Pb with G++ 3.4.2 MinGW and inline assembly

Pb with G++ 3.4.2 MinGW and inline assembly

[Studious Apprentice]

Hello !

G++ seems to use a register which should have been clobbered with inline 
assembly.

I am using the following assembly code (80x86) to inline a fast memcpy for 
variable dword lengths arguments. The program works well in debug mode :"g++ 
-g" but not in optimized mode : "g++ -g -Wall -O2 -DNDEBUG". The compilation 
is fine but GCC reuses the EDI register after inlining this routine, which 
hangs my program. It is no longer possible to explicitly indicate a register 
as clobbered when it is already used as a parameter, so I do not see any 
workaround for what looks a bug.

Any idea ?

Thanks in advance,

Charles

inline void fast_memcopy
(void * where, void const * from, std::size_t times)
{
	__asm__ __volatile__
		(
		"cld\n\t"
		"rep\n\t"
		"movsl"
		:
	: "S"(from), "D"(where), "c"(times)
		: "memory"
		);
}

Namespace problem

[Edward Yang]

I am not sure if it is a Microsoft specific extension.

The following code compiles correctly using the latest C/C++ compiler 
(2005) from Microsoft.

namespace C
{
    enum T
    {
        A,
        B,
        C,
    };
}

int a = C::T::A;

When I compile it using MinGW, gcc produces:

main.cxx:163: error: `C::T' is not a class or namespace
main.cxx:163: error: expected primary-expression before ';' token

Re: Namespace problem

[Gabriel Dos Reis]

Edward Yang <neo_in_matrix@fastmail.fm> writes:

| I am not sure if it is a Microsoft specific extension.

It is.  

-- Gaby