT_EQ(Max, SaturatingAdd(Max, Max));
-}
-
-TEST(MathExtras, SaturatingAdd) {
- SaturatingAddTestHelper<uint8_t>();
- SaturatingAddTestHelper<uint16_t>();
- SaturatingAddTestHelper<uint32_t>();
- SaturatingAddTestHelper<uint64_t>();
-}
-
}