MaskRay added inline comments.
================ Comment at: clang/lib/CodeGen/CGBuiltin.cpp:13319 + Value *Features = Builder.CreateAlignedLoad( + Int32Ty, Builder.CreateGEP(ATy, CpuFeatures2, Idxs), + CharUnits::fromQuantity(4)); ---------------- FreddyYe wrote: > MaskRay wrote: > > FreddyYe wrote: > > > Will function multi version also be fixed in this patch? > > > https://gcc.godbolt.org/z/cafhs9qbG If so, need to add test in > > > clang/test/CodeGen/attr-target-mv.c > > The `target` attribute has strange semantics for overloading: > > ``` > > int __attribute__((target("arch=skylake"))) foo(void) {return 0;} > > int __attribute__((target("arch=x86-64"))) foo(void) {return 1;} > > ``` > > is not allowed in C mode of GCC. > > > > I think such use cases are not recommended in C++. > > > > If we don't use overloading, `int __attribute__((target("arch=x86-64"))) > > foo(void) {return 1;}` is supported by Clang today and this patch does not > > intend to change anything about it. > I think behavior for `target` attribute is not only overloading but also > function multiversioning for redefined functions. And seems like C model of > gcc haven't supported is due to it will target C23 standard: > https://clang.llvm.org/docs/AttributeReference.html#target > Comparing to gcc, clang misses not only `target` attribute but also other > cpuname/feature related features for "x86-64*". See > https://gcc.godbolt.org/z/arhne35GG (Seems gcc defined x86-64* as not only > cpu name but also feature name.) Anyway, this patch is targeting for > `target_clones` attribute only. So no problem here. > So no problem here. Right. Not supporting C and requiring duplicate definitions makes `target` not really useful. https://gcc.gnu.org/pipermail/gcc-patches/2015-October/430585.html Jeff Law said: "I wasn't aware that multi-versioning was only implemented for C++, that seems fairly lame. I hope I didn't approve that :-)" Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D158329/new/ https://reviews.llvm.org/D158329 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
