tree d541f2cf70f6a2e5123300e99062c825637b4fc6
parent 4019f0843ff2efdde366402f692f0853a206bac8
author Jim Stichnoth <stichnot@chromium.org> 1418996544 -0800
committer Jim Stichnoth <stichnot@chromium.org> 1418996544 -0800

Subzero: Randomize register assignment.

Randomize the order that registers appear in the free list.  Only
randomize fully "equivalent" registers to ensure no extra spills.

This adds the -randomize-regalloc option.

This is a continuation of https://codereview.chromium.org/456033003/ which Matt owns.

BUG= none
R=jfb@chromium.org

Review URL: https://codereview.chromium.org/807293003