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SPIRV-Tools/test/hex_float_test.cpp
David Neto 8dc0030ecb
spirv-as: Avoid overflow when parsing exponents on hex floats (#4874) 
* spirv-as: Avoid overflow when parsing exponents on hex floats

When an exponent is so large that it would overflow the int
type in the parser, saturate the exponent.
This allows extremely large exponents, and saturates
to infinity when the exponent is positive, and zero when the exponent
is negative.

Fixes #4721.

* Avoid unexpected narrowing conversions from arithmetic operations

Co-authored-by: Alastair F. Donaldson <alastair.donaldson@imperial.ac.uk>
2022-07-28 09:40:07 -04:00

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// Copyright (c) 2015-2016 The Khronos Group Inc.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
#include <cfloat>
#include <cmath>
#include <cstdio>
#include <limits>
#include <sstream>
#include <string>
#include <tuple>
#include <utility>
#include <vector>
#include "gmock/gmock.h"
#include "source/util/hex_float.h"
#include "test/unit_spirv.h"
namespace spvtools {
namespace utils {
namespace {
using ::testing::Eq;
// In this file "encode" means converting a number into a string,
// and "decode" means converting a string into a number.
using HexFloatTest =
::testing::TestWithParam<std::pair<FloatProxy<float>, std::string>>;
using DecodeHexFloatTest =
::testing::TestWithParam<std::pair<std::string, FloatProxy<float>>>;
using HexDoubleTest =
::testing::TestWithParam<std::pair<FloatProxy<double>, std::string>>;
using DecodeHexDoubleTest =
::testing::TestWithParam<std::pair<std::string, FloatProxy<double>>>;
using RoundTripFloatTest = ::testing::TestWithParam<float>;
using RoundTripDoubleTest = ::testing::TestWithParam<double>;
// Hex-encodes a float value.
template <typename T>
std::string EncodeViaHexFloat(const T& value) {
std::stringstream ss;
ss << HexFloat<T>(value);
return ss.str();
}
// The following two tests can't be DRY because they take different parameter
// types.
TEST_P(HexFloatTest, EncodeCorrectly) {
EXPECT_THAT(EncodeViaHexFloat(GetParam().first), Eq(GetParam().second));
}
TEST_P(HexDoubleTest, EncodeCorrectly) {
EXPECT_THAT(EncodeViaHexFloat(GetParam().first), Eq(GetParam().second));
}
// Decodes a hex-float string.
template <typename T>
FloatProxy<T> Decode(const std::string& str) {
HexFloat<FloatProxy<T>> decoded(0.f);
EXPECT_TRUE((std::stringstream(str) >> decoded).eof());
return decoded.value();
}
TEST_P(HexFloatTest, DecodeCorrectly) {
EXPECT_THAT(Decode<float>(GetParam().second), Eq(GetParam().first));
}
TEST_P(HexDoubleTest, DecodeCorrectly) {
EXPECT_THAT(Decode<double>(GetParam().second), Eq(GetParam().first));
}
INSTANTIATE_TEST_SUITE_P(
Float32Tests, HexFloatTest,
::testing::ValuesIn(std::vector<std::pair<FloatProxy<float>, std::string>>({
{0.f, "0x0p+0"},
{1.f, "0x1p+0"},
{2.f, "0x1p+1"},
{3.f, "0x1.8p+1"},
{0.5f, "0x1p-1"},
{0.25f, "0x1p-2"},
{0.75f, "0x1.8p-1"},
{-0.f, "-0x0p+0"},
{-1.f, "-0x1p+0"},
{-0.5f, "-0x1p-1"},
{-0.25f, "-0x1p-2"},
{-0.75f, "-0x1.8p-1"},
// Larger numbers
{512.f, "0x1p+9"},
{-512.f, "-0x1p+9"},
{1024.f, "0x1p+10"},
{-1024.f, "-0x1p+10"},
{1024.f + 8.f, "0x1.02p+10"},
{-1024.f - 8.f, "-0x1.02p+10"},
// Small numbers
{1.0f / 512.f, "0x1p-9"},
{1.0f / -512.f, "-0x1p-9"},
{1.0f / 1024.f, "0x1p-10"},
{1.0f / -1024.f, "-0x1p-10"},
{1.0f / 1024.f + 1.0f / 8.f, "0x1.02p-3"},
{1.0f / -1024.f - 1.0f / 8.f, "-0x1.02p-3"},
// lowest non-denorm
{float(ldexp(1.0f, -126)), "0x1p-126"},
{float(ldexp(-1.0f, -126)), "-0x1p-126"},
// Denormalized values
{float(ldexp(1.0f, -127)), "0x1p-127"},
{float(ldexp(1.0f, -127) / 2.0f), "0x1p-128"},
{float(ldexp(1.0f, -127) / 4.0f), "0x1p-129"},
{float(ldexp(1.0f, -127) / 8.0f), "0x1p-130"},
{float(ldexp(-1.0f, -127)), "-0x1p-127"},
{float(ldexp(-1.0f, -127) / 2.0f), "-0x1p-128"},
{float(ldexp(-1.0f, -127) / 4.0f), "-0x1p-129"},
{float(ldexp(-1.0f, -127) / 8.0f), "-0x1p-130"},
{float(ldexp(1.0, -127) + (ldexp(1.0, -127) / 2.0f)), "0x1.8p-127"},
{float(ldexp(1.0, -127) / 2.0 + (ldexp(1.0, -127) / 4.0f)),
"0x1.8p-128"},
})));
INSTANTIATE_TEST_SUITE_P(
Float32NanTests, HexFloatTest,
::testing::ValuesIn(std::vector<std::pair<FloatProxy<float>, std::string>>({
// Various NAN and INF cases
{uint32_t(0xFF800000), "-0x1p+128"}, // -inf
{uint32_t(0x7F800000), "0x1p+128"}, // inf
{uint32_t(0xFFC00000), "-0x1.8p+128"}, // -nan
{uint32_t(0xFF800100), "-0x1.0002p+128"}, // -nan
{uint32_t(0xFF800c00), "-0x1.0018p+128"}, // -nan
{uint32_t(0xFF80F000), "-0x1.01ep+128"}, // -nan
{uint32_t(0xFFFFFFFF), "-0x1.fffffep+128"}, // -nan
{uint32_t(0x7FC00000), "0x1.8p+128"}, // +nan
{uint32_t(0x7F800100), "0x1.0002p+128"}, // +nan
{uint32_t(0x7f800c00), "0x1.0018p+128"}, // +nan
{uint32_t(0x7F80F000), "0x1.01ep+128"}, // +nan
{uint32_t(0x7FFFFFFF), "0x1.fffffep+128"}, // +nan
})));
INSTANTIATE_TEST_SUITE_P(
Float64Tests, HexDoubleTest,
::testing::ValuesIn(
std::vector<std::pair<FloatProxy<double>, std::string>>({
{0., "0x0p+0"},
{1., "0x1p+0"},
{2., "0x1p+1"},
{3., "0x1.8p+1"},
{0.5, "0x1p-1"},
{0.25, "0x1p-2"},
{0.75, "0x1.8p-1"},
{-0., "-0x0p+0"},
{-1., "-0x1p+0"},
{-0.5, "-0x1p-1"},
{-0.25, "-0x1p-2"},
{-0.75, "-0x1.8p-1"},
// Larger numbers
{512., "0x1p+9"},
{-512., "-0x1p+9"},
{1024., "0x1p+10"},
{-1024., "-0x1p+10"},
{1024. + 8., "0x1.02p+10"},
{-1024. - 8., "-0x1.02p+10"},
// Large outside the range of normal floats
{ldexp(1.0, 128), "0x1p+128"},
{ldexp(1.0, 129), "0x1p+129"},
{ldexp(-1.0, 128), "-0x1p+128"},
{ldexp(-1.0, 129), "-0x1p+129"},
