On 06/18/2015 11:32 AM, Eric Botcazou wrote:
The attached patch teaches regrename to validate insns affected by each
register renaming before making the change. I can see at least two
other ways to handle this -- earlier, by rejecting renamings that result
in invalid instructions when it's searching for the best renaming; or
later, by validating the entire set of renamings as a group instead of
incrementally for each one -- but doing it all in regname_do_replace
seems least disruptive and risky in terms of the existing code.
OK, but the patch looks incomplete, rename_chains should be adjusted
as well,
i.e. regrename_do_replace should now return a boolean.
Like this? I tested this on nios2 and x86_64-linux-gnu, as before, plus
built for aarch64-linux-gnu and ran the gcc testsuite.
The c6x back end also calls regrename_do_replace. I am not set up to
build or test on that target, and Bernd told me off-list that it would
never fail on that target anyway so I have left that code alone.
-Sandra
regrename-2.log
2015-06-23 Chung-Lin Tang<cltang@codesourcery.com>
Sandra Loosemore<sandra@codesourcery.com>
gcc/
* regrename.h (regrename_do_replace): Change to return bool.
* regrename.c (rename_chains): Check return value of
regname_do_replace.
(regrename_do_replace): Re-validate the modified insns and
return bool status.
* config/aarch64/cortex-a57-fma-steering.c (rename_single_chain):
Update to match rename_chains changes.