From patchwork Fri Sep 17 16:13:22 2010
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Subject: Allow in-place gimple folding of OBJ_TYPE_REF
From: Martin Jambor <mjambor@suse.cz>
X-Patchwork-Id: 65086
Message-Id: <20100917161321.GH4049@virgil.arch.suse.de>
To: GCC Patches <gcc-patches@gcc.gnu.org>
Cc: Richard Guenther <rguenther@suse.de>
Date: Fri, 17 Sep 2010 18:13:22 +0200

Hi,

there is no reason why OBJ_TYPE_REF calls cannot be folded in-place.
This patch allows that.

Bootstrapped and tested on x86_64-linux, OK for trunk?

Thanks,

Martin



2010-09-16  Martin Jambor  <mjambor@suse.cz>

	* gimple-fold.c (fold_gimple_call): New parameter inplace, do not fold
	builtins if it is true.
	(fold_stmt_1): Call, fold_gimple_call always, pass inplace as a
	parameter.

Index: icln/gcc/gimple-fold.c
===================================================================
--- icln.orig/gcc/gimple-fold.c
+++ icln/gcc/gimple-fold.c
@@ -1482,7 +1482,7 @@ gimple_fold_obj_type_ref (tree ref, tree
    It is assumed that the operands have been previously folded.  */
 
 static bool
-fold_gimple_call (gimple_stmt_iterator *gsi)
+fold_gimple_call (gimple_stmt_iterator *gsi, bool inplace)
 {
   gimple stmt = gsi_stmt (*gsi);
 
@@ -1490,7 +1490,7 @@ fold_gimple_call (gimple_stmt_iterator *
 
   /* Check for builtins that CCP can handle using information not
      available in the generic fold routines.  */
-  if (callee && DECL_BUILT_IN (callee))
+  if (!inplace && callee && DECL_BUILT_IN (callee))
     {
       tree result = gimple_fold_builtin (stmt);
 
@@ -1507,7 +1507,6 @@ fold_gimple_call (gimple_stmt_iterator *
          there requires that we create a new CALL_EXPR, and that requires
          copying EH region info to the new node.  Easier to just do it
          here where we can just smash the call operand.  */
-      /* ??? Is there a good reason not to do this in fold_stmt_inplace?  */
       callee = gimple_call_fn (stmt);
       if (TREE_CODE (callee) == OBJ_TYPE_REF
           && TREE_CODE (OBJ_TYPE_REF_OBJECT (callee)) == ADDR_EXPR)
@@ -1574,9 +1573,7 @@ fold_stmt_1 (gimple_stmt_iterator *gsi,
 		changed = true;
 	      }
 	  }
-      /* The entire statement may be replaced in this case.  */
-      if (!inplace)
-	changed |= fold_gimple_call (gsi);
+      changed |= fold_gimple_call (gsi, inplace);
       break;
 
     case GIMPLE_ASM: