vect: Create array_slice of live-out stmts

This patch constructs an array_slice of the scalar statements that
produce live-out reduction results in the original unvectorised loop.
There are three cases:

- SLP reduction chains: the final SLP stmt is live-out
- full SLP reductions: all SLP stmts are live-out
- non-SLP reductions: the single scalar stmt is live-out

This is a slight simplification on its own, mostly because it maans
“group_size” has a consistent meaning throughout the function.
The main justification though is that it helps with later patches.

gcc/
	* tree-vect-loop.c (vect_create_epilog_for_reduction): Truncate
	scalar_results to group_size elements after reducing down from
	N*group_size elements.  Construct an array_slice of the live-out
	stmts and assert that there is one stmt per scalar result.

0 files changed, 0 insertions, 0 deletions