{ldexp(1.0, 128) + ldexp(1.0, 90), "0x1.0000000004p+128"},
{ldexp(1.0, 129) + ldexp(1.0, 120), "0x1.008p+129"},
{ldexp(-1.0, 128) + ldexp(1.0, 90), "-0x1.fffffffff8p+127"},
{ldexp(-1.0, 129) + ldexp(1.0, 120), "-0x1.ffp+128"},
// Small numbers
{1.0 / 512., "0x1p-9"},
{1.0 / -512., "-0x1p-9"},
{1.0 / 1024., "0x1p-10"},
{1.0 / -1024., "-0x1p-10"},
{1.0 / 1024. + 1.0 / 8., "0x1.02p-3"},
{1.0 / -1024. - 1.0 / 8., "-0x1.02p-3"},
// Small outside the range of normal floats
{ldexp(1.0, -128), "0x1p-128"},
{ldexp(1.0, -129), "0x1p-129"},
{ldexp(-1.0, -128), "-0x1p-128"},
{ldexp(-1.0, -129), "-0x1p-129"},
{ldexp(1.0, -128) + ldexp(1.0, -90), "0x1.0000000004p-90"},
{ldexp(1.0, -129) + ldexp(1.0, -120), "0x1.008p-120"},
{ldexp(-1.0, -128) + ldexp(1.0, -90), "0x1.fffffffff8p-91"},
{ldexp(-1.0, -129) + ldexp(1.0, -120), "0x1.ffp-121"},
// lowest non-denorm
{ldexp(1.0, -1022), "0x1p-1022"},
{ldexp(-1.0, -1022), "-0x1p-1022"},
// Denormalized values
{ldexp(1.0, -1023), "0x1p-1023"},
{ldexp(1.0, -1023) / 2.0, "0x1p-1024"},
{ldexp(1.0, -1023) / 4.0, "0x1p-1025"},
{ldexp(1.0, -1023) / 8.0, "0x1p-1026"},
{ldexp(-1.0, -1024), "-0x1p-1024"},
{ldexp(-1.0, -1024) / 2.0, "-0x1p-1025"},
{ldexp(-1.0, -1024) / 4.0, "-0x1p-1026"},
{ldexp(-1.0, -1024) / 8.0, "-0x1p-1027"},
{ldexp(1.0, -1023) + (ldexp(1.0, -1023) / 2.0), "0x1.8p-1023"},
{ldexp(1.0, -1023) / 2.0 + (ldexp(1.0, -1023) / 4.0),
"0x1.8p-1024"},
})));
INSTANTIATE_TEST_SUITE_P(
Float64NanTests, HexDoubleTest,
::testing::ValuesIn(std::vector<
std::pair<FloatProxy<double>, std::string>>({
// Various NAN and INF cases
{uint64_t(0xFFF0000000000000LL), "-0x1p+1024"}, // -inf
{uint64_t(0x7FF0000000000000LL), "0x1p+1024"}, // +inf
{uint64_t(0xFFF8000000000000LL), "-0x1.8p+1024"}, // -nan
{uint64_t(0xFFF0F00000000000LL), "-0x1.0fp+1024"}, // -nan
{uint64_t(0xFFF0000000000001LL), "-0x1.0000000000001p+1024"}, // -nan
{uint64_t(0xFFF0000300000000LL), "-0x1.00003p+1024"}, // -nan
{uint64_t(0xFFFFFFFFFFFFFFFFLL), "-0x1.fffffffffffffp+1024"}, // -nan
{uint64_t(0x7FF8000000000000LL), "0x1.8p+1024"}, // +nan
{uint64_t(0x7FF0F00000000000LL), "0x1.0fp+1024"}, // +nan
{uint64_t(0x7FF0000000000001LL), "0x1.0000000000001p+1024"}, // -nan
{uint64_t(0x7FF0000300000000LL), "0x1.00003p+1024"}, // -nan
{uint64_t(0x7FFFFFFFFFFFFFFFLL), "0x1.fffffffffffffp+1024"}, // -nan
})));
// Tests that encoding a value and decoding it again restores
// the same value.
TEST_P(RoundTripFloatTest, CanStoreAccurately) {
std::stringstream ss;
ss << FloatProxy<float>(GetParam());
ss.seekg(0);
FloatProxy<float> res;
ss >> res;
EXPECT_THAT(GetParam(), Eq(res.getAsFloat()));
}
TEST_P(RoundTripDoubleTest, CanStoreAccurately) {
std::stringstream ss;
ss << FloatProxy<double>(GetParam());
ss.seekg(0);
FloatProxy<double> res;
ss >> res;
EXPECT_THAT(GetParam(), Eq(res.getAsFloat()));
}
INSTANTIATE_TEST_SUITE_P(
Float32StoreTests, RoundTripFloatTest,
::testing::ValuesIn(std::vector<float>(
{// Value requiring more than 6 digits of precision to be
// represented accurately.
3.0000002f})));
INSTANTIATE_TEST_SUITE_P(
Float64StoreTests, RoundTripDoubleTest,
::testing::ValuesIn(std::vector<double>(
{// Value requiring more than 15 digits of precision to be
// represented accurately.
1.5000000000000002})));
TEST(HexFloatStreamTest, OperatorLeftShiftPreservesFloatAndFill) {
std::stringstream s;
s << std::setw(4) << std::oct << std::setfill('x') << 8 << " "
<< FloatProxy<float>(uint32_t(0xFF800100)) << " " << std::setw(4) << 9;
EXPECT_THAT(s.str(), Eq(std::string("xx10 -0x1.0002p+128 xx11")));
}
TEST(HexDoubleStreamTest, OperatorLeftShiftPreservesFloatAndFill) {
std::stringstream s;
s << std::setw(4) << std::oct << std::setfill('x') << 8 << " "
<< FloatProxy<double>(uint64_t(0x7FF0F00000000000LL)) << " " << std::setw(4)
<< 9;
EXPECT_THAT(s.str(), Eq(std::string("xx10 0x1.0fp+1024 xx11")));
}
TEST_P(DecodeHexFloatTest, DecodeCorrectly) {
EXPECT_THAT(Decode<float>(GetParam().first), Eq(GetParam().second));
}
TEST_P(DecodeHexDoubleTest, DecodeCorrectly) {
EXPECT_THAT(Decode<double>(GetParam().first), Eq(GetParam().second));
}
INSTANTIATE_TEST_SUITE_P(
Float32DecodeTests, DecodeHexFloatTest,
::testing::ValuesIn(std::vector<std::pair<std::string, FloatProxy<float>>>({
{"0x0p+000", 0.f},
{"0x0p0", 0.f},
{"0x0p-0", 0.f},
// flush to zero cases
{"0x1p-500", 0.f}, // Exponent underflows.
{"-0x1p-500", -0.f},
{"0x0.00000000001p-126", 0.f}, // Fraction causes underflow.
{"-0x0.0000000001p-127", -0.f},
{"-0x0.01p-142", -0.f}, // Fraction causes additional underflow.
{"0x0.01p-142", 0.f},
// Some floats that do not encode the same way as they decode.
{"0x2p+0", 2.f},
{"0xFFp+0", 255.f},
{"0x0.8p+0", 0.5f},
{"0x0.4p+0", 0.25f},
})));
INSTANTIATE_TEST_SUITE_P(
Float32DecodeInfTests, DecodeHexFloatTest,
::testing::ValuesIn(std::vector<std::pair<std::string, FloatProxy<float>>>({
// inf cases
{"-0x1p+128", uint32_t(0xFF800000)}, // -inf
{"0x32p+127", uint32_t(0x7F800000)}, // inf
{"0x32p+500", uint32_t(0x7F800000)}, // inf
{"-0x32p+127", uint32_t(0xFF800000)}, // -inf
})));
INSTANTIATE_TEST_SUITE_P(
Float64DecodeTests, DecodeHexDoubleTest,
::testing::ValuesIn(
std::vector<std::pair<std::string, FloatProxy<double>>>({
{"0x0p+000", 0.},
{"0x0p0", 0.},
{"0x0p-0", 0.},
// flush to zero cases
{"0x1p-5000", 0.}, // Exponent underflows.
{"-0x1p-5000", -0.},
{"0x0.0000000000000001p-1023", 0.}, // Fraction causes underflow.
{"-0x0.000000000000001p-1024", -0.},
{"-0x0.01p-1090", -0.f}, // Fraction causes additional underflow.
{"0x0.01p-1090", 0.},
// Some floats that do not encode the same way as they decode.
