tree 94b14eeacec319fba2d2469792d8691984e727ea
parent fb0a4a8ed3eaf6f702297d378d0b7ff4858ba89a
author Peter Collingbourne <peter@pcc.me.uk> 1619121597 -0700
committer Copybara-Service <copybara-worker@google.com> 1620612550 -0700

scudo: Optimize getSizeLSBByClassId() by compressing the table into an integer if possible. NFCI.

With AndroidSizeClassMap all of the LSBs are in the range 4-6 so we
only need 2 bits of information per size class. Furthermore we have
32 size classes, which conveniently lets us fit all of the information
into a 64-bit integer. Do so if possible so that we can avoid a table
lookup entirely.

Differential Revision: https://reviews.llvm.org/D101105

GitOrigin-RevId: a6500b013a257c969e19ce0d8414ff43fe9bd4fa