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From: "zhenqiang.chen at arm dot com" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug tree-optimization/63743] Thumb1: big regression for float operators by r216728
Date: Wed, 05 Nov 2014 09:40:00 -0000
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https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63743

--- Comment #2 from Zhenqiang Chen <zhenqiang.chen at arm dot com> ---
(In reply to Jakub Jelinek from comment #1)
> Were we swapping operands before?  I mean, if you rewrite the testcase to
> swap the * arguments in the source, did you get the same more efficient code
> in the past?

Yes. I tried the test case:

double
test1 (double x, double y)
{
  return x * (x + y);
}
double
test2 (double x, double y)
{
  return (x + y) * x;
}

Without r216728, I got efficient codes for both functions. But with r216728, I
got inefficient codes for both functions.