[PATCH] PR opt/13037: "Same" BIVs in update_giv_derive

[Gabriel Dos Reis]

Roger Sayle <roger@eyesopen.com> writes:


[...]

| The relatively simple fix is to ignore duplicate/redudant biv insns
| as we do in other passes.
| 
| The following patch has been tested on i686-pc-linux-gnu against
| both mainline and gcc-3_3-branch, with complete bootstraps, all
| languages except treelang (and Ada on the 3.3 branch), and regression
| tested with a top-level "make -k check" with no new failures.  The
| new testcase derived from the PR passes on 3.3 with this patch but
| fails without.
| 
| Ok for mainline and the 3.3 branch?

If approved by a middle-end maintainer, please apply it to 3_3-branch.

Thanks,

-- Gaby