Bisect tool: Support print IR differences before and after bisection
This patch provides an option to print out IR differences before and
after pass/transformation level bisection.
This feature will help if user want to know what exactly does the bad
pass/transformation do to IR. It added two extra run with `-S` and
`-emit-llvm` to generate two IR files and use `diff` to compare them.
Note: `--ir_diff` option only works when pass_bisect is enabled.
BUG=chromium:878954
TEST=Ran test successfully with Android compiler wrapper.
Change-Id: Ia691dc6f23331a3e584eaf9e390edeeb990f3c87
Reviewed-on: https://chromium-review.googlesource.com/1220015
Commit-Ready: Zhizhou Yang <zhizhouy@google.com>
Tested-by: Zhizhou Yang <zhizhouy@google.com>
Reviewed-by: Caroline Tice <cmtice@chromium.org>
Reviewed-by: George Burgess <gbiv@chromium.org>
2 files changed