{"0x2p+0", 2.},
{"0xFFp+0", 255.},
{"0x0.8p+0", 0.5},
{"0x0.4p+0", 0.25},
})));
INSTANTIATE_TEST_SUITE_P(
Float64DecodeInfTests, DecodeHexDoubleTest,
::testing::ValuesIn(
std::vector<std::pair<std::string, FloatProxy<double>>>({
// inf cases
{"-0x1p+1024", uint64_t(0xFFF0000000000000)}, // -inf
{"0x32p+1023", uint64_t(0x7FF0000000000000)}, // inf
{"0x32p+5000", uint64_t(0x7FF0000000000000)}, // inf
{"-0x32p+1023", uint64_t(0xFFF0000000000000)}, // -inf
})));
TEST(FloatProxy, ValidConversion) {
EXPECT_THAT(FloatProxy<float>(1.f).getAsFloat(), Eq(1.0f));
EXPECT_THAT(FloatProxy<float>(32.f).getAsFloat(), Eq(32.0f));
EXPECT_THAT(FloatProxy<float>(-1.f).getAsFloat(), Eq(-1.0f));
EXPECT_THAT(FloatProxy<float>(0.f).getAsFloat(), Eq(0.0f));
EXPECT_THAT(FloatProxy<float>(-0.f).getAsFloat(), Eq(-0.0f));
EXPECT_THAT(FloatProxy<float>(1.2e32f).getAsFloat(), Eq(1.2e32f));
EXPECT_TRUE(std::isinf(FloatProxy<float>(uint32_t(0xFF800000)).getAsFloat()));
EXPECT_TRUE(std::isinf(FloatProxy<float>(uint32_t(0x7F800000)).getAsFloat()));
EXPECT_TRUE(std::isnan(FloatProxy<float>(uint32_t(0xFFC00000)).getAsFloat()));
EXPECT_TRUE(std::isnan(FloatProxy<float>(uint32_t(0xFF800100)).getAsFloat()));
EXPECT_TRUE(std::isnan(FloatProxy<float>(uint32_t(0xFF800c00)).getAsFloat()));
EXPECT_TRUE(std::isnan(FloatProxy<float>(uint32_t(0xFF80F000)).getAsFloat()));
EXPECT_TRUE(std::isnan(FloatProxy<float>(uint32_t(0xFFFFFFFF)).getAsFloat()));
EXPECT_TRUE(std::isnan(FloatProxy<float>(uint32_t(0x7FC00000)).getAsFloat()));
EXPECT_TRUE(std::isnan(FloatProxy<float>(uint32_t(0x7F800100)).getAsFloat()));
EXPECT_TRUE(std::isnan(FloatProxy<float>(uint32_t(0x7f800c00)).getAsFloat()));
EXPECT_TRUE(std::isnan(FloatProxy<float>(uint32_t(0x7F80F000)).getAsFloat()));
EXPECT_TRUE(std::isnan(FloatProxy<float>(uint32_t(0x7FFFFFFF)).getAsFloat()));
EXPECT_THAT(FloatProxy<float>(uint32_t(0xFF800000)).data(), Eq(0xFF800000u));
EXPECT_THAT(FloatProxy<float>(uint32_t(0x7F800000)).data(), Eq(0x7F800000u));
EXPECT_THAT(FloatProxy<float>(uint32_t(0xFFC00000)).data(), Eq(0xFFC00000u));
EXPECT_THAT(FloatProxy<float>(uint32_t(0xFF800100)).data(), Eq(0xFF800100u));
EXPECT_THAT(FloatProxy<float>(uint32_t(0xFF800c00)).data(), Eq(0xFF800c00u));
EXPECT_THAT(FloatProxy<float>(uint32_t(0xFF80F000)).data(), Eq(0xFF80F000u));
EXPECT_THAT(FloatProxy<float>(uint32_t(0xFFFFFFFF)).data(), Eq(0xFFFFFFFFu));
EXPECT_THAT(FloatProxy<float>(uint32_t(0x7FC00000)).data(), Eq(0x7FC00000u));
EXPECT_THAT(FloatProxy<float>(uint32_t(0x7F800100)).data(), Eq(0x7F800100u));
EXPECT_THAT(FloatProxy<float>(uint32_t(0x7f800c00)).data(), Eq(0x7f800c00u));
EXPECT_THAT(FloatProxy<float>(uint32_t(0x7F80F000)).data(), Eq(0x7F80F000u));
EXPECT_THAT(FloatProxy<float>(uint32_t(0x7FFFFFFF)).data(), Eq(0x7FFFFFFFu));
}
TEST(FloatProxy, Nan) {
EXPECT_TRUE(FloatProxy<float>(uint32_t(0xFFC00000)).isNan());
EXPECT_TRUE(FloatProxy<float>(uint32_t(0xFF800100)).isNan());
EXPECT_TRUE(FloatProxy<float>(uint32_t(0xFF800c00)).isNan());
EXPECT_TRUE(FloatProxy<float>(uint32_t(0xFF80F000)).isNan());
EXPECT_TRUE(FloatProxy<float>(uint32_t(0xFFFFFFFF)).isNan());
EXPECT_TRUE(FloatProxy<float>(uint32_t(0x7FC00000)).isNan());
EXPECT_TRUE(FloatProxy<float>(uint32_t(0x7F800100)).isNan());
EXPECT_TRUE(FloatProxy<float>(uint32_t(0x7f800c00)).isNan());
EXPECT_TRUE(FloatProxy<float>(uint32_t(0x7F80F000)).isNan());
EXPECT_TRUE(FloatProxy<float>(uint32_t(0x7FFFFFFF)).isNan());
}
TEST(FloatProxy, Negation) {
EXPECT_THAT((-FloatProxy<float>(1.f)).getAsFloat(), Eq(-1.0f));
EXPECT_THAT((-FloatProxy<float>(0.f)).getAsFloat(), Eq(-0.0f));
EXPECT_THAT((-FloatProxy<float>(-1.f)).getAsFloat(), Eq(1.0f));
EXPECT_THAT((-FloatProxy<float>(-0.f)).getAsFloat(), Eq(0.0f));
EXPECT_THAT((-FloatProxy<float>(32.f)).getAsFloat(), Eq(-32.0f));
EXPECT_THAT((-FloatProxy<float>(-32.f)).getAsFloat(), Eq(32.0f));
EXPECT_THAT((-FloatProxy<float>(1.2e32f)).getAsFloat(), Eq(-1.2e32f));
EXPECT_THAT((-FloatProxy<float>(-1.2e32f)).getAsFloat(), Eq(1.2e32f));
EXPECT_THAT(
(-FloatProxy<float>(std::numeric_limits<float>::infinity())).getAsFloat(),
Eq(-std::numeric_limits<float>::infinity()));
EXPECT_THAT((-FloatProxy<float>(-std::numeric_limits<float>::infinity()))
.getAsFloat(),
Eq(std::numeric_limits<float>::infinity()));
}
// Test conversion of FloatProxy values to strings.
//
// In previous cases, we always wrapped the FloatProxy value in a HexFloat
// before conversion to a string. In the following cases, the FloatProxy
// decides for itself whether to print as a regular number or as a hex float.
using FloatProxyFloatTest =
::testing::TestWithParam<std::pair<FloatProxy<float>, std::string>>;
using FloatProxyDoubleTest =
::testing::TestWithParam<std::pair<FloatProxy<double>, std::string>>;
// Converts a float value to a string via a FloatProxy.
template <typename T>
std::string EncodeViaFloatProxy(const T& value) {
std::stringstream ss;
ss << value;
return ss.str();
}
// Converts a floating point string so that the exponent prefix
// is 'e', and the exponent value does not have leading zeros.
// The Microsoft runtime library likes to write things like "2.5E+010".
// Convert that to "2.5e+10".
// We don't care what happens to strings that are not floating point
// strings.
std::string NormalizeExponentInFloatString(std::string in) {
std::string result;
// Reserve one spot for the terminating null, even when the sscanf fails.
std::vector<char> prefix(in.size() + 1);
char e;
char plus_or_minus;
int exponent; // in base 10
if ((4 == std::sscanf(in.c_str(), "%[-+.0123456789]%c%c%d", prefix.data(), &e,
&plus_or_minus, &exponent)) &&
(e == 'e' || e == 'E') &&
(plus_or_minus == '-' || plus_or_minus == '+')) {
// It looks like a floating point value with exponent.
std::stringstream out;
out << prefix.data() << 'e' << plus_or_minus << exponent;
result = out.str();
} else {
result = in;
}
return result;
}
TEST(NormalizeFloat, Sample) {
EXPECT_THAT(NormalizeExponentInFloatString(""), Eq(""));
EXPECT_THAT(NormalizeExponentInFloatString("1e-12"), Eq("1e-12"));
EXPECT_THAT(NormalizeExponentInFloatString("1E+14"), Eq("1e+14"));
EXPECT_THAT(NormalizeExponentInFloatString("1e-0012"), Eq("1e-12"));
EXPECT_THAT(NormalizeExponentInFloatString("1.263E+014"), Eq("1.263e+14"));
}
// The following two tests can't be DRY because they take different parameter
// types.
