This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
Re: [Patch, _eh, dawin, Version2] Allow targets to suppress epilogues in _eh frames.
On 16 Aug 2010, at 05:15, Jack Howarth wrote:
I am also seeing the failure...
FAIL: gfortran.dg/g77/980701-0.f -Os execution test
Hm. This test does not contain any (overt) exception handling, I
guess we must be seeing an interaction with the fortran runtime
(or some aspect of the optimize for smallest code which is unexpected
--- note that m32 forces frame pointers on for optimize_size).
The salient difference between trunk and the patched version is that
there are no unwind frames emitted for the patched version.
Un-patched trunk sets -fasynchronous-unwind-tables.
The test passes if either
-fno-omit-frame-pointers
or
-funwind-tables
is given.
this can be replicated on un-patched trunk by passing '-fno-
asynchronous-frame-tables'.
Given that -fno-asynchronous-frame-tables does not sit well with
dawin...
I could arrange either to default to "-funwind-tables" on m64 (at
least for fortran) but please note the following:
======
apple_local 4.2.1 (5646) gcc/config/i386/i386.c:
if (TARGET_64BIT)
{
/* Mach-O doesn't support omitting the frame pointer for now. */
if (flag_omit_frame_pointer == 2)
flag_omit_frame_pointer = (TARGET_MACHO ? 0 : 1);
but we have recently changed trunk to this:
if (TARGET_64BIT)
{
if (flag_zee == 2)
flag_zee = 1;
if (flag_omit_frame_pointer == 2)
flag_omit_frame_pointer = 1;
------
If you know that the "does not support" is no longer true for Darwin10
- then, fine, we can arrange the target over-rides to switch it off
for Darwin10.
Otherwise, I'm not sure how we can justify omitting frame pointers by
default for m64 OSX
Mike?
cheers,
Iain
- References:
- [Patch, _eh, dawin] Allow targets to suppress epilogues in _eh frames.
- Re: [Patch, _eh, dawin] Allow targets to suppress epilogues in _eh frames.
- [Patch, _eh, dawin, Version2] Allow targets to suppress epilogues in _eh frames.
- Re: [Patch, _eh, dawin, Version2] Allow targets to suppress epilogues in _eh frames.
- Re: [Patch, _eh, dawin, Version2] Allow targets to suppress epilogues in _eh frames.