Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Add constraint for layout_left|right|stride::stride(), and add test #238

Merged
merged 6 commits into from
Feb 24, 2023
Merged

Add constraint for layout_left|right|stride::stride(), and add test #238

Show file tree
Hide file tree
Changes from 5 commits
Commits
Show all changes
6 commits
Select commit Hold shift + click to select a range
b421aa5
Add constraint for layout_left|right|stride::stride(), and add test
youyu3 Feb 3, 2023
1e81887
Unnecessary change...
youyu3 Feb 3, 2023
18f3e1e
Fix tests for clang and icpx CI builds
youyu3 Feb 3, 2023
087c14c
Constraints for C++20 only
youyu3 Feb 11, 2023
078e87d
Update README
youyu3 Feb 11, 2023
45a00ca
One big constexpr if protection for all runtime checks on rank
youyu3 Feb 15, 2023
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Loading
Jump to
Jump to file
Failed to load files.
Loading
Diff view
Diff view
1 change: 1 addition & 0 deletions README.md
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -66,6 +66,7 @@ When not in C++23 mode the implementation deviates from the proposal as follows:
- mdspan has a default constructor even in cases where it shouldn't (i.e. all static extents, and default constructible mapping/accessor)
- the conditional explicit markup is missing, making certain constructors implicit
- most notably you can implicitly convert from dynamic extent to static extent, which you can't in C++20 mode
- there is a constraint on `layout_left::mapping::stride()`, `layout_right::mapping::stride()` and `layout_stride::mapping::stride()` that `extents_type::rank() > 0` is `true`, which is not implemented in C++17 or C++14.

### C++14
- deduction guides don't exist
Expand Down
6 changes: 5 additions & 1 deletion include/experimental/__p0009_bits/layout_left.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -177,7 +177,11 @@ class layout_left::mapping {
MDSPAN_INLINE_FUNCTION constexpr bool is_strided() const noexcept { return true; }

MDSPAN_INLINE_FUNCTION
constexpr index_type stride(rank_type i) const noexcept {
constexpr index_type stride(rank_type i) const noexcept
#if MDSPAN_HAS_CXX_20
requires ( Extents::rank() > 0 )
#endif
{
index_type value = 1;
for(rank_type r=0; r<i; r++) value*=__extents.extent(r);
return value;
Expand Down
6 changes: 5 additions & 1 deletion include/experimental/__p0009_bits/layout_right.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -179,7 +179,11 @@ class layout_right::mapping {
MDSPAN_INLINE_FUNCTION constexpr bool is_strided() const noexcept { return true; }

MDSPAN_INLINE_FUNCTION
constexpr index_type stride(rank_type i) const noexcept {
constexpr index_type stride(rank_type i) const noexcept
#if MDSPAN_HAS_CXX_20
requires ( Extents::rank() > 0 )
#endif
{
index_type value = 1;
for(rank_type r=extents_type::rank()-1; r>i; r--) value*=__extents.extent(r);
return value;
Expand Down
6 changes: 5 additions & 1 deletion include/experimental/__p0009_bits/layout_stride.hpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -432,7 +432,11 @@ struct layout_stride {


MDSPAN_INLINE_FUNCTION
constexpr index_type stride(rank_type r) const noexcept {
constexpr index_type stride(rank_type r) const noexcept
#if MDSPAN_HAS_CXX_20
requires ( Extents::rank() > 0 )
#endif
{
return __strides_storage()[r];
}

Expand Down
12 changes: 9 additions & 3 deletions tests/test_exhaustive_layouts.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -391,9 +391,15 @@ TYPED_TEST(TestLayoutConversion, implicit_conversion) {
#endif
map1 = typename TestFixture::map_1_t(map2);

for(size_t r=0; r != this->exts1.rank(); ++r) {
ASSERT_EQ(map1.extents().extent(r), map2.extents().extent(r));
ASSERT_EQ(map1.stride(r), map2.stride(r));
#if MDSPAN_HAS_CXX_20
if constexpr (TestFixture::exts_1_t::rank() > 0) {
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

We still test this with C++14

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Given my other comment, I would just protect the condition with whether C++20 is on.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Works for me. Will update.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Updated. May not be the best-looking #ifs...

Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This code should be fine even if MDSPAN_HAS_CXX_20 defined, because the constraint on stride(r) won't come into play, no? I'd rather have fewer macros if we can avoid it.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

This check is for the case when exts_1_t::rank() == 0 in the C++20 mode, in which case we have the constraint and it'll result in a compilation error without the if constexpr.
Well, that being said, I think we should only protect the line that calls stride(). I'll fix that.

