Re: [Gnash-commit] [SCM] Gnash branch, master, updated. release_0_8_9_final-1673-g75671d1

[Bastiaan Jacques]

GCC produces identical code for either version, at least on my system.

Bastiaan

On Tue, 23 Jul 2013, Richard Wilbur wrote:

> On Wed, Jul 17, 2013 at 4:24 PM, Bastiaan Jacques <address@hidden> wrote:
> > diff --git a/libcore/vm/ASHandlers.cpp b/libcore/vm/ASHandlers.cpp
> > +inline boost::uint32_t
> > +saneShiftParam(boost::int32_t value)
> > +{
> > +    // NOTE: ISO-IEC 14882:2003 5.8.1: "The behavior is undefined if the right
> > +    // operand is negative, or greater than or equal to the length in bits of
> > +    // the promoted left operand."
> > +    boost::uint32_t rv = value;
> > +    return rv % 32;
> > +}
>
> Regarding efficiency, I would recommend in this case considering the
> alternative (with identical results):
> return rv & (32 - 1);
> which can be rephrased
> return rv & 31;
> or, if you prefer hexadecimal
> return rv & 0x1f;