[committed] Fix tree sharing in mips_gimplify_va_arg_expr

[Richard Sandiford]

Hmm.  It seems I've been using mipsisa64-elfoabi so much that it's
many months since I last tried mipsisa64-elf.  Now I have, and a lot
of tests fail due to invalid tree sharing in mips_gimplify_va_arg_expr.

Tested on mipsisa64-elf and applied.

Richard


gcc/
	* config/mips/mips.c (mips_gimplify_va_arg_expr): Fix invalid
	tree sharing.

Index: gcc/config/mips/mips.c
===================================================================
--- gcc/config/mips/mips.c	2009-02-15 10:41:59.000000000 +0000
+++ gcc/config/mips/mips.c	2009-02-15 10:52:15.000000000 +0000
@@ -5292,10 +5292,10 @@ mips_gimplify_va_arg_expr (tree valist, 
       if (GET_MODE_CLASS (TYPE_MODE (type)) == MODE_FLOAT
 	  && GET_MODE_SIZE (TYPE_MODE (type)) <= UNITS_PER_FPVALUE)
 	{
-	  top = build3 (COMPONENT_REF, TREE_TYPE (f_ftop), valist, f_ftop,
-		        NULL_TREE);
-	  off = build3 (COMPONENT_REF, TREE_TYPE (f_foff), valist, f_foff,
-		        NULL_TREE);
+	  top = build3 (COMPONENT_REF, TREE_TYPE (f_ftop),
+			unshare_expr (valist), f_ftop, NULL_TREE);
+	  off = build3 (COMPONENT_REF, TREE_TYPE (f_foff),
+			unshare_expr (valist), f_foff, NULL_TREE);
 
 	  /* When va_start saves FPR arguments to the stack, each slot
 	     takes up UNITS_PER_HWFPVALUE bytes, regardless of the
@@ -5322,17 +5322,17 @@ mips_gimplify_va_arg_expr (tree valist, 
 	}
       else
 	{
-	  top = build3 (COMPONENT_REF, TREE_TYPE (f_gtop), valist, f_gtop,
-		        NULL_TREE);
-	  off = build3 (COMPONENT_REF, TREE_TYPE (f_goff), valist, f_goff,
-		        NULL_TREE);
+	  top = build3 (COMPONENT_REF, TREE_TYPE (f_gtop),
+			unshare_expr (valist), f_gtop, NULL_TREE);
+	  off = build3 (COMPONENT_REF, TREE_TYPE (f_goff),
+			unshare_expr (valist), f_goff, NULL_TREE);
 	  rsize = (size + UNITS_PER_WORD - 1) & -UNITS_PER_WORD;
 	  if (rsize > UNITS_PER_WORD)
 	    {
 	      /* [1] Emit code for: off &= -rsize.	*/
-	      t = build2 (BIT_AND_EXPR, TREE_TYPE (off), off,
+	      t = build2 (BIT_AND_EXPR, TREE_TYPE (off), unshare_expr (off),
 			  build_int_cst (TREE_TYPE (off), -rsize));
-	      gimplify_assign (off, t, pre_p);
+	      gimplify_assign (unshare_expr (off), t, pre_p);
 	    }
 	  osize = rsize;
 	}
@@ -5363,12 +5363,14 @@ mips_gimplify_va_arg_expr (tree valist, 
 	{
 	  /* [9] Emit: ovfl = ((intptr_t) ovfl + osize - 1) & -osize.  */
 	  u = size_int (osize - 1);
-	  t = build2 (POINTER_PLUS_EXPR, TREE_TYPE (ovfl), ovfl, u);
+	  t = build2 (POINTER_PLUS_EXPR, TREE_TYPE (ovfl),
+		      unshare_expr (ovfl), u);
 	  t = fold_convert (sizetype, t);
 	  u = size_int (-osize);
 	  t = build2 (BIT_AND_EXPR, sizetype, t, u);
 	  t = fold_convert (TREE_TYPE (ovfl), t);
-	  align = build2 (MODIFY_EXPR, TREE_TYPE (ovfl), ovfl, t);
+	  align = build2 (MODIFY_EXPR, TREE_TYPE (ovfl),
+			  unshare_expr (ovfl), t);
 	}
       else
 	align = NULL;