TEST_P(FloatProxyFloatTest, EncodeCorrectly) {
EXPECT_THAT(
NormalizeExponentInFloatString(EncodeViaFloatProxy(GetParam().first)),
Eq(GetParam().second));
}
TEST_P(FloatProxyDoubleTest, EncodeCorrectly) {
EXPECT_THAT(
NormalizeExponentInFloatString(EncodeViaFloatProxy(GetParam().first)),
Eq(GetParam().second));
}
INSTANTIATE_TEST_SUITE_P(
Float32Tests, FloatProxyFloatTest,
::testing::ValuesIn(std::vector<std::pair<FloatProxy<float>, std::string>>({
// Zero
{0.f, "0"},
// Normal numbers
{1.f, "1"},
{-0.25f, "-0.25"},
{1000.0f, "1000"},
// Still normal numbers, but with large magnitude exponents.
{float(ldexp(1.f, 126)), "8.50705917e+37"},
{float(ldexp(-1.f, -126)), "-1.17549435e-38"},
// denormalized values are printed as hex floats.
{float(ldexp(1.0f, -127)), "0x1p-127"},
{float(ldexp(1.5f, -128)), "0x1.8p-128"},
{float(ldexp(1.25, -129)), "0x1.4p-129"},
{float(ldexp(1.125, -130)), "0x1.2p-130"},
{float(ldexp(-1.0f, -127)), "-0x1p-127"},
{float(ldexp(-1.0f, -128)), "-0x1p-128"},
{float(ldexp(-1.0f, -129)), "-0x1p-129"},
{float(ldexp(-1.5f, -130)), "-0x1.8p-130"},
// NaNs
{FloatProxy<float>(uint32_t(0xFFC00000)), "-0x1.8p+128"},
{FloatProxy<float>(uint32_t(0xFF800100)), "-0x1.0002p+128"},
{std::numeric_limits<float>::infinity(), "0x1p+128"},
{-std::numeric_limits<float>::infinity(), "-0x1p+128"},
})));
INSTANTIATE_TEST_SUITE_P(
Float64Tests, FloatProxyDoubleTest,
::testing::ValuesIn(
std::vector<std::pair<FloatProxy<double>, std::string>>({
{0., "0"},
{1., "1"},
{-0.25, "-0.25"},
{1000.0, "1000"},
// Large outside the range of normal floats
{ldexp(1.0, 128), "3.4028236692093846e+38"},
{ldexp(1.5, 129), "1.0208471007628154e+39"},
{ldexp(-1.0, 128), "-3.4028236692093846e+38"},
{ldexp(-1.5, 129), "-1.0208471007628154e+39"},
// Small outside the range of normal floats
{ldexp(1.5, -129), "2.2040519077917891e-39"},
{ldexp(-1.5, -129), "-2.2040519077917891e-39"},
// lowest non-denorm
{ldexp(1.0, -1022), "2.2250738585072014e-308"},
{ldexp(-1.0, -1022), "-2.2250738585072014e-308"},
// Denormalized values
{ldexp(1.125, -1023), "0x1.2p-1023"},
{ldexp(-1.375, -1024), "-0x1.6p-1024"},
// NaNs
{uint64_t(0x7FF8000000000000LL), "0x1.8p+1024"},
{uint64_t(0xFFF0F00000000000LL), "-0x1.0fp+1024"},
// Infinity
{std::numeric_limits<double>::infinity(), "0x1p+1024"},
{-std::numeric_limits<double>::infinity(), "-0x1p+1024"},
})));
// double is used so that unbiased_exponent can be used with the output
// of ldexp directly.
int32_t unbiased_exponent(double f) {
return HexFloat<FloatProxy<float>>(static_cast<float>(f))
.getUnbiasedNormalizedExponent();
}
int16_t unbiased_half_exponent(uint16_t f) {
return HexFloat<FloatProxy<Float16>>(f).getUnbiasedNormalizedExponent();
}
TEST(HexFloatOperationTest, UnbiasedExponent) {
// Float cases
EXPECT_EQ(0, unbiased_exponent(ldexp(1.0f, 0)));
EXPECT_EQ(-32, unbiased_exponent(ldexp(1.0f, -32)));
EXPECT_EQ(42, unbiased_exponent(ldexp(1.0f, 42)));
EXPECT_EQ(125, unbiased_exponent(ldexp(1.0f, 125)));
EXPECT_EQ(128,
HexFloat<FloatProxy<float>>(std::numeric_limits<float>::infinity())
.getUnbiasedNormalizedExponent());
EXPECT_EQ(-100, unbiased_exponent(ldexp(1.0f, -100)));
EXPECT_EQ(-127, unbiased_exponent(ldexp(1.0f, -127))); // First denorm
EXPECT_EQ(-128, unbiased_exponent(ldexp(1.0f, -128)));
EXPECT_EQ(-129, unbiased_exponent(ldexp(1.0f, -129)));
EXPECT_EQ(-140, unbiased_exponent(ldexp(1.0f, -140)));
// Smallest representable number
EXPECT_EQ(-126 - 23, unbiased_exponent(ldexp(1.0f, -126 - 23)));
// Should get rounded to 0 first.
EXPECT_EQ(0, unbiased_exponent(ldexp(1.0f, -127 - 23)));
// Float16 cases
// The exponent is represented in the bits 0x7C00
// The offset is -15
EXPECT_EQ(0, unbiased_half_exponent(0x3C00));
EXPECT_EQ(3, unbiased_half_exponent(0x4800));
EXPECT_EQ(-1, unbiased_half_exponent(0x3800));
EXPECT_EQ(-14, unbiased_half_exponent(0x0400));
EXPECT_EQ(16, unbiased_half_exponent(0x7C00));
EXPECT_EQ(10, unbiased_half_exponent(0x6400));
// Smallest representable number
EXPECT_EQ(-24, unbiased_half_exponent(0x0001));
}
// Creates a float that is the sum of 1/(2 ^ fractions[i]) for i in factions
float float_fractions(const std::vector<uint32_t>& fractions) {
float f = 0;
for (int32_t i : fractions) {
f += std::ldexp(1.0f, -i);
}
return f;
}
// Returns the normalized significand of a HexFloat<FloatProxy<float>>
// that was created by calling float_fractions with the input fractions,
// raised to the power of exp.
uint32_t normalized_significand(const std::vector<uint32_t>& fractions,
uint32_t exp) {
return HexFloat<FloatProxy<float>>(
static_cast<float>(ldexp(float_fractions(fractions), exp)))
.getNormalizedSignificand();
}
// Sets the bits from MSB to LSB of the significand part of a float.
// For example 0 would set the bit 23 (counting from LSB to MSB),
// and 1 would set the 22nd bit.
uint32_t bits_set(const std::vector<uint32_t>& bits) {
const uint32_t top_bit = 1u << 22u;
uint32_t val = 0;
for (uint32_t i : bits) {
val |= top_bit >> i;
}
return val;
}
// The same as bits_set but for a Float16 value instead of 32-bit floating
// point.
