Force consecutive operation when using asm volatile macro

[Jari Kuusisto <jari dot h dot kuusisto at gmail dot com>]

Hello,

I've successfully updated gcc 2.95.3 to 4.3.2 (made necessary syntax 
changes to code etc.).

With GCC 2.95.3 I've used a critical section asm volatile macro to enter 
and exit critical sections in the code. When entering critical section, 
there are two asm volatile lines needed. On critical section exit only 
one asm volatile line is required.

After upgrading from gcc 2.95.3 to 4.3.2 the critical section handling 
in the code stopped working. It seems that some of the code that should 
be in critical section seems to be relocated outside the critical 
section. I do know that asm volatile does not guarantee consecutive 
execution of the code. I also know that using singe asm would fix this 
problem, but in my case it is not possible.

I've managed to to get around this problem by replacing the critical 
section macros with assembler functions as the blr instruction forces 
the correct consecutive operation when entering and exiting critical 
section. However, this function call type implementation seems to 
significantly slow down runtime operation of the software. The result is 
that the performance improvement gained with new gcc optimizations is 
waisted due to this  function call  type implementation.

If I enable all other optimizations from -O2 but not the 
-freorder-blocks the code is working with the old asm volatile macros, 
but this is not an option.

Is there any other way to force the consecutive operation of asm 
volatile macros?

BR. Jari Kuusisto