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Diffstat (limited to 'gcc/ch/loop.c')
| -rw-r--r-- | gcc/ch/loop.c | 1234 |
1 files changed, 0 insertions, 1234 deletions
diff --git a/gcc/ch/loop.c b/gcc/ch/loop.c deleted file mode 100644 index d42c65f8077..00000000000 --- a/gcc/ch/loop.c +++ /dev/null @@ -1,1234 +0,0 @@ -/* Implement looping actions for CHILL. - Copyright (C) 1992, 1993, 1994, 1998, 1999, 2000 - Free Software Foundation, Inc. - -This file is part of GNU CC. - -GNU CC is free software; you can redistribute it and/or modify -it under the terms of the GNU General Public License as published by -the Free Software Foundation; either version 2, or (at your option) -any later version. - -GNU CC is distributed in the hope that it will be useful, -but WITHOUT 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 -along with GNU CC; see the file COPYING. If not, write to -the Free Software Foundation, 59 Temple Place - Suite 330, -Boston, MA 02111-1307, USA. */ - -#include "config.h" -#include "system.h" -#include "tree.h" -#include "ch-tree.h" -#include "lex.h" -#include "flags.h" -#include "actions.h" -#include "input.h" -#include "obstack.h" -#include "assert.h" -#include "rtl.h" -#include "toplev.h" - -/* if the user codes '-flocal-loop-counter' on the command line, - ch-actions.c (lang_decode_option) will set this flag. */ -int flag_local_loop_counter = 1; - -/* forward declarations */ -static int declare_temps PARAMS ((void)); -static int initialize_iter_var PARAMS ((void)); -static void maybe_skip_loop PARAMS ((void)); -static int bottom_loop_end_check PARAMS ((void)); -static int increment_temps PARAMS ((void)); -static tree build_temporary_variable PARAMS ((const char *, tree)); -static tree maybe_make_for_temp PARAMS ((tree, const char *, tree)); -#if 0 -static tree chill_unsigned_type PARAMS ((tree)); -#endif - -/* In terms of the parameters passed to build_loop_iterator, - * there are several types of loops. They are encoded by - * the ITER_TYPE enumeration. - * - * 1) DO FOR EVER; ... OD - * indicated by a NULL_TREE start_exp, step_exp and end_exp, - * condition == NULL, in_flag = 0, and ever_flag == 1 in the - * first ITERATOR. - * - * 2) DO WHILE cond; ... OD - * indicated by NULL_TREE start_exp, step_exp and end_exp, - * in_flag = 0, and condition != NULL. - * - * 3) DO; ... OD - * indicated by NULL_TREEs in start_exp, step_exp and end_exp, - * condition != NULL, in_flag == 0 and ever_flag == 0. This - * is not really a loop, but a compound statement. - * - * 4) DO FOR user_var := start_exp - * [DOWN] TO end_exp BY step_exp; ... DO - * indicated by non-NULL_TREE start_exp, step_exp and end_exp. - * - * 5) DO FOR user_var [DOWN] IN discrete_mode; ... OD - * indicated by in_flag == 1. start_exp is a non-NULL_TREE - * discrete mode, with an optional down_flag. - * - * 6) DO FOR user_var [DOWN] IN powerset_expr; ... OD - * indicated by in_flag == 1. start_exp is a non-NULL_TREE - * powerset mode, with an optional down_flag. - * - * 7) DO FOR user_var [DOWN] IN location; ... OD - * indicated by in_flag == 1. start_exp is a non-NULL_TREE - * location mode, with an optional down_flag. - */ -typedef enum -{ - DO_FOREVER, - DO_OD, - DO_STEP, - DO_POWERSET, - DO_LOC, - DO_LOC_VARYING -} ITER_TYPE; - - -typedef struct iterator -{ -/* These variables only have meaning in the first ITERATOR structure. */ - ITER_TYPE itype; /* type of this iterator */ - int error_flag; /* TRUE if no loop was started due to - user error */ - int down_flag; /* TRUE if DOWN was coded */ - -/* These variables have meaning in every ITERATOR structure. */ - tree user_var; /* user's explicit iteration variable */ - tree start_exp; /* user's start expression - or IN expression of a FOR .. IN*/ - tree step_exp; /* user's