X-Git-Url: http://git.sourceforge.jp/view?a=blobdiff_plain;f=gcc%2Fstor-layout.c;h=a1ac0008c75464e74729ffefadf876d4a4c7a957;hb=a62aa377b4ef69d833d284fe4a5c2ee9c96bc9d3;hp=dc573a2f52fc058fc74ab766e59e10c8dc2863c0;hpb=9faf44d607eac99a28edbec0beea479c3417ffe4;p=pf3gnuchains%2Fgcc-fork.git diff --git a/gcc/stor-layout.c b/gcc/stor-layout.c index dc573a2f52f..a1ac0008c75 100644 --- a/gcc/stor-layout.c +++ b/gcc/stor-layout.c @@ -1,7 +1,7 @@ /* C-compiler utilities for types and variables storage layout Copyright (C) 1987, 1988, 1992, 1993, 1994, 1995, 1996, 1996, 1998, - 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010 - Free Software Foundation, Inc. + 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, + 2011 Free Software Foundation, Inc. This file is part of GCC. @@ -32,7 +32,6 @@ along with GCC; see the file COPYING3. If not see #include "expr.h" #include "output.h" #include "diagnostic-core.h" -#include "toplev.h" #include "ggc.h" #include "target.h" #include "langhooks.h" @@ -66,10 +65,6 @@ static int excess_unit_span (HOST_WIDE_INT, HOST_WIDE_INT, HOST_WIDE_INT, #endif extern void debug_rli (record_layout_info); -/* SAVE_EXPRs for sizes of types and decls, waiting to be expanded. */ - -static GTY(()) VEC(tree,gc) *pending_sizes; - /* Show that REFERENCE_TYPES are internal and should use address_mode. Called only by front end. */ @@ -79,48 +74,12 @@ internal_reference_types (void) reference_types_internal = 1; } -/* Get a VEC of all the objects put on the pending sizes list. */ - -VEC(tree,gc) * -get_pending_sizes (void) -{ - VEC(tree,gc) *chain = pending_sizes; - - pending_sizes = 0; - return chain; -} - -/* Add EXPR to the pending sizes list. */ - -void -put_pending_size (tree expr) -{ - /* Strip any simple arithmetic from EXPR to see if it has an underlying - SAVE_EXPR. */ - expr = skip_simple_arithmetic (expr); - - if (TREE_CODE (expr) == SAVE_EXPR) - VEC_safe_push (tree, gc, pending_sizes, expr); -} - -/* Put a chain of objects into the pending sizes list, which must be - empty. */ - -void -put_pending_sizes (VEC(tree,gc) *chain) -{ - gcc_assert (!pending_sizes); - pending_sizes = chain; -} - /* Given a size SIZE that may not be a constant, return a SAVE_EXPR to serve as the actual size-expression for a type or decl. */ tree variable_size (tree size) { - tree save; - /* Obviously. */ if (TREE_CONSTANT (size)) return size; @@ -130,42 +89,13 @@ variable_size (tree size) if (CONTAINS_PLACEHOLDER_P (size)) return self_referential_size (size); - /* If the language-processor is to take responsibility for variable-sized - items (e.g., languages which have elaboration procedures like Ada), - just return SIZE unchanged. */ - if (lang_hooks.decls.global_bindings_p () < 0) - return size; - - size = save_expr (size); - - /* If an array with a variable number of elements is declared, and - the elements require destruction, we will emit a cleanup for the - array. That cleanup is run both on normal exit from the block - and in the exception-handler for the block. Normally, when code - is used in both ordinary code and in an exception handler it is - `unsaved', i.e., all SAVE_EXPRs are recalculated. However, we do - not wish to