[Bug tree-optimization/15255] [tree-ssa] a * 2 + a * 2 is not converted to a * 4

["rguenth at gcc dot gnu dot org" <gcc-bugzilla at gcc dot gnu dot org>]

------- Comment #11 from rguenth at gcc dot gnu dot org  2008-08-13 08:58 -------
Subject: Bug 15255

Author: rguenth
Date: Wed Aug 13 08:57:20 2008
New Revision: 139048

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=139048
Log:
2008-08-13  Richard Guenther  <rguenther@suse.de>

        PR tree-optimization/15255
        * tree-ssa-reassoc.c (linearize_expr_tree): Declare.
        (struct oecount_s): New struct and VEC types.
        (cvec): New global.
        (oecount_hash): New function.
        (oecount_eq): Likewise.
        (oecount_cmp): Likewise.
        (zero_one_operation): New function.
        (build_and_add_sum): Likewise.
        (undistribute_ops_list): Perform un-distribution of multiplication
        and division on the chain of summands.
        (should_break_up_subtract): Also break up subtracts for factors.
        (reassociate_bb): Delete dead visited statements.
        Call undistribute_ops_list.  Re-sort and optimize if it did something.
        * passes.c (init_optimization_passes): Move DSE before
        reassociation.
        * tree-ssa-loop-niter.c (stmt_dominates_stmt_p): Correctly handle
        PHI nodes.

        * gcc.dg/tree-ssa/reassoc-14.c: New testcase.
        * gcc.dg/tree-ssa/reassoc-15.c: Likewise.
        * gcc.dg/tree-ssa/reassoc-16.c: Likewise.
        * gcc.dg/torture/reassoc-1.c: Likewise.
        * gcc.dg/tree-ssa/recip-2.c: Adjust.
        * gcc.dg/tree-ssa/recip-6.c: Likewise.
        * gcc.dg/tree-ssa/recip-7.c: Likewise.
        * gfortran.dg/reassoc_4.f: Likewise.

Added:
    trunk/gcc/testsuite/gcc.dg/torture/reassoc-1.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-14.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-15.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-16.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-17.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/reassoc-18.c
    trunk/gcc/testsuite/gfortran.dg/reassoc_4.f
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/passes.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.dg/tree-ssa/recip-2.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/recip-6.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/recip-7.c
    trunk/gcc/tree-ssa-loop-niter.c
    trunk/gcc/tree-ssa-reassoc.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=15255