tree 53594ad274112b8cd8f57ae012c80bff84f11fbc
parent 1c340f9020a642eeac39aae8e685a0a1ca2785a0
author serge-sans-paille <sguelton@redhat.com> 1618323272 +0200
committer Copybara-Service <copybara-worker@google.com> 1618720115 -0700

Simplify BitVector code

Instead of managing memory by hand, delegate it to std::vector. This makes the
code much simpler, and also avoids repeatedly computing the storage size.

According to valgrind --tool=callgrind, this also slightly decreases the
instruction count, but by a small margin.

This is a recommit of 82f0e3d3ea6bf927e3397b2fb423abbc5821a30f with one usage
fixed in llvm/lib/CodeGen/RegisterScavenging.cpp.

Not the slight API change: BitVector::clear() now has the same behavior as any
other container: it does not free memory, but indeed sets the size of the
BitVector to 0. It is thus incorrect to access its content right afterwards, a
scenario which wasn't enforced in previous implementation.

Differential Revision: https://reviews.llvm.org/D100387

GitOrigin-RevId: 550ed575cbbd2c81cb855d4debb4a215ae75ef1e