[Bug regression/49572] [4.4 Regression]: gcc.dg/tree-ssa/20030709-2.c scan-tree-dump-times cddce2 ".rtmem" 0

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

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49572

Eric Botcazou <ebotcazou at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |rguenth at gcc dot gnu.org

--- Comment #8 from Eric Botcazou <ebotcazou at gcc dot gnu.org> 2011-06-30 09:01:00 UTC ---
> After tuplification, DOM records the type of the LHS of assignment statements
> as the type of the expression.  And then it tests the compatibility of these
> types.

Maybe DOM could use the type of the RHS instead in the GIMPLE_SINGLE_RHS case.

On the 4.4 branch, the code generated for the testcase at -O2 is pessimized:

--- old//20030709-2.s   2011-06-30 10:41:30.000000000 +0200
+++ new/20030709-2.s    2011-06-29 12:01:55.000000000 +0200
@@ -8,7 +8,8 @@
        movl    %esp, %ebp
        movl    8(%ebp), %eax
        popl    %ebp
-       cmpl    $1, (%eax)
+       movl    (%eax), %eax
+       cmpl    $1, %eax
        sbbl    %eax, %eax
        ret
        .size   get_alias_set, .-get_alias_set

but it isn't on the other branches.  But DOM is hindered on all branches.