bool
CodeGeneratorX86Shared::visitAbsF(LAbsF *ins)
{
    FloatRegister input = ToFloatRegister(ins->input());
    JS_ASSERT(input == ToFloatRegister(ins->output()));
    // Same trick as visitAbsD above.
    masm.loadConstantFloat32(SpecificFloatNaN(0, FloatSignificandBits), ScratchFloatReg);
    masm.andps(ScratchFloatReg, input);
    return true;
}
Example #2
0
static void
TestFloatsAreApproximatelyEqual()
{
  float epsilon = mozilla::detail::FuzzyEqualsEpsilon<float>::value();
  float lessThanEpsilon = epsilon / 2.0f;
  float moreThanEpsilon = epsilon * 2.0f;

  // Additive tests using the default epsilon
  // ... around 1.0
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0f, 1.0f + lessThanEpsilon));
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0f, 1.0f - lessThanEpsilon));
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0f, 1.0f + epsilon));
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0f, 1.0f - epsilon));
  MOZ_ASSERT(!FuzzyEqualsAdditive(1.0f, 1.0f + moreThanEpsilon));
  MOZ_ASSERT(!FuzzyEqualsAdditive(1.0f, 1.0f - moreThanEpsilon));
  // ... around 1.0e2 (this is near the upper bound of the range where
  // adding moreThanEpsilon will still be representable and return false)
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0e2f, 1.0e2f + lessThanEpsilon));
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0e2f, 1.0e2f + epsilon));
  MOZ_ASSERT(!FuzzyEqualsAdditive(1.0e2f, 1.0e2f + moreThanEpsilon));
  // ... around 1.0e-10
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0e-10f, 1.0e-10f + lessThanEpsilon));
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0e-10f, 1.0e-10f + epsilon));
  MOZ_ASSERT(!FuzzyEqualsAdditive(1.0e-10f, 1.0e-10f + moreThanEpsilon));
  // ... straddling 0
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0e-6f, -1.0e-6f));
  MOZ_ASSERT(!FuzzyEqualsAdditive(1.0e-5f, -1.0e-5f));
  // Using a small epsilon
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0e-5f, 1.0e-5f + 1.0e-10f, 1.0e-9f));
  MOZ_ASSERT(!FuzzyEqualsAdditive(1.0e-5f, 1.0e-5f + 1.0e-10f, 1.0e-11f));
  // Using a big epsilon
  MOZ_ASSERT(FuzzyEqualsAdditive(1.0e20f, 1.0e20f + 1.0e15f, 1.0e16f));
  MOZ_ASSERT(!FuzzyEqualsAdditive(1.0e20f, 1.0e20f + 1.0e15f, 1.0e14f));

  // Multiplicative tests using the default epsilon
  // ... around 1.0
  MOZ_ASSERT(FuzzyEqualsMultiplicative(1.0f, 1.0f + lessThanEpsilon));
  MOZ_ASSERT(FuzzyEqualsMultiplicative(1.0f, 1.0f - lessThanEpsilon));
  MOZ_ASSERT(FuzzyEqualsMultiplicative(1.0f, 1.0f + epsilon));
  MOZ_ASSERT(!FuzzyEqualsMultiplicative(1.0f, 1.0f - epsilon));
  MOZ_ASSERT(!FuzzyEqualsMultiplicative(1.0f, 1.0f + moreThanEpsilon));
  MOZ_ASSERT(!FuzzyEqualsMultiplicative(1.0f, 1.0f - moreThanEpsilon));
  // ... around 1.0e10
  MOZ_ASSERT(FuzzyEqualsMultiplicative(1.0e10f, 1.0e10f + (lessThanEpsilon * 1.0e10f)));
  MOZ_ASSERT(!FuzzyEqualsMultiplicative(1.0e10f, 1.0e10f + (moreThanEpsilon * 1.0e10f)));
  // ... around 1.0e-10
  MOZ_ASSERT(FuzzyEqualsMultiplicative(1.0e-10f, 1.0e-10f + (lessThanEpsilon * 1.0e-10f)));
  MOZ_ASSERT(!FuzzyEqualsMultiplicative(1.0e-10f, 1.0e-10f + (moreThanEpsilon * 1.0e-10f)));
  // ... straddling 0
  MOZ_ASSERT(!FuzzyEqualsMultiplicative(1.0e-6f, -1.0e-6f));
  MOZ_ASSERT(FuzzyEqualsMultiplicative(1.0e-6f, -1.0e-6f, 1.0e2f));
  // Using a small epsilon
  MOZ_ASSERT(FuzzyEqualsMultiplicative(1.0e-5f, 1.0e-5f + 1.0e-10f, 1.0e-4f));
  MOZ_ASSERT(!FuzzyEqualsMultiplicative(1.0e-5f, 1.0e-5f + 1.0e-10f, 1.0e-5f));
  // Using a big epsilon
  MOZ_ASSERT(FuzzyEqualsMultiplicative(1.0f, 2.0f, 1.0f));
  MOZ_ASSERT(!FuzzyEqualsMultiplicative(1.0f, 2.0f, 0.1f));

  // "real world case"
  float oneThird = 10.0f / 3.0f;
  MOZ_ASSERT(FuzzyEqualsAdditive(10.0f, 3.0f * oneThird));
  MOZ_ASSERT(FuzzyEqualsMultiplicative(10.0f, 3.0f * oneThird));
  // NaN check
  MOZ_ASSERT(!FuzzyEqualsAdditive(SpecificFloatNaN(1, 1), SpecificFloatNaN(1, 1)));
  MOZ_ASSERT(!FuzzyEqualsAdditive(SpecificFloatNaN(1, 2), SpecificFloatNaN(0, 8)));
  MOZ_ASSERT(!FuzzyEqualsMultiplicative(SpecificFloatNaN(1, 1), SpecificFloatNaN(1, 1)));
  MOZ_ASSERT(!FuzzyEqualsMultiplicative(SpecificFloatNaN(1, 2), SpecificFloatNaN(0, 200)));
}