------- Comment #5 from zadeck at naturalbridge dot com 2007-07-02 19:12 ------- Subject: Re: Runtime failure in SPEC CPU2000 benchmark fma3d and applu
wilson at specifix dot com wrote: > ------- Comment #4 from wilson at specifix dot com 2007-07-02 18:34 ------- > Subject: Re: Runtime failure in SPEC CPU2000 benchmark > fma3d and applu > > On Sat, 2007-06-30 at 02:10 +0000, zadeck at naturalbridge dot com > >> and then define ARCH_DOES_NOT_USE_DWARF2 in the right place in the ia-64. >> > > We do use DWARF2 debug info, just not DWARF2 unwind info. So this name > is a little misleading. However, this does sound like a good idea. > > The name was just something I threw out, I was just looking to get to the right answer by only hacking (and testing a single port). > There is already a macro TARGET_UNWIND_INFO that we should be able to > use for this. This is defined for targets that have their own > non-DWARF2 unwind info format. This is defined by only 2 targets: IA-64 > and ARM BPABI. The change you suggested would be safe for IA-64. I > don't know about ARM BPABI. I know ARM BPABI has its own unwind info > format, but don't know any details. > > The ARM case is strange. It is setting both DWARF2_UNWIND_INFO and > TARGET_UNWIND_INFO. This seems broken to me, as it means we may emit > two different kinds of unwind info. This conflicts with the original > IA-64 usage of this macro, which wants only the one non-DWARF2 unwind > info. However, this means that disabling the defaults.h code for > DWARF2_UNWIND_INFO will have no effect for arm as it already sets > DWARF2_UNWIND_INFO, so this should be OK. I will have to build an ARM > target and check to see what is really happening here. > > I looked a bit more at what happens if DWARF2_UNWIND_INFO is defined to > 0. There are a number of targets that already do this, and the docs say > that this disables use of dwarf2 unwind info, but enables use of dwarf > frame info for the debugger. But the dwarf2 frame info is redundant for > IA-64 because we already have frame info in the IA-64 unwind info, and > the debugger already knows how to use this frame info. Unfortunately, > the docs say that defining TARGET_UNWIND_INFO is supposed to generate > dwarf2 frame info for the debugger. So this will not work for IA-64 as > currently documented. > Lets see if an arm person is willing to talk about this. kenny > > -- http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32552
