[turbofan] Fix HashCode/Equals for floating point operators.

Those floating point constant operators require bitwise handling of
their parameters, otherwise 0.0 equals -0.0. This is solved in a
general way by adding new base::bit_equal_to and base::bit_hash
function objects.

TEST=unittests
R=svenpanne@chromium.org

Review URL: https://codereview.chromium.org/636953002

git-svn-id: https://v8.googlecode.com/svn/branches/bleeding_edge@24450 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/base/functional.h

@@ -6,6 +6,7 @@
 #define V8_BASE_FUNCTIONAL_H_
 
 #include <cstddef>
+#include <cstring>
 #include <functional>
 #include <utility>
 
@@ -67,7 +68,17 @@ V8_INLINE size_t hash_combine(size_t seed) { return seed; }
 size_t hash_combine(size_t seed, size_t value);
 template <typename T, typename... Ts>
 V8_INLINE size_t hash_combine(T const& v, Ts const&... vs) {
-  return hash_combine(hash<T>()(v), hash_combine(vs...));
+  return hash_combine(hash_combine(vs...), hash<T>()(v));
+}
+
+
+template <typename Iterator>
+V8_INLINE size_t hash_range(Iterator first, Iterator last) {
+  size_t seed = 0;
+  for (; first != last; ++first) {
+    seed = hash_combine(seed, *first);
+  }
+  return seed;
 }
 
 
@@ -103,6 +114,16 @@ V8_INLINE size_t hash_value(double v) {
   return v != 0.0 ? hash_value(bit_cast<uint64_t>(v)) : 0;
 }
 
+template <typename T, size_t N>
+V8_INLINE size_t hash_value(const T (&v)[N]) {
+  return hash_range(v, v + N);
+}
+
+template <typename T, size_t N>
+V8_INLINE size_t hash_value(T (&v)[N]) {
+  return hash_range(v, v + N);
+}
+
 template <typename T>
 V8_INLINE size_t hash_value(T* const& v) {
   return hash_value(bit_cast<uintptr_t>(v));
@@ -148,13 +169,55 @@ struct hash<T*> : public std::unary_function<T*, size_t> {
   }
 };
 
-template <typename T1, typename T2>
-struct hash<std::pair<T1, T2> >
-    : public std::unary_function<std::pair<T1, T2>, size_t> {
-  V8_INLINE size_t operator()(std::pair<T1, T2> const& v) const {
-    return ::v8::base::hash_value(v);
-  }
-};
+
+// base::bit_equal_to is a function object class for bitwise equality
+// comparison, similar to std::equal_to, except that the comparison is performed
+// on the bit representation of the operands.
+//
+// base::bit_hash is a function object class for bitwise hashing, similar to
+// base::hash. It can be used together with base::bit_equal_to to implement a
+// hash data structure based on the bitwise representation of types.
+
+template <typename T>
+struct bit_equal_to : public std::binary_function<T, T, bool> {};
+
+template <typename T>
+struct bit_hash : public std::unary_function<T, size_t> {};
+
+#define V8_BASE_BIT_SPECIALIZE_TRIVIAL(type)                 \
+  template <>                                                \
+  struct bit_equal_to<type> : public std::equal_to<type> {}; \
+  template <>                                                \
+  struct bit_hash<type> : public hash<type> {};
+V8_BASE_BIT_SPECIALIZE_TRIVIAL(signed char)
+V8_BASE_BIT_SPECIALIZE_TRIVIAL(unsigned char)
+V8_BASE_BIT_SPECIALIZE_TRIVIAL(short)           // NOLINT(runtime/int)
+V8_BASE_BIT_SPECIALIZE_TRIVIAL(unsigned short)  // NOLINT(runtime/int)
+V8_BASE_BIT_SPECIALIZE_TRIVIAL(int)
+V8_BASE_BIT_SPECIALIZE_TRIVIAL(unsigned int)
+V8_BASE_BIT_SPECIALIZE_TRIVIAL(long)                // NOLINT(runtime/int)
+V8_BASE_BIT_SPECIALIZE_TRIVIAL(unsigned long)       // NOLINT(runtime/int)
+V8_BASE_BIT_SPECIALIZE_TRIVIAL(long long)           // NOLINT(runtime/int)
+V8_BASE_BIT_SPECIALIZE_TRIVIAL(unsigned long long)  // NOLINT(runtime/int)
+#undef V8_BASE_BIT_SPECIALIZE_TRIVIAL
+
+#define V8_BASE_BIT_SPECIALIZE_BIT_CAST(type, btype)                          \
+  template <>                                                                 \
+  struct bit_equal_to<type> : public std::binary_function<type, type, bool> { \
+    V8_INLINE bool operator()(type lhs, type rhs) const {                     \
+      return bit_cast<btype>(lhs) == bit_cast<btype>(rhs);                    \
+    }                                                                         \
+  };                                                                          \
+  template <>                                                                 \
+  struct bit_hash<type> : public std::unary_function<type, size_t> {          \
+    V8_INLINE size_t operator()(type v) const {                               \
+      hash<btype> h;                                                          \
+      return h(bit_cast<btype>(v));                                           \
+    }                                                                         \
+  };
+V8_BASE_BIT_SPECIALIZE_BIT_CAST(float, uint32_t)
+V8_BASE_BIT_SPECIALIZE_BIT_CAST(double, uint64_t)
+#undef V8_BASE_BIT_SPECIALIZE_BIT_CAST
 
