[libc++] Also provide an alignment assumption for vector in C++03 mode #124839
Conversation
This file contains hidden or bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
llvmbot
added
the
libc++
|
@llvm/pr-subscribers-libcxx Author: Louis Dionne (ldionne) ChangesThere's no reason not to, and it's easy enough to do using enable_if. As a drive-by change, also add a missing _LIBCPP_NO_CFI attribute on __add_alignment_assumption. Full diff: https://github.com/llvm/llvm-project/pull/124839.diff 1 Files Affected:
diff --git a/libcxx/include/__vector/vector.h b/libcxx/include/__vector/vector.h
index 66cb622e209633..2a79868c94b2cc 100644
--- a/libcxx/include/__vector/vector.h
+++ b/libcxx/include/__vector/vector.h
@@ -783,14 +783,18 @@ class _LIBCPP_TEMPLATE_VIS vector {
_LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI void __move_assign_alloc(vector&, false_type) _NOEXCEPT {}
- static _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI pointer __add_alignment_assumption(pointer __p) _NOEXCEPT {
-#ifndef _LIBCPP_CXX03_LANG
- if constexpr (is_pointer<pointer>::value) {
- if (!__libcpp_is_constant_evaluated()) {
- return static_cast<pointer>(__builtin_assume_aligned(__p, alignof(decltype(*__p))));
- }
+ template <class _Ptr = pointer, __enable_if_t<is_pointer<_Ptr>::value, int> = 0>
+ static _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI pointer
+ __add_alignment_assumption(_Ptr __p) _NOEXCEPT {
+ if (!__libcpp_is_constant_evaluated()) {
+ return static_cast<pointer>(__builtin_assume_aligned(__p, alignof(decltype(*__p))));
}
-#endif
+ return __p;
+ }
+
+ template <class _Ptr = pointer, __enable_if_t<!is_pointer<_Ptr>::value, int> = 0>
+ static _LIBCPP_CONSTEXPR_SINCE_CXX20 _LIBCPP_HIDE_FROM_ABI _LIBCPP_NO_CFI pointer
+ __add_alignment_assumption(_Ptr __p) _NOEXCEPT {
return __p;
}
};
|
There's no reason not to, and it's easy enough to do using enable_if. As a drive-by change, also add a missing _LIBCPP_NO_CFI attribute on __add_alignment_assumption.
ldionne
force-pushed
the
review/vector-alignment-assumption
branch
from
9a87269 to
bba08e7
Compare
|
/cherry-pick ccb08b9 |
|
/pull-request #125860 |
swift-ci
pushed a commit
to swiftlang/llvm-project
that referenced
this pull request
Feb 11, 2025
llvm#124839) There's no reason not to, and it's easy enough to do using enable_if. As a drive-by change, also add a missing _LIBCPP_NO_CFI attribute on __add_alignment_assumption. (cherry picked from commit ccb08b9)
Icohedron
pushed a commit
to Icohedron/llvm-project
that referenced
this pull request
Feb 11, 2025
llvm#124839) There's no reason not to, and it's easy enough to do using enable_if. As a drive-by change, also add a missing _LIBCPP_NO_CFI attribute on __add_alignment_assumption.
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
Add this suggestion to a batch that can be applied as a single commit.
This suggestion is invalid because no changes were made to the code.
Suggestions cannot be applied while the pull request is closed.
Suggestions cannot be applied while viewing a subset of changes.
Only one suggestion per line can be applied in a batch.
Add this suggestion to a batch that can be applied as a single commit.
Applying suggestions on deleted lines is not supported.
You must change the existing code in this line in order to create a valid suggestion.
Outdated suggestions cannot be applied.
This suggestion has been applied or marked resolved.
Suggestions cannot be applied from pending reviews.
Suggestions cannot be applied on multi-line comments.
Suggestions cannot be applied while the pull request is queued to merge.
Suggestion cannot be applied right now. Please check back later.
There's no reason not to, and it's easy enough to do using enable_if. As a drive-by change, also add a missing _LIBCPP_NO_CFI attribute on __add_alignment_assumption.