do that here; the array-size is the same in both - places. */ - save = skip_simple_arithmetic (size); - - if (cfun && cfun->dont_save_pending_sizes_p) - /* The front-end doesn't want us to keep a list of the expressions - that determine sizes for variable size objects. Trust it. */ - return size; - + /* If we are in the global binding level, we can't make a SAVE_EXPR + since it may end up being shared across functions, so it is up + to the front-end to deal with this case. */ if (lang_hooks.decls.global_bindings_p ()) - { - if (TREE_CONSTANT (size)) - error ("type size can%'t be explicitly evaluated"); - else - error ("variable-size type declared outside of any function"); - - return size_one_node; - } - - put_pending_size (save); + return size; - return size; + return save_expr (size); } /* An array of functions used for self-referential size computation. */ @@ -247,6 +177,9 @@ copy_self_referential_tree_r (tree *tp, int *walk_subtrees, void *data) else if (code == SAVE_EXPR) return error_mark_node; + else if (code == STATEMENT_LIST) + gcc_unreachable (); + return copy_tree_r (tp, walk_subtrees, data); } @@ -368,7 +301,7 @@ self_referential_size (tree size) VEC_safe_push (tree, gc, size_functions, fndecl); /* Replace the original expression with a call to the size function. */ - return build_call_expr_loc_vec (input_location, fndecl, args); + return build_call_expr_loc_vec (UNKNOWN_LOCATION, fndecl, args); } /* Take, queue and compile all the size functions. It is essential that @@ -547,6 +480,34 @@ get_mode_alignment (enum machine_mode mode) return MIN (BIGGEST_ALIGNMENT, MAX (1, mode_base_align[mode]*BITS_PER_UNIT)); } +/* Return the natural mode of an array, given that it is SIZE bytes in + total and has elements of type ELEM_TYPE. */ + +static enum machine_mode +mode_for_array (tree elem_type, tree size) +{ + tree elem_size; + unsigned HOST_WIDE_INT int_size, int_elem_size; + bool limit_p; + + /* One-element arrays get the component type's mode. */ + elem_size = TYPE_SIZE (elem_type); + if (simple_cst_equal (size, elem_size)) + return TYPE_MODE (elem_type); + + limit_p = true; + if (host_integerp (size, 1) && host_integerp (elem_size, 1)) + { + int_size = tree_low_cst (size, 1); + int_elem_size = tree_low_cst (elem_size, 1); + if (int_elem_size > 0 + && int_size % int_elem_size == 0 + && targetm.array_mode_supported_p (TYPE_MODE (elem_type), + int_size / int_elem_size)) + limit_p = false; + } + return mode_for_size_tree (size, MODE_INT, limit_p); +} /* Subroutine of layout_decl: Force alignment required for the data type. But if the decl itself wants greater alignment, don't override that. */ @@ -661,12 +622,13 @@ layout_decl (tree decl, unsigned int known_align) /* See if we can use an ordinary integer mode for a bit-field. Conditions are: a fixed size that is correct for another mode, occupying a complete byte or bytes on proper boundary, - and not volatile or not -fstrict-volatile-bitfields. */ + and not -fstrict-volatile-bitfields. If the latter is set, + we unfortunately can't check TREE_THIS_VOLATILE, as a cast + may make a volatile object later. */ if (TYPE_SIZE (type) != 0 && TREE_CODE (TYPE_SIZE (type)) == INTEGER_CST && GET_MODE_CLASS (TYPE_MODE (type)) == MODE_INT - && !