https://gcc.gnu.org/bugzilla/show_bug.cgi?id=113280
Alexander Monakov <amonakov at gcc dot gnu.org> changed:
What |Removed |Added
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CC| |amonakov at gcc dot gnu.org
--- Comment #6 from Alexander Monakov <amonakov at gcc dot gnu.org> ---
>From the context given in the gcc-help thread, the goal is to place an
optimization barrier in a sequence of floating-point calculation. "+r" is
inappropriate for floats, as it usually incurs a reload from a floating-point
register to a GPR and back, and there's no universal constraint for FP regs
(e.g. on amd64 it is "+x" for SSE registers, but "+t" for long double (or x87
FPU on 32-bit x86)).
