tree 2de426c65defb59f2231693177c0456226b33a69
parent fb3ec3d0d29f919e9334e0d4bddfddffb6c64986
author Guillaume Chatelet <gchatelet@google.com> 1610702805 +0000
committer Copybara-Service <copybara-worker@google.com> 1611100261 -0800

[libc] Allow customization of memcpy via flags.

 - Adds LLVM_LIBC_IS_DEFINED macro to libc/src/__support/common.h
 - Adds a few knobs to memcpy to help with experimentations:
   - LLVM_LIBC_MEMCPY_X86_USE_ONLY_REPMOVSB replaces the implementation with a single call to rep;movsb
   - LLVM_LIBC_MEMCPY_X86_USE_REPMOVSB_FROM_SIZE customizes where the usage of rep;movsb

Differential Revision: https://reviews.llvm.org/D94692

GitOrigin-RevId: a10300a2b27c426556f9266364337d5d546a3c14