From: Thomas Koenig <tkoenig@netcologne.de>
To: "Mikael Morin" <mikael.morin@sfr.fr>,
"Dominique d'Humières" <dominiq@lps.ens.fr>
Cc: GCC Patches <gcc-patches@gcc.gnu.org>,
GNU GFortran <fortran@gcc.gnu.org>
Subject: Re: [patch, fortran, RFC] First steps towards inlining matmul
Date: Sat, 11 Apr 2015 17:01:00 -0000 [thread overview]
Message-ID: <55295358.60707@netcologne.de> (raw)
In-Reply-To: <552924F2.6000406@sfr.fr>
Hi Mikael,
>> Still to do: Bounds checking (a rather big one),
> ... as you do a front-end to front-end transformation, you get bounds
> checking for free, don't you?
Only partially.
What the patch does is
integer i,j,k
c = 0
do j=0, size(b,2)-1
do k=0, size(a, 2)-1
do i=0, size(a, 1)-1
c(i * stride(c,1) + lbound(c,1), j * stride(c,2) +
lbound(c,2)) =
c(i * stride(c,1) + lbound(c,1), j * stride(c,2) + lbound(c,2)) +
a(i * stride(a,1) + lbound(a,1), k * stride(a,2) +
lbound(a,2)) *
b(k * stride(b,1) + lbound(b,1), j * stride(b,2) + lbound(b,2))
end do
end do
end do
If size(b,2) < size(c,2) or size(a,1) < size(c,1) or
size(a,2) < size(b,1), this will not get caught - no
array bounds violation in the DO loops, but illegal
code nonetheless.
Also, the error message is different, which should also be
changed.
What I would like to add to check before the loop, and then
add a "do not bounds-check" flag to the reference.
Thomas
next prev parent reply other threads:[~2015-04-11 17:01 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-04-05 13:55 Dominique Dhumieres
2015-04-05 14:33 ` Thomas Koenig
2015-04-05 18:25 ` Dominique d'Humières
2015-04-05 20:37 ` Thomas Koenig
2015-04-05 23:15 ` Dominique d'Humières
2015-04-06 12:18 ` Dominique d'Humières
2015-04-09 22:18 ` Thomas Koenig
2015-04-10 14:15 ` Dominique d'Humières
2015-04-10 16:57 ` Dominique d'Humières
2015-04-11 12:24 ` Thomas Koenig
2015-04-11 13:43 ` Mikael Morin
2015-04-11 17:01 ` Thomas Koenig [this message]
-- strict thread matches above, loose matches on Subject: below --
2015-04-05 12:32 Thomas Koenig
2015-04-05 13:20 ` Jerry DeLisle
2015-04-05 13:48 ` Thomas Koenig
2015-04-07 19:24 ` David Malcolm
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