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Re: RFA: patch solving PR/15921


On Tue, Jun 15, 2004 at 11:50:40AM -0400, Vladimir Makarov wrote:
>  The reload pass can assign the same hard register to uninitialized
> pseudo-register and early clobbered pseudo-register in an insn if the
> pseudo-register is used first time in given BB and not lived at the BB
> start.  It results in compiler crash.

I have trouble correlating this description of the problem with dje's
description in http://gcc.gnu.org/ml/gcc-patches/2004-06/msg00939.html.
In particular, (clobber (match_scratch:SI 2 "=&r")) is not an
uninitialized pseudo-register.  It's a scratch register whose lifetime
is the duration of the instruction, including overlap with its inputs.

Could you explain the problem a bit more?  As it is, the patch seems
to be papering over something elsewhere.


r~


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