Patchwork PowerPC64 large toc model

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Submitter Alan Modra
Date June 25, 2010, 10:43 a.m.
Message ID <20100625104301.GI21855@bubble.grove.modra.org>
Download mbox | patch
Permalink /patch/56901/
State New
Headers show

Comments

Alan Modra - June 25, 2010, 10:43 a.m.
On Tue, Jun 08, 2010 at 10:27:03PM +0930, Alan Modra wrote:
> -mcmodel=medium
>   uses 32-bit toc offsets and addresses static data, string constants
>   etc. relative to the toc pointer.  Limits data to around 2G.

We now have the mcmodel=medium optimization in the linker, so there
isn't much point in having this in gcc.  Patch preapproved by David
and committed after bootstrap and regression testing.

	* doc/invoke.texi: Delete mcmodel=medium from powerpc options.
	* config/rs6000/rs6000.h (enum rs6000_cmodel): Delete CMODEL_MEDIUM.
	* config/rs6000/linux64.h (SUBSUBTARGET_OVERRIDE_OPTIONS): Set
	CMODEL_LARGE as default.
	* config/rs6000/rs6000.c (rs6000_handle_option): Remove mcmodel=medium.
	(offsettable_ok_by_alignment): Delete.
	(rs6000_emit_move): Remove mcmodel=medium optimization.

Patch

Index: gcc/doc/invoke.texi
===================================================================
--- gcc/doc/invoke.texi	(revision 161360)
+++ gcc/doc/invoke.texi	(working copy)
@@ -14987,11 +14987,6 @@  scheduling parameters set by @option{-mt
 Generate PowerPC64 code for the small model: The TOC is limited to
 64k.
 
-@item -mcmodel=medium
-@opindex mcmodel=medium
-Generate PowerPC64 code for the medium model: The TOC and other static
-data may be up to a total of 4G in size.
-
 @item -mcmodel=large
 @opindex mcmodel=large
 Generate PowerPC64 code for the large model: The TOC may be up to 4G
Index: gcc/config/rs6000/linux64.h
===================================================================
--- gcc/config/rs6000/linux64.h	(revision 161360)
+++ gcc/config/rs6000/linux64.h	(working copy)
@@ -134,7 +134,7 @@  extern enum rs6000_cmodel cmodel;
 	  else							\
 	    {							\
 	      if (!rs6000_explicit_options.cmodel)		\
-		SET_CMODEL (CMODEL_MEDIUM);			\
+		SET_CMODEL (CMODEL_LARGE);			\
 	      if (cmodel != CMODEL_SMALL)			\
 		{						\
 		  TARGET_NO_FP_IN_TOC = 0;			\
Index: gcc/config/rs6000/rs6000.c
===================================================================
--- gcc/config/rs6000/rs6000.c	(revision 161360)
+++ gcc/config/rs6000/rs6000.c	(working copy)
@@ -3653,8 +3653,6 @@  rs6000_handle_option (size_t code, const
     case OPT_mcmodel_:
       if (strcmp (arg, "small") == 0)
 	cmodel = CMODEL_SMALL;
-      else if (strcmp (arg, "medium") == 0)
-	cmodel = CMODEL_MEDIUM;
       else if (strcmp (arg, "large") == 0)
 	cmodel = CMODEL_LARGE;
       else
@@ -6636,36 +6634,6 @@  rs6000_eliminate_indexed_memrefs (rtx op
 			       copy_addr_to_reg (XEXP (operands[1], 0)));
 }
 
-/* Return true if memory accesses to DECL are known to never straddle
-   a 32k boundary.  */
-
-static bool
-offsettable_ok_by_alignment (tree decl)
-{
-  unsigned HOST_WIDE_INT dsize;
-
-  /* Presume any compiler generated symbol_ref is suitably aligned.  */
-  if (!decl)
-    return true;
-
-  if (TREE_CODE (decl) != VAR_DECL
-      && TREE_CODE (decl) != PARM_DECL
-      && TREE_CODE (decl) != RESULT_DECL
-      && TREE_CODE (decl) != FIELD_DECL)
-    return true;
-
-  if (!host_integerp (DECL_SIZE_UNIT (decl), 1))
-    return false;
-
-  dsize = tree_low_cst (DECL_SIZE_UNIT (decl), 1);
-  if (dsize <= 1)
-    return true;
-  if (dsize > 32768)
-    return false;
-
-  return DECL_ALIGN_UNIT (decl) >= dsize;
-}
-
 /* Emit a move from SOURCE to DEST in mode MODE.  */
 void
 rs6000_emit_move (rtx dest, rtx source, enum machine_mode mode)
@@ -6979,16 +6947,11 @@  rs6000_emit_move (rtx dest, rtx source, 
       /* If this is a SYMBOL_REF that refers to a constant pool entry,
 	 and we have put it in the TOC, we just need to make a TOC-relative
 	 reference to it.  */
-      if ((TARGET_TOC
-	   && GET_CODE (operands[1]) == SYMBOL_REF
-	   && constant_pool_expr_p (operands[1])
-	   && ASM_OUTPUT_SPECIAL_POOL_ENTRY_P (get_pool_constant (operands[1]),
-					       get_pool_mode (operands[1])))
-	  || (TARGET_CMODEL == CMODEL_MEDIUM
-	      && GET_CODE (operands[1]) == SYMBOL_REF
-	      && !CONSTANT_POOL_ADDRESS_P (operands[1])
-	      && SYMBOL_REF_LOCAL_P (operands[1])
-	      && offsettable_ok_by_alignment (SYMBOL_REF_DECL (operands[1]))))
+      if (TARGET_TOC
+	  && GET_CODE (operands[1]) == SYMBOL_REF
+	  && constant_pool_expr_p (operands[1])
+	  && ASM_OUTPUT_SPECIAL_POOL_ENTRY_P (get_pool_constant (operands[1]),
+					      get_pool_mode (operands[1])))
 	{
 	  rtx reg = NULL_RTX;
 	  if (TARGET_CMODEL != CMODEL_SMALL)
Index: gcc/config/rs6000/rs6000.h
===================================================================
--- gcc/config/rs6000/rs6000.h	(revision 161360)
+++ gcc/config/rs6000/rs6000.h	(working copy)
@@ -295,11 +295,9 @@  extern const char *host_detect_local_cpu
 
 /* Code model for 64-bit linux.
    small: 16-bit toc offsets.
-   medium: 32-bit toc offsets, static data and code within 2G of TOC pointer.
-   large: 32-bit toc offsets, no limit on static data and code.  */
+   large: 32-bit toc offsets.  */
 enum rs6000_cmodel {
   CMODEL_SMALL,
-  CMODEL_MEDIUM,
   CMODEL_LARGE
 };