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Postings from February 2003
On måndag, feb 10, 2003, at 23:03 Europe/Stockholm, perl5-porters-return-71692-arthur=contiller.se@perl.org wrote: > > 50% of the time your function/label/loop/jump is 16 byte aligned. > 50% of the time your function/label/loop/jump is "randomly" aligned > > So, a slight code size change early on in a file can cause the > remaining > functions to ping either onto, or off alignment. Hence later loops in > completely unrelated code can happen to become optimally aligned, and > go > faster. And similarly other loops which were optimally aligned will now > go unaligned, and go more slowly. > > This is probably the right default for the general case, but it is > counterproductive for benchmarking small code changes. So on gcc 2.95 > I'm > compiling with: > > -O -malign-loops=3 -malign-jumps=3 -malign-functions=3 > -mpreferred-stack-boundary=3 -march=i686 > > (thats 2**3, ie 8) > > and on gcc 3.2 on a different machine: > -O3 -falign-loops=16 -falign-jumps=16 -falign-functions=16 > -mpreferred-stack-boundary=3 -march=i586 > Does compiling with these settings make general perl faster? ArthurThread Previous | Thread Next