(TREE_THIS_VOLATILE (decl) - && flag_strict_volatile_bitfields > 0)) + && flag_strict_volatile_bitfields <= 0) { enum machine_mode xmode = mode_for_size_tree (DECL_SIZE (decl), MODE_INT, 1); @@ -974,7 +936,8 @@ update_alignment_for_field (record_layout_info rli, tree field, applies if there was an immediately prior, nonzero-size bitfield. (That's the way it is, experimentally.) */ if ((!is_bitfield && !DECL_PACKED (field)) - || (!integer_zerop (DECL_SIZE (field)) + || ((DECL_SIZE (field) == NULL_TREE + || !integer_zerop (DECL_SIZE (field))) ? !DECL_PACKED (field) : (rli->prev_field && DECL_BIT_FIELD_TYPE (rli->prev_field) @@ -1178,15 +1141,14 @@ place_field (record_layout_info rli, tree field) } /* Does this field automatically have alignment it needs by virtue - of the fields that precede it and the record's own alignment? - We already align ms_struct fields, so don't re-align them. */ - if (known_align < desired_align - && !targetm.ms_bitfield_layout_p (rli->t)) + of the fields that precede it and the record's own alignment? */ + if (known_align < desired_align) { /* No, we need to skip space before this field. Bump the cumulative size to multiple of field alignment. */ - if (DECL_SOURCE_LOCATION (field) != BUILTINS_LOCATION) + if (!targetm.ms_bitfield_layout_p (rli->t) + && DECL_SOURCE_LOCATION (field) != BUILTINS_LOCATION) warning (OPT_Wpadded, "padding struct to align %q+D", field); /* If the alignment is still within offset_align, just align @@ -1208,7 +1170,8 @@ place_field (record_layout_info rli, tree field) if (! TREE_CONSTANT (rli->offset)) rli->offset_align = desired_align; - + if (targetm.ms_bitfield_layout_p (rli->t)) + rli->prev_field = NULL; } /* Handle compatibility with PCC. Note that if the record has any @@ -1923,9 +1886,9 @@ layout_type (tree type) TYPE_UNSIGNED (type) = TYPE_UNSIGNED (TREE_TYPE (type)); TYPE_SIZE_UNIT (type) = int_const_binop (MULT_EXPR, TYPE_SIZE_UNIT (innertype), - size_int (nunits), 0); + size_int (nunits)); TYPE_SIZE (type) = int_const_binop (MULT_EXPR, TYPE_SIZE (innertype), - bitsize_int (nunits), 0); + bitsize_int (nunits)); /* Always naturally align vectors. This prevents ABI changes depending on whether or not native vector modes are supported. */ @@ -1997,15 +1960,15 @@ layout_type (tree type) if (integer_zerop (element_size)) length = size_zero_node; - /* The initial subtraction should happen in the original type so - that (possible) negative values are handled appropriately. */ + /* The computation should happen in the original signedness so + that (possible) negative values are handled appropriately + when determining overflow. */ else length - = size_binop (PLUS_EXPR, size_one_node, - fold_convert (sizetype, - fold_build2 (MINUS_EXPR, - TREE_TYPE (lb), - ub, lb))); + = fold_convert (sizetype, + size_binop (PLUS_EXPR, + build_int_cst (TREE_TYPE (lb), 1), + size_binop (MINUS_EXPR, ub, lb))); TYPE_SIZE (type) = size_binop (MULT_EXPR, element_size, fold_convert (bitsizetype, @@ -2029,11 +1992,6 @@ layout_type (tree type) #else TYPE_ALIGN (type) = MAX (TYPE_ALIGN (element), BITS_PER_UNIT); #endif - if (!TYPE_SIZE (element)) - /* We