Randall R Schulz <rrschulz at cris dot com> wrote: > A couple of months ago, someone reported on how local (stack) > allocations larger than a certain threshold were allocated on the heap. > In fact, you, Danny, contributed materially to that thread: Subject > "Strange behaviour of gcc" starting with a posting by > [EMAIL PROTECTED] on Dec. 24, 2002. >
No that's not quite right: Stack allocations larger than one page (4KB) cause gcc to probe the stack. The allocation is still static I think, also, the stack probe is automatically called in main, to force alignment of stack to a page boundary. Be aware, there is a bug in GCC-3.2 with respect to _alloca and optimization (particulary-fomit-frame-pointer), reported on this list by someone called Fish and on GCC lists. It is fixed (at least in part) in 3.3 and higher. > In that case Fabrizio > wanted to avoid the dependence that heap allocation created on the > runtime or C library. That was C/C++ code and I don't know where this > allocation strategy is implemented--i.e., whether it's in a > language-specific front-end or a language-independent back-end of GCC > (and here we should emphasise the official name: the GNU Compiler > Collection, not the GNU C Compiler as many believe it to mean) The stack probe default is target-specific, language-independent. Danny http://mobile.yahoo.com.au - Yahoo! Mobile - Exchange IMs with Messenger friends on your Telstra or Vodafone mobile phone. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Bug reporting: http://cygwin.com/bugs.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
