Jonathan Kinsey wrote:
Tim Prince wrote:
I don't remember what was said in the past, but any gcc function which
uses SSE parallel instructions must be called from a gcc function which
passes a 16-byte aligned stack. So you may be able to overcome it by
interposing a wrapper function at the thread entry point (which does not
use parallel SSE), with all gcc functions compiled with normal options
(not -Os, which sets a smaller value in -mpreferred-stack-alignment).
To speculate further, possibly your pthreads library was compiled with
options which don't pass 16-byte aligned stack.
Thanks for the reply - no help though:
By a wrapper function, if you mean for f() to call say g() - this makes
no difference (command line: gcc -msse test.c -otest.exe).
gcc doesn't seem to recognize -mpreferred-stack-alignment=8 as a valid
option.
I'm not using pthreads, so it's not that either.
Sorry, you should have checked me. 'info gcc'
-mpreferred-stack-boundary=4 (2^4 == 16) is needed, and would be set
by options other than -O2. So, not specifying any relevant options
should be OK, but the function you call first in the thread must not
have any sse, if this is the problem.
I guess I don't understand where you got your function to start a thread.
