[PATCH] D119176: [demangler][NFC] Utility header cleanups

[Nathan Sidwell via Phabricator via llvm-commits]

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A few items I came across ...

a) Using a do...while loop in the number formatter means we do not have to special case zero.

b) Let's use 'if (auto size = ...) {}' for appending to the output buffer.

c) We should also be using memcpy there, not memmove -- the string being appended is never part of the current buffer.

d) Let's put all the operator<< functions together.

e) I find 'if (cond) frob(..., true) ; elseOD frob(..., false)' somewhat confusing.  Let's just use std::abs in the signed integer printer and let CSE decide about the duplicate < 0 testing.

f) Let's have as many as possible return *this.  That's both more consistent, and allows tailcalls in some cases (the actual number formatter has a local array though).

These changes removed around 100 bytes from the demangler's instructions on x86_64.


https://reviews.llvm.org/D119176

Files:
  libcxxabi/src/demangle/Utility.h
  llvm/include/llvm/Demangle/Utility.h

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