/**************************************************************************** * * * GNAT COMPILER COMPONENTS * * * * C U I N T P * * * * C Implementation File * * * * Copyright (C) 1992-2005 Free Software Foundation, Inc. * * * * GNAT is free software; you can redistribute it and/or modify it under * * terms of the GNU General Public License as published by the Free Soft- * * ware Foundation; either version 2, or (at your option) any later ver- * * sion. GNAT is distributed in the hope that it will be useful, but WITH- * * OUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY * * or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License * * for more details. You should have received a copy of the GNU General * * Public License distributed with GNAT; see file COPYING. If not, write * * to the Free Software Foundation, 51 Franklin Street, Fifth Floor, * * Boston, MA 02110-1301, USA. * * * * GNAT was originally developed by the GNAT team at New York University. * * Extensive contributions were provided by Ada Core Technologies Inc. * * * ****************************************************************************/ /* This file corresponds to the Ada package body Uintp. It was created manually from the files uintp.ads and uintp.adb. */ #include "config.h" #include "system.h" #include "coretypes.h" #include "tm.h" #include "tree.h" #include "ada.h" #include "types.h" #include "uintp.h" #include "atree.h" #include "elists.h" #include "nlists.h" #include "stringt.h" #include "fe.h" #include "gigi.h" #include "ada-tree.h" /* Universal integers are represented by the Uint type which is an index into the Uints_Ptr table containing Uint_Entry values. A Uint_Entry contains an index and length for getting the "digits" of the universal integer from the Udigits_Ptr table. For efficiency, this method is used only for integer values larger than the constant Uint_Bias. If a Uint is less than this constant, then it contains the integer value itself. The origin of the Uints_Ptr table is adjusted so that a Uint value of Uint_Bias indexes the first element. First define a utility function that operates like build_int_cst for integral types and does a conversion to floating-point for real types. */ static tree build_cst_from_int (tree type, HOST_WIDE_INT low) { if (TREE_CODE (type) == REAL_TYPE) return convert (type, build_int_cst (NULL_TREE, low)); else return force_fit_type (build_int_cst (type, low), false, false, false); } /* Similar to UI_To_Int, but return a GCC INTEGER_CST or REAL_CST node, depending on whether TYPE is an integral or real type. Overflow is tested by the constant-folding used to build the node. TYPE is the GCC type of the resulting node. */ tree UI_To_gnu (Uint Input, tree type) { tree gnu_ret; /* We might have a TYPE with biased representation and be passed an unbiased value that doesn't fit. We always use an unbiased type able to hold any such possible value for intermediate computations, and then rely on a conversion back to TYPE to perform the bias adjustment when need be. */ int biased_type_p = (TREE_CODE (type) == INTEGER_TYPE && TYPE_BIASED_REPRESENTATION_P (type)); tree comp_type = biased_type_p ? get_base_type (type) : type; if (Input <= Uint_Direct_Last) gnu_ret = build_cst_from_int (comp_type, Input - Uint_Direct_Bias); else { Int Idx = Uints_Ptr[Input].Loc; Pos Length = Uints_Ptr[Input].Length; Int First = Udigits_Ptr[Idx]; tree gnu_base; gcc_assert (Length > 0); /* The computations we perform below always require a type at least as large as an integer not to overflow. REAL types are always fine, but INTEGER or ENUMERAL types we are handed may be too short. We use a base integer type node for the computations in this case and will convert the final result back to the incoming type later on. */ if (TREE_CODE (comp_type) != REAL_TYPE && TYPE_PRECISION (comp_type) < TYPE_PRECISION (integer_type_node)) comp_type = integer_type_node; gnu_base = build_cst_from_int (comp_type, Base); gnu_ret = build_cst_from_int (comp_type, First); if (First < 0) for (Idx++, Length--; Length; Idx++, Length--) gnu_ret = fold (build2 (MINUS_EXPR, comp_type, fold (build2 (MULT_EXPR, comp_type, gnu_ret, gnu_base)), build_cst_from_int (comp_type, Udigits_Ptr[Idx]))); else for (Idx++, Length--; Length; Idx++, Length--) gnu_ret = fold (build2 (PLUS_EXPR, comp_type, fold (build2 (MULT_EXPR, comp_type, gnu_ret, gnu_base)), build_cst_from_int (comp_type, Udigits_Ptr[Idx]))); } gnu_ret = convert (type, gnu_ret); /* We don't need any NOP_EXPR or NON_LVALUE_EXPR on GNU_RET. */ while ((TREE_CODE (gnu_ret) == NOP_EXPR || TREE_CODE (gnu_ret) == NON_LVALUE_EXPR) && TREE_TYPE (TREE_OPERAND (gnu_ret, 0)) == TREE_TYPE (gnu_ret)) gnu_ret = TREE_OPERAND (gnu_ret, 0); return gnu_ret; }