[MPlayer-dev-eng] add -Wall to default CFLAGS

[Sven Gothel]

On Saturday 05 May 2007 at 18:16, Michael Niedermayer wrote:
> Hi
> 
> On Sat, May 05, 2007 at 11:13:51AM -0700, Trent Piepho wrote:
> > On Sat, 5 May 2007, Michael Niedermayer wrote:
> > > > static unsigned long long attribute_used __attribute__((aligned(8))) null_one = 0x0000ffff0000ffffULL;
> > > > static unsigned long long attribute_used __attribute__((aligned(8))) one_null = 0xffff0000ffff0000ULL;
> > > >
> > > > I think I'll move this all back into standalone assembler anyway (to match
> > > > rest of mpg123 code)...
> > >
> > > ive not followed this discussion but data accessed by asm should be
> > > (u)intXX_t not int/long (long) later is _wrong_, long long could be
> > > >64bit (yes i know this is not likely but still ...)
> > 
> > For values used in computing addresses, and not just pointers but an array
> > index used in a scale-index-base addresst too, using 'long' will make code
> > work on both ia32 and x86-64.
> > 
> > uint32_t result;
> > uint32_t *base;
> > long index;
> > asm("mov (%1, %2, 4), %0" : "=r"(result) : "r"(base), "r"(index));
> > 
> > Since ia32 uses 32-bit pointers and x86-64 uses 64 bit, the pointer base
> > will be a different size.  It's important that %2 match this size for the
> > instuction to be valid.  If you use "int" or "uint32_t" for index, it will
> > use a 32-bit register, and you get an invalid address like (%rax, %ebx, 4).
> > I suppose the most correct type would be "intptr_t", but long works and gcc
> > inline assembly is by it's nature non-portable.
> 
> intels c compiler supports gcc-asm too IIRC
> so yes IMHO intptr_t would be correct and long just happens to work
> that is long could easily be 32bit on x86-64 with some compiler ...
> 

yeah, but we should keep our mind open to other architectures.

so, when it comes to hardware, the fixed types are more appropriate,
and ASM is such a case, IMHO.

Cheers, Sven

> [...]
> 



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