Alex Coplan <alex.cop...@arm.com> writes:
> This patch adjusts the mem{cpy,set} expansion in the aarch64 backend to use
> individual loads/stores instead of ldp/stp at expand time. The idea is to
> rely
> on the ldp fusion pass to fuse the accesses together later in the RTL
> pipeline.
>
> The earlier parts of the RTL pipeline should be able to do a better job with
> the
> individual (non-paired) accesses, especially given that an earlier patch in
> this
> series moves the pair representation to use unspecs.
>
> Bootstrapped/regtested as a series on aarch64-linux-gnu, OK for trunk?
>
> Thanks,
> Alex
>
> gcc/ChangeLog:
>
> * config/aarch64/aarch64.cc
> (aarch64_copy_one_block_and_progress_pointers): Emit individual
> accesses instead of load/store pairs.
> (aarch64_set_one_block_and_progress_pointer): Likewise.
OK, thanks.
Richard
> ---
> gcc/config/aarch64/aarch64.cc | 12 ++++++++----
> 1 file changed, 8 insertions(+), 4 deletions(-)
>
> diff --git a/gcc/config/aarch64/aarch64.cc b/gcc/config/aarch64/aarch64.cc
> index 1f6094bf1bc..315ba7119c0 100644
> --- a/gcc/config/aarch64/aarch64.cc
> +++ b/gcc/config/aarch64/aarch64.cc
> @@ -25457,9 +25457,12 @@ aarch64_copy_one_block_and_progress_pointers (rtx
> *src, rtx *dst,
> /* "Cast" the pointers to the correct mode. */
> *src = adjust_address (*src, mode, 0);
> *dst = adjust_address (*dst, mode, 0);
> - /* Emit the memcpy. */
> - emit_insn (aarch64_gen_load_pair (reg1, reg2, *src));
> - emit_insn (aarch64_gen_store_pair (*dst, reg1, reg2));
> + /* Emit the memcpy. The load/store pair pass should form
> + a load/store pair from these moves. */
> + emit_move_insn (reg1, *src);
> + emit_move_insn (reg2, aarch64_progress_pointer (*src));
> + emit_move_insn (*dst, reg1);
> + emit_move_insn (aarch64_progress_pointer (*dst), reg2);
> /* Move the pointers forward. */
> *src = aarch64_move_pointer (*src, 32);
> *dst = aarch64_move_pointer (*dst, 32);
> @@ -25638,7 +25641,8 @@ aarch64_set_one_block_and_progress_pointer (rtx src,
> rtx *dst,
> /* "Cast" the *dst to the correct mode. */
> *dst = adjust_address (*dst, mode, 0);
> /* Emit the memset. */
> - emit_insn (aarch64_gen_store_pair (*dst, src, src));
> + emit_move_insn (*dst, src);
> + emit_move_insn (aarch64_progress_pointer (*dst), src);
>
> /* Move the pointers forward. */
> *dst = aarch64_move_pointer (*dst, 32);
