RE: [PATCH, ARM] Implement __builtin_trap

["Ian Bolton" <ian dot bolton at arm dot com>]

> > Hi,
> >
> > Currently, on ARM, you have to either call abort() or raise(SIGTRAP)
> > to achieve a handy crash.
> >
> > This patch allows you to instead call __builtin_trap() which is much
> > more efficient at falling over because it becomes just a single
> > instruction that will trap for you.
> >
> > Two testcases have been added (for ARM and Thumb) and both pass.
> >
> >
> > Note: This is a modified version of a patch originally submitted by
> Mark
> > Mitchell back in 2010, which came in response to PR target/59091.
> >
> > http://gcc.gnu.org/ml/gcc-patches/2010-09/msg00639.html
> > http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59091
> >
> > The main update, other than cosmetic differences, is that we've
> chosen
> > the same ARM encoding as LLVM for practical purposes.  (The Thumb
> > encoding in Mark's patch already matched LLVM.)
> >
> >
> > OK for trunk?
> >
> > Cheers,
> > Ian
> >
> >
> > 2013-12-04  Ian Bolton  <ian.bolton@arm.com>
> >            Mark Mitchell  <mark@codesourcery.com>
> >
> > gcc/
> >    * config/arm/arm.md (trap): New pattern.
> >    * config/arm/types.md: Added a type for trap.
> >
> > testsuite/
> >    * gcc.target/arm/builtin-trap.c: New test.
> >    * gcc.target/arm/thumb-builtin-trap.c: Likewise.
> > <aarch32-builtin-trap-v2.txt>
> 
> This needs to set the conds attribute to "unconditional".  Otherwise
> the ARM backend might try to turn this into a conditional instruction.
> 
> R.

Thanks, Richard. I fixed it up, tested it and committed as trivial
difference compared to what was approved already.

Attachment: aarch32-builtin-trap-v3.txt
Description: Text document