Messages in this thread | | | Subject | Re: remove the last set_fs() in common code, and remove it for x86 and powerpc v3 | From | Christophe Leroy <> | Date | Thu, 10 Sep 2020 10:13:42 +0200 |
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Le 10/09/2020 à 10:04, David Laight a écrit : > From: Linus Torvalds >> Sent: 09 September 2020 22:34 >> On Wed, Sep 9, 2020 at 11:42 AM Segher Boessenkool >> <segher@kernel.crashing.org> wrote: >>> >>> It will not work like this in GCC, no. The LLVM people know about that. >>> I do not know why they insist on pushing this, being incompatible and >>> everything. >> >> Umm. Since they'd be the ones supporting this, *gcc* would be the >> incompatible one, not clang. > > I had an 'interesting' idea. > > Can you use a local asm register variable as an input and output to > an 'asm volatile goto' statement? > > Well you can - but is it guaranteed to work :-) >
With gcc at least it should work according to https://gcc.gnu.org/onlinedocs/gcc/Local-Register-Variables.html
They even explicitely tell: "The only supported use for this feature is to specify registers for input and output operands when calling Extended asm "
Christophe
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