uint16_t half_bits_set(const std::vector<uint32_t>& bits) {
const uint32_t top_bit = 1u << 9u;
uint32_t val = 0;
for (uint32_t i : bits) {
val |= top_bit >> i;
}
return static_cast<uint16_t>(val);
}
TEST(HexFloatOperationTest, NormalizedSignificand) {
// For normalized numbers (the following) it should be a simple matter
// of getting rid of the top implicit bit
EXPECT_EQ(bits_set({}), normalized_significand({0}, 0));
EXPECT_EQ(bits_set({0}), normalized_significand({0, 1}, 0));
EXPECT_EQ(bits_set({0, 1}), normalized_significand({0, 1, 2}, 0));
EXPECT_EQ(bits_set({1}), normalized_significand({0, 2}, 0));
EXPECT_EQ(bits_set({1}), normalized_significand({0, 2}, 32));
EXPECT_EQ(bits_set({1}), normalized_significand({0, 2}, 126));
// For denormalized numbers we expect the normalized significand to
// shift as if it were normalized. This means, in practice that the
// top_most set bit will be cut off. Looks very similar to above (on purpose)
EXPECT_EQ(bits_set({}),
normalized_significand({0}, static_cast<uint32_t>(-127)));
EXPECT_EQ(bits_set({3}),
normalized_significand({0, 4}, static_cast<uint32_t>(-128)));
EXPECT_EQ(bits_set({3}),
normalized_significand({0, 4}, static_cast<uint32_t>(-127)));
EXPECT_EQ(bits_set({}),
normalized_significand({22}, static_cast<uint32_t>(-127)));
EXPECT_EQ(bits_set({0}),
normalized_significand({21, 22}, static_cast<uint32_t>(-127)));
}
// Returns the 32-bit floating point value created by
// calling setFromSignUnbiasedExponentAndNormalizedSignificand
// on a HexFloat<FloatProxy<float>>
float set_from_sign(bool negative, int32_t unbiased_exponent,
uint32_t significand, bool round_denorm_up) {
HexFloat<FloatProxy<float>> f(0.f);
f.setFromSignUnbiasedExponentAndNormalizedSignificand(
negative, unbiased_exponent, significand, round_denorm_up);
return f.value().getAsFloat();
}
TEST(HexFloatOperationTests,
SetFromSignUnbiasedExponentAndNormalizedSignificand) {
EXPECT_EQ(1.f, set_from_sign(false, 0, 0, false));
// Tests insertion of various denormalized numbers with and without round up.
EXPECT_EQ(static_cast<float>(ldexp(1.f, -149)),
set_from_sign(false, -149, 0, false));
EXPECT_EQ(static_cast<float>(ldexp(1.f, -149)),
set_from_sign(false, -149, 0, true));
EXPECT_EQ(0.f, set_from_sign(false, -150, 1, false));
EXPECT_EQ(static_cast<float>(ldexp(1.f, -149)),
set_from_sign(false, -150, 1, true));
EXPECT_EQ(ldexp(1.0f, -127), set_from_sign(false, -127, 0, false));
EXPECT_EQ(ldexp(1.0f, -128), set_from_sign(false, -128, 0, false));
EXPECT_EQ(float_fractions({0, 1, 2, 5}),
set_from_sign(false, 0, bits_set({0, 1, 4}), false));
EXPECT_EQ(ldexp(float_fractions({0, 1, 2, 5}), -32),
set_from_sign(false, -32, bits_set({0, 1, 4}), false));
EXPECT_EQ(ldexp(float_fractions({0, 1, 2, 5}), -128),
set_from_sign(false, -128, bits_set({0, 1, 4}), false));
// The negative cases from above.
EXPECT_EQ(-1.f, set_from_sign(true, 0, 0, false));
EXPECT_EQ(-ldexp(1.0, -127), set_from_sign(true, -127, 0, false));
EXPECT_EQ(-ldexp(1.0, -128), set_from_sign(true, -128, 0, false));
EXPECT_EQ(-float_fractions({0, 1, 2, 5}),
set_from_sign(true, 0, bits_set({0, 1, 4}), false));
EXPECT_EQ(-ldexp(float_fractions({0, 1, 2, 5}), -32),
set_from_sign(true, -32, bits_set({0, 1, 4}), false));
EXPECT_EQ(-ldexp(float_fractions({0, 1, 2, 5}), -128),
set_from_sign(true, -128, bits_set({0, 1, 4}), false));
}
TEST(HexFloatOperationTests, NonRounding) {
// Rounding from 32-bit hex-float to 32-bit hex-float should be trivial,
// except in the denorm case which is a bit more complex.
using HF = HexFloat<FloatProxy<float>>;
bool carry_bit = false;
round_direction rounding[] = {round_direction::kToZero,
round_direction::kToNearestEven,
round_direction::kToPositiveInfinity,
round_direction::kToNegativeInfinity};
// Everything fits, so this should be straight-forward
for (round_direction round : rounding) {
EXPECT_EQ(bits_set({}),
HF(0.f).getRoundedNormalizedSignificand<HF>(round, &carry_bit));
EXPECT_FALSE(carry_bit);
EXPECT_EQ(bits_set({0}),
HF(float_fractions({0, 1}))
.getRoundedNormalizedSignificand<HF>(round, &carry_bit));
EXPECT_FALSE(carry_bit);
EXPECT_EQ(bits_set({1, 3}),
HF(float_fractions({0, 2, 4}))
.getRoundedNormalizedSignificand<HF>(round, &carry_bit));
EXPECT_FALSE(carry_bit);
EXPECT_EQ(
bits_set({0, 1, 4}),
HF(static_cast<float>(-ldexp(float_fractions({0, 1, 2, 5}), -128)))
.getRoundedNormalizedSignificand<HF>(round, &carry_bit));
EXPECT_FALSE(carry_bit);
EXPECT_EQ(bits_set({0, 1, 4, 22}),
HF(static_cast<float>(float_fractions({0, 1, 2, 5, 23})))
.getRoundedNormalizedSignificand<HF>(round, &carry_bit));
EXPECT_FALSE(carry_bit);
}
}
using RD = round_direction;
struct RoundSignificandCase {
float source_float;
std::pair<int16_t, bool> expected_results;
round_direction round;
};
using HexFloatRoundTest = ::testing::TestWithParam<RoundSignificandCase>;
TEST_P(HexFloatRoundTest, RoundDownToFP16) {
using HF = HexFloat<FloatProxy<float>>;
using HF16 = HexFloat<FloatProxy<Float16>>;
HF input_value(GetParam().source_float);
bool carry_bit = false;
EXPECT_EQ(GetParam().expected_results.first,
input_value.getRoundedNormalizedSignificand<HF16>(GetParam().round,
&carry_bit));
EXPECT_EQ(carry_bit, GetParam().expected_results.second);
}
// clang-format off
INSTANTIATE_TEST_SUITE_P(F32ToF16, HexFloatRoundTest,
::testing::ValuesIn(std::vector<RoundSignificandCase>(
{
{float_fractions({0}), std::make_pair(half_bits_set({}), false), RD::kToZero},
{float_fractions({0}), std::make_pair(half_bits_set({}), false), RD::kToNearestEven},
{float_fractions({0}), std::make_pair(half_bits_set({}), false), RD::kToPositiveInfinity},
{float_fractions({0}), std::make_pair(half_bits_set({}), false), RD::kToNegativeInfinity},
{float_fractions({0, 1}), std::make_pair(half_bits_set({0}), false), RD::kToZero},
{float_fractions({0, 1, 11}), std::make_pair(half_bits_set({0}), false), RD::kToZero},
{float_fractions({0, 1, 11}), std::make_pair(half_bits_set({0, 9}), false), RD::kToPositiveInfinity},
{float_fractions({0, 1, 11}), std::make_pair(half_bits_set({0}), false), RD::kToNegativeInfinity},
{float_fractions({0, 1, 11}), std::make_pair(half_bits_set({0}), false), RD::kToNearestEven},
{float_fractions({0, 1, 10, 11}), std::make_pair(half_bits_set({0, 9}), false), RD::kToZero},
{float_fractions({0, 1, 10, 11}), std::make_pair(half_bits_set({0, 8}), false), RD::kToPositiveInfinity},
{float_fractions({0, 1, 10, 11}), std::make_pair(half_bits_set({0, 9}), false), RD::kToNegativeInfinity},
{float_fractions({0, 1, 10, 11}), std::make_pair(half_bits_set({0, 8}), false), RD::kToNearestEven},
{float_fractions({0, 1, 11, 12}), std::make_pair(half_bits_set({0}), false), RD::kToZero},
{float_fractions({0, 1, 11, 12}), std::make_pair(half_bits_set({0, 9}), false), RD::kToPositiveInfinity},
{float_fractions({0, 1, 11, 12}), std::make_pair(half_bits_set({0}), false), RD::kToNegativeInfinity},
{float_fractions({0, 1, 11, 12}), std::make_pair(half_bits_set({0, 9}), false), RD::kToNearestEven},
{-float_fractions({0, 1, 11, 12}), std::make_pair(half_bits_set({0}), false), RD::kToZero},
{-float_fractions({0, 1, 11, 12}), std::make_pair(half_bits_set({0}), false), RD::kToPositiveInfinity},
{-float_fractions({0, 1, 11, 12}), std::make_pair(half_bits_set({0, 9}), false), RD::kToNegativeInfinity},
{-float_fractions({0, 1, 11, 12}), std::make_pair(half_bits_set({0, 9}), false), RD::kToNearestEven},
{float_fractions({0, 1, 11, 22}), std::make_pair(half_bits_set({0}), false), RD::kToZero},
{float_fractions({0, 1, 11, 22}), std::make_pair(half_bits_set({0, 9}), false), RD::kToPositiveInfinity},
{float_fractions({0, 1, 11, 22}), std::make_pair(half_bits_set({0}), false), RD::kToNegativeInfinity},
{float_fractions({0, 1, 11, 22}), std::make_pair(half_bits_set({0, 9}), false), RD::kToNearestEven},
// Carries
{float_fractions({0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}), std::make_pair(half_bits_set({0, 1, 2, 3, 4, 5, 6, 7, 8, 9}), false), RD::kToZero},
{float_fractions({0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}), std::make_pair(half_bits_set({}), true), RD::kToPositiveInfinity},
{float_fractions({0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}), std::make_pair(half_bits_set({0, 1, 2, 3, 4, 5, 6, 7, 8, 9}), false), RD::kToNegativeInfinity},
{float_fractions({0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11}), std::make_pair(half_bits_set({}), true), RD::kToNearestEven},
// Cases where original number was denorm. Note: this should have no effect
// the number is pre-normalized.
