yaxunl added inline comments.
================ Comment at: clang/lib/CodeGen/BackendUtil.cpp:486 + if (LangOpts.HIP) + Options.AllowFPOpFusion = llvm::FPOpFusion::Standard; + ---------------- tra wrote: > yaxunl wrote: > > tra wrote: > > > I don't think it's a good idea to force this. > > > > > > Perhaps a better way to address this would be to set HIP-specific default > > > to Standard where CUDA does it: > > > https://github.com/llvm/llvm-project/blob/master/clang/lib/Frontend/CompilerInvocation.cpp#L2415 > > > > > > Currently HIP inherits this setting from CUDA. > > We want to keep -ffp-contract=fast for frontend so that we can continue > > emitting fmul/fadd insts with contract flag in IR for HIP programs. We only > > want to change the backend fp fuse option. Currently there is no separate > > clang option to set backend fp fuse option. > I do not see any references to `AllowFPOpFusion` anywhere under `clang/` > other than in this function. > Perhaps I'm missing something. How/where does it make a difference in the > front-end other than setting the option for the back-end? > > > -ffp-contract not only sets backend fp fuse option, but also setFPContractMode https://github.com/llvm/llvm-project/blob/2e204e23911b1f8bd1463535da40c6e48747a138/clang/include/clang/Basic/LangOptions.h#L413 which enables allowFPContractAcrossStatement https://github.com/llvm/llvm-project/blob/2e204e23911b1f8bd1463535da40c6e48747a138/clang/include/clang/Basic/LangOptions.h#L439 which sets llvm::FastMathFlags https://github.com/llvm/llvm-project/blob/d3205bbca3e0002d76282878986993e7e7994779/clang/lib/CodeGen/CodeGenFunction.cpp#L129 which causes fmul/fadd to have contract flag CHANGES SINCE LAST ACTION https://reviews.llvm.org/D90174/new/ https://reviews.llvm.org/D90174 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
