Patchwork [i386] : Fix for PR/36834

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Submitter Kai Tietz
Date Dec. 3, 2010, 11:31 a.m.
Message ID <AANLkTikcaKnhwDyLAjjrrww4V1ej-AjbLcUa3t_cttCO@mail.gmail.com>
Download mbox | patch
Permalink /patch/74112/
State New
Headers show

Comments

Kai Tietz - Dec. 3, 2010, 11:31 a.m.
Hello,

this patch addresses described bug report at
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36834

ChangeLog

gcc/
2010-12-03  Kai Tietz

	PR target/36834
	* config/i386/i386.c (ix86_keep_aggregate_return_pointer):
	New local function.
	(ix86_return_pops_args): Use ix86_keep_aggregate_return_pointer
	function instead of KEEP_AGGREGATE_RETURN_POINTER.
	(ix86_handle_keep_aggregate_return_ptr_attrib): New handler.
	(ix86_attribute_table): Add new attributes
	dont_keep_aggregate_return_pointer and keep_aggregate_return_pointer.
	* doc/extend.texi (dont_keep_aggregate_return_pointer): Add
	attribute documentation.
	(keep_aggregate_return_pointer): Likewise.

gcc/testsuite/
2010-12-03  Kai Tietz

	PR target/36834
	* gcc.target/i386/aggregate-ret1.c: New.
	* gcc.target/i386/aggregate-ret2.c: New.

Tested for i686-w64-mingw32, x86_64-w64-mingw32, i686-pc-cygwin. Ok for apply?

Regards,
Kai
NightStrike - Dec. 14, 2010, 3:23 p.m.
On Fri, Dec 3, 2010 at 6:31 AM, Kai Tietz <ktietz70@googlemail.com> wrote:
> Hello,
>
> this patch addresses described bug report at
> http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36834
>
> ChangeLog
>
> gcc/
> 2010-12-03  Kai Tietz
>
>        PR target/36834
>        * config/i386/i386.c (ix86_keep_aggregate_return_pointer):
>        New local function.
>        (ix86_return_pops_args): Use ix86_keep_aggregate_return_pointer
>        function instead of KEEP_AGGREGATE_RETURN_POINTER.
>        (ix86_handle_keep_aggregate_return_ptr_attrib): New handler.
>        (ix86_attribute_table): Add new attributes
>        dont_keep_aggregate_return_pointer and keep_aggregate_return_pointer.
>        * doc/extend.texi (dont_keep_aggregate_return_pointer): Add
>        attribute documentation.
>        (keep_aggregate_return_pointer): Likewise.
>
> gcc/testsuite/
> 2010-12-03  Kai Tietz
>
>        PR target/36834
>        * gcc.target/i386/aggregate-ret1.c: New.
>        * gcc.target/i386/aggregate-ret2.c: New.
>
> Tested for i686-w64-mingw32, x86_64-w64-mingw32, i686-pc-cygwin. Ok for apply?
>
> Regards,
> Kai
>

Ping

Patch

Index: gcc/gcc/config/i386/i386.c
===================================================================
--- gcc.orig/gcc/config/i386/i386.c	2010-12-03 10:12:09.000000000 +0100
+++ gcc/gcc/config/i386/i386.c	2010-12-03 11:54:08.811957100 +0100
@@ -5428,6 +5428,19 @@  ix86_eax_live_at_start_p (void)
   return REGNO_REG_SET_P (df_get_live_out (ENTRY_BLOCK_PTR), 0);
 }
 
+static bool
+ix86_keep_aggregate_return_pointer (tree fntype)
+{
+  if (lookup_attribute ("keep_aggregate_return_pointer",
+			TYPE_ATTRIBUTES (fntype)))
+    return true;
+  if (lookup_attribute ("dont_keep_aggregate_return_pointer",
+			TYPE_ATTRIBUTES (fntype)))
+    return false;
+  
+  return KEEP_AGGREGATE_RETURN_POINTER != 0;
+}
+
 /* Value is the number of bytes of arguments automatically
    popped when returning from a subroutine call.
    FUNDECL is the declaration node of the function (as a tree),
@@ -5472,7 +5485,7 @@  ix86_return_pops_args (tree fundecl, tre
 
   /* Lose any fake structure return argument if it is passed on the stack.  */
   if (aggregate_value_p (TREE_TYPE (funtype), fundecl)
-      && !KEEP_AGGREGATE_RETURN_POINTER)
+      && !ix86_keep_aggregate_return_pointer (funtype))
     {
       int nregs = ix86_function_regparm (funtype, fundecl);
       if (nregs == 0)
@@ -29052,6 +29065,59 @@  x86_order_regs_for_local_alloc (void)
      reg_alloc_order [pos++] = 0;
 }
 
