fhahn added a comment. In D113779#3130744 <https://reviews.llvm.org/D113779#3130744>, @DavidSpickett wrote:
> There was a similar proposal for crypto https://reviews.llvm.org/D60472. > > Quoting @manojgupta for the pitch for that: > >> 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. > > Concerns were raised there. > > Seems like we're balancing adding a bunch of (clang only for at least the > short term) options versus making the build system(s) cope with having to > track what the last `-march` was. Thanks for sharing the related patch/discussion. > versus making the build system(s) cope with having to track what the last > `-march` was. Please see my earlier response. There can be use cases where the build system may not know what the last `-march` was, because the user may not have specified an explicit `-march` (e.g. they want to use the default picked by the compiler). Is there a way for the build system to conveniently determine what the default architecture version of the compiler is? Also pushing this to the build system vendors means we need to convince X build-system vendors to adjust their implementations. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D113779/new/ https://reviews.llvm.org/D113779 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
