Optimize checkError (#3840)
Inspired by recent discussion whether we should validate each
instruction and what is cost for it - surprisingly the checks themselves
were cheap, the cost came from the way checkError was written.
The function constructed a std::stringstream unconditionally, *before*
the early-out taken when the condition is satisfied, and the SPIRVCK /
SPIRVCKRT macros built a std::string ("std::string() + (ErrMsg)") at
every call site. Both costs were therefore paid even on the error check
success path.
Moved "std::stringstream SS" past the early-out in checkError(). Added a
const char* checkError overload that returns before constructing any
std::string when the condition holds.
Changed SPIRVCK/SPIRVCKRT to pass the message through directly.
On OpVariable-heavy modules it improves translation time by 5-10%.
Assisted-By: Claude Fable 5
Original commit:
https://github.com/KhronosGroup/SPIRV-LLVM-Translator/commit/7d7593251d75942