step expression */ - tree end_exp; /* user's end expression */ - tree start_temp; /* temp holding evaluated start_exp */ - tree end_temp; /* temp holding evaluated end_exp */ - tree step_temp; /* temp holding evaluated step_exp */ - tree powerset_temp; /* temp holding user's initial powerset expression */ - tree loc_ptr_temp; /* temp holding count for LOC enumeration ptr */ - tree iter_var; /* hidden variable for the loop */ - tree iter_type; /* hidden variable's type */ - tree stepin_type; /* saved type for a DO FOR IN loop */ - tree base_type; /* LOC enumeration base type */ - struct iterator *next; /* ptr to next iterator for this loop */ -} ITERATOR; - -/* - * There's an entry like this for each nested DO loop. - * The list is maintained by push_loop_block - * and pop_loop_block. - */ -typedef struct loop { - struct loop *nxt_level; /* pointer to enclosing loop */ - ITERATOR *iter_list; /* iterators for the current loop */ -} LOOP; - -static LOOP *loopstack = (LOOP *)0; - -#if 0 - -Here is a CHILL DO FOR statement: - -DO FOR user_var := start_exp BY step_exp [DOWN] TO end_exp - WHILE condition; - -For this loop to be 'safe', like a Pascal FOR loop, the start, -end, and increment expressions are computed once, before the -assignment to the iteration variable and saved in temporaries, -before the first assignment of the iteration variable, so the -following works: - - FOR i := (i+1) TO (i+10) DO - -To prevent changes to the start/end/step expressions from -effecting the loop''s termination, and to make the loop end-check -as simple as possible, we evaluate the step expression into -a temporary and compute a hidden iteration count before entering -the loop''s body. User code cannot effect the counter, and the -end-loop check simply decrements the counter and checks for zero. - -The whole phrase FOR iter := ... TO end_exp can be repeated -multiple times, with different user-iteration variables. This -is discussed later. - -The loop counter calculations need careful design since a loop -from MININT TO MAXINT must work, in the precision of integers. - -Here''s how it works, in C: - - 0) The DO ... OD loop is simply a block with - its own scope. - - 1) The DO FOR EVER is simply implemented: - - loop_top: - . - . body of loop - . - goto loop_top - end_loop: - - 2) The DO WHILE is also simple: - - - loop_top: - if (!condition) goto end_loop - . - . body of loop - . - goto loop_top - end_loop: - - - 3) The DO FOR [while condition] loop (no DOWN) - - push a new scope, - decl iter_var - - step_temp = step_exp - start_temp = start_exp - end_temp = end_exp - if (end_exp < start_exp) goto end_loop - /* following line is all unsigned arithmetic */ - iter_var = (end_exp - start_exp) / step_exp - user_var = start_temp - loop_top: - if (!condition) goto end_loop - . - . body of loop - . - if (iter_var == 0) goto end_loop - iter_var-- - user_var += step_temp - goto loop_top - end_loop: - pop scope - - 4) The for [while condition] loop (with DOWN) - - push a new scope, - decl iter - step_temp = step_exp - start_temp = start_exp - end_temp = end_exp - if (end_exp > start_exp) goto end_loop - /* following line is all unsigned arithmetic */ - iter_var = (start_exp - end_exp) / step_exp - user_var = start_temp - loop_top: - if (!condition) goto end_loop - . - . body of loop - . - if (iter_var == 0) goto end_loop - iter_var-- - user_var -= step_temp - goto loop_top - end_loop: - pop scope - - - 5) The range loop, which iterates over a mode''s possible - values, works just like the above step loops, but with - the start and end values taken from the mode''s lower - and upper domain values. - - - 6) The FOR IN loop, where a location enumeration is - specified (see spec on page 81 of Z.200, bottom - of page 186): - - push a new scope, - decl