#endif
for(size_t r=0; r != this->exts1.rank(); ++r) {
ASSERT_EQ(map1.extents().extent(r), map2.extents().extent(r));
ASSERT_EQ(map1.stride(r), map2.stride(r));
}
#if MDSPAN_HAS_CXX_20
}
#endif
}

34 changes: 34 additions & 0 deletions tests/test_layout_ctors.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -239,3 +239,37 @@ TEST(TestLayoutRightCTAD, test_layout_right_ctad) {
ASSERT_TRUE(m.is_exhaustive());
}
#endif

#if MDSPAN_HAS_CXX_20
template< class T, class RankType, class = void >
struct is_stride_avail : std::false_type {};

template< class T, class RankType >
struct is_stride_avail< T
, RankType
, std::enable_if_t< std::is_same< decltype( std::declval<T>().stride( std::declval<RankType>() ) )
, typename T::index_type
>::value
>
> : std::true_type {};

TEST(TestLayoutLeftStrideConstraint, test_layout_left_stride_constraint) {
stdex::extents<int,16> ext1d{};
stdex::layout_left::mapping m1d{ext1d};
ASSERT_TRUE ((is_stride_avail< decltype(m1d), int >::value));

stdex::extents<int> ext0d{};
stdex::layout_left::mapping m0d{ext0d};
ASSERT_FALSE((is_stride_avail< decltype(m0d), int >::value));
}

TEST(TestLayoutRightStrideConstraint, test_layout_right_stride_constraint) {
stdex::extents<int,16> ext1d{};
stdex::layout_right::mapping m1d{ext1d};
ASSERT_TRUE ((is_stride_avail< decltype(m1d), int >::value));

stdex::extents<int> ext0d{};
stdex::layout_right::mapping m0d{ext0d};
ASSERT_FALSE((is_stride_avail< decltype(m0d), int >::value));
}
#endif
23 changes: 23 additions & 0 deletions tests/test_layout_stride.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -206,3 +206,26 @@ TEST(TestLayoutStrideCTAD, test_ctad) {
}
#endif

#if MDSPAN_HAS_CXX_20
template< class T, class RankType, class = void >
struct is_stride_avail : std::false_type {};

template< class T, class RankType >
struct is_stride_avail< T
, RankType
, std::enable_if_t< std::is_same< decltype( std::declval<T>().stride( std::declval<RankType>() ) )
, typename T::index_type
>::value
>
> : std::true_type {};

TEST(TestLayoutStrideStrideConstraint, test_layout_stride_stride_constraint) {
stdex::extents<int,16> ext1d{};
stdex::layout_stride::mapping m1d{ext1d, std::array<int,1>{1}};
ASSERT_TRUE ((is_stride_avail< decltype(m1d), int >::value));

stdex::extents<int> ext0d{};
stdex::layout_stride::mapping m0d{ext0d, std::array<int,0>{}};
ASSERT_FALSE((is_stride_avail< decltype(m0d), int >::value));
}
#endif
24 changes: 21 additions & 3 deletions tests/test_mdarray_ctors.cpp
View file
Open in desktop
Original file line number Diff line number Diff line change
Expand Up @@ -143,15 +143,33 @@ void check_correctness(MDA& m, size_t rank, size_t rank_dynamic,
ASSERT_EQ(m.rank_dynamic(), rank_dynamic);
if(rank>0) {
ASSERT_EQ(m.extent(0), extent_0);
ASSERT_EQ(m.stride(0), stride_0);
#if MDSPAN_HAS_CXX_20
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

can't we just move that above 144. After all runtime wise these checks anyway only execute if rank>0 and we don't need to check that it compiles, there are other tests which do taht.

Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

And I mean with that we only need one big constexpr if protection for all runtime check rank clauses.

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

That makes sense. Updated.

if constexpr (MDA::extents_type::rank()>0) {
Copy link
Member

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

same as above.

#endif
ASSERT_EQ(m.stride(0), stride_0);
#if MDSPAN_HAS_CXX_20
}
#endif
}
if(rank>1) {
ASSERT_EQ(m.extent(1), extent_1);
ASSERT_EQ(m.stride(1), stride_1);
#if MDSPAN_HAS_CXX_20
if constexpr (MDA::extents_type::rank()>0) {
#endif
ASSERT_EQ(m.stride(1), stride_1);
#if MDSPAN_HAS_CXX_20
}
#endif
}
if(rank>2) {
ASSERT_EQ(m.extent(2), extent_2);
ASSERT_EQ(m.stride(2), stride_2);
#if MDSPAN_HAS_CXX_20
if constexpr (MDA::extents_type::rank()>0) {
#endif
ASSERT_EQ(m.stride(2), stride_2);
#if MDSPAN_HAS_CXX_20
}
#endif
}
if(ptr_matches)
ASSERT_EQ(m.data(),ptr);
Expand Down