 }  // namespace base
 }  // namespace v8

src/compiler/common-operator.cc

@@ -150,15 +150,17 @@ const Operator* CommonOperatorBuilder::Int64Constant(int64_t value) {
 
 const Operator* CommonOperatorBuilder::Float32Constant(volatile float value) {
   return new (zone())
-      Operator1<float>(IrOpcode::kFloat32Constant, Operator::kPure, 0, 1,
-                       "Float32Constant", value);
+      Operator1<float, base::bit_equal_to<float>, base::bit_hash<float>>(
+          IrOpcode::kFloat32Constant, Operator::kPure, 0, 1, "Float32Constant",
+          value);
 }
 
 
 const Operator* CommonOperatorBuilder::Float64Constant(volatile double value) {
   return new (zone())
-      Operator1<double>(IrOpcode::kFloat64Constant, Operator::kPure, 0, 1,
-                        "Float64Constant", value);
+      Operator1<double, base::bit_equal_to<double>, base::bit_hash<double>>(
+          IrOpcode::kFloat64Constant, Operator::kPure, 0, 1, "Float64Constant",
+          value);
 }
 
 
@@ -172,8 +174,9 @@ const Operator* CommonOperatorBuilder::ExternalConstant(
 
 const Operator* CommonOperatorBuilder::NumberConstant(volatile double value) {
   return new (zone())
-      Operator1<double>(IrOpcode::kNumberConstant, Operator::kPure, 0, 1,
-                        "NumberConstant", value);
+      Operator1<double, base::bit_equal_to<double>, base::bit_hash<double>>(
+          IrOpcode::kNumberConstant, Operator::kPure, 0, 1, "NumberConstant",
+          value);
 }
 
 

