steplong added a comment. In D126984#3574077 <https://reviews.llvm.org/D126984#3574077>, @aeubanks wrote:
> In D126984#3574046 <https://reviews.llvm.org/D126984#3574046>, @aaron.ballman > wrote: > >> In D126984#3571573 <https://reviews.llvm.org/D126984#3571573>, @aeubanks >> wrote: >> >>> IIRC in the past there was a strong preference to not have the pass manager >>> support this sort of thing >>> if you want to support this, there should be an RFC for how the >>> optimization part of this will work as it may require invasive changes to >>> the LLVM pass manager >>> >>> (if this is purely a clang frontend thing then ignore me) >> >> Hmm, does the pass manager have to support anything here? The only Clang >> codegen changes are for emitting IR attributes that we already emitted based >> on command line flags/other attributes, so I had the impression this would >> not be invasive for the backend at all. > > if we're allowing individual functions to specify that they want the `-O1` > pipeline when everything else in the module should be compiled with `-O2`, > that's a huge change in the pass manager. but perhaps I'm misunderstanding > the point of this patch That makes sense. The MSVC pragma allows 4 options, "stgy": | Parameter | On | Off | | --------- | ----------------------------------------------------------------------------------------------------------- | | | g | Deprecated | Deprecated | | s | Add MinSize | Remove MinSize (I think this would be difficult to do if -Os is passed on the cmdline) | | t | Add -O2 (We can't support -O2 with this attribute so ignore) | Add Optnone | | y | Add frame-pointers (We can't support -f arguments with the attribute in this patch so we are ignoring this) | No frame-pointers (Same thing as on) | | For our use case, I think we only really see `#pragma optimize("", off)` and `#pragma optimize("", on)`, so I'm not opposed to abandoning this patch and just supporting the common use case for now. I think `#pragma optimize("", on)` would just mean do nothing and apply whatever is on the command line and `#pragma optimize("", off)` would mean add optnone to the functions below it Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D126984/new/ https://reviews.llvm.org/D126984 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
