On Tue, Feb 2, 2021 at 8:19 AM Jeffrey Walton <[email protected]> wrote:
>
> On Tue, Feb 2, 2021 at 8:00 AM Michael Weiser <[email protected]> wrote:
> >
> > > > llvm-as wouldn't recognize pmull instruction without
> > > > adding -march=armv8-a+crypto flag at least with the version I use 
> > > > "3.8.1"
> >
> > 3.8.1 was released in 2017. It might not support recent
> > aarch64 additions regarding .arch directive and friends.
> >
> > > > I tried both .arch armv8-a+crypto and .arch_extension crypto and they
> > > > worked only for gas while llvm-as produces errors for pmull using.
> > > Is there any documentation for llvm-as? Best I could find is the minimal
> > > man page https://www.llvm.org/docs/CommandGuide/llvm-as.html, with no
> > > info whatsoever on, e.g., supported pseudoops.
> >
> > I think my mentioning of llvm-as was a red herring. Looking at the
> > output of clang -v, llvm-as isn't involved at all. This is supported by
> > the man page stating that llvm-as accepts LLVM assembly and emits LLVM
> > bytecode. It appears, clang implements the assembler internally and we'd
> > need documentation on that. The clang man page even says so):
>
> Clang always uses its integrated assembler unless you pass
> -fno-integrated-as. If you use -fno-integrated-as, then be sure you
> have an assembler that supports the ISA you are targeting. On OS X,
> GNU's AS may not support the ISA.
>
> Clang's assembler is crippled on OS X. Apple's Clang still does not
> support pmull or crc instructions.

And I forgot to mention... On OS X, when using a port like MacPorts
with GCC... You want to pass -Wa,-q to GCC so GCC uses Clang's
integrated assembler. Without -Wa,-q, GCC will try to use GNU's AS.

Jeff
_______________________________________________
nettle-bugs mailing list
[email protected]
http://lists.lysator.liu.se/mailman/listinfo/nettle-bugs

Reply via email to