[SYCL][NFC] Remove a bunch of unnecessary std::string allocations #3347
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Apparently we have some static globals of type std::string to represent a string-literal. The result is that we get some std::string constructors (and thus allocations!) for no reason. These are only ever used as StringRef. This patch replaces those with constexpr llvm::StringLiteral types, which is a constexpr-constructed StringRef. These don't require allocations like std::string, so the initialization becomes a no-op. Additionally, these were being copied at least 1x later on, so the switch there likely saves runtime allocations as well.
erichkeane
requested review from
elizabethandrews and
premanandrao
as code owners
premanandrao
approved these changes
Mar 11, 2021
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Apparently we have some static globals of type std::string to represent
a string-literal. The result is that we get some std::string
constructors (and thus allocations!) for no reason. These are only ever
used as StringRef.
This patch replaces those with constexpr llvm::StringLiteral types,
which is a constexpr-constructed StringRef. These don't require
allocations like std::string, so the initialization becomes a no-op.
Additionally, these were being copied at least 1x later on, so the
switch there likely saves runtime allocations as well.