gcc/
	* config/i386/i386.c (ix86_reassociation_width): Add alternative for
	vector case.
	* config/i386/i386.h (TARGET_VECTOR_PARALLEL_EXECUTION): New.
	* config/i386/x86-tune.def (X86_TUNE_VECTOR_PARALLEL_EXECUTION): New.
	* tree-vect-data-refs.c (vect_shift_permute_load_chain): New.
	Introduces alternative way of loads group permutaions.
	(vect_transform_grouped_load): Try alternative way of permutations.

gcc/testsuite/
	PR tree-optimization/52252
	* gcc.target/i386/pr52252-atom.c: Test on loads group of size 3.
	* gcc.target/i386/pr52252-core.c: Ditto.

	PR tree-optimization/61403
	* gcc.target/i386/pr61403.c: Test on loads and stores group of size 3.

From-SVN: r211769