Stoorx added a comment.
I've looked through usages of `getClobbers` again, and found that in each case
the result if the function is casted to `std::string`.
clang/lib/CodeGen/CGBuiltin.cpp
clang/lib/CodeGen/CGStmt.cpp
std::string Constraints = "=r,*Z,~{memory}";
std::string MachineClobbers =
static_cast<std::string>(CGF.getTarget().getClobbers());
if (!MachineClobbers.empty()) {
Constraints += ',';
Constraints += MachineClobbers;
}
I think we can 'make two deals with one shot' if we would:
- Make `std::string_view` as a return type of `getClobbers` (by value, since
the `std::string_view` is 'TriviallyCopyable')
- (Maybe) Make private static field of `std::string` type for actual clobber
value (or `std::string_view` type since it can be constexpr-constructed)
- Return the value of this field from `getClobbers`
- Change type of MachineClobbers (in usages, see example above) variable to
`std::string_view` since it actually used for read-only access. (We do not need
to construct `std::string` and destruct it almost immediately)
As a result we get:
- More robust usage of `getClobbers` (a bit ridiculous but...)
- Zero unnecessary allocations
(Also: I've discovered that `llvm::StringRef` is exact the same thing as
`std::string_view`. I think of it so much :^) )
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D148799/new/
https://reviews.llvm.org/D148799
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