tree-dfa.c (get_ref_base_and_extent): Replace bit_offset and computations with it with a HOST_WIDE_INT variable.

2007-03-27  Richard Guenther  <rguenther@suse.de>

	* tree-dfa.c (get_ref_base_and_extent): Replace bit_offset and
	computations with it with a HOST_WIDE_INT variable.

From-SVN: r123259

2 files changed, 28 insertions, 30 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 1f5a44c..7600b6e 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2007-03-27  Richard Guenther  <rguenther@suse.de>
+
+	* tree-dfa.c (get_ref_base_and_extent): Replace bit_offset and
+	computations with it with a HOST_WIDE_INT variable.  
+
 2007-03-26  Mike Stump  <mrs@apple.com>
 
 	* config/rs6000/darwin.h (DARWIN_MINVERSION_SPEC): Add
diff --git a/gcc/tree-dfa.c b/gcc/tree-dfa.c
index a1200eb..b23c531 100644
--- a/gcc/tree-dfa.c
+++ b/gcc/tree-dfa.c
@@ -859,7 +859,7 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
   HOST_WIDE_INT bitsize = -1;
   HOST_WIDE_INT maxsize = -1;
   tree size_tree = NULL_TREE;
-  tree bit_offset = bitsize_zero_node;
+  HOST_WIDE_INT bit_offset = 0;
   bool seen_variable_array_ref = false;
 
   gcc_assert (!SSA_VAR_P (exp));
@@ -896,8 +896,7 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
       switch (TREE_CODE (exp))
 	{
 	case BIT_FIELD_REF:
-	  bit_offset = size_binop (PLUS_EXPR, bit_offset,
-				   TREE_OPERAND (exp, 2));
+	  bit_offset += tree_low_cst (TREE_OPERAND (exp, 2), 1);
 	  break;
 
 	case COMPONENT_REF:
@@ -907,14 +906,11 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
 
 	    if (this_offset && TREE_CODE (this_offset) == INTEGER_CST)
 	      {
-		this_offset = size_binop (MULT_EXPR,
-					  fold_convert (bitsizetype,
-							this_offset),
-					  bitsize_unit_node);
-		bit_offset = size_binop (PLUS_EXPR,
-				         bit_offset, this_offset);
-		bit_offset = size_binop (PLUS_EXPR, bit_offset,
-					 DECL_FIELD_BIT_OFFSET (field));
+		HOST_WIDE_INT hthis_offset = tree_low_cst (this_offset, 1);
+
+		hthis_offset *= BITS_PER_UNIT;
+		bit_offset += hthis_offset;
+		bit_offset += tree_low_cst (DECL_FIELD_BIT_OFFSET (field), 1);
 	      }
 	    else
 	      {
@@ -925,8 +921,7 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
 		if (maxsize != -1
 		    && csize && host_integerp (csize, 1))
 		  {
-		    maxsize = (TREE_INT_CST_LOW (csize)
-			       - TREE_INT_CST_LOW (bit_offset));
+		    maxsize = (TREE_INT_CST_LOW (csize) - bit_offset);
 		  }
 		else
 		  maxsize = -1;
@@ -941,17 +936,17 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
 	    tree low_bound = array_ref_low_bound (exp);
 	    tree unit_size = array_ref_element_size (exp);
 
-	    if (! integer_zerop (low_bound))
-	      index = fold_build2 (MINUS_EXPR, TREE_TYPE (index),
-				   index, low_bound);
-	    index = size_binop (MULT_EXPR,
-				fold_convert (sizetype, index), unit_size);
-	    if (TREE_CODE (index) == INTEGER_CST)
+	    /* If the resulting bit-offset is constant, track it.  */
+	    if (host_integerp (index, 0)
+		&& host_integerp (low_bound, 0)
+		&& host_integerp (unit_size, 1))
 	      {
-		index = size_binop (MULT_EXPR,
-				    fold_convert (bitsizetype, index),
-				    bitsize_unit_node);
-		bit_offset = size_binop (PLUS_EXPR, bit_offset, index);
+		HOST_WIDE_INT hindex = tree_low_cst (index, 0);
+
+		hindex -= tree_low_cst (low_bound, 0);
+		hindex *= tree_low_cst (unit_size, 1);
+		hindex *= BITS_PER_UNIT;
+		bit_offset += hindex;
 
 		/* An array ref with a constant index up in the structure
 		   hierarchy will constrain the size of any variable array ref
@@ -967,8 +962,7 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
 		if (maxsize != -1
 		    && asize && host_integerp (asize, 1))
 		  {
-		    maxsize = (TREE_INT_CST_LOW (asize)
-			       - TREE_INT_CST_LOW (bit_offset));
+		    maxsize = (TREE_INT_CST_LOW (asize) - bit_offset);
 		  }
 		else
 		  maxsize = -1;
@@ -984,8 +978,7 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
 	  break;
 
 	case IMAGPART_EXPR:
-	  bit_offset = size_binop (PLUS_EXPR, bit_offset,
-				   bitsize_int (bitsize));
+	  bit_offset += bitsize;
 	  break;
 
 	case VIEW_CONVERT_EXPR:
@@ -1011,14 +1004,14 @@ get_ref_base_and_extent (tree exp, HOST_WIDE_INT *poffset,
   if (seen_variable_array_ref
       && maxsize != -1
       && host_integerp (TYPE_SIZE (TREE_TYPE (exp)), 1)
-      && TREE_INT_CST_LOW (bit_offset) + maxsize
-	 == TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp))))
+      && bit_offset + maxsize
+	   == (signed)TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (exp))))
     maxsize = -1;
 
   /* ???  Due to negative offsets in ARRAY_REF we can end up with
      negative bit_offset here.  We might want to store a zero offset
      in this case.  */
-  *poffset = TREE_INT_CST_LOW (bit_offset);
+  *poffset = bit_offset;
   *psize = bitsize;
   *pmax_size = maxsize;