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[Commited] Fix latent bug in simplify_subreg


Ian Lance Taylor agrees with my analysis that the code to handle SUBREGs
of CONCATs in simplify_subreg contains a latent bug.  When determining
whether the SUBREG refers to the first or second component of a CONCAT the
current code checks the offset against the mode of the full CONCAT, not of
its components.  This was spotted by visual inspection, so I've no test
case.

The following patch has been tested on i686-pc-linux-gnu with a full "make
bootstrap", all default languages including Ada, and regression tested
with a top-level "make -k check" with no new failures.

Committed to mainline as revision 120101.

2006-12-20  Roger Sayle  <roger@eyesopen.com>

        * simplify-rtx.c (simplify_subreg): Use the correct mode when
        determining whether a SUBREG of a CONCAT refers to the first or
        second component.

Roger
-- 

Attachment: patchd.txt
Description: Text document


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