[PATCH AArch64]Support missing vcond pattern by adding/using vec_cmp/vcond_mask patterns.

[Bin Cheng <Bin dot Cheng at arm dot com>]

Hi,
Alan and Renlin noticed that some vcond patterns are not supported in AArch64(or AArch32?) backend, and they both had some patches fixing this.  After investigation, I agree with them that vcond/vcondu in AArch64's backend should be re-implemented using vec_cmp/vcond_mask patterns, so here comes this patch which is based on Alan's.  This patch supports all vcond/vcondu patterns by implementing/using vec_cmp and vcond_mask patterns.  Different to the original patch, it doesn't change GCC's expanding process, and it keeps vcond patterns.  The patch also introduces vec_cmp*_internal to support special case optimization for vcond/vcondu which current implementation does.
Apart from Alan's patch, I also learned ideas from Renlin's, and it is my change that shall be blamed if any potential bug is introduced.

With this patch, GCC's test condition "vect_cond_mixed" can be enabled on AArch64 (in a following patch).
Bootstrap and test on AArch64.  Is it OK?  BTW, this patch is necessary for gcc.dg/vect/PR56541.c (on AArch64) which was added before in tree if-conversion patch.

Thanks,
bin

2016-05-11  Alan Lawrence  <alan.lawrence@arm.com>
	    Renlin Li  <renlin.li@arm.com>
	    Bin Cheng  <bin.cheng@arm.com>

	* config/aarch64/iterators.md (V_cmp_mixed, v_cmp_mixed): New.
	* config/aarch64/aarch64-simd.md (<su><maxmin>v2di3): Call
	gen_vcondv2div2di instead of gen_aarch64_vcond_internalv2div2di.
	(aarch64_vcond_internal<mode><mode>): Delete pattern.
	(aarch64_vcond_internal<VDQF_COND:mode><VDQF:mode>): Ditto.
	(vcond_mask_<mode><v_cmp_result>): New pattern.
	(vec_cmp<mode><mode>_internal, vec_cmp<mode><mode>): New pattern.
	(vec_cmp<mode><v_cmp_result>_internal): New pattern.
	(vec_cmp<mode><v_cmp_result>, vec_cmpu<mode><mode>): New pattern.
	(vcond<mode><mode>): Re-implement using vec_cmp and vcond_mask.
	(vcondu<mode><mode>): Ditto.
	(vcond<v_cmp_result><mode>): Delete.
	(vcond<v_cmp_mixed><mode>): New pattern.
	(vcondu<mode><v_cmp_mixed>): New pattern.
	(aarch64_cmtst<mode>): Revise comment using aarch64_vcond instead
	of aarch64_vcond_internal.

gcc/testsuite/ChangeLog
2016-05-11  Bin Cheng  <bin.cheng@arm.com>

	* gcc.target/aarch64/vect-vcond.c: New test.

Attachment: aarch64-vcond-20160509.txt
Description: aarch64-vcond-20160509.txt