Gcc 3.4.4 release.

1 files changed, 107 insertions, 5 deletions

diff --git a/contrib/gcc/dojump.c b/contrib/gcc/dojump.c
index 6b9569b..b232576 100644
--- a/contrib/gcc/dojump.c
+++ b/contrib/gcc/dojump.c
@@ -1,6 +1,6 @@
 /* Convert tree expression to rtl instructions, for GNU compiler.
    Copyright (C) 1988, 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999,
-   2000, 2001, 2002, 2003 Free Software Foundation, Inc.
+   2000, 2001, 2002, 2003, 2004 Free Software Foundation, Inc.
 
 This file is part of GCC.
 
@@ -33,7 +33,9 @@ Software Foundation, 59 Temple Place - Suite 330, Boston, MA
 #include "expr.h"
 #include "optabs.h"
 #include "langhooks.h"
+#include "ggc.h"
 
+static bool prefer_and_bit_test (enum machine_mode, int);
 static void do_jump_by_parts_greater (tree, int, rtx, rtx);
 static void do_jump_by_parts_equality (tree, rtx, rtx);
 static void do_compare_and_jump	(tree, enum rtx_code, enum rtx_code, rtx,
@@ -48,6 +50,15 @@ init_pending_stack_adjust (void)
   pending_stack_adjust = 0;
 }
 
+/* Discard any pending stack adjustment.  This avoid relying on the
+   RTL optimizers to remove useless adjustments when we know the
+   stack pointer value is dead.  */
+void discard_pending_stack_adjust (void)
+{
+  stack_pointer_delta -= pending_stack_adjust;
+  pending_stack_adjust = 0;
+}
+
 /* When exiting from function, if safe, clear out any pending stack adjust
    so the adjustment won't get done.
 
@@ -62,10 +73,7 @@ clear_pending_stack_adjust (void)
       && EXIT_IGNORE_STACK
       && ! (DECL_INLINE (current_function_decl) && ! flag_no_inline)
       && ! flag_inline_functions)
-    {
-      stack_pointer_delta -= pending_stack_adjust,
-      pending_stack_adjust = 0;
-    }
+    discard_pending_stack_adjust ();
 }
 
 /* Pop any previously-pushed arguments that have not been popped yet.  */
@@ -101,6 +109,45 @@ jumpif (tree exp, rtx label)
   do_jump (exp, NULL_RTX, label);
 }
 
+/* Used internally by prefer_and_bit_test.  */
+
+static GTY(()) rtx and_reg;
+static GTY(()) rtx and_test;
+static GTY(()) rtx shift_test;
+
+/* Compare the relative costs of "(X & (1 << BITNUM))" and "(X >> BITNUM) & 1"
+   where X is an arbitrary register of mode MODE.  Return true if the former
+   is preferred.  */
+
+static bool
+prefer_and_bit_test (enum machine_mode mode, int bitnum)
+{
+  if (and_test == 0)
+    {
+      /* Set up rtxes for the two variations.  Use NULL as a placeholder
+	 for the BITNUM-based constants.  */
+      and_reg = gen_rtx_REG (mode, FIRST_PSEUDO_REGISTER);
+      and_test = gen_rtx_AND (mode, and_reg, NULL);
+      shift_test = gen_rtx_AND (mode, gen_rtx_ASHIFTRT (mode, and_reg, NULL),
+				const1_rtx);
+    }
+  else
+    {
+      /* Change the mode of the previously-created rtxes.  */
+      PUT_MODE (and_reg, mode);
+      PUT_MODE (and_test, mode);
+      PUT_MODE (shift_test, mode);
+      PUT_MODE (XEXP (shift_test, 0), mode);
+    }
+
+  /* Fill in the integers.  */
+  XEXP (and_test, 1) = GEN_INT ((unsigned HOST_WIDE_INT) 1 << bitnum);
+  XEXP (XEXP (shift_test, 0), 1) = GEN_INT (bitnum);
+
+  return (rtx_cost (and_test, IF_THEN_ELSE)
+	  <= rtx_cost (shift_test, IF_THEN_ELSE));
+}
+
 /* Generate code to evaluate EXP and jump to IF_FALSE_LABEL if
    the result is zero, or IF_TRUE_LABEL if the result is one.
    Either of IF_FALSE_LABEL and IF_TRUE_LABEL may be zero,
@@ -206,6 +253,59 @@ do_jump (tree exp, rtx if_false_label, rtx if_true_label)
       break;
 
     case BIT_AND_EXPR:
+      /* fold_single_bit_test() converts (X & (1 << C)) into (X >> C) & 1.
+	 See if the former is preferred for jump tests and restore it
+	 if so.  */
+      if (integer_onep (TREE_OPERAND (exp, 1)))
+	{
+	  tree exp0 = TREE_OPERAND (exp, 0);
+	  rtx set_label, clr_label;
+
+	  /* Strip narrowing integral type conversions.  */
+	  while ((TREE_CODE (exp0) == NOP_EXPR
+		  || TREE_CODE (exp0) == CONVERT_EXPR
+		  || TREE_CODE (exp0) == NON_LVALUE_EXPR)
+		 && TREE_OPERAND (exp0, 0) != error_mark_node
+		 && TYPE_PRECISION (TREE_TYPE (exp0))
+		    <= TYPE_PRECISION (TREE_TYPE (TREE_OPERAND (exp0, 0))))
+	    exp0 = TREE_OPERAND (exp0, 0);
+
+	  /* "exp0 ^ 1" inverts the sense of the single bit test.  */
+	  if (TREE_CODE (exp0) == BIT_XOR_EXPR
+	      && integer_onep (TREE_OPERAND (exp0, 1)))
+	    {
+	      exp0 = TREE_OPERAND (exp0, 0);
+	      clr_label = if_true_label;
+	      set_label = if_false_label;
+	    }
+	  else
+	    {
+	      clr_label = if_false_label;
+	      set_label = if_true_label;
+	    }
+
+	  if (TREE_CODE (exp0) == RSHIFT_EXPR)
+	    {
+	      tree arg = TREE_OPERAND (exp0, 0);
+	      tree shift = TREE_OPERAND (exp0, 1);
+	      tree argtype = TREE_TYPE (arg);
+	      if (TREE_CODE (shift) == INTEGER_CST
+		  && compare_tree_int (shift, 0) >= 0
+		  && compare_tree_int (shift, HOST_BITS_PER_WIDE_INT) < 0
+		  && prefer_and_bit_test (TYPE_MODE (argtype),
+					  TREE_INT_CST_LOW (shift)))
+		{
+		  HOST_WIDE_INT mask = (HOST_WIDE_INT) 1
+				       << TREE_INT_CST_LOW (shift);
+		  tree t = build_int_2 (mask, 0);
+		  TREE_TYPE (t) = argtype;
+		  do_jump (build (BIT_AND_EXPR, argtype, arg, t),
+			   clr_label, set_label);
+		  break;
+		}
+	    }
+	}
+
       /* If we are AND'ing with a small constant, do this comparison in the
          smallest type that fits.  If the machine doesn't have comparisons
          that small, it will be converted back to the wider comparison.
@@ -997,3 +1097,5 @@ do_compare_and_jump (tree exp, enum rtx_code signed_code,
                             ? expr_size (TREE_OPERAND (exp, 0)) : NULL_RTX),
                            if_false_label, if_true_label);
 }
+
+#include "gt-dojump.h"