On 05/31/2015 08:20 PM, Kugan wrote:
On 30/05/15 14:54, Jeff Law wrote:
On 05/29/2015 12:32 AM, Kugan wrote:
PR target/65768
* cprop.c (try_replace_reg): Check cost of constants before
propagating.
I should have also noted, fresh bootstrap & regression test is needed
too.
Thanks Jeff for the comments. I did a fresh bootstrap and regression
testing on x86_64-linux-gnu with no new regression. I will wait for
you ACK.
Can you address the 3 issues in my prior message? I'll include them
here for clarity:
--
The "const_p" variable is poorly named, though I can kindof see how you
settled on it. Maybe "check_rtx_costs" or something along those lines
would be better.
The comment for the second hunk would probably be better as:
/* If TO is a constant, check the cost of the set after propagation
to the cost of the set before the propagation. If the cost is
higher, then do not replace FROM with TO. */
You should try to produce a testcase where this change shows a code
generation improvement. Given we're checking target costs, that test
will naturally be target specific. But please do try.
So with the two nits fixed and a testcase, I think this can go forward.
--
Thanks Jeff and apologies for missing your previous email. I have now
fixed the comments as you suggested and changed the PR target/65768
testcase such that it tests this case.
I will commit it if there is no objections to this.
No objections. Thanks for your patience on this!
jeff
