2006-11-03 Paolo Bonzini <bonzini@gnu.org>

            Steven Bosscher  <stevenb.gcc@gmail.com>

        * fwprop.c: New file.
        * Makefile.in: Add fwprop.o.
        * tree-pass.h (pass_rtl_fwprop, pass_rtl_fwprop_with_addr): New.
        * passes.c (init_optimization_passes): Schedule forward propagation.
        * rtlanal.c (loc_mentioned_in_p): Support NULL value of the second
        parameter.
        * timevar.def (TV_FWPROP): New.
        * common.opt (-fforward-propagate): New.
        * opts.c (decode_options): Enable forward propagation at -O2.
        * gcse.c (one_cprop_pass): Do not run local cprop unless touching jumps.
        * cse.c (fold_rtx_subreg, fold_rtx_mem, fold_rtx_mem_1, find_best_addr,
        canon_for_address, table_size): Remove.
        (new_basic_block, insert, remove_from_table): Remove references to
        table_size.
        (fold_rtx): Process SUBREGs and MEMs with equiv_constant, make
        simplification loop more straightforward by not calling fold_rtx
        recursively.
        (equiv_constant): Move here a small part of fold_rtx_subreg,
        do not call fold_rtx.  Call avoid_constant_pool_reference
        to process MEMs.
        * recog.c (canonicalize_change_group): New.
        * recog.h (canonicalize_change_group): New.

        * doc/invoke.texi (Optimization Options): Document fwprop.
        * doc/passes.texi (RTL passes): Document fwprop.



git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@118475 138bc75d-0d04-0410-961f-82ee72b054a4

1 files changed, 22 insertions, 0 deletions

diff --git a/gcc/recog.c b/gcc/recog.c
index a3948a729e0..18ad72f2d4e 100644
--- a/gcc/recog.c
+++ b/gcc/recog.c
@@ -238,6 +238,28 @@ validate_change (rtx object, rtx *loc, rtx new, int in_group)
     return apply_change_group ();
 }
 
+/* Keep X canonicalized if some changes have made it non-canonical; only
+   modifies the operands of X, not (for example) its code.  Simplifications
+   are not the job of this routine.
+
+   Return true if anything was changed.  */
+bool
+canonicalize_change_group (rtx insn, rtx x)
+{
+  if (COMMUTATIVE_P (x)
+      && swap_commutative_operands_p (XEXP (x, 0), XEXP (x, 1)))
+    {
+      /* Oops, the caller has made X no longer canonical.
+	 Let's redo the changes in the correct order.  */
+      rtx tem = XEXP (x, 0);
+      validate_change (insn, &XEXP (x, 0), XEXP (x, 1), 1);
+      validate_change (insn, &XEXP (x, 1), tem, 1);
+      return true;
+    }
+  else
+    return false;
+}
+  
 
 /* This subroutine of apply_change_group verifies whether the changes to INSN
    were valid; i.e. whether INSN can still be recognized.  */