v8/test/cctest/test-double.cc

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// Copyright 2006-2008 the V8 project authors. All rights reserved.
#include <stdlib.h>
#include "v8.h"
#include "platform.h"
#include "cctest.h"
#include "diy-fp.h"
#include "double.h"
using namespace v8::internal;
TEST(Uint64Conversions) {
// Start by checking the byte-order.
uint64_t ordered = V8_2PART_UINT64_C(0x01234567, 89ABCDEF);
CHECK_EQ(3512700564088504e-318, Double(ordered).value());
uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
CHECK_EQ(5e-324, Double(min_double64).value());
uint64_t max_double64 = V8_2PART_UINT64_C(0x7fefffff, ffffffff);
CHECK_EQ(1.7976931348623157e308, Double(max_double64).value());
}
TEST(AsDiyFp) {
uint64_t ordered = V8_2PART_UINT64_C(0x01234567, 89ABCDEF);
DiyFp diy_fp = Double(ordered).AsDiyFp();
CHECK_EQ(0x12 - 0x3FF - 52, diy_fp.e());
// The 52 mantissa bits, plus the implicit 1 in bit 52 as a UINT64.
CHECK(V8_2PART_UINT64_C(0x00134567, 89ABCDEF) == diy_fp.f()); // NOLINT
uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
diy_fp = Double(min_double64).AsDiyFp();
CHECK_EQ(-0x3FF - 52 + 1, diy_fp.e());
// This is a denormal; so no hidden bit.
CHECK(1 == diy_fp.f()); // NOLINT
uint64_t max_double64 = V8_2PART_UINT64_C(0x7fefffff, ffffffff);
diy_fp = Double(max_double64).AsDiyFp();
CHECK_EQ(0x7FE - 0x3FF - 52, diy_fp.e());
CHECK(V8_2PART_UINT64_C(0x001fffff, ffffffff) == diy_fp.f()); // NOLINT
}
TEST(AsNormalizedDiyFp) {
uint64_t ordered = V8_2PART_UINT64_C(0x01234567, 89ABCDEF);
DiyFp diy_fp = Double(ordered).AsNormalizedDiyFp();
CHECK_EQ(0x12 - 0x3FF - 52 - 11, diy_fp.e());
CHECK((V8_2PART_UINT64_C(0x00134567, 89ABCDEF) << 11) ==
diy_fp.f()); // NOLINT
uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
diy_fp = Double(min_double64).AsNormalizedDiyFp();
CHECK_EQ(-0x3FF - 52 + 1 - 63, diy_fp.e());
// This is a denormal; so no hidden bit.
CHECK(V8_2PART_UINT64_C(0x80000000, 00000000) == diy_fp.f()); // NOLINT
uint64_t max_double64 = V8_2PART_UINT64_C(0x7fefffff, ffffffff);
diy_fp = Double(max_double64).AsNormalizedDiyFp();
CHECK_EQ(0x7FE - 0x3FF - 52 - 11, diy_fp.e());
CHECK((V8_2PART_UINT64_C(0x001fffff, ffffffff) << 11) ==
diy_fp.f()); // NOLINT
}
TEST(IsDenormal) {
uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
CHECK(Double(min_double64).IsDenormal());
uint64_t bits = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF);
CHECK(Double(bits).IsDenormal());
bits = V8_2PART_UINT64_C(0x00100000, 00000000);
CHECK(!Double(bits).IsDenormal());
}
TEST(IsSpecial) {
CHECK(Double(V8_INFINITY).IsSpecial());
CHECK(Double(-V8_INFINITY).IsSpecial());
CHECK(Double(OS::nan_value()).IsSpecial());
uint64_t bits = V8_2PART_UINT64_C(0xFFF12345, 00000000);
CHECK(Double(bits).IsSpecial());
// Denormals are not special:
CHECK(!Double(5e-324).IsSpecial());
CHECK(!Double(-5e-324).IsSpecial());
// And some random numbers:
CHECK(!Double(0.0).IsSpecial());
CHECK(!Double(-0.0).IsSpecial());
CHECK(!Double(1.0).IsSpecial());
CHECK(!Double(-1.0).IsSpecial());
CHECK(!Double(1000000.0).IsSpecial());
CHECK(!Double(-1000000.0).IsSpecial());
CHECK(!Double(1e23).IsSpecial());
CHECK(!Double(-1e23).IsSpecial());
CHECK(!Double(1.7976931348623157e308).IsSpecial());
CHECK(!Double(-1.7976931348623157e308).IsSpecial());
}
TEST(IsInfinite) {
CHECK(Double(V8_INFINITY).IsInfinite());
CHECK(Double(-V8_INFINITY).IsInfinite());
CHECK(!Double(OS::nan_value()).IsInfinite());
CHECK(!Double(0.0).IsInfinite());
CHECK(!Double(-0.0).IsInfinite());
CHECK(!Double(1.0).IsInfinite());
CHECK(!Double(-1.0).IsInfinite());
uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
CHECK(!Double(min_double64).IsInfinite());
}
TEST(IsNan) {
CHECK(Double(OS::nan_value()).IsNan());
uint64_t other_nan = V8_2PART_UINT64_C(0xFFFFFFFF, 00000001);
CHECK(Double(other_nan).IsNan());
CHECK(!Double(V8_INFINITY).IsNan());
CHECK(!Double(-V8_INFINITY).IsNan());
CHECK(!Double(0.0).IsNan());
CHECK(!Double(-0.0).IsNan());
CHECK(!Double(1.0).IsNan());
CHECK(!Double(-1.0).IsNan());
uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
CHECK(!Double(min_double64).IsNan());
}
TEST(Sign) {
CHECK_EQ(1, Double(1.0).Sign());
CHECK_EQ(1, Double(V8_INFINITY).Sign());
CHECK_EQ(-1, Double(-V8_INFINITY).Sign());
CHECK_EQ(1, Double(0.0).Sign());
CHECK_EQ(-1, Double(-0.0).Sign());
uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
CHECK_EQ(1, Double(min_double64).Sign());
}
TEST(NormalizedBoundaries) {
DiyFp boundary_plus;
DiyFp boundary_minus;
DiyFp diy_fp = Double(1.5).AsNormalizedDiyFp();
Double(1.5).NormalizedBoundaries(&boundary_minus, &boundary_plus);
CHECK_EQ(diy_fp.e(), boundary_minus.e());
CHECK_EQ(diy_fp.e(), boundary_plus.e());
// 1.5 does not have a significand of the form 2^p (for some p).
