[PATCH, pretty-ipa] Use useless_type_conversion_p() instead of types_compatible_p()

[Martin Jambor <mjambor at suse dot cz>]

Hi,

SRAs in pretty-ipa branch  use unnecessarily strict predicate for type
compatibility, checking  that the types  need no conversion  both ways
when actually only one direction  is necessary.  The patch below fixes
this  by  replacing  all  uses  of types_compatible_p()  by  calls  to
useless_type_conversion_p(),  sometimes   swapping  the  arguments  as
necessary.

Bootstrapped and tested on x86_64-linux, I am about to commit it
shortly.

Thanks,

Martin


2009-04-02  Martin Jambor  <mjambor@suse.cz>

	* ipa-sra.c (sra_ipa_modify_expr): Use useless_type_conversion_p
	instead of types_compatible_p.
	(build_access_expr_1): Use useless_type_conversion_p instead of
	types_compatible_p.
	(sra_intra_modify_expr): Use useless_type_conversion_p instead of
	types_compatible_p.
	(load_assign_lhs_subreplacements): Use useless_type_conversion_p
	instead of types_compatible_p.
	(sra_intra_modify_assign): Use useless_type_conversion_p instead of
	types_compatible_p.

Index: isra/gcc/ipa-sra.c
===================================================================
--- isra.orig/gcc/ipa-sra.c
+++ isra/gcc/ipa-sra.c
@@ -2338,7 +2338,7 @@ sra_ipa_modify_expr (tree *expr, gimple_
       fprintf (dump_file, "\n");
     }
 
-  if (!types_compatible_p (cand->type, TREE_TYPE (*expr)))
+  if (!useless_type_conversion_p (TREE_TYPE (*expr), cand->type))
     {
       tree vce = build1 (VIEW_CONVERT_EXPR, TREE_TYPE (*expr), src);
       *expr = vce;
@@ -2381,7 +2381,8 @@ build_access_expr_1 (tree *res, tree typ
       tree tr_size, index;
       HOST_WIDE_INT el_size;
 
-      if (offset == 0 && exp_type && types_compatible_p (type, exp_type))
+      if (offset == 0 && exp_type
+	  && useless_type_conversion_p (exp_type, type))
 	return true;
 
       switch (TREE_CODE (type))
@@ -3437,7 +3438,7 @@ sra_intra_modify_expr (tree *expr, gimpl
       gimple *stmt = gsi_stmt_ptr (gsi);
 
       push_stmt_changes (stmt);
-      if (!types_compatible_p (type, access->type))
+      if (!useless_type_conversion_p (type, access->type))
 	sra_fix_incompatible_types_for_expr (expr, type, access, gsi, write);
       else
 	*expr = get_access_replacement (access);
@@ -3507,7 +3508,7 @@ load_assign_lhs_subreplacements (struct
 	    {
 	      gimple stmt;
 
-	      if (types_compatible_p (lacc->type, racc->type))
+	      if (useless_type_conversion_p (lacc->type, racc->type))
 		stmt = gimple_build_assign (get_access_replacement (lacc),
 					    get_access_replacement (racc));
 	      else
@@ -3783,7 +3784,7 @@ sra_intra_modify_assign (gimple *stmt, g
     {
       pop_stmt_changes (stmt);
 
-      if (!types_compatible_p (ltype, rtype))
+      if (!useless_type_conversion_p (ltype, rtype))
 	fix_modified_assign_compatibility (gsi, stmt, lacc, racc,
 					   lhs, &rhs, ltype, rtype);
     }