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Re: Question about CASE_DROPS_THROUGH

From: Richard Henderson <rth at redhat dot com>
To: Zack Weinberg <zack at codesourcery dot com>
Cc: Roger Sayle <roger at eyesopen dot com>, Steven Bosscher <stevenb at suse dot de>, gcc at gcc dot gnu dot org
Date: Mon, 21 Jun 2004 01:50:59 -0700
Subject: Re: Question about CASE_DROPS_THROUGH
References: <Pine.LNX.4.44.0406202149050.7588-100000@www.eyesopen.com> <87isdlbhn6.fsf@taltos.codesourcery.com>

On Sun, Jun 20, 2004 at 10:32:29PM -0700, Zack Weinberg wrote:
> Good point.  The NOTE is definitely what I would try first.

The jump should reference the table directly (as well).  Quite
a few targets use pc-relative loads from the jump table, and
so there *is* no load separate from the jump insn.

Anyway, the simplest way out for VAX, should anyone care about
it ever again, is simply to emit a jump directly after the 
case instruction.  Which lets us kill CASE_DROPS_THROUGH, since
the logical unit of the two now doesn't drop through.


r~

References:
- Re: Question about CASE_DROPS_THROUGH
  - From: Roger Sayle
- Re: Question about CASE_DROPS_THROUGH
  - From: Zack Weinberg

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