multiple compound blocks in C

For the current batch of C compilers, I'm curious as to whether faster
code is generated if variables local to a code fragment are declared
locally within a compound block. In other words, is it better to structure
a function body thus:


f( ... )
{
        { <local definitions> <code block> }
{ <local definitions> <code block> }
...
}


Or is the live variable analysis and register allocation good enough that
it makes no difference as far as speed of the generated code is concerned
? Stack frame size is not my concern, only speed.


I'm not interested in speculation; I'd like to hear from people who have
specifically looked at currently available compiler output on RISC
processors, especially, the DEC Alpha, HP-PA-RISC, and SPARC.


Ram (ram@aqm.com)
--

Return to the comp.compilers page.
Search the comp.compilers archives again.