2016-08-24  Michael Collison <michael.collison@linaro.org>
	    Michael Collison <michael.collison@arm.com>

	* config/arm/arm-modes.def: Add new condition code mode CC_V
	to represent the overflow bit.
	* config/arm/arm.c (maybe_get_arm_condition_code):
	Add support for CC_Vmode.
	(arm_gen_unlikely_cbranch): New function to generate common
	rtl conditional branches for overflow patterns.
	* config/arm/arm-protos.h: Add prototype for
	arm_gen_unlikely_cbranch.
	* config/arm/arm.md (addv<mode>4, add<mode>3_compareV,
	addsi3_compareV_upper): New patterns to support signed
	builtin overflow add operations.
	(uaddv<mode>4, add<mode>3_compareC, addsi3_compareV_upper):
	New patterns to support unsigned builtin add overflow operations.
	(subv<mode>4, sub<mode>3_compare1): New patterns to support signed
	builtin overflow subtract operations,
	(usubv<mode>4): New patterns to support unsigned builtin subtract
	overflow operations.
	(negvsi3, negvdi3, negdi2_compare, negsi2_carryin_compare): New patterns
	to support builtin overflow negate operations.
	* gcc.target/arm/builtin_saddl.c: New testcase.
	* gcc.target/arm/builtin_saddll.c: New testcase.
	* gcc.target/arm/builtin_uaddl.c: New testcase.
	* gcc.target/arm/builtin_uaddll.c: New testcase.
	* gcc.target/arm/builtin_ssubl.c: New testcase.
	* gcc.target/arm/builtin_ssubll.c: New testcase.
	* gcc.target/arm/builtin_usubl.c: New testcase.
	* gcc.target/arm/builtin_usubll.c: New testcase.


Co-Authored-By: Michael Collison <michael.collison@arm.com>

From-SVN: r239739