// Therefore its boundaries are at the same distance.
CHECK(diy_fp.f() - boundary_minus.f() == boundary_plus.f() - diy_fp.f());
CHECK((1 << 10) == diy_fp.f() - boundary_minus.f()); // NOLINT
diy_fp = Double(1.0).AsNormalizedDiyFp();
Double(1.0).NormalizedBoundaries(&boundary_minus, &boundary_plus);
CHECK_EQ(diy_fp.e(), boundary_minus.e());
CHECK_EQ(diy_fp.e(), boundary_plus.e());
// 1.0 does have a significand of the form 2^p (for some p).
// Therefore its lower boundary is twice as close as the upper boundary.
CHECK_GT(boundary_plus.f() - diy_fp.f(), diy_fp.f() - boundary_minus.f());
CHECK((1 << 9) == diy_fp.f() - boundary_minus.f()); // NOLINT
CHECK((1 << 10) == boundary_plus.f() - diy_fp.f()); // NOLINT
uint64_t min_double64 = V8_2PART_UINT64_C(0x00000000, 00000001);
diy_fp = Double(min_double64).AsNormalizedDiyFp();
Double(min_double64).NormalizedBoundaries(&boundary_minus, &boundary_plus);
CHECK_EQ(diy_fp.e(), boundary_minus.e());
CHECK_EQ(diy_fp.e(), boundary_plus.e());
// min-value does not have a significand of the form 2^p (for some p).
// Therefore its boundaries are at the same distance.
CHECK(diy_fp.f() - boundary_minus.f() == boundary_plus.f() - diy_fp.f());
// Denormals have their boundaries much closer.
CHECK((static_cast<uint64_t>(1) << 62) ==
diy_fp.f() - boundary_minus.f()); // NOLINT
uint64_t smallest_normal64 = V8_2PART_UINT64_C(0x00100000, 00000000);
diy_fp = Double(smallest_normal64).AsNormalizedDiyFp();
Double(smallest_normal64).NormalizedBoundaries(&boundary_minus,
&boundary_plus);
CHECK_EQ(diy_fp.e(), boundary_minus.e());
CHECK_EQ(diy_fp.e(), boundary_plus.e());
// Even though the significand is of the form 2^p (for some p), its boundaries
// are at the same distance. (This is the only exception).
CHECK(diy_fp.f() - boundary_minus.f() == boundary_plus.f() - diy_fp.f());
CHECK((1 << 10) == diy_fp.f() - boundary_minus.f()); // NOLINT
uint64_t largest_denormal64 = V8_2PART_UINT64_C(0x000FFFFF, FFFFFFFF);
diy_fp = Double(largest_denormal64).AsNormalizedDiyFp();
Double(largest_denormal64).NormalizedBoundaries(&boundary_minus,
&boundary_plus);
CHECK_EQ(diy_fp.e(), boundary_minus.e());
CHECK_EQ(diy_fp.e(), boundary_plus.e());
CHECK(diy_fp.f() - boundary_minus.f() == boundary_plus.f() - diy_fp.f());
CHECK((1 << 11) == diy_fp.f() - boundary_minus.f()); // NOLINT
uint64_t max_double64 = V8_2PART_UINT64_C(0x7fefffff, ffffffff);
diy_fp = Double(max_double64).AsNormalizedDiyFp();
Double(max_double64).NormalizedBoundaries(&boundary_minus, &boundary_plus);
CHECK_EQ(diy_fp.e(), boundary_minus.e());
CHECK_EQ(diy_fp.e(), boundary_plus.e());
// max-value does not have a significand of the form 2^p (for some p).
// Therefore its boundaries are at the same distance.
CHECK(diy_fp.f() - boundary_minus.f() == boundary_plus.f() - diy_fp.f());
CHECK((1 << 10) == diy_fp.f() - boundary_minus.f()); // NOLINT
}
TEST(NextDouble) {
CHECK_EQ(4e-324, Double(0.0).NextDouble());
CHECK_EQ(0.0, Double(-0.0).NextDouble());
CHECK_EQ(-0.0, Double(-4e-324).NextDouble());
Double d0(-4e-324);
Double d1(d0.NextDouble());
Double d2(d1.NextDouble());
CHECK_EQ(-0.0, d1.value());
CHECK_EQ(0.0, d2.value());
CHECK_EQ(4e-324, d2.NextDouble());
CHECK_EQ(-1.7976931348623157e308, Double(-V8_INFINITY).NextDouble());
CHECK_EQ(V8_INFINITY,
Double(V8_2PART_UINT64_C(0x7fefffff, ffffffff)).NextDouble());
}