Use single-iteration epilogues when peeling for gaps
This patch adds support for fully-masking loops that require peeling
for gaps. It peels exactly one scalar iteration and uses the masked
loop to handle the rest. Previously we would fall back on using a
standard unmasked loop instead.
2018-01-13 Richard Sandiford <richard.sandiford@linaro.org>
Alan Hayward <alan.hayward@arm.com>
David Sherwood <david.sherwood@arm.com>
gcc/
* tree-vect-loop-manip.c (vect_gen_scalar_loop_niters): Replace
vfm1 with a bound_epilog parameter.
(vect_do_peeling): Update calls accordingly, and move the prologue
call earlier in the function. Treat the base bound_epilog as 0 for
fully-masked loops and retain vf - 1 for other loops. Add 1 to
this base when peeling for gaps.
* tree-vect-loop.c (vect_analyze_loop_2): Allow peeling for gaps
with fully-masked loops.
(vect_estimate_min_profitable_iters): Handle the single peeled
iteration in that case.
gcc/testsuite/
* gcc.target/aarch64/sve/struct_vect_18.c: Check the number
of branches.
* gcc.target/aarch64/sve/struct_vect_19.c: Likewise.
* gcc.target/aarch64/sve/struct_vect_20.c: New test.
* gcc.target/aarch64/sve/struct_vect_20_run.c: Likewise.
* gcc.target/aarch64/sve/struct_vect_21.c: Likewise.
* gcc.target/aarch64/sve/struct_vect_21_run.c: Likewise.
* gcc.target/aarch64/sve/struct_vect_22.c: Likewise.
* gcc.target/aarch64/sve/struct_vect_22_run.c: Likewise.
* gcc.target/aarch64/sve/struct_vect_23.c: Likewise.
* gcc.target/aarch64/sve/struct_vect_23_run.c: Likewise.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@256635 138bc75d-0d04-0410-961f-82ee72b054a4
14 files changed: