[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.

Attachment: aarch32-builtin-trap-v2.txt
Description: Text document