Scarfski/filament
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

fix utils::ctz() when builtins are not available

Browse Source 
Our fallback 64-bits ctz() was completely wrong. 
The unit tests were wrong too.
This commit is contained in:
Pixelflinger
2020-03-09 23:12:29 -07:00
committed by Mathias Agopian
parent a2c6c34739
commit 8fb65a19b4
2 changed files with 47 additions and 41 deletions
Download Patch File Download Diff File Expand all files Collapse all files

26
libs/utils/test/test_algorithm.cpp
View File

@@ -33,25 +33,25 @@ static inline T count_trailing_zeros(T v) noexcept {
}
TEST(AlgorithmTest, details_clz) {
for (uint64_t i = 1, j = 63; i < 64; i *= 2, j--) {
for (uint64_t i = 1, j = 63; j < 64; i *= 2, j--) {
EXPECT_EQ(j, details::clz(i));
EXPECT_EQ(j, details::clz(i|1));
}
for (uint32_t i = 1, j = 31; i < 32; i *= 2, j--) {
for (uint32_t i = 1, j = 31; j < 32; i *= 2, j--) {
EXPECT_EQ(j, details::clz(i));
EXPECT_EQ(j, details::clz(i|1));
}
}
TEST(AlgorithmTest, clz) {
for (uint64_t i = 1, j = 63; i < 64; i *= 2, j--) {
for (uint64_t i = 1, j = 63; j < 64; i *= 2, j--) {
EXPECT_EQ(j, clz(i));
EXPECT_EQ(j, clz(i|1));
EXPECT_EQ(j, details::clz(i));
EXPECT_EQ(j, details::clz(i|1));
EXPECT_EQ(j, count_leading_zeros(i));
}
for (uint32_t i = 1, j = 31; i < 32; i *= 2, j--) {
for (uint32_t i = 1, j = 31; j < 32; i *= 2, j--) {
EXPECT_EQ(j, clz(i));
EXPECT_EQ(j, clz(i|1));
EXPECT_EQ(j, details::clz(i));
@@ -61,21 +61,21 @@ TEST(AlgorithmTest, clz) {
}
TEST(AlgorithmTest, details_ctz) {
for (uint64_t i = 1, j = 0; i < 64; i *= 2, j++) {
for (uint64_t i = 1, j = 0; j < 64; i *= 2, j++) {
EXPECT_EQ(j, details::ctz(i));
}
for (uint32_t i = 1, j = 0; i < 32; i *= 2, j++) {
for (uint32_t i = 1, j = 0; j < 32; i *= 2, j++) {
EXPECT_EQ(j, details::ctz(i));
}
}
TEST(AlgorithmTest, ctz) {
for (uint64_t i = 1, j = 0; i < 64; i *= 2, j++) {
for (uint64_t i = 1, j = 0; j < 64; i *= 2, j++) {
EXPECT_EQ(j, ctz(i));
EXPECT_EQ(j, details::ctz(i));
EXPECT_EQ(j, count_trailing_zeros(i));
}
for (uint32_t i = 1, j = 0; i < 32; i *= 2, j++) {
for (uint32_t i = 1, j = 0; j < 32; i *= 2, j++) {
EXPECT_EQ(j, ctz(i));
EXPECT_EQ(j, details::ctz(i));
EXPECT_EQ(j, count_trailing_zeros(i));
@@ -99,13 +99,13 @@ TEST(AlgorithmTest, details_popcount) {
EXPECT_EQ(16, details::popcount(uint32_t(0x55555555)));
EXPECT_EQ(32, details::popcount(uint64_t(0x5555555555555555)));
for (uint64_t i = 1, j = 63; i < 64; i *= 2, j--) {
for (uint64_t i = 1, j = 63; j < 64; i *= 2, j--) {
EXPECT_EQ(1, details::popcount(i));
}
for (uint32_t i = 1, j = 31; i < 32; i *= 2, j--) {
for (uint32_t i = 1, j = 31; j < 32; i *= 2, j--) {
EXPECT_EQ(1, details::popcount(i));
}
for (uint8_t i = 1, j = 7; i < 8; i *= 2, j--) {
for (uint8_t i = 1, j = 7; j < 8; i *= 2, j--) {
EXPECT_EQ(1, details::popcount(i));
}
}
@@ -130,10 +130,10 @@ TEST(AlgorithmTest, popcount) {
for (uint64_t i = 1, j = 63; i < 64; i *= 2, j--) {
EXPECT_EQ(1, popcount(i));
}
for (uint32_t i = 1, j = 31; i < 32; i *= 2, j--) {
for (uint32_t i = 1, j = 31; j < 32; i *= 2, j--) {
EXPECT_EQ(1, popcount(i));
}
for (uint8_t i = 1, j = 7; i < 8; i *= 2, j--) {
for (uint8_t i = 1, j = 7; j < 8; i *= 2, j--) {
EXPECT_EQ(1, popcount(i));
}
}