This reverts commit 390ac823178fc1073612b4c8a38835f441138d9d.
It broke the sphinx publish bots for our documentation:
https://lab.llvm.org/buildbot/#/builders/242/builds/1130
because that machine has GCC 9.4.0 which does not know about C++23
This commit does a pass of clang-format over files in libc++ that
don't require major changes to conform to our style guide, or for
which we're not overly concerned about conflicting with in-flight
patches or hindering the git blame.
This roughly covers:
- benchmarks
- range algorithms
- concepts
- type traits
I did a manual verification of all the changes, and in particular I
applied clang-format on/off annotations in a few places where the
result was less readable after than before. This was not necessary
in a lot of places, however I did find that clang-format had pretty
bad taste when it comes to formatting concepts.
Differential Revision: https://reviews.llvm.org/D153140
Even if these comments have a benefit in .h files (for editors that
care about language but can't be configured to treat .h as C++ code),
they certainly have no benefit for files with the .cpp extension.
Discussed in D110794.
This patch rewrites a few loops in deque and split_buffer to better
optimize the codegen. For constructors like
`deque<unsigned char> d(500000, 0);` this patch results in a 2x speedup.
The patch improves the codegen in roughly three ways:
1. Changes do { ... } while (...) loops into more typical for loops.
The optimizer can reason about normal looking loops better.
2. Split the iteration over a range into (A) iteration over the blocks,
then (B) iteration within the block. This nested structure helps LLVM
lower the inner loop to `memset`.
3. Do fewer things each iteration. Some of these loops were incrementing
or changing 4-5 variables every loop (in addition to the
construction). Previously most loops would increment the end pointer,
the size, and decrement the count of remaining items to construct.
Now we only increment a single pointer for most iterations.
llvm-svn: 368547