{static_cast<float>(ldexp(float_fractions({0, 1, 11, 13}), -128)), std::make_pair(half_bits_set({0}), false), RD::kToZero},
{static_cast<float>(ldexp(float_fractions({0, 1, 11, 13}), -129)), std::make_pair(half_bits_set({0, 9}), false), RD::kToPositiveInfinity},
{static_cast<float>(ldexp(float_fractions({0, 1, 11, 13}), -131)), std::make_pair(half_bits_set({0}), false), RD::kToNegativeInfinity},
{static_cast<float>(ldexp(float_fractions({0, 1, 11, 13}), -130)), std::make_pair(half_bits_set({0, 9}), false), RD::kToNearestEven},
})));
// clang-format on
struct UpCastSignificandCase {
uint16_t source_half;
uint32_t expected_result;
};
using HexFloatRoundUpSignificandTest =
::testing::TestWithParam<UpCastSignificandCase>;
TEST_P(HexFloatRoundUpSignificandTest, Widening) {
using HF = HexFloat<FloatProxy<float>>;
using HF16 = HexFloat<FloatProxy<Float16>>;
bool carry_bit = false;
round_direction rounding[] = {round_direction::kToZero,
round_direction::kToNearestEven,
round_direction::kToPositiveInfinity,
round_direction::kToNegativeInfinity};
// Everything fits, so everything should just be bit-shifts.
for (round_direction round : rounding) {
carry_bit = false;
HF16 input_value(GetParam().source_half);
EXPECT_EQ(
GetParam().expected_result,
input_value.getRoundedNormalizedSignificand<HF>(round, &carry_bit))
<< std::hex << "0x"
<< input_value.getRoundedNormalizedSignificand<HF>(round, &carry_bit)
<< " 0x" << GetParam().expected_result;
EXPECT_FALSE(carry_bit);
}
}
INSTANTIATE_TEST_SUITE_P(
F16toF32, HexFloatRoundUpSignificandTest,
// 0xFC00 of the source 16-bit hex value cover the sign and the exponent.
// They are ignored for this test.
::testing::ValuesIn(std::vector<UpCastSignificandCase>({
{0x3F00, 0x600000},
{0x0F00, 0x600000},
{0x0F01, 0x602000},
{0x0FFF, 0x7FE000},
})));
struct DownCastTest {
float source_float;
uint16_t expected_half;
std::vector<round_direction> directions;
};
std::string get_round_text(round_direction direction) {
#define CASE(round_direction) \
case round_direction: \
return #round_direction
switch (direction) {
CASE(round_direction::kToZero);
CASE(round_direction::kToPositiveInfinity);
CASE(round_direction::kToNegativeInfinity);
CASE(round_direction::kToNearestEven);
}
#undef CASE
return "";
}
using HexFloatFP32To16Tests = ::testing::TestWithParam<DownCastTest>;
TEST_P(HexFloatFP32To16Tests, NarrowingCasts) {
using HF = HexFloat<FloatProxy<float>>;
using HF16 = HexFloat<FloatProxy<Float16>>;
HF f(GetParam().source_float);
for (auto round : GetParam().directions) {
HF16 half(0);
f.castTo(half, round);
EXPECT_EQ(GetParam().expected_half, half.value().getAsFloat().get_value())
<< get_round_text(round) << " " << std::hex
<< BitwiseCast<uint32_t>(GetParam().source_float)
<< " cast to: " << half.value().getAsFloat().get_value();
}
}
const uint16_t positive_infinity = 0x7C00;
const uint16_t negative_infinity = 0xFC00;
INSTANTIATE_TEST_SUITE_P(
F32ToF16, HexFloatFP32To16Tests,
::testing::ValuesIn(std::vector<DownCastTest>({
// Exactly representable as half.
{0.f,
0x0,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{-0.f,
0x8000,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{1.0f,
0x3C00,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{-1.0f,
0xBC00,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{float_fractions({0, 1, 10}),
0x3E01,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{-float_fractions({0, 1, 10}),
0xBE01,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{static_cast<float>(ldexp(float_fractions({0, 1, 10}), 3)),
0x4A01,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{static_cast<float>(-ldexp(float_fractions({0, 1, 10}), 3)),
0xCA01,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
// Underflow
{static_cast<float>(ldexp(1.0f, -25)),
0x0,
{RD::kToZero, RD::kToNegativeInfinity, RD::kToNearestEven}},
{static_cast<float>(ldexp(1.0f, -25)), 0x1, {RD::kToPositiveInfinity}},
{static_cast<float>(-ldexp(1.0f, -25)),
0x8000,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNearestEven}},
{static_cast<float>(-ldexp(1.0f, -25)),
0x8001,
{RD::kToNegativeInfinity}},
{static_cast<float>(ldexp(1.0f, -24)),
0x1,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
// Overflow
{static_cast<float>(ldexp(1.0f, 16)),
positive_infinity,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{static_cast<float>(ldexp(1.0f, 18)),
positive_infinity,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{static_cast<float>(ldexp(1.3f, 16)),
positive_infinity,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{static_cast<float>(-ldexp(1.0f, 16)),
negative_infinity,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{static_cast<float>(-ldexp(1.0f, 18)),
negative_infinity,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{static_cast<float>(-ldexp(1.3f, 16)),
negative_infinity,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
// Transfer of Infinities
{std::numeric_limits<float>::infinity(),
positive_infinity,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
{-std::numeric_limits<float>::infinity(),
negative_infinity,
{RD::kToZero, RD::kToPositiveInfinity, RD::kToNegativeInfinity,
RD::kToNearestEven}},
// Nans are below because we cannot test for equality.
})));
struct UpCastCase {
uint16_t source_half;
float expected_float;
};
using HexFloatFP16To32Tests = ::testing::TestWithParam<UpCastCase>;
TEST_P(HexFloatFP16To32Tests, WideningCasts) {
using HF = HexFloat<FloatProxy<float>>;
using HF16 = HexFloat<FloatProxy<Float16>>;
HF16 f(GetParam().source_half);
round_direction rounding[] = {round_direction::kToZero,
round_direction::kToNearestEven,
round_direction::kToPositiveInfinity,
round_direction::kToNegativeInfinity};
// Everything fits, so everything should just be bit-shifts.
for (round_direction round : rounding) {
HF flt(0.f);
f.castTo(flt, round);
EXPECT_EQ(GetParam().expected_float, flt.value().getAsFloat())
<< get_round_text(round) << " " << std::hex
<< BitwiseCast<uint16_t>(GetParam().source_half)
<< " cast to: " << flt.value().getAsFloat();
}
}
INSTANTIATE_TEST_SUITE_P(
F16ToF32, HexFloatFP16To32Tests,
::testing::ValuesIn(std::vector<UpCastCase>({
{0x0000, 0.f},
{0x8000, -0.f},
{0x3C00, 1.0f},
{0xBC00, -1.0f},
{0x3F00, float_fractions({0, 1, 2})},
{0xBF00, -float_fractions({0, 1, 2})},
{0x3F01, float_fractions({0, 1, 2, 10})},
{0xBF01, -float_fractions({0, 1, 2, 10})},
// denorm
{0x0001, static_cast<float>(ldexp(1.0, -24))},
{0x0002, static_cast<float>(ldexp(1.0, -23))},
{0x8001, static_cast<float>(-ldexp(1.0, -24))},
{0x8011, static_cast<float>(-ldexp(1.0, -20) + -ldexp(1.0, -24))},
// inf
{0x7C00, std::numeric_limits<float>::infinity()},
{0xFC00, -std::numeric_limits<float>::infinity()},
})));
TEST(HexFloatOperationTests, NanTests) {
using HF = HexFloat<FloatProxy<float>>;
using HF16 = HexFloat<FloatProxy<Float16>>;
round_direction rounding[] = {round_direction::kToZero,
round_direction::kToNearestEven,
round_direction::kToPositiveInfinity,
round_direction::kToNegativeInfinity};
// Everything fits, so everything should just be bit-shifts.