test/unittests/base/functional-unittest.cc

@@ -97,6 +97,39 @@ TYPED_TEST(FunctionalTest, HashIsOkish) {
 }
 
 
+TYPED_TEST(FunctionalTest, HashValueArrayUsesHashRange) {
+  TypeParam values[128];
+  this->rng()->NextBytes(&values, sizeof(values));
+  EXPECT_EQ(hash_range(values, values + arraysize(values)), hash_value(values));
+}
+
+
+TYPED_TEST(FunctionalTest, BitEqualTo) {
+  bit_equal_to<TypeParam> pred;
+  for (size_t i = 0; i < 128; ++i) {
+    TypeParam v1, v2;
+    this->rng()->NextBytes(&v1, sizeof(v1));
+    this->rng()->NextBytes(&v2, sizeof(v2));
+    EXPECT_PRED2(pred, v1, v1);
+    EXPECT_PRED2(pred, v2, v2);
+    EXPECT_EQ(memcmp(&v1, &v2, sizeof(TypeParam)) == 0, pred(v1, v2));
+  }
+}
+
+
+TYPED_TEST(FunctionalTest, BitEqualToImpliesSameBitHash) {
+  bit_hash<TypeParam> h;
+  bit_equal_to<TypeParam> e;
+  TypeParam values[32];
+  this->rng()->NextBytes(&values, sizeof(values));
+  TRACED_FOREACH(TypeParam, v1, values) {
+    TRACED_FOREACH(TypeParam, v2, values) {
+      if (e(v1, v2)) EXPECT_EQ(h(v1), h(v2));
+    }
+  }
+}
+
+
 namespace {
 
 struct Foo {
@@ -125,5 +158,39 @@ TEST(FunctionalTest, HashUsesArgumentDependentLookup) {
   }
 }
 
+
+TEST(FunctionalTest, BitEqualToFloat) {
+  bit_equal_to<float> pred;
+  EXPECT_FALSE(pred(0.0f, -0.0f));
+  EXPECT_FALSE(pred(-0.0f, 0.0f));
+  float const qNaN = std::numeric_limits<float>::quiet_NaN();
+  float const sNaN = std::numeric_limits<float>::signaling_NaN();
+  EXPECT_PRED2(pred, qNaN, qNaN);
+  EXPECT_PRED2(pred, sNaN, sNaN);
+}
+
+
+TEST(FunctionalTest, BitHashFloatDifferentForZeroAndMinusZero) {
+  bit_hash<float> h;
+  EXPECT_NE(h(0.0f), h(-0.0f));
+}
+
+
+TEST(FunctionalTest, BitEqualToDouble) {
+  bit_equal_to<double> pred;
+  EXPECT_FALSE(pred(0.0, -0.0));
+  EXPECT_FALSE(pred(-0.0, 0.0));
+  double const qNaN = std::numeric_limits<double>::quiet_NaN();
+  double const sNaN = std::numeric_limits<double>::signaling_NaN();
+  EXPECT_PRED2(pred, qNaN, qNaN);
+  EXPECT_PRED2(pred, sNaN, sNaN);
+}
+
+
+TEST(FunctionalTest, BitHashDoubleDifferentForZeroAndMinusZero) {
+  bit_hash<double> h;
+  EXPECT_NE(h(0.0), h(-0.0));
+}
+
 }  // namespace base
 }  // namespace v8

test/unittests/compiler/common-operator-unittest.cc

@@ -133,23 +133,93 @@ class CommonOperatorTest : public TestWithZone {
 
 const int kArguments[] = {1, 5, 6, 42, 100, 10000, kMaxInt};
 
-const float kFloat32Values[] = {
-    std::numeric_limits<float>::min(), -1.0f, -0.0f, 0.0f, 1.0f,
-    std::numeric_limits<float>::max()};
+
+const float kFloatValues[] = {-std::numeric_limits<float>::infinity(),
+                              std::numeric_limits<float>::min(),
+                              -1.0f,
+                              -0.0f,
+                              0.0f,
+                              1.0f,
+                              std::numeric_limits<float>::max(),
+                              std::numeric_limits<float>::infinity(),
+                              std::numeric_limits<float>::quiet_NaN(),
+                              std::numeric_limits<float>::signaling_NaN()};
+
+
+const double kDoubleValues[] = {-std::numeric_limits<double>::infinity(),
+                                std::numeric_limits<double>::min(),
+                                -1.0,
+                                -0.0,
+                                0.0,
+                                1.0,
+                                std::numeric_limits<double>::max(),
+                                std::numeric_limits<double>::infinity(),
+                                std::numeric_limits<double>::quiet_NaN(),
+                                std::numeric_limits<double>::signaling_NaN()};
 
