[Bug tree-optimization/16163] New: [3.5 Regression] O(N^2) in expand

[belyshev at lubercy dot com]

This patch:

2004-06-21  Richard Kenner  <kenner@vlsi1.ultra.nyu.edu>

	* Makefile.in (gimplify.o): Add cgraph.h.
        ...

introduced big slowdown on attached testcase. benchmark:

N               T (before)      T (after)
------------------------------------------------
 4096             5.0             14.0
 8192            10.1             44.9
16384            20.7            156.6
32768            42.3            581.5

N is number of elements in structure,
T is compilation time in seconds.
GCC invoked as './cc1 bench.c -O1 -o /dev/null'

-- 
           Summary: [3.5 Regression] O(N^2) in expand
           Product: gcc
           Version: 3.5.0
            Status: UNCONFIRMED
          Keywords: compile-time-hog
          Severity: normal
          Priority: P2
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: belyshev at lubercy dot com
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=16163