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Commit 679d1187 by Carl Woffenden Committed by Commit Bot
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Fix to build with VS2019

When building with VS2019 (using is_clang=false) multiples of the following error are given: ../../src/common/mathutil.cpp(75): error C4244: '=': conversion from 'double' to 'float', possible loss of data (This is due to pow(), when passed an int for the second param, widens the first param to a double then returns a double). Since the code was being changed the opportunity was taken to: - add missing unit tests for the two 999E5 conversions - optimise out the common pow() functions The unit tests were written against the original implementation, then the optimisations added and verified against the original results. Bug: angleproject:5521, dawn:602 Change-Id: Ic9e5eaedbe3fc7ceeed697898823b76dffcd989a Reviewed-on: https://chromium-review.googlesource.com/c/angle/angle/+/2624888 Commit-Queue: Jamie Madill <jmadill@chromium.org> Reviewed-by: 's avatarJamie Madill <jmadill@chromium.org>
parent 68ac4e43
Showing with 104 additions and 13 deletions
AUTHORS
...@@ -36,6 +36,7 @@ Arm Ltd. ...@@ -36,6 +36,7 @@ Arm Ltd.
Broadcom Inc. Broadcom Inc.
Facebook, Inc. Facebook, Inc.
The Khronos Group, Inc. The Khronos Group, Inc.
Numfum GmbH
Jacek Caban Jacek Caban
Mark Callow Mark Callow
......
CONTRIBUTORS
...@@ -197,3 +197,6 @@ The Khronos Group, Inc. ...@@ -197,3 +197,6 @@ The Khronos Group, Inc.
Igalia, S.L. Igalia, S.L.
Jose Dapena Paz Jose Dapena Paz
Numfum GmbH
Carl Woffenden
src/common/mathutil.cpp
...@@ -31,6 +31,9 @@ constexpr int g_sharedexp_bias = 15; ...@@ -31,6 +31,9 @@ constexpr int g_sharedexp_bias = 15;
// N is the number of mantissa bits per component (9) // N is the number of mantissa bits per component (9)
constexpr int g_sharedexp_mantissabits = 9; constexpr int g_sharedexp_mantissabits = 9;
// number of mantissa bits per component pre-biased
constexpr int g_sharedexp_biased_mantissabits = g_sharedexp_bias + g_sharedexp_mantissabits;
// Emax is the maximum allowed biased exponent value (31) // Emax is the maximum allowed biased exponent value (31)
constexpr int g_sharedexp_maxexponent = 31; constexpr int g_sharedexp_maxexponent = 31;
...@@ -51,17 +54,15 @@ unsigned int convertRGBFloatsTo999E5(float red, float green, float blue) ...@@ -51,17 +54,15 @@ unsigned int convertRGBFloatsTo999E5(float red, float green, float blue)
const float exp_p = const float exp_p =
std::max<float>(-g_sharedexp_bias - 1, floor(log(max_c))) + 1 + g_sharedexp_bias; std::max<float>(-g_sharedexp_bias - 1, floor(log(max_c))) + 1 + g_sharedexp_bias;
const int max_s = static_cast<int>( const int max_s = static_cast<int>(
floor((max_c / (pow(2.0f, exp_p - g_sharedexp_bias - g_sharedexp_mantissabits))) + 0.5f)); floor((max_c / (pow(2.0f, exp_p - g_sharedexp_biased_mantissabits))) + 0.5f));
const int exp_s = const int exp_s =
static_cast<int>((max_s < pow(2.0f, g_sharedexp_mantissabits)) ? exp_p : exp_p + 1); static_cast<int>((max_s < pow(2.0f, g_sharedexp_mantissabits)) ? exp_p : exp_p + 1);
const float pow2_exp = pow(2.0f, static_cast<float>(exp_s) - g_sharedexp_biased_mantissabits);
RGB9E5Data output; RGB9E5Data output;
output.R = static_cast<unsigned int>( output.R = static_cast<unsigned int>(floor((red_c / pow2_exp) + 0.5f));
floor((red_c / (pow(2.0f, exp_s - g_sharedexp_bias - g_sharedexp_mantissabits))) + 0.5f)); output.G = static_cast<unsigned int>(floor((green_c / pow2_exp) + 0.5f));
output.G = static_cast<unsigned int>( output.B = static_cast<unsigned int>(floor((blue_c / pow2_exp) + 0.5f));
floor((green_c / (pow(2.0f, exp_s - g_sharedexp_bias - g_sharedexp_mantissabits))) + 0.5f));
