On Thu, Jun 23, 2016 at 04:48:14PM +0100, Dominik Vogt wrote:
> Third version of the patch. Changes:
>
> * Corrected a typo in a test case comment.
> * Verify that stack variable alignment does not force the frame
> pointer into existence (with -fomit-frame-pointer)
>
> The test should hopefully run on all targets. Tested on s390,
> s390x biarch, x86_64. The only open question I'm aware of is the
> stack-usage-2.c test. I guess foo3() will not generate
>
> stack usage might be ... bytes
>
> On any target anymore, and using alloca() with a constant size
> results in "unbounded". It's unclear to me whether that message
> is ever generated, and if so, how to trigger it.
> --- a/gcc/cfgexpand.c
> +++ b/gcc/cfgexpand.c
> @@ -1186,6 +1190,18 @@ expand_stack_vars (bool (*pred) (size_t), struct
> stack_vars_data *data)
> /* Large alignment is only processed in the last pass. */
> if (pred)
> continue;
> +
> + if (large_allocsize && ! large_allocation_done)
> + {
> + /* Allocate space the virtual stack vars area in the
> + prologue. */
> + HOST_WIDE_INT loffset;
> +
> + loffset = alloc_stack_frame_space (INTVAL (large_allocsize),
> + PREFERRED_STACK_BOUNDARY);
^^^^^^^^^^^^^^^^^^^^^^^^
Uh, this must be PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT.
Ciao
Dominik ^_^ ^_^
--
Dominik Vogt
IBM Germany
