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[Ada] Fix vectorization glitch on some platforms

Message ID 201112181539.05070.ebotcazou@adacore.com
State New
Headers show

Commit Message

Eric Botcazou Dec. 18, 2011, 2:39 p.m. UTC 
This fixes a missed vectorization on platforms where fat pointers are passed by 
reference (most 32-bit RISC architectures and x86-64/Windows).

Tested on i586-suse-linux, applied on the mainline.


2011-12-18  Eric Botcazou  <ebotcazou@adacore.com>

	* gcc-interface/decl.c (gnat_to_gnu_param): Add comment about double
	reference and DECL_POINTS_TO_READONLY_P.
	* gcc-interface/trans.c (Identifier_to_gnu) <by_ref>: Always set the
	TREE_READONLY flag on the first dereference of a double dereference.
diff mbox

Patch

Index: gcc-interface/decl.c
===================================================================
--- gcc-interface/decl.c	(revision 182433)
+++ gcc-interface/decl.c	(working copy)
@@ -5587,6 +5587,10 @@  gnat_to_gnu_param (Entity_Id gnat_param,
   DECL_BY_COMPONENT_PTR_P (gnu_param) = by_component_ptr;
   DECL_BY_DESCRIPTOR_P (gnu_param) = (mech == By_Descriptor ||
                                       mech == By_Short_Descriptor);
+  /* Note that, in case of a parameter passed by double reference, the
+     DECL_POINTS_TO_READONLY_P flag is meant for the second reference.
+     The first reference always points to read-only, as it points to
+     the second reference, i.e. the reference to the actual parameter.  */
   DECL_POINTS_TO_READONLY_P (gnu_param)
     = (ro_param && (by_ref || by_component_ptr));
   DECL_CAN_NEVER_BE_NULL_P (gnu_param) = Can_Never_Be_Null (gnat_param);
Index: gcc-interface/trans.c
===================================================================
--- gcc-interface/trans.c	(revision 182433)
+++ gcc-interface/trans.c	(working copy)
@@ -1038,8 +1038,9 @@  Identifier_to_gnu (Node_Id gnat_node, tr
 	  if (TREE_CODE (gnu_result) == INDIRECT_REF)
 	    TREE_THIS_NOTRAP (gnu_result) = 1;
 
-	  if (read_only)
-	    TREE_READONLY (gnu_result) = 1;
+	  /* The first reference, in case of a double reference, always points
+	     to read-only, see gnat_to_gnu_param for the rationale.  */
+	  TREE_READONLY (gnu_result) = 1;
 	}
 
       /* If it's a PARM_DECL to foreign convention subprogram, convert it.  */