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Re: GNU C++ Inline Assembler


Thanks ALL, I think I can continue doing my work soon now.
I understand that I'd lose a lot of preformance doing it the MS way.
But, well I dont need speed =) Since I am a RCE I need it to check if I was
sure the code did that I thought it would do. ^^

But, yea this will help me.
I'll read the three links I've got from you guys and then Ill continue
asking Quesitons if something is still not clear to me.

Thanks for everything.

Cheers,
Robin


Bob Plantz wrote:
> 
> On Mon, 2008-08-11 at 18:07 -0700, Brian Dessent wrote:
> 
>> Because the MSVC style of inline assembler doesn't allow for specifying
>> any constraints such as which registers or stack slots are clobbered. 
>> This means that compiler can't assume anything about the state before
>> and after the block, it must just throw away all dataflow information it
>> had before the block and assume everything was clobbered, leading to
>> tons of useless redundant loads/stores.  The GNU style inline asm works
>> within the framework of the optimizing compiler, rather than outside it
>> by totally going behind it's back.
>> 
>> Read the long thread that starts here:
>> <http://gcc.gnu.org/ml/gcc/2004-05/threads.html#00070>.
> 
> Thank you for the explanation and the link. I've never been a Microsoft
> programmer, and I haven't used CodeWarrior (Mac PowerPC) for  a long
> time. I had forgotten about that technique of inline assembly.
> 
> Bob
> 
> 
> 
> 

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