for (round_direction round : rounding) {
HF16 f16(0);
HF f(0.f);
HF(std::numeric_limits<float>::quiet_NaN()).castTo(f16, round);
EXPECT_TRUE(f16.value().isNan());
HF(std::numeric_limits<float>::signaling_NaN()).castTo(f16, round);
EXPECT_TRUE(f16.value().isNan());
HF16(0x7C01).castTo(f, round);
EXPECT_TRUE(f.value().isNan());
HF16(0x7C11).castTo(f, round);
EXPECT_TRUE(f.value().isNan());
HF16(0xFC01).castTo(f, round);
EXPECT_TRUE(f.value().isNan());
HF16(0x7C10).castTo(f, round);
EXPECT_TRUE(f.value().isNan());
HF16(0xFF00).castTo(f, round);
EXPECT_TRUE(f.value().isNan());
}
}
// A test case for parsing good and bad HexFloat<FloatProxy<T>> literals.
template <typename T>
struct FloatParseCase {
std::string literal;
bool negate_value;
bool expect_success;
HexFloat<FloatProxy<T>> expected_value;
};
using ParseNormalFloatTest = ::testing::TestWithParam<FloatParseCase<float>>;
TEST_P(ParseNormalFloatTest, Samples) {
std::stringstream input(GetParam().literal);
HexFloat<FloatProxy<float>> parsed_value(0.0f);
ParseNormalFloat(input, GetParam().negate_value, parsed_value);
EXPECT_NE(GetParam().expect_success, input.fail())
<< " literal: " << GetParam().literal
<< " negate: " << GetParam().negate_value;
if (GetParam().expect_success) {
EXPECT_THAT(parsed_value.value(), Eq(GetParam().expected_value.value()))
<< " literal: " << GetParam().literal
<< " negate: " << GetParam().negate_value;
}
}
// Returns a FloatParseCase with expected failure.
template <typename T>
FloatParseCase<T> BadFloatParseCase(std::string literal, bool negate_value,
T expected_value) {
HexFloat<FloatProxy<T>> proxy_expected_value(expected_value);
return FloatParseCase<T>{literal, negate_value, false, proxy_expected_value};
}
// Returns a FloatParseCase that should successfully parse to a given value.
template <typename T>
FloatParseCase<T> GoodFloatParseCase(std::string literal, bool negate_value,
T expected_value) {
HexFloat<FloatProxy<T>> proxy_expected_value(expected_value);
return FloatParseCase<T>{literal, negate_value, true, proxy_expected_value};
}
INSTANTIATE_TEST_SUITE_P(
FloatParse, ParseNormalFloatTest,
::testing::ValuesIn(std::vector<FloatParseCase<float>>{
// Failing cases due to trivially incorrect syntax.
BadFloatParseCase("abc", false, 0.0f),
BadFloatParseCase("abc", true, 0.0f),
// Valid cases.
GoodFloatParseCase("0", false, 0.0f),
GoodFloatParseCase("0.0", false, 0.0f),
GoodFloatParseCase("-0.0", false, -0.0f),
GoodFloatParseCase("2.0", false, 2.0f),
GoodFloatParseCase("-2.0", false, -2.0f),
GoodFloatParseCase("+2.0", false, 2.0f),
// Cases with negate_value being true.
GoodFloatParseCase("0.0", true, -0.0f),
GoodFloatParseCase("2.0", true, -2.0f),
// When negate_value is true, we should not accept a
// leading minus or plus.
BadFloatParseCase("-0.0", true, 0.0f),
BadFloatParseCase("-2.0", true, 0.0f),
BadFloatParseCase("+0.0", true, 0.0f),
BadFloatParseCase("+2.0", true, 0.0f),
// Overflow is an error for 32-bit float parsing.
BadFloatParseCase("1e40", false, FLT_MAX),
BadFloatParseCase("1e40", true, -FLT_MAX),
BadFloatParseCase("-1e40", false, -FLT_MAX),
// We can't have -1e40 and negate_value == true since
// that represents an original case of "--1e40" which
// is invalid.
}));
using ParseNormalFloat16Test =
::testing::TestWithParam<FloatParseCase<Float16>>;
TEST_P(ParseNormalFloat16Test, Samples) {
std::stringstream input(GetParam().literal);
HexFloat<FloatProxy<Float16>> parsed_value(0);
ParseNormalFloat(input, GetParam().negate_value, parsed_value);
EXPECT_NE(GetParam().expect_success, input.fail())
<< " literal: " << GetParam().literal
<< " negate: " << GetParam().negate_value;
if (GetParam().expect_success) {
EXPECT_THAT(parsed_value.value(), Eq(GetParam().expected_value.value()))
<< " literal: " << GetParam().literal
<< " negate: " << GetParam().negate_value;
}
}
INSTANTIATE_TEST_SUITE_P(
Float16Parse, ParseNormalFloat16Test,
::testing::ValuesIn(std::vector<FloatParseCase<Float16>>{
// Failing cases due to trivially incorrect syntax.
BadFloatParseCase<Float16>("abc", false, uint16_t{0}),
BadFloatParseCase<Float16>("abc", true, uint16_t{0}),
// Valid cases.
GoodFloatParseCase<Float16>("0", false, uint16_t{0}),
GoodFloatParseCase<Float16>("0.0", false, uint16_t{0}),
GoodFloatParseCase<Float16>("-0.0", false, uint16_t{0x8000}),
GoodFloatParseCase<Float16>("2.0", false, uint16_t{0x4000}),
GoodFloatParseCase<Float16>("-2.0", false, uint16_t{0xc000}),
GoodFloatParseCase<Float16>("+2.0", false, uint16_t{0x4000}),
// Cases with negate_value being true.
GoodFloatParseCase<Float16>("0.0", true, uint16_t{0x8000}),
GoodFloatParseCase<Float16>("2.0", true, uint16_t{0xc000}),
// When negate_value is true, we should not accept a leading minus or
// plus.
BadFloatParseCase<Float16>("-0.0", true, uint16_t{0}),
BadFloatParseCase<Float16>("-2.0", true, uint16_t{0}),
BadFloatParseCase<Float16>("+0.0", true, uint16_t{0}),
BadFloatParseCase<Float16>("+2.0", true, uint16_t{0}),
}));
// A test case for detecting infinities.