output.B = static_cast<unsigned int>(
floor((blue_c / (pow(2.0f, exp_s - g_sharedexp_bias - g_sharedexp_mantissabits))) + 0.5f));
output.E = exp_s; output.E = exp_s;
return bitCast<unsigned int>(output); return bitCast<unsigned int>(output);
...@@ -71,12 +72,12 @@ void convert999E5toRGBFloats(unsigned int input, float *red, float *green, float ...@@ -71,12 +72,12 @@ void convert999E5toRGBFloats(unsigned int input, float *red, float *green, float
{ {
const RGB9E5Data *inputData = reinterpret_cast<const RGB9E5Data *>(&input); const RGB9E5Data *inputData = reinterpret_cast<const RGB9E5Data *>(&input);
*red = const float pow2_exp =
inputData->R * pow(2.0f, (int)inputData->E - g_sharedexp_bias - g_sharedexp_mantissabits); pow(2.0f, static_cast<float>(inputData->E) - g_sharedexp_biased_mantissabits);
*green =
inputData->G * pow(2.0f, (int)inputData->E - g_sharedexp_bias - g_sharedexp_mantissabits); *red = inputData->R * pow2_exp;
*blue = *green = inputData->G * pow2_exp;
inputData->B * pow(2.0f, (int)inputData->E - g_sharedexp_bias - g_sharedexp_mantissabits); *blue = inputData->B * pow2_exp;
} }
} // namespace gl } // namespace gl
src/common/mathutil_unittest.cpp
...@@ -379,4 +379,90 @@ TEST(MathUtilTest, Float32ToFloat16) ...@@ -379,4 +379,90 @@ TEST(MathUtilTest, Float32ToFloat16)
ASSERT_EQ(float32ToFloat16(1.0f), 0x3C00); ASSERT_EQ(float32ToFloat16(1.0f), 0x3C00);
} }
// Tests the RGB float to 999E5 conversion
TEST(MathUtilTest, convertRGBFloatsTo999E5)
{
const int numTests = 18;
const float input[numTests][3] = {// The basics
{0.0f, 0.0f, 0.0f},
{0.0f, 0.0f, 1.0f},
{0.0f, 1.0f, 0.0f},
{0.0f, 1.0f, 1.0f},
{1.0f, 0.0f, 0.0f},
{1.0f, 0.0f, 1.0f},
{1.0f, 1.0f, 0.0f},
{1.0f, 1.0f, 1.0f},
// Extended range
{0.0f, 0.0f, 1.5f},
{0.0f, 2.0f, 0.0f},
{0.0f, 2.5f, 3.0f},
{3.5f, 0.0f, 0.0f},
{4.0f, 0.0f, 4.5f},
{5.0f, 5.5f, 0.0f},
{6.0f, 6.5f, 7.0f},
// Random
{0.1f, 9.6f, 3.2f},
{2.0f, 1.7f, 8.6f},
{0.7f, 4.2f, 9.1f}};
const unsigned int result[numTests] = {// The basics
0x00000000, 0x84000000, 0x80020000, 0x84020000,
0x80000100, 0x84000100, 0x80020100, 0x84020100,
// Extended range
0x86000000, 0x88020000, 0x8E028000, 0x880001C0,
0x94800100, 0x9002C140, 0x97034180,
// Random
0x999A6603, 0x9C4C6C40, 0x9C8D0C16};
for (int i = 0; i < numTests; i++)
{
EXPECT_EQ(convertRGBFloatsTo999E5(input[i][0], input[i][1], input[i][2]), result[i]);
}
}
// Tests the 999E5 to RGB float conversion
TEST(MathUtilTest, convert999E5toRGBFloats)
{
const int numTests = 18;
const float result[numTests][3] = {// The basics
{0.0f, 0.0f, 0.0f},
{0.0f, 0.0f, 1.0f},
{0.0f, 1.0f, 0.0f},
{0.0f, 1.0f, 1.0f},
{1.0f, 0.0f, 0.0f},
{1.0f, 0.0f, 1.0f},
{1.0f, 1.0f, 0.0f},
{1.0f, 1.0f, 1.0f},
// Extended range
{0.0f, 0.0f, 1.5f},
{0.0f, 2.0f, 0.0f},
{0.0f, 2.5f, 3.0f},
{3.5f, 0.0f, 0.0f},
{4.0f, 0.0f, 4.5f},
{5.0f, 5.5f, 0.0f},
{6.0f, 6.5f, 7.0f},
// Random
{0.1f, 9.6f, 3.2f},
{2.0f, 1.7f, 8.6f},
{0.7f, 4.2f, 9.1f}};
const unsigned int input[numTests] = {// The basics
0x00000000, 0x84000000, 0x80020000, 0x84020000,
0x80000100, 0x84000100, 0x80020100, 0x84020100,
// Extended range
0x86000000, 0x88020000, 0x8E028000, 0x880001C0,
0x94800100, 0x9002C140, 0x97034180,
// Random
0x999A6603, 0x9C4C6C40, 0x9C8D0C16};
// Note: quite a low tolerance is required
const float floatFaultTolerance = 0.05f;
float outR, outG, outB;
for (int i = 0; i < numTests; i++)
{
convert999E5toRGBFloats(input[i], &outR, &outG, &outB);
EXPECT_NEAR(result[i][0], outR, floatFaultTolerance);
EXPECT_NEAR(result[i][1], outG, floatFaultTolerance);
EXPECT_NEAR(result[i][2], outB, floatFaultTolerance);
}
}
} // anonymous namespace } // anonymous namespace
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