Re: lua_number2int in bitwise operators Lua 5.2 work 3 (MSVC)

[KHMan <keinhong@...>]

Roberto Ierusalimschy wrote:
> > > Another hypothesis is that the compiler is transforming the
> > > snippet "fistp m64; mov r32, mem" into "fistp m32; mov r32, mem"
> > > because it forgot that there can be side-effects from narrowing a
> > > 64 bit fistp into a 32 bit fistp, even if the upper 32 bits of the
> > > 64 bit result are never used.
> > Time to check the assembly output I guess, but this is MSVC which I
> > am still avoiding installing... I do feel bad throwing about
> > armchair hypotheses, so I'll slinker away for now and find some time
> > later to see for myself the behaviour of fistp in compiler-generated
> > code... :-)
>
> What is the bug, to begin with? In my tests (MSVC) everything works
> fine.

Probably nothing. Joonas mentioned the 0xFF000000 case but Dmitry 
was using lua_number2int() there. I'm not sure if Joonas is basing 
this on Dmitry's posting or his own testing or knowledge.

--
Cheers,
Kein-Hong Man (esq.)
Kuala Lumpur, Malaysia