Date: Thu, 25 Apr 2019 22:23:09 -0400
From: Alvaro Herrera <alvherre@2ndquadrant.com>
To: Peter Geoghegan <pg@bowt.ie>
Cc: Tom Lane <tgl@sss.pgh.pa.us>,
	PostgreSQL Hackers <pgsql-hackers@lists.postgresql.org>
Subject: Re: Reducing the runtime of the core regression tests
Message-ID: <20190426022309.GA11555@alvherre.pgsql>
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On 2019-Apr-25, Peter Geoghegan wrote:

> On Fri, Apr 12, 2019 at 10:24 AM Alvaro Herrera
> <alvherre@2ndquadrant.com> wrote:
> > Hmm, it's odd, because
> > https://coverage.postgresql.org/src/backend/access/nbtree/nbtutils.c.gcov.html
> > still shows that function doing that.  pg_config shows:
> >
> > $ ./pg_config --configure
> > '--enable-depend' '--enable-coverage' '--enable-tap-tests' '--enable-nls' '--with-python' '--with-perl' '--with-tcl' '--with-openssl' '--with-libxml' '--with-ldap' '--with-pam' 'CFLAGS=-O0'
> 
> So, we're currently using this on coverage.postgresql.org? We've switched?

Yes, I changed it the day you first suggested it.

> I noticed a better example of weird line counts today, this time
> within _bt_check_rowcompare():
> 
>     1550           4 :             cmpresult = 0;
>     1551           4 :             if (subkey->sk_flags & SK_ROW_END)
>     1552        1292 :                 break;
>     1553           0 :             subkey++;
>     1554           0 :             continue;
> 
> I would expect the "break" statement to have a line count that is no
> greater than that of the first two lines that immediately precede, and
> yet it's far far greater (1292 is greater than 4). It looks like there
> has been some kind of loop transformation.

Maybe it takes more than -O0 in cflags to disable those, but as I said,
the compile lines do show the -O0.

-- 
Álvaro Herrera                https://www.2ndQuadrant.com/
PostgreSQL Development, 24x7 Support, Remote DBA, Training & Services