Perf/lexer faster slow get char and size #70543
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Do you have benchmarks? |
See the commit: c9d34da |
Instead of passing the Size by reference, assuming it is initialized,
return it alongside the expected char result as a POD.
This makes the interface less error prone: previous interface expected
the Size reference to be initialized, and it was often forgotten,
leading to uninitialized variable usage. This patch fixes the issue.
This also generates faster code, as the returned POD (a char and an
unsigned) fits in 64 bits. The speedup according to compile time tracker
reach -O.7%, with a good number of -0.4%. Details are available on
https://llvm-compile-time-tracker.com/compare.php?from=3fe63f81fcb999681daa11b2890c82fda3aaeef5&to=fc76a9202f737472ecad4d6e0b0bf87a013866f3&stat=instructions:u
And icing on the cake, on my setup it also shaves 2kB out of
libclang-cpp :-)
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@cor3ntin yep, looks better with a small struct, update pushed |
| if (C1 != '0') | ||
| return false; | ||
| char C2 = Lexer::getCharAndSizeNoWarn(Start + Size, Size, LangOpts); | ||
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| auto CharAndSize2 = |
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You can reuse CharAndSize here
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Yeah, but I find it less confusing like this.
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✅ With the latest revision this PR passed the C/C++ code formatter. |
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This patch broke builders like Solaris/amd64 that include |
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This breaks building: http://45.33.8.238/linux/121901/step_4.txt Please take a look and revert for now if it takes a while to fix. |
This reverts commit d8f5a18. Breaks build, see: #70543 (comment)
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Reverted in 1c876ff for now. |
merges to d346c82 [OpenMP] Associate the KernelEnvironment with the GenericKernelTy (llvm#70383) and reverts to buy time to inegrate it in properly. Also brings in 8f5a18b6e58 Perf/lexer faster slow get char and size (llvm#70543) which is reverted upstream 9 commits later. Change-Id: Idb81b74c26b78bff856d7e4119036918629e47f9
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recommited as 8116b6d |
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