mibintc added inline comments.
================ Comment at: clang/lib/CodeGen/CGBuiltin.cpp:2844 + return RValue::get( + Builder.CreateArithmeticFence(ArgValue, ConvertType(ArgType))); + return RValue::get(ArgValue); ---------------- mibintc wrote: > mibintc wrote: > > kpn wrote: > > > Does this say that the fence will be silently dropped if any of the fast > > > math flags are disabled? Silently dropping something used for correctness > > > makes me nervous. Is there a case where all of these flags are required > > > for correct behavior of the fence? > > Yes that is the idea, the clang builtin is only meaningful for float > > operations when -ffast-math is enabled. If fast math isn't enabled then > > the operations should already be performed strictly. I didn't have > > "isFast", should rewrite with isFast to make it easier to understand > Oops I'm wrong. @kbsmith1 tells me only the reassoc bit is interesting. i'll > need to fix this in the documentation etc. Thanks for your careful reading. BTW in the options parsing, any of the unsafe fp math options freciprocal-math, fsigned-zeros and fapprox-func have the effect of enabing LangOptions.AllowFPReassoc. This is in the file Options.td Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D100118/new/ https://reviews.llvm.org/D100118 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