iter_var as an unsigned integer - loc_ptr_temp as pointer to a composite base type - - if array is varying - iter_var = array''s length field - else - iter_var = sizeof array / sizeof base_type - loc_ptr_temp = &of highest or lowest indexable entry - loop_top: - if (!condition) goto end_loop - . - . body of loop - . - iter_var-- - if (iter_var == 0) goto end_loop - loc_ptr_temp +/-= sizeof array base_type - goto loop_top - end_loop: - pop scope - - 7) The DO FOR (DOWN) IN powerset_exp - - push a new scope, - decl iterator as basetype of powerset - - powerset_temp := save_expr (start_exp) - iter_var := DOWN ? length : 0 - loop_top: - if (DOWN) - iter_var := __ffsetclrpowerset (powerset_temp, length, - iter_var); - else - iter_var := __ffsetclrpowerset (powrset_temp, iter_var, 0); - if (iter_var < 0) goto end_loop; - user_var = iter_var + min_value; - if (!condition) goto end_loop - if (!DOWN) iter_var +:= 1; - . - . body of loop - . - goto loop_top - end_loop: - pop scope - - -So, here''s the general DO FOR schema, as implemented here: - - expand_start_loop -- start the loop''s control scope - -- start scope for synthesized loop variables - declare_temps -- create, initialize temporary variables - maybe_skip_loop -- skip loop if end conditions unsatisfiable - initialize_iter_var -- initialize the iteration counter - -- initialize user''s loop variable - expand_start_loop -- generate top-of-loop label - top_loop_end_check -- generate while code and/or - powerset find-a-bit function call - . - . - . user''s loop body code - . - . - bottom_loop_end_check -- exit if counter has become zero - increment_temps -- update temps for next iteration - expand_end_loop -- generate jump back to top of loop - expand_end_cond -- generate label for end of conditional - -- end of scope for synthesized loop variables - free_iterators -- free up iterator space - -When there are two or more iterator phrases, each of the -above loop steps must act upon all iterators. For example, -the 'increment_temps' step must increment all temporaries -(associated with all iterators). - - NOTE: Z.200, section 10.1 says that a block is ... - "the actions statement list in a do action, including any - loop counter and while control". This means that an exp- - ression in a WHILE control can include references to the - loop counters created for the loop''s exclusive use. - Example: - - DCL a (1:10) INT; - DCL j INT; - DO FOR j IN a WHILE j > 0; - ... - OD; - The 'j' referenced in the while is the loc-identity 'j' - created inside the loop''s scope, and NOT the 'j' declared - before the loop. -#endif - -/* - * The following routines are called directly by the - * CHILL parser. - */ -void -push_loop_block () -{ - LOOP *temp = (LOOP *)xmalloc (sizeof (LOOP)); - - /* push a new loop onto the stack */ - temp->nxt_level = loopstack; - temp->iter_list = (ITERATOR *)0; - loopstack = temp; -} - -void -pop_loop_block () -{ - LOOP *do_temp = loopstack; - ITERATOR *ip; - - /* pop loop block off the list */ - loopstack = do_temp->nxt_level; - - /* free the loop's iterator blocks */ - ip = do_temp->iter_list; - while (ip != NULL) - { - ITERATOR *temp = ip->next; - free (ip); - ip = temp; - } - free (do_temp); -} - -void -begin_loop_scope () -{ - pushlevel (1); - - if (pass >= 2) - { - declare_temps (); - - clear_last_expr (); - push_momentary (); - expand_start_bindings (0); - } - - push_handler (); - -} - - -void -end_loop_scope (opt_label) - tree opt_label; -{ - if (opt_label) - possibly_define_exit_label (opt_label); - - if (pass == 2) - { - expand_end_bindings (getdecls (), kept_level_p (), 0); - pop_momentary (); - } - poplevel (kept_level_p (), 1, 0); -} - - -/* we need the above 2 functions somehow modified for initialising - of non-value arrays */ - -void -nonvalue_begin_loop_scope () -{ - pushlevel (0); /* this happens only in pass 2 */ - - declare_temps (); - - clear_last_expr (); - push_momentary (); - expand_start_bindings (0); -} - -void -nonvalue_end_loop_scope () -{ - expand_end_bindings (getdecls (), kept_level_p (), 0); - pop_momentary (); - poplevel (kept_level_p (), 1, 0); -} - -/* The iterator structure records all aspects of a - * 'FOR i := start [DOWN] TO end' clause or - * 'FOR i IN modename' or 'FOR i IN powerset' clause. - * It's saved on the iter_list of the current LOOP. - */ -void -build_loop_iterator (user_var, start_exp, step_exp, end_exp, - down_flag, in_flag, ever_flag) - tree user_var, start_exp, step_exp, end_exp; - int down_flag, in_flag, ever_flag; -{ - ITERATOR *ip = (ITERATOR *)xmalloc (sizeof (ITERATOR)); - - /* chain this iterator onto the current loop */ - if (loopstack->iter_list == NULL) - loopstack->iter_list = ip; - else - { - ITERATOR *temp = loopstack->iter_list; - while (temp->next != NULL) - temp = temp->next; - temp->next = ip; - } - - ip->user_var = user_var; - ip->start_exp = start_exp; - ip->step_exp = step_exp; - ip->end_exp = end_exp; - ip->start_temp = NULL_TREE; - ip->end_temp = NULL_TREE; - ip->step_temp = NULL_TREE; - ip->down_flag = down_flag; - ip->powerset_temp = NULL_TREE; - ip->iter_var = NULL_TREE; - ip->iter_type = NULL_TREE; - ip->stepin_type = NULL_TREE; - ip->loc_ptr_temp = NULL_TREE; - ip->error_flag = 1; /* assume error will be found */ - ip->next = (ITERATOR *)0; - - if (ever_flag) - ip->itype = DO_FOREVER; - else if (in_flag && start_exp != NULL_TREE) - { - if (TREE_CODE (start_exp) == ERROR_MARK) - return; - if (TREE_TYPE (start_exp) == NULL_TREE) - { - if (TREE_CODE (start_exp) == CONSTRUCTOR) - error ("modeless tuple not allowed in this context"); - else - error ("IN expression does not have a mode"); - return; - } - if (TREE_CODE (TREE_TYPE (start_exp)) == SET_TYPE) - { - if (CH_BOOLS_TYPE_P (TREE_TYPE (start_exp))) - { - sorry ("location enumeration for BOOLS"); - return; - } - ip->itype = DO_POWERSET; - } - else if (discrete_type_p (TREE_TYPE (ip->start_exp))) - { - /* range enumeration */ - tree type = TREE_TYPE (ip->start_exp); - /* save the original type for later use in determine to do a - rangecheck or not */ - ip->stepin_type = type; - ip->itype = DO_STEP; - if (ip->down_flag) - { - ip->start_exp = build_chill_upper (type); - ip->end_exp = build_chill_lower (type); - } - else - { - ip->start_exp = build_chill_lower (type); - ip->end_exp = build_chill_upper (type); - } - } - else if (TREE_CODE (TREE_TYPE (ip->start_exp)) == ARRAY_TYPE) - { - if (TYPE_PACKED (TREE_TYPE (ip->start_exp))) - { - sorry ("location enumeration for bit-packed arrays"); - return; - } - ip->itype = DO_LOC; - } - else if (chill_varying_type_p (TREE_TYPE (ip->start_exp))) - ip->itype = DO_LOC_VARYING; - else - { - error ("Loop's IN expression is not a composite object"); - return; - } - } - else - ip->itype = DO_STEP; - if (ip->itype == DO_STEP) - { - struct ch_class class; - - if (ip->step_exp == NULL_TREE) - ip->step_exp = integer_one_node; - - if (! discrete_type_p (TREE_TYPE (ip->start_exp))) - { - error ("start expr must have discrete mode"); - return; - } - if (TREE_CODE (TREE_TYPE (ip->start_exp)) == ENUMERAL_TYPE - && CH_ENUM_IS_NUMBERED (TREE_TYPE (ip->start_exp))) - { - error ("DO FOR start expression is a numbered SET"); - return; - } - if (TREE_CODE (ip->end_exp) == ERROR_MARK) - return; - if (TREE_CODE (TREE_TYPE (ip->end_exp)) == ENUMERAL_TYPE - && CH_ENUM_IS_NUMBERED (TREE_TYPE (ip->end_exp))) - { - error ("TO expression is a numbered SET"); - return; - } - if (! discrete_type_p (TREE_TYPE (ip->end_exp))) - { - error ("TO expr must have discrete mode"); - return; - } - if (! CH_COMPATIBLE_CLASSES (ip->