From: Jakub Jelinek <jakub@redhat.com>
To: Eric Botcazou <ebotcazou@adacore.com>
Cc: gcc@gcc.gnu.org
Subject: Re: Problem with SSA inlining and default defs
Date: Sun, 16 Dec 2007 18:10:00 -0000 [thread overview]
Message-ID: <20071216180653.GE2947@sunsite.mff.cuni.cz> (raw)
In-Reply-To: <200712161854.29543.ebotcazou@adacore.com>
On Sun, Dec 16, 2007 at 06:54:29PM +0100, Eric Botcazou wrote:
> How SSA inlining and default defs for uninitialized variables are supposed to
> interact? Suppose you have the following situation
>
> BB0 ...
> | \
> (ab) | BB1 s_2 = f(s_1(D))
> | /
> BB2 s_3 = PHI <s_1(D), s2>
>
> in a function that gets inlined into a loop. The liveness of s_1(D) in BB0
> will propagate to BB2 along the backwards edge and you get overlapping live
> ranges for s_1(D) and s_3. If s_1(D) is SSA_NAME_OCCURS_IN_ABNORMAL_PHI, the
> compilation will abort during SSA coalescing because they must be coalesced.
This sounds like PR31081.
Jakub
next prev parent reply other threads:[~2007-12-16 18:01 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-12-16 18:01 Eric Botcazou
2007-12-16 18:10 ` Jakub Jelinek [this message]
2007-12-16 18:27 ` Eric Botcazou
2007-12-16 19:45 ` Jakub Jelinek
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