On 10/11/13 20:11, Zhenqiang Chen wrote:
-----Original Message-----
From: Jeff Law [mailto:l...@redhat.com]
Sent: Friday, October 11, 2013 1:20 PM
To: Zhenqiang Chen
Cc: gcc-patches@gcc.gnu.org
Subject: Re: [PATCH] Reassociate X == CST1 || X == CST2 if popcount (CST2
-
CST1) == 1 into ((X - CST1) & ~(CST2 - CST1)) == 0
On 10/10/13 03:25, Zhenqiang Chen wrote:
It comes from Coremark. The code is:
if (NEXT_SYMBOL == '+' || NEXT_SYMBOL == '-')
I should have guessed ;-)
For ARM, there are three instructions rather than 4 (in thumb state).
For some older gcc, I got performance improvement on ARM chromebook.
But I can not reproduce the performance gain now.
I will collect logs during GCC bootstrap.
Thanks. It doesn't have to be anything particularly complex. When I'm
looking at a transformation I usually just put a printf when it triggers
and grep
for the string in a make log.
Thanks. I check the make log. There are 1906 occurrences.
Wow. That's awsome. Thanks,
jeff
