[PATCH] D60472: [AArch64][PowerPC][Driver] Allow setting crypto feature through -mcrypto for ARM/AArch64

Wed Apr 10 07:37:11 PDT 2019

manojgupta added a comment.

The motivation for this change is to make "crypto" setting an additive option e.g. like "-mavx" used in many media packages.  Some packages in Chrome want to enable crypto conditionally for a few files to allow crypto feature to be used based on runtime cpu detection. They set "-march=armv8+crypto" flag but it gets overridden by the global "-march=armv8a" flag set by the build system in Chrome OS because the target cpu does not support crypto causing compile-time errors. 
Ability to specify "-mcrypto"  standalone makes it an additive option and ensures that it it is not lost. i.e. this will help in decoupling  "-mcrypto" from "-march" so that they could be set independently. The current additive alternate is  '-Xclang -target-feature -Xclang "+crypto" ' which is ugly.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D60472/new/

https://reviews.llvm.org/D60472