jcranmer-intel wrote: > > > I'd like to see this change land, but with the "-mdaz-ftz" option removed > > > (because I don't think it's useful). That would fix the critical problem > > > of fast-math infecting shared libraries with the ftz setting, and we > > > could straighten out the other problems, which are relatively minor, > > > afterwards. > > > > > > There is, without this change, no way to control whether or not > > `crtfastmath.o` is linked independent of all of the other fast-math > > options. The `-mdaz-ftz` option would at least add a flag to explicitly > > control the parameter (for the people who care), and we can then have > > discussions about different ways to effect setting DAZ/FTZ bits or what > > options imply `-mdaz-ftz` in future PRs. That alone makes it a worthy > > addition IMHO; the compatibility with gcc is another nice feature. > > You can always link crtfastmath.o directly, of course. Ultimately, I don't > think the compiler should ever be adding the crtfastmath.o file. I would > prefer to insert code directly into the entry function as @arsenm indicated > the AMDGPU backend does for kernels. That would then be controlled by the > -fdenormal-fp-math option or something more explicitly linked to the entry > function. > > I don't want to add -mdaz-ftz because once we do we're kind of stuck with it. > If you don't add it here, we'd continue the current behavior of linking with > crtfastmath.o normally but we'd stop infecting shared libraries with it.
I don't think it's unreasonable to switch the logic of `-mdaz-ftz` from linking a file with a global initializer that sets the flags to making it emit the entry-point call to such a function instead, it still largely follows the same logic to me. And having a command line flag makes it easier for users to access rather than manually linking in a file located who-knows-where in the toolchain (although I suspect anyone who cares hard enough would rather just write the calls to set FTZ/DAZ than track it down from the toolchain). https://github.com/llvm/llvm-project/pull/80475 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
