re PR tree-optimization/71915 (A missed opportunity for SLSR)

re PR tree-optimization/71915 (A missed opportunity for SLSR)

[gcc]

2016-10-30  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	PR tree-optimization/71915
	PR tree-optimization/71490
	* gimple-ssa-strength-reduction.c (struct slsr_cand_d): Add
	stride_type field.
	(find_basis_for_base_expr): Require stride types to match when
	seeking a basis.
	(alloc_cand_and_find_basis): Record the stride type.
	(slsr_process_phi): Pass stride type to alloc_cand_and_find_basis.
	(backtrace_base_for_ref): Pass types to legal_cast_p_1 rather than
	the expressions having those types.
	(slsr_process_ref): Pass stride type to alloc_cand_and_find_basis.
	(create_mul_ssa_cand): Likewise.
	(create_mul_imm_cand): Likewise.
	(create_add_ssa_cand): Likewise.
	(create_add_imm_cand): Likewise.
	(legal_cast_p_1): Change interface to accept types rather than the
	expressions having those types.
	(legal_cast_p): Pass types to legal_cast_p_1.
	(slsr_process_cast): Pass stride type to
	alloc_cand_and_find_basis.
	(slsr_process_copy): Likewise.
	(dump_candidate): Display stride type when a cast exists.
	(create_add_on_incoming_edge): Introduce a cast when necessary for
	the stride type.
	(analyze_increments): Change the code checking for invalid casts
	to rely on the stride type, and update the documentation and
	example.  Change the code checking for pointer multiplies to rely
	on the stride type.
	(insert_initializers): Introduce a cast when necessary for the
	stride type.  Use the stride type for the type of the initializer.

[gcc/testsuite]

2016-10-30  Bill Schmidt  <wschmidt@linux.vnet.ibm.com>

	PR tree-optimization/71915
	PR tree-optimization/71490
	* gcc.dg/tree-ssa/pr54245.c: Delete.
	* gcc.dg/tree-ssa/slsr-8.c: Adjust for new optimization and
	document why.

From-SVN: r241695