On 08/22/2017 08:15 AM, Wilco Dijkstra wrote: > Jeff Law wrote: > On 07/26/2017 05:29 PM, Wilco Dijkstra wrote: > >>> But then the check size_align % MAX_SUPPORTED_STACK_ALIGNMENT != 0 >>> seems wrong too given that round_push uses a different alignment to align >>> to. >> I had started to dig into the history of this code, but just didn't have >> the time to do so fully before needing to leave for the day. To some >> degree I was hoping you knew the rationale behind the test against >> MAX_SUPPORTED_STACK_ALIGNMENT and I wouldn't have to do a ton of digging :-) > > I looked further into this - it appears this works correctly since it is only > bypassed if > size_align is already maximally aligned. round_push aligns to the preferred > alignment, > which may be lower or equal to MAX_SUPPORTED_STACK_ALIGNMENT (which is > at least STACK_BOUNDARY). > > Here is the updated version: > > ChangeLog: > 2017-08-22 Wilco Dijkstra <wdijk...@arm.com> > > * explow.c (get_dynamic_stack_size): Improve dynamic alignment. OK. I wonder if this will make it easier to write stack-clash tests of the dynamic space for boundary conditions :-) I was always annoyed that I had to fiddle around with magic adjustments to the sizes of objects to tickle boundary cases.
jeff
