fold-const.c (fold): New case.

	* fold-const.c (fold) <ARRAY_REF>: New case.  Try to fold constant
	reference in constructor with non self-referential type.

ada/
	* utils2.c (build_binary_op): Fold ARRAY_REF and ARRAY_RANGE_REF too.

From-SVN: r133977

7 files changed, 114 insertions, 2 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3e15824..b4e1c51 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,10 @@
 2008-04-07  Eric Botcazou  <ebotcazou@adacore.com>
 
+	* fold-const.c (fold) <ARRAY_REF>: New case.  Try to fold constant
+	reference in constructor with non self-referential type.
+
+2008-04-07  Eric Botcazou  <ebotcazou@adacore.com>
+
 	Removal of Return with Depressed Stack Pointer support
 	* tree.h (TYPE_RETURNS_STACK_DEPRESSED): Delete.
 	(ECF_SP_DEPRESSED): Likewise.
diff --git a/gcc/ada/ChangeLog b/gcc/ada/ChangeLog
index 44c64ce..826cd0d 100644
--- a/gcc/ada/ChangeLog
+++ b/gcc/ada/ChangeLog
@@ -1,5 +1,9 @@
 2008-04-07  Eric Botcazou  <ebotcazou@adacore.com>
 
+	* utils2.c (build_binary_op): Fold ARRAY_REF and ARRAY_RANGE_REF too.
+
+2008-04-07  Eric Botcazou  <ebotcazou@adacore.com>
+
 	* gigi.h (create_subprog_type): Remove returns_with_dsp parameter.
 	* decl.c (gnat_to_gnu_entity): Adjust for above new prototype.
 	* utils.c (create_subprog_type): Remove returns_with_dsp parameter.
diff --git a/gcc/ada/utils2.c b/gcc/ada/utils2.c
index e990867..8eddde2 100644
--- a/gcc/ada/utils2.c
+++ b/gcc/ada/utils2.c
@@ -1017,8 +1017,8 @@ build_binary_op (enum tree_code op_code, tree result_type,
   else if (TREE_CODE (right_operand) == NULL_EXPR)
     return build1 (NULL_EXPR, operation_type, TREE_OPERAND (right_operand, 0));
   else if (op_code == ARRAY_REF || op_code == ARRAY_RANGE_REF)
-    result = build4 (op_code, operation_type, left_operand,
-		     right_operand, NULL_TREE, NULL_TREE);
+    result = fold (build4 (op_code, operation_type, left_operand,
+			   right_operand, NULL_TREE, NULL_TREE));
   else
     result
       = fold_build2 (op_code, operation_type, left_operand, right_operand);
diff --git a/gcc/fold-const.c b/gcc/fold-const.c
index ef95ae3..5a101f2 100644
--- a/gcc/fold-const.c
+++ b/gcc/fold-const.c
@@ -13086,6 +13086,45 @@ fold (tree expr)
 
   switch (code)
     {
+    case ARRAY_REF:
+      {
+	tree op0 = TREE_OPERAND (t, 0);
+	tree op1 = TREE_OPERAND (t, 1);
+
+	if (TREE_CODE (op1) == INTEGER_CST
+	    && TREE_CODE (op0) == CONSTRUCTOR
+	    && ! type_contains_placeholder_p (TREE_TYPE (op0)))
+	  {
+	    VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (op0);
+	    unsigned HOST_WIDE_INT end = VEC_length (constructor_elt, elts);
+	    unsigned HOST_WIDE_INT begin = 0;
+
+	    /* Find a matching index by means of a binary search.  */
+	    while (begin != end)
+	      {
+		unsigned HOST_WIDE_INT middle = (begin + end) / 2;
+		tree index = VEC_index (constructor_elt, elts, middle)->index;
+
+		if (TREE_CODE (index) == INTEGER_CST
+		    && tree_int_cst_lt (index, op1))
+		  begin = middle + 1;
+		else if (TREE_CODE (index) == INTEGER_CST
+			 && tree_int_cst_lt (op1, index))
+		  end = middle;
+		else if (TREE_CODE (index) == RANGE_EXPR
+			 && tree_int_cst_lt (TREE_OPERAND (index, 1), op1))
+		  begin = middle + 1;
+		else if (TREE_CODE (index) == RANGE_EXPR
+			 && tree_int_cst_lt (op1, TREE_OPERAND (index, 0)))
+		  end = middle;
+		else
+		  return VEC_index (constructor_elt, elts, middle)->value;
+	      }
+	  }
+
+	return t;
+      }
+
     case CONST_DECL:
       return fold (DECL_INITIAL (t));
 
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index beac0eb..d4e38e8 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2008-04-07  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* gnat.dg/array4.adb: New test.
+	* gnat.dg/specs/static_initializer2.ads: Likewise.
+
 2008-04-06  Richard Guenther  <rguenther@suse.de>
 
 	PR tree-optimization/35400
diff --git a/gcc/testsuite/gnat.dg/array4.adb b/gcc/testsuite/gnat.dg/array4.adb
new file mode 100644
index 0000000..048698a
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/array4.adb
@@ -0,0 +1,37 @@
+-- { dg-do run }
+
+procedure Array4 is
+
+   type A is array (1..5) of Integer;
+   f : constant A := (1, 2, 3, 4, 5);
+
+   i1 : integer renames f(1);
+   i2 : integer renames f(2);
+   i3 : integer renames f(3);
+   i4 : integer renames f(4);
+   i5 : integer renames f(5);
+
+   procedure Link_Failure;
+   pragma Import (C, Link_Failure);
+
+begin
+  if i1 /= 1 then
+    Link_Failure;
+  end if;
+
+  if i2 /= 2 then
+    Link_Failure;
+  end if;
+
+  if i3 /= 3 then
+    Link_Failure;
+  end if;
+
+  if i4 /= 4 then
+    Link_Failure;
+  end if;
+
+  if i5 /= 5 then
+    Link_Failure;
+  end if;
+end;
diff --git a/gcc/testsuite/gnat.dg/specs/static_initializer2.ads b/gcc/testsuite/gnat.dg/specs/static_initializer2.ads
new file mode 100644
index 0000000..3b27f26
--- /dev/null
+++ b/gcc/testsuite/gnat.dg/specs/static_initializer2.ads
@@ -0,0 +1,22 @@
+-- { dg-do compile }
+
+package Static_Initializer2 is
+
+   type A is array (1..5) of Integer;
+   f : constant A := (1, 2, 3, 4, 5);
+
+   i1 : integer renames f(1);
+   i2 : integer renames f(2);
+   i3 : integer renames f(3);
+   i4 : integer renames f(4);
+   i5 : integer renames f(5);
+
+   b1 : boolean := i1 = 1;
+   b2 : boolean := i2 = 2;
+   b3 : boolean := i3 = 3;
+   b4 : boolean := i4 = 4;
+   b5 : boolean := i5 = 5;
+
+end Static_Initializer2;
+
+-- { dg-final { scan-assembler-not "elabs" } }