template <typename T>
struct OverflowParseCase {
std::string input;
bool expect_success;
T expected_value;
};
using FloatProxyParseOverflowFloatTest =
::testing::TestWithParam<OverflowParseCase<float>>;
TEST_P(FloatProxyParseOverflowFloatTest, Sample) {
std::istringstream input(GetParam().input);
HexFloat<FloatProxy<float>> value(0.0f);
input >> value;
EXPECT_NE(GetParam().expect_success, input.fail());
if (GetParam().expect_success) {
EXPECT_THAT(value.value().getAsFloat(), GetParam().expected_value);
}
}
INSTANTIATE_TEST_SUITE_P(
FloatOverflow, FloatProxyParseOverflowFloatTest,
::testing::ValuesIn(std::vector<OverflowParseCase<float>>({
{"0", true, 0.0f},
{"0.0", true, 0.0f},
{"1.0", true, 1.0f},
{"1e38", true, 1e38f},
{"-1e38", true, -1e38f},
{"1e40", false, FLT_MAX},
{"-1e40", false, -FLT_MAX},
{"1e400", false, FLT_MAX},
{"-1e400", false, -FLT_MAX},
})));
using FloatProxyParseOverflowDoubleTest =
::testing::TestWithParam<OverflowParseCase<double>>;
TEST_P(FloatProxyParseOverflowDoubleTest, Sample) {
std::istringstream input(GetParam().input);
HexFloat<FloatProxy<double>> value(0.0);
input >> value;
EXPECT_NE(GetParam().expect_success, input.fail());
if (GetParam().expect_success) {
EXPECT_THAT(value.value().getAsFloat(), Eq(GetParam().expected_value));
}
}
INSTANTIATE_TEST_SUITE_P(
DoubleOverflow, FloatProxyParseOverflowDoubleTest,
::testing::ValuesIn(std::vector<OverflowParseCase<double>>({
{"0", true, 0.0},
{"0.0", true, 0.0},
{"1.0", true, 1.0},
{"1e38", true, 1e38},
{"-1e38", true, -1e38},
{"1e40", true, 1e40},
{"-1e40", true, -1e40},
{"1e400", false, DBL_MAX},
{"-1e400", false, -DBL_MAX},
})));
using FloatProxyParseOverflowFloat16Test =
::testing::TestWithParam<OverflowParseCase<uint16_t>>;
TEST_P(FloatProxyParseOverflowFloat16Test, Sample) {
std::istringstream input(GetParam().input);
HexFloat<FloatProxy<Float16>> value(0);
input >> value;
EXPECT_NE(GetParam().expect_success, input.fail())
<< " literal: " << GetParam().input;
if (GetParam().expect_success) {
EXPECT_THAT(value.value().data(), Eq(GetParam().expected_value))
<< " literal: " << GetParam().input;
}
}
INSTANTIATE_TEST_SUITE_P(
Float16Overflow, FloatProxyParseOverflowFloat16Test,
::testing::ValuesIn(std::vector<OverflowParseCase<uint16_t>>({
{"0", true, uint16_t{0}},
{"0.0", true, uint16_t{0}},
{"1.0", true, uint16_t{0x3c00}},
// Overflow for 16-bit float is an error, and returns max or
// lowest value.
{"1e38", false, uint16_t{0x7bff}},
{"1e40", false, uint16_t{0x7bff}},
{"1e400", false, uint16_t{0x7bff}},
{"-1e38", false, uint16_t{0xfbff}},
{"-1e40", false, uint16_t{0xfbff}},
{"-1e400", false, uint16_t{0xfbff}},
})));
TEST(FloatProxy, Max) {
EXPECT_THAT(FloatProxy<Float16>::max().getAsFloat().get_value(),
Eq(uint16_t{0x7bff}));
EXPECT_THAT(FloatProxy<float>::max().getAsFloat(),
Eq(std::numeric_limits<float>::max()));
EXPECT_THAT(FloatProxy<double>::max().getAsFloat(),
Eq(std::numeric_limits<double>::max()));
}
TEST(FloatProxy, Lowest) {
EXPECT_THAT(FloatProxy<Float16>::lowest().getAsFloat().get_value(),
Eq(uint16_t{0xfbff}));
EXPECT_THAT(FloatProxy<float>::lowest().getAsFloat(),
Eq(std::numeric_limits<float>::lowest()));
EXPECT_THAT(FloatProxy<double>::lowest().getAsFloat(),
Eq(std::numeric_limits<double>::lowest()));
}
template <typename T>
struct StreamParseCase {
StreamParseCase(const std::string& lit, bool succ, const std::string& suffix,
T value)
: literal(lit),
expect_success(succ),
expected_suffix(suffix),
expected_value(HexFloat<FloatProxy<T>>(value)) {}
std::string literal;
bool expect_success;
std::string expected_suffix;
HexFloat<FloatProxy<T>> expected_value;
};
template <typename T>
std::ostream& operator<<(std::ostream& os, const StreamParseCase<T>& fspc) {
os << "StreamParseCase(" << fspc.literal
<< ", expect_success:" << int(fspc.expect_success) << ","
<< fspc.expected_suffix << "," << fspc.expected_value << ")";
return os;
}
using FloatStreamParseTest = ::testing::TestWithParam<StreamParseCase<float>>;
TEST_P(FloatStreamParseTest, Samples) {
std::stringstream input(GetParam().literal);
HexFloat<FloatProxy<float>> parsed_value(0.0f);
// Hex floats must be read with the stream input operator.
input >> parsed_value;
if (GetParam().expect_success) {
EXPECT_FALSE(input.fail());
std::string suffix;
input >> suffix;
// EXPECT_EQ(suffix, GetParam().expected_suffix);
EXPECT_EQ(parsed_value.value().getAsFloat(),
GetParam().expected_value.value().getAsFloat());
} else {
EXPECT_TRUE(input.fail());
}
}
INSTANTIATE_TEST_SUITE_P(
HexFloatExponentMissingDigits, FloatStreamParseTest,
::testing::ValuesIn(std::vector<StreamParseCase<float>>{
{"0x1.0p1", true, "", 2.0f},
{"0x1.0p1a", true, "a", 2.0f},
{"-0x1.0p1f", true, "f", -2.0f},
{"0x1.0p", false, "", 0.0f},
{"0x1.0pa", false, "", 0.0f},
{"0x1.0p!", false, "", 0.0f},
{"0x1.0p+", false, "", 0.0f},
{"0x1.0p+a", false, "", 0.0f},
{"0x1.0p+!", false, "", 0.0f},
{"0x1.0p-", false, "", 0.0f},
{"0x1.0p-a", false, "", 0.0f},
{"0x1.0p-!", false, "", 0.0f},
{"0x1.0p++", false, "", 0.0f},
{"0x1.0p+-", false, "", 0.0f},
{"0x1.0p-+", false, "", 0.0f},
{"0x1.0p--", false, "", 0.0f}}));
INSTANTIATE_TEST_SUITE_P(
HexFloatExponentTrailingSign, FloatStreamParseTest,
::testing::ValuesIn(std::vector<StreamParseCase<float>>{
// Don't consume a sign after the binary exponent digits.
{"0x1.0p1", true, "", 2.0f},
{"0x1.0p1+", true, "+", 2.0f},
{"0x1.0p1-", true, "-", 2.0f}}));
INSTANTIATE_TEST_SUITE_P(
HexFloatPositiveExponentOverflow, FloatStreamParseTest,
::testing::ValuesIn(std::vector<StreamParseCase<float>>{
// Positive exponents
{"0x1.0p1", true, "", 2.0f}, // fine, a normal number
{"0x1.0p15", true, "", 32768.0f}, // fine, a normal number
{"0x1.0p127", true, "", float(ldexp(1.0f, 127))}, // good large number
{"0x0.8p128", true, "", float(ldexp(1.0f, 127))}, // good large number
{"0x0.1p131", true, "", float(ldexp(1.0f, 127))}, // good large number
{"0x0.01p135", true, "", float(ldexp(1.0f, 127))}, // good large number
{"0x1.0p128", true, "", float(ldexp(1.0f, 128))}, // infinity
{"0x1.0p4294967295", true, "", float(ldexp(1.0f, 128))}, // infinity
{"0x1.0p5000000000", true, "", float(ldexp(1.0f, 128))}, // infinity
{"0x0.0p5000000000", true, "", 0.0f}, // zero mantissa, zero result
}));
INSTANTIATE_TEST_SUITE_P(
HexFloatNegativeExponentOverflow, FloatStreamParseTest,
::testing::ValuesIn(std::vector<StreamParseCase<float>>{
// Positive results, digits before '.'
{"0x1.0p-126", true, "",
float(ldexp(1.0f, -126))}, // fine, a small normal number
{"0x1.0p-127", true, "", float(ldexp(1.0f, -127))}, // denorm number
{"0x1.0p-149", true, "",
float(ldexp(1.0f, -149))}, // smallest positive denormal
{"0x0.8p-148", true, "",
float(ldexp(1.0f, -149))}, // smallest positive denormal
{"0x0.1p-145", true, "",
float(ldexp(1.0f, -149))}, // smallest positive denormal
{"0x0.01p-141", true, "",
float(ldexp(1.0f, -149))}, // smallest positive denormal
// underflow rounds down to zero
{"0x1.0p-150", true, "", 0.0f},
{"0x1.0p-4294967296", true, "",
0.0f}, // avoid exponent overflow in parser
{"0x1.0p-5000000000", true, "",
0.0f}, // avoid exponent overflow in parser
{"0x0.0p-5000000000", true, "", 0.0f}, // zero mantissa, zero result
}));
// TODO(awoloszyn): Add fp16 tests and HexFloatTraits.
} // namespace
} // namespace utils
} // namespace spvtools
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