+/* Handle a "dont_keep_aggregate_return_pointer" or
+   "keep_aggregate_return_pointer" attribut; arguments as
+   in struct attribute_spec handler.  */
+static tree
+ix86_handle_keep_aggregate_return_ptr_attrib (tree *node, tree name,
+					      tree args ATTRIBUTE_UNUSED,
+					      int flags ATTRIBUTE_UNUSED,
+					      bool *no_add_attrs)
+{
+  if (TREE_CODE (*node) != FUNCTION_TYPE
+      && TREE_CODE (*node) != METHOD_TYPE
+      && TREE_CODE (*node) != FIELD_DECL
+      && TREE_CODE (*node) != TYPE_DECL)
+    {
+      warning (OPT_Wattributes, "%qE attribute only applies to functions",
+	       name);
+      *no_add_attrs = true;
+      return NULL_TREE;
+    }
+  if (TARGET_64BIT)
+    {
+      warning (OPT_Wattributes, "%qE attribute only available for 32-bit",
+	       name);
+      *no_add_attrs = true;
+      return NULL_TREE;
+    }
+  if (is_attribute_p ("dont_keep_aggregate_return_pointer", name))
+    {
+      if (lookup_attribute ("keep_aggregate_return_pointer",
+			    TYPE_ATTRIBUTES (*node)))
+        {
+	  error ("dont_keep_aggregate_return_pointer and "
+		 "keep_aggregate_return_pointer attributes "
+		 "are not compatible");
+	}
+      return NULL_TREE;
+    }
+  else if (is_attribute_p ("keep_aggregate_return_pointer", name))
+    {
+      if (lookup_attribute ("dont_keep_aggregate_return_pointer",
+			    TYPE_ATTRIBUTES (*node)))
+        {
+	  error ("keep_aggregate_return_pointer and "
+		 "dont_keep_aggregate_return_pointer attributes "
+		 "are not compatible");
+	}
+
+      return NULL_TREE;
+    }
+
+  return NULL_TREE;
+}
+
 /* Handle a "ms_abi" or "sysv" attribute; arguments as in
    struct attribute_spec.handler.  */
 static tree
@@ -32221,6 +32287,10 @@  static const struct attribute_spec ix86_
   { "ms_abi", 0, 0, false, true, true, ix86_handle_abi_attribute },
   { "sysv_abi", 0, 0, false, true, true, ix86_handle_abi_attribute },
   { "ms_hook_prologue", 0, 0, true, false, false, ix86_handle_fndecl_attribute },
+  { "dont_keep_aggregate_return_pointer", 0, 0, false, true, true,
+    ix86_handle_keep_aggregate_return_ptr_attrib },
+  { "keep_aggregate_return_pointer", 0, 0, false, true, true,
+    ix86_handle_keep_aggregate_return_ptr_attrib },
   /* End element.  */
   { NULL,        0, 0, false, false, false, NULL }
 };
Index: gcc/gcc/doc/extend.texi
===================================================================
--- gcc.orig/gcc/doc/extend.texi	2010-11-22 14:41:40.000000000 +0100
+++ gcc/gcc/doc/extend.texi	2010-12-03 12:20:06.487884300 +0100
@@ -2823,6 +2823,19 @@  when targeting Windows.  On all other sy
 Note, the @code{ms_abi} attribute for Windows targets currently requires
 the @option{-maccumulate-outgoing-args} option.
 
+@item dont_keep_aggregate_return_pointer/keep_aggregate_return_pointer
+@cindex @code{dont_keep_aggregate_return_pointer} attribute
+@cindex @code{keep_aggregate_return_pointer} attribute
+
+On 32-bit i?86-*-* targets, you can control by those attributes for
+aggregate return in memory, if the caller is responsible to pop the hidden
+pointer together with the rest of the arguments, or if the callee is responsible
+to pop hidden pointer.
+
+For i?86-netware, the caller pops the stack for the hidden arguments pointing
+to aggregate return value.  This differs from the default i386 ABI which assumes
+that the callee pops the stack for hidden pointer.
+
 @item ms_hook_prologue
 @cindex @code{ms_hook_prologue} attribute
 
Index: gcc/gcc/testsuite/gcc.target/i386/aggregate-ret1.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ gcc/gcc/testsuite/gcc.target/i386/aggregate-ret1.c	2010-12-03 12:04:11.558266500 +0100
@@ -0,0 +1,28 @@ 
+/* target/36834 */
+/* Check that, with keep_aggregate_return_pointer attribute,  callee does
+   not pop the stack for the implicit pointer arg when returning a large
+   structure in memory.  */
+/* { dg-do compile { target i?86-*-* } } */
+
+struct foo {
+  int a;
+  int b;
+  int c;
+  int d;
+};
+
+__attribute__ ((keep_aggregate_return_pointer))
+struct foo
+bar (void)
+{
+  struct foo retval;
+  retval.a = 1;
+  retval.b = 2;
+  retval.c = 3;
+  retval.d = 4;
+  return retval;
+}
+
+/* { dg-final { scan-assembler-not "ret\[ \t\]\\\$4" } } */
+
+
Index: gcc/gcc/testsuite/gcc.target/i386/aggregate-ret2.c
===================================================================
--- /dev/null	1970-01-01 00:00:00.000000000 +0000
+++ gcc/gcc/testsuite/gcc.target/i386/aggregate-ret2.c	2010-12-03 12:07:19.688082500 +0100
@@ -0,0 +1,28 @@ 
+/* target/36834 */
+/* Check that, with dont_keep_aggregate_return_pointer attribute,  callee
+   pops the stack for the implicit pointer arg when returning a large
+   structure in memory.  */
+/* { dg-do compile { target i?86-*-* } } */
+
+struct foo {
+  int a;
+  int b;
+  int c;
+  int d;
+};
+
+__attribute__ ((dont_keep_aggregate_return_pointer))
+struct foo
+bar (void)
+{
+  struct foo retval;
+  retval.a = 1;
+  retval.b = 2;
+  retval.c = 3;
+  retval.d = 4;
+  return retval;
+}
+
+/* { dg-final { scan-assembler "ret\[ \t\]\\\$4" } } */
+
+