don't know the size of the underlying element type, so - our alignment calculations will be wrong, forcing us to - fall back on structural equality. */ - SET_TYPE_STRUCTURAL_EQUALITY (type); TYPE_USER_ALIGN (type) = TYPE_USER_ALIGN (element); SET_TYPE_MODE (type, BLKmode); if (TYPE_SIZE (type) != 0 @@ -2045,14 +2003,8 @@ layout_type (tree type) && (TYPE_MODE (TREE_TYPE (type)) != BLKmode || TYPE_NO_FORCE_BLK (TREE_TYPE (type)))) { - /* One-element arrays get the component type's mode. */ - if (simple_cst_equal (TYPE_SIZE (type), - TYPE_SIZE (TREE_TYPE (type)))) - SET_TYPE_MODE (type, TYPE_MODE (TREE_TYPE (type))); - else - SET_TYPE_MODE (type, mode_for_size_tree (TYPE_SIZE (type), - MODE_INT, 1)); - + SET_TYPE_MODE (type, mode_for_array (TREE_TYPE (type), + TYPE_SIZE (type))); if (TYPE_MODE (type) != BLKmode && STRICT_ALIGNMENT && TYPE_ALIGN (type) < BIGGEST_ALIGNMENT && TYPE_ALIGN (type) < GET_MODE_ALIGNMENT (TYPE_MODE (type))) @@ -2137,12 +2089,12 @@ vector_type_mode (const_tree t) gcc_assert (TREE_CODE (t) == VECTOR_TYPE); - mode = t->type.mode; + mode = t->type_common.mode; if (VECTOR_MODE_P (mode) && (!targetm.vector_mode_supported_p (mode) || !have_regs_of_mode[mode])) { - enum machine_mode innermode = TREE_TYPE (t)->type.mode; + enum machine_mode innermode = TREE_TYPE (t)->type_common.mode; /* For integers, try mapping it to a same-sized scalar mode. */ if (GET_MODE_CLASS (innermode) == MODE_INT) @@ -2238,93 +2190,76 @@ make_accum_type (int precision, int unsignedp, int satp) return type; } -/* Initialize sizetype and bitsizetype to a reasonable and temporary - value to enable integer types to be created. */ +/* Initialize sizetypes so layout_type can use them. */ void initialize_sizetypes (void) { - tree t = make_node (INTEGER_TYPE); - int precision = GET_MODE_BITSIZE (SImode); - - SET_TYPE_MODE (t, SImode); - TYPE_ALIGN (t) = GET_MODE_ALIGNMENT (SImode); - TYPE_IS_SIZETYPE (t) = 1; - TYPE_UNSIGNED (t) = 1; - TYPE_SIZE (t) = build_int_cst (t, precision); - TYPE_SIZE_UNIT (t) = build_int_cst (t, GET_MODE_SIZE (SImode)); - TYPE_PRECISION (t) = precision; - - set_min_and_max_values_for_integral_type (t, precision, true); - - sizetype = t; - bitsizetype = build_distinct_type_copy (t); -} - -/* Make sizetype a version of TYPE, and initialize *sizetype accordingly. - We do this by overwriting the stub sizetype and bitsizetype nodes created - by initialize_sizetypes. This makes sure that (a) anything stubby about - them no longer exists and (b) any INTEGER_CSTs created with such a type, - remain valid. */ - -void -set_sizetype (tree type) -{ - tree t, max; - int oprecision = TYPE_PRECISION (type); - /* The *bitsizetype types use a precision that avoids overflows when - calculating signed sizes / offsets in bits. However, when - cross-compiling from a 32 bit to a 64 bit host, we are limited to 64 bit - precision. */ - int precision - = MIN (oprecision + BITS_PER_UNIT_LOG + 1, MAX_FIXED_MODE_SIZE); - precision - = GET_MODE_PRECISION (smallest_mode_for_size (precision, MODE_INT)); - if (precision > HOST_BITS_PER_WIDE_INT * 2) - precision = HOST_BITS_PER_WIDE_INT * 2; - - /* sizetype must be an unsigned type. */ - gcc_assert (TYPE_UNSIGNED (type)); - - t = build_distinct_type_copy (type); - /* We want to use sizetype's cache, as we will be replacing that type. */ - TYPE_CACHED_VALUES (t) = TYPE_CACHED_VALUES (sizetype); - TYPE_CACHED_VALUES_P (t) = TYPE_CACHED_VALUES_P (sizetype); - TREE_TYPE (TYPE_CACHED_VALUES (t)) = type; - TYPE_UID (t) = TYPE_UID (sizetype); - TYPE_IS_SIZETYPE (t) = 1; - - /* Replace our original stub sizetype. */ - memcpy (sizetype, t, tree_size (sizetype)); - TYPE_MAIN_VARIANT (sizetype) = sizetype; - TYPE_CANONICAL (sizetype) = sizetype; - + int precision, bprecision; + + /* Get sizetypes precision from the SIZE_TYPE target macro. */ + if (strcmp (SIZE_TYPE, "unsigned int") == 0) + precision = INT_TYPE_SIZE; + else if (strcmp (SIZE_TYPE, "long unsigned int") == 0) + precision = LONG_TYPE_SIZE; + else if (strcmp (SIZE_TYPE, "long long unsigned int") == 0) + precision = LONG_LONG_TYPE_SIZE; + else if (strcmp (SIZE_TYPE, "short unsigned int") == 0) + precision = SHORT_TYPE_SIZE; + else + gcc_unreachable (); + + bprecision + = MIN (precision + BITS_PER_UNIT_LOG + 1, MAX_FIXED_MODE_SIZE); + bprecision + = GET_MODE_PRECISION (smallest_mode_for_size (bprecision, MODE_INT)); + if (bprecision > HOST_BITS_PER_WIDE_INT * 2) + bprecision = HOST_BITS_PER_WIDE_INT * 2; + + /* Create stubs for sizetype and bitsizetype so we can create constants. */ + sizetype = make_node (INTEGER_TYPE); + TYPE_NAME (sizetype) = get_identifier ("sizetype"); + TYPE_PRECISION (sizetype) = precision; + TYPE_UNSIGNED (sizetype) = 1; + TYPE_IS_SIZETYPE (sizetype) = 1; + bitsizetype = make_node (INTEGER_TYPE); + TYPE_NAME (bitsizetype) = get_identifier ("bitsizetype"); + TYPE_PRECISION (bitsizetype) = bprecision; + TYPE_UNSIGNED (bitsizetype) = 1; + TYPE_IS_SIZETYPE (bitsizetype) = 1; + + /* Now layout both types manually. */ + SET_TYPE_MODE (sizetype, smallest_mode_for_size (precision, MODE_INT)); + TYPE_ALIGN (sizetype) = GET_MODE_ALIGNMENT (TYPE_MODE (sizetype)); + TYPE_SIZE (sizetype) = bitsize_int (precision); + TYPE_SIZE_UNIT (sizetype) = size_int (GET_MODE_SIZE (TYPE_MODE (sizetype))); + set_min_and_max_values_for_integral_type (sizetype, precision, + /*is_unsigned=*/true); /* sizetype is unsigned but we need to fix TYPE_MAX_VALUE so that it is sign-extended in a way consistent with force_fit_type. */ - max = TYPE_MAX_VALUE (sizetype); TYPE_MAX_VALUE (sizetype) - = double_int_to_tree (sizetype, tree_to_double_int (max)); - - t = make_node (INTEGER_TYPE); - TYPE_NAME (t) = get_identifier ("bit_size_type"); - /* We want to use bitsizetype's cache, as we will be replacing that type. */ - TYPE_CACHED_VALUES (t) = TYPE_CACHED_VALUES (bitsizetype); - TYPE_CACHED_VALUES_P (t) = TYPE_CACHED_VALUES_P (bitsizetype); - TYPE_PRECISION (t) = precision; - TYPE_UID (t) = TYPE_UID (bitsizetype); - TYPE_IS_SIZETYPE (t) = 1; - - /* Replace our original stub bitsizetype. */ - memcpy (bitsizetype, t, tree_size (bitsizetype)); - TYPE_MAIN_VARIANT (bitsizetype) = bitsizetype; - TYPE_CANONICAL (bitsizetype) = bitsizetype; - - fixup_unsigned_type (bitsizetype); + = double_int_to_tree (sizetype, + tree_to_double_int (TYPE_MAX_VALUE (sizetype))); + + SET_TYPE_MODE (bitsizetype, smallest_mode_for_size (bprecision, MODE_INT)); + TYPE_ALIGN (bitsizetype) = GET_MODE_ALIGNMENT (TYPE_MODE (bitsizetype)); + TYPE_SIZE (bitsizetype) = bitsize_int (bprecision); + TYPE_SIZE_UNIT (bitsizetype) + = size_int (GET_MODE_SIZE (TYPE_MODE (bitsizetype))); + set_min_and_max_values_for_integral_type (bitsizetype, bprecision, + /*is_unsigned=*/true); + /* bitsizetype is unsigned but we need to fix TYPE_MAX_VALUE so that it is + sign-extended in a way consistent with force_fit_type. */ + TYPE_MAX_VALUE (bitsizetype) + = double_int_to_tree (bitsizetype, + tree_to_double_int (TYPE_MAX_VALUE (bitsizetype))); /* Create the signed variants of *sizetype. */ - ssizetype = make_signed_type (oprecision); + ssizetype = make_signed_type (TYPE_PRECISION (sizetype)); + TYPE_NAME (ssizetype) = get_identifier ("ssizetype"); TYPE_IS_SIZETYPE (ssizetype) = 1; - sbitsizetype = make_signed_type (precision); + sbitsizetype = make_signed_type (TYPE_PRECISION (bitsizetype)); + TYPE_NAME (sbitsizetype) = get_identifier ("sbitsizetype"); TYPE_IS_SIZETYPE (sbitsizetype) = 1; } @@ -2433,6 +2368,13 @@ fixup_unsigned_type (tree type) /* Find the best machine mode to use when referencing a bit field of length BITSIZE bits starting at BITPOS. + BITREGION_START is the bit position of the first bit in this + sequence of bit fields. BITREGION_END is the last bit in this + sequence. If these two fields are non-zero, we should restrict the + memory access to a maximum sized chunk of + BITREGION_END - BITREGION_START + 1. Otherwise, we are allowed to touch + any adjacent non bit-fields. + The underlying object is known to be aligned to a boundary of ALIGN bits. If LARGEST_MODE is not VOIDmode, it means that we should not use a mode larger than LARGEST_MODE (usually SImode). @@ -2450,18 +2392,29 @@ fixup_unsigned_type (tree type) decide which of the above modes should be used. */ enum machine_mode -get_best_mode (int bitsize, int bitpos, unsigned int align, +get_best_mode (int bitsize, int bitpos, + unsigned HOST_WIDE_INT bitregion_start, + unsigned HOST_WIDE_INT bitregion_end, + unsigned int align, enum machine_mode largest_mode, int volatilep) { enum machine_mode mode; unsigned int unit = 0; + unsigned HOST_WIDE_INT maxbits; + + /* If unset, no restriction. */ + if (!bitregion_end) + maxbits = MAX_FIXED_MODE_SIZE; + else + maxbits = (bitregion_end - bitregion_start) % align + 1; /* Find the narrowest integer mode that contains the bit field. */ for (mode = GET_CLASS_NARROWEST_MODE (MODE_INT); mode != VOIDmode; mode = GET_MODE_WIDER_MODE (mode)) { unit = GET_MODE_BITSIZE (mode); - if ((bitpos % unit) + bitsize <= unit) + if (unit == GET_MODE_PRECISION (mode) + && (bitpos % unit) + bitsize <= unit) break; } @@ -2486,9 +2439,11 @@ get_best_mode (int bitsize, int bitpos, unsigned int align, tmode = GET_MODE_WIDER_MODE (tmode)) { unit = GET_MODE_BITSIZE (tmode); - if (bitpos / unit == (bitpos + bitsize - 1) / unit + if (unit == GET_MODE_PRECISION (tmode) + && bitpos / unit == (bitpos + bitsize - 1) / unit && unit <= BITS_PER_WORD && unit <= MIN (align, BIGGEST_ALIGNMENT) + && unit <= maxbits && (largest_mode == VOIDmode || unit <= GET_MODE_BITSIZE (largest_mode))) wide_mode = tmode;