[Bug middle-end/47602] Permit inline asm to clobber PIC register

[ebotcazou at gcc dot gnu.org]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=47602

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

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--- Comment #9 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-02-04 08:48:46 UTC ---
> I'm suggesting saving and restoring it around the asm statement itself, not in
> the prologue and epilogue.

Although the error was primarily RTH's idea, I still think it's very
reasonable.
When you write inline asm, you're expecting a certain degree of control over
the generated code; knowing that you're clobbering the PIC register can be
useful, especially on a register-starved architecture like the x86.  If you
stand by your clobbering, then writing the conditional save-and-restore code is
trivial.