[PATCH] Fix ICE in expand_cse_reciprocals (PR tree-optimization/42078)

[Alexandre Oliva]

On Jun  3, 2011, Alexandre Oliva <aoliva@redhat.com> wrote:

> According to http://gcc.gnu.org/ml/gcc-patches/2009-11/msg01082.html
> on Nov 20, 2009, Alexandre Oliva <aoliva@redhat.com> wrote:

>> On Nov 19, 2009, Richard Guenther <richard.guenther@gmail.com> wrote:
>>> In fact this exchanging of the LHS (or rather invalidating of the
>>> SSA name value) should be a helper function that knows
>>> the implementation details and avoids going through releasing
>>> and allocating the name.

>> Okie dokie, here's a sequence of patches that implements helper
>> functions for this sort of stuff.

>> The first patch introduces machinery to propagate “dying” DEFs into
>> debug stmts, while replacing them with other SSA_NAMEs.

> This is already in.

>> The second extends it so as to enable the old LHS to be redefined
>> e.g. in terms of the new LHS.  IIRC this may be useful in some other
>> transformations that, in the process of introducing VTA, I changed from
>> modifying stmts in place to inserting new stmts and removing others.  I
>> haven't looked for them yet.

>> The third uses this new feature for the case at hand, while avoiding
>> computing the reciprocal expression if we know it won't be used.

> Updated versions of these follow.  Regstrapped on x86_64-linux-gnu and
> i686-linux-gnu.  Ok to install?

I was asked to submit these again in stage1, so...  Ping?
(updated and re-tested)

-------------- next part --------------
A non-text attachment was scrubbed...
Name: vta-debug-temps-explicit-values-pr42078.patch
Type: text/x-diff
Size: 9599 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20120409/061c1a86/attachment.bin>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: vta-cse-reciprocals-preserve-pr42078.patch
Type: text/x-diff
Size: 1512 bytes
Desc: not available
URL: <http://gcc.gnu.org/pipermail/gcc-patches/attachments/20120409/061c1a86/attachment-0001.bin>
-------------- next part --------------


-- 
Alexandre Oliva, freedom fighter    http://FSFLA.org/~lxoliva/
You must be the change you wish to see in the world. -- Gandhi
Be Free! -- http://FSFLA.org/   FSF Latin America board member
Free Software Evangelist      Red Hat Brazil Compiler Engineer