[Bug tree-optimization/29789] Missed invariant out of the loop with conditionals and shifts

Sun, 22 Apr 2007 04:27:12 -0700 


------- Comment #8 from rguenth at gcc dot gnu dot org  2007-04-22 12:27 -------
Subject: Bug 29789

Author: rguenth
Date: Sun Apr 22 12:26:49 2007
New Revision: 124042

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=124042
Log:
2007-04-22  Richard Guenther  <[EMAIL PROTECTED]>

        PR tree-optimization/29789
        * tree-ssa-loop-im.c (stmt_cost): Adjust cost of shifts.
        (rewrite_reciprocal): New helper split out from
        determine_invariantness_stmt.
        (rewrite_bittest): Likewise.
        (determine_invariantness_stmt): Rewrite (A >> B) & 1 to
        A & (1 << B) if (1 << B) is loop invariant but (A >> B)
        is not.

        * gcc.dg/tree-ssa/ssa-lim-1.c: New testcase.
        * gcc.dg/tree-ssa/ssa-lim-2.c: Likewise.

Added:
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-lim-1.c
    trunk/gcc/testsuite/gcc.dg/tree-ssa/ssa-lim-2.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/tree-ssa-loop-im.c


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29789

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