 }  // namespace
 
 
 TEST_F(CommonOperatorTest, Float32Constant) {
-  TRACED_FOREACH(float, value, kFloat32Values) {
+  TRACED_FOREACH(float, value, kFloatValues) {
     const Operator* op = common()->Float32Constant(value);
-    EXPECT_FLOAT_EQ(value, OpParameter<float>(op));
+    EXPECT_PRED2(base::bit_equal_to<float>(), value, OpParameter<float>(op));
+    EXPECT_EQ(0, OperatorProperties::GetValueInputCount(op));
+    EXPECT_EQ(0, OperatorProperties::GetTotalInputCount(op));
+    EXPECT_EQ(0, OperatorProperties::GetControlOutputCount(op));
+    EXPECT_EQ(0, OperatorProperties::GetEffectOutputCount(op));
+    EXPECT_EQ(1, OperatorProperties::GetValueOutputCount(op));
+  }
+  TRACED_FOREACH(float, v1, kFloatValues) {
+    TRACED_FOREACH(float, v2, kFloatValues) {
+      const Operator* op1 = common()->Float32Constant(v1);
+      const Operator* op2 = common()->Float32Constant(v2);
+      EXPECT_EQ(bit_cast<uint32_t>(v1) == bit_cast<uint32_t>(v2),
+                op1->Equals(op2));
+    }
+  }
+}
+
+
+TEST_F(CommonOperatorTest, Float64Constant) {
+  TRACED_FOREACH(double, value, kFloatValues) {
+    const Operator* op = common()->Float64Constant(value);
+    EXPECT_PRED2(base::bit_equal_to<double>(), value, OpParameter<double>(op));
     EXPECT_EQ(0, OperatorProperties::GetValueInputCount(op));
     EXPECT_EQ(0, OperatorProperties::GetTotalInputCount(op));
     EXPECT_EQ(0, OperatorProperties::GetControlOutputCount(op));
     EXPECT_EQ(0, OperatorProperties::GetEffectOutputCount(op));
     EXPECT_EQ(1, OperatorProperties::GetValueOutputCount(op));
   }
+  TRACED_FOREACH(double, v1, kFloatValues) {
+    TRACED_FOREACH(double, v2, kFloatValues) {
+      const Operator* op1 = common()->Float64Constant(v1);
+      const Operator* op2 = common()->Float64Constant(v2);
+      EXPECT_EQ(bit_cast<uint64_t>(v1) == bit_cast<uint64_t>(v2),
+                op1->Equals(op2));
+    }
+  }
+}
+
+
+TEST_F(CommonOperatorTest, NumberConstant) {
+  TRACED_FOREACH(double, value, kFloatValues) {
+    const Operator* op = common()->NumberConstant(value);
+    EXPECT_PRED2(base::bit_equal_to<double>(), value, OpParameter<double>(op));
+    EXPECT_EQ(0, OperatorProperties::GetValueInputCount(op));
+    EXPECT_EQ(0, OperatorProperties::GetTotalInputCount(op));
+    EXPECT_EQ(0, OperatorProperties::GetControlOutputCount(op));
+    EXPECT_EQ(0, OperatorProperties::GetEffectOutputCount(op));
+    EXPECT_EQ(1, OperatorProperties::GetValueOutputCount(op));
+  }
+  TRACED_FOREACH(double, v1, kFloatValues) {
+    TRACED_FOREACH(double, v2, kFloatValues) {
+      const Operator* op1 = common()->NumberConstant(v1);
+      const Operator* op2 = common()->NumberConstant(v2);
+      EXPECT_EQ(bit_cast<uint64_t>(v1) == bit_cast<uint64_t>(v2),
+                op1->Equals(op2));
+    }
+  }
 }