[Bug c++/40460] Enormous memory usage during compilation with -O2 or -O3 optimizations.

[rguenth at gcc dot gnu dot org]

------- Comment #2 from rguenth at gcc dot gnu dot org  2009-06-16 13:20 -------
Oh, this is yet another case of SCEV going crazy..., called from complete
unrolling in this case.

0x000000000118bcc5 in chrec_fold_multiply (type=0x7ffff7ee8540, 
    op0=0x7ffff273a500, op1=0x7ffff7f14b40)
    at /space/rguenther/src/svn/trunk/gcc/tree-chrec.c:401
401               return build_polynomial_chrec 
Value returned is $14 = (union tree_node *) 0x7fffe7099780
(gdb) call debug_generic_expr ($14)
{{{{{{D.21167_5 * 512, +, D.21167_5 * 1024}_1, +, {D.21167_5 * 1024, +,
D.21167_5 * 2048}_1}_1, +, {{D.21167_5 * 1024, +, D.21167_5 * 2048}_1, +,
{D.21167_5 * 2048, +, D.21167_5 * 4096}_1}_1}_1, +, {{{D.21167_5 * 1024, +,
D.21167_5 * 2048}_1, +, {D.21167_5 * 2048, +, D.21167_5 * 4096}_1}_1, +,
{{D.21167_5 * 2048, +, D.21167_5 * 4096}_1, +, {D.21167_5 * 4096, +, D.21167_5
* 8192}_1}_1}_1}_1, +, {{{{D.21167_5 * 1024, +, D.21167_5 * 2048}_1, +,
{D.21167_5 * 2048, +, D.21167_5 * 4096}_1}_1, +, {{D.21167_5 * 2048, +,
D.21167_5 * 4096}_1, +, {D.21167_5 * 4096, +, D.21167_5 * 8192}_1}_1}_1, +,
{{{D.21167_5 * 2048, +, D.21167_5 * 4096}_1, +, {D.21167_5 * 4096, +, D.21167_5
* 8192}_1}_1, +, {{D.21167_5 * 4096, +, D.21167_5 * 8192}_1, +, {D.21167_5 *
8192, +, D.21167_5 * 16384}_1}_1}_1}_1}_1, +, {{{{{D.21167_5 * 1024, +,
D.21167_5 * 2048}_1, +, {D.21167_5 * 2048, +, D.21167_5 * 4096}_1}_1, +,
{{D.21167_5 * 2048, +, D.21167_5 * 4096}_1, +, {D.21167_5 * 4096, +, D.21167_5
* 8192}_1}_1}_1, +, {{{D.21167_5 * 2048, +, D.21167_5 * 4096}_1, +, {D.21167_5
* 4096, +, D.21167_5 * 8192}_1}_1, +, {{D.21167_5 * 4096, +, D.21167_5 *
8192}_1, +, {D.21167_5 * 8192, +, D.21167_5 * 16384}_1}_1}_1}_1, +,
{{{{D.21167_5 * 2048, +, D.21167_5 * 4096}_1, +, {D.21167_5 * 4096, +,
D.21167_5 * 8192}_1}_1, +, {{D.21167_5 * 4096, +, D.21167_5 * 8192}_1, +,
{D.21167_5 * 8192, +, D.21167_5 * 16384}_1}_1}_1, +, {{{D.21167_5 * 4096, +,
D.21167_5 * 8192}_1, +, {D.21167_5 * 8192, +, D.21167_5 * 16384}_1}_1, +,
{{D.21167_5 * 8192, +, D.21167_5 * 16384}_1, +, {D.21167_5 * 16384, +,
D.21167_5 * 32768}_1}_1}_1}_1}_1}_1

I will have a look.


-- 

rguenth at gcc dot gnu dot org changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |spop at gcc dot gnu dot org
         AssignedTo|unassigned at gcc dot gnu   |rguenth at gcc dot gnu dot
                   |dot org                     |org
             Status|NEW                         |ASSIGNED
   Last reconfirmed|2009-06-16 13:09:08         |2009-06-16 13:20:02
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=40460