[llvm-commits] [llvm] r167740 - in /llvm/trunk: lib/Transforms/Scalar/Reassociate.cpp test/Transforms/Reassociate/mul_neg.ll test/Transforms/Reassociate/multistep.ll

[Eli Friedman]

On Mon, Nov 12, 2012 at 11:34 AM, Shuxin Yang <shuxin.llvm at gmail.com> wrote:
> Author: shuxin_yang
> Date: Mon Nov 12 13:34:11 2012
> New Revision: 167740
>
> URL: http://llvm.org/viewvc/llvm-project?rev=167740&view=rev
> Log:
> This change is to fix rdar://12571717 which is about assertion in Reassociate pass.
>
> The assertion is trigged when the Reassociater tries to transform expression
>      ... + 2 * n * 3 + 2 * m + ...
>   into:
>      ... + 2 * (n*3 + m).
>
> In the process of the transformation, a helper routine folds the constant 2*3 into 6,
> confusing optimizer which is trying the to eliminate the common factor 2, and cannot
> find 2 any more.
>
> Review is pending. But I'd like commit first in order to help those who are waiting
> for this fix.

No; this is not how our review system works; you're not allowed to
commit without review just because some particular customer needs a
fix.  We have private branches for that sort of thing.

-Eli