gcc: another round of merges from the gcc pre-43 branch.

Bring The following revisions from the gcc43 branch[1]:

118360, 118361, 118363, 118576, 119820,
123906, 125246, and 125721.

They all have in common that the were merged long ago
into Apple's gcc and should help improve the general
quality of the compiler and make it easier to bring
new features from Apple's gcc42.

For details please review the additions to the files:
gcc/ChangeLog.gcc43
gcc/cp/ChangeLog.gcc43 (new, adds previous revisions)

Reference:
[1] http://gcc.gnu.org/viewcvs/gcc/trunk/?pathrev=126700

Obtained from:	gcc pre4.3 (GPLv2) branch
MFC after:	3 weeks

1 files changed, 97 insertions, 0 deletions

diff --git a/contrib/gcc/builtins.c b/contrib/gcc/builtins.c
index a65d725..ffae159 100644
--- a/contrib/gcc/builtins.c
+++ b/contrib/gcc/builtins.c
@@ -4589,6 +4589,30 @@ expand_builtin_alloca (tree arglist, rtx target)
   return result;
 }
 
+/* Expand a call to a bswap builtin.  The arguments are in ARGLIST.  MODE
+   is the mode to expand with.  */
+
+static rtx
+expand_builtin_bswap (tree arglist, rtx target, rtx subtarget)
+{
+  enum machine_mode mode;
+  tree arg;
+  rtx op0;
+
+  if (!validate_arglist (arglist, INTEGER_TYPE, VOID_TYPE))
+    return 0;
+
+  arg = TREE_VALUE (arglist);
+  mode = TYPE_MODE (TREE_TYPE (arg));
+  op0 = expand_expr (arg, subtarget, VOIDmode, 0);
+
+  target = expand_unop (mode, bswap_optab, op0, target, 1);
+
+  gcc_assert (target);
+
+  return convert_to_mode (mode, target, 0);
+}
+
 /* Expand a call to a unary builtin.  The arguments are in ARGLIST.
    Return 0 if a normal call should be emitted rather than expanding the
    function in-line.  If convenient, the result should be placed in TARGET.
@@ -5877,6 +5901,14 @@ expand_builtin (tree exp, rtx target, rtx subtarget, enum machine_mode mode,
       expand_stack_restore (TREE_VALUE (arglist));
       return const0_rtx;
 
+    case BUILT_IN_BSWAP32:
+    case BUILT_IN_BSWAP64:
+      target = expand_builtin_bswap (arglist, target, subtarget);
+
+      if (target)
+	return target;
+      break;
+
     CASE_INT_FN (BUILT_IN_FFS):
     case BUILT_IN_FFSIMAX:
       target = expand_builtin_unop (target_mode, arglist, target,
@@ -7539,6 +7571,67 @@ fold_builtin_bitop (tree fndecl, tree arglist)
   return NULL_TREE;
 }
 
+/* Fold function call to builtin_bswap and the long and long long
+   variants.  Return NULL_TREE if no simplification can be made.  */
+static tree
+fold_builtin_bswap (tree fndecl, tree arglist)
+{
+  tree arg;
+
+  if (! validate_arglist (arglist, INTEGER_TYPE, VOID_TYPE))
+    return 0;
+
+  /* Optimize constant value.  */
+  arg = TREE_VALUE (arglist);
+  if (TREE_CODE (arg) == INTEGER_CST && ! TREE_CONSTANT_OVERFLOW (arg))
+    {
+      HOST_WIDE_INT hi, width, r_hi = 0;
+      unsigned HOST_WIDE_INT lo, r_lo = 0;
+      tree type;
+
+      type = TREE_TYPE (arg);
+      width = TYPE_PRECISION (type);
+      lo = TREE_INT_CST_LOW (arg);
+      hi = TREE_INT_CST_HIGH (arg);
+
+      switch (DECL_FUNCTION_CODE (fndecl))
+	{
+	  case BUILT_IN_BSWAP32:
+	  case BUILT_IN_BSWAP64:
+	    {
+	      int s;
+
+	      for (s = 0; s < width; s += 8)
+		{
+		  int d = width - s - 8;
+		  unsigned HOST_WIDE_INT byte;
+
+		  if (s < HOST_BITS_PER_WIDE_INT)
+		    byte = (lo >> s) & 0xff;
+		  else
+		    byte = (hi >> (s - HOST_BITS_PER_WIDE_INT)) & 0xff;
+
+		  if (d < HOST_BITS_PER_WIDE_INT)
+		    r_lo |= byte << d;
+		  else
+		    r_hi |= byte << (d - HOST_BITS_PER_WIDE_INT);
+		}
+	    }
+
+	    break;
+
+	default:
+	  gcc_unreachable ();
+	}
+
+      if (width < HOST_BITS_PER_WIDE_INT)
+	return build_int_cst (TREE_TYPE (TREE_TYPE (fndecl)), r_lo);
+      else
+	return build_int_cst_wide (TREE_TYPE (TREE_TYPE (fndecl)), r_lo, r_hi);
+    }
+
+  return NULL_TREE;
+}
 /* Return true if EXPR is the real constant contained in VALUE.  */
 
 static bool
@@ -9053,6 +9146,10 @@ fold_builtin_1 (tree fndecl, tree arglist, bool ignore)
     CASE_FLT_FN (BUILT_IN_LLRINT):
       return fold_fixed_mathfn (fndecl, arglist);
 
+    case BUILT_IN_BSWAP32:
+    case BUILT_IN_BSWAP64:
+      return fold_builtin_bswap (fndecl, arglist);
+
     CASE_INT_FN (BUILT_IN_FFS):
     CASE_INT_FN (BUILT_IN_CLZ):
     CASE_INT_FN (BUILT_IN_CTZ):