[mythtv] [patch] mythtv-HOWTO-5.html - compiling for different processors

[Daniel Thor Kristjansson]

On Tue, 28 Dec 2004, Isaac Richards wrote:
]> This patch removes the -mfpmath=sse performance recommendation, but
]> keeps the additional archs, such as the winchip, the updated C3 info,
]> and other Intel and AMD processors.
]
]Have you profiled on each of those processors to see if setting the arch 
]actually creates faster code?  I've seen -march=athlon-xp create 50% slower 
]code than -march=pentiumpro with a recent gcc..
]
]Isaac

No, I only have Intel processors at my disposal. Compiling for pentium4 
gives me a 30% speed boost. For the rest, I based this on the gcc 
manual. I've heard rumors about xp optimization being broken, but I 
can't verify this myself.

I made this patch to the documentation because someone was having 
problems compiling mmx_gcc.cpp because they were targeting the 
pentiumpro, which did not support MMX. The compiler, rightly, did 
not generate the MMX code.

-- Daniel