[PATCH][Aarch64] v2: Arithmetic overflow subv patterns [Patch 3/4]

[Michael Collison]

This is a re-spin of a AArch64 patch that adds support for builtin arithmetic 
overflow operations. This update separates the patch into multiple pieces and 
addresses comments made by Richard Earnshaw here:

https://gcc.gnu.org/ml/gcc-patches/2017-07/msg00249.html

Original patch and motivation for patch here:

This patch contains new patterns for subv<mode> overflow patterns.

https://gcc.gnu.org/ml/gcc-patches/2017-05/msg01512.html

Bootstrapped and tested on aarch64-linux-gnu. Okay for trunk?

2017-10-26  Michael Collison  <michael.colli...@arm.com>
            Richard Henderson <r...@redhat.com>

        * config/aarch64/aarch64.md (subv<GPI>4, usubv<GPI>4): New patterns.
        (subti): Handle op1 zero.
        (subvti4, usub4ti4): New.
        (*sub<GPI>3_compare1_imm): New.
        (sub<GPI>3_carryinCV): New.
        (*sub<GPI>3_carryinCV_z1_z2, *sub<GPI>3_carryinCV_z1): New.
        (*sub<GPI>3_carryinCV_z2, *sub<GPI>3_carryinCV): New.

gnutools-6308-subv-v2.patch.patch
Description: gnutools-6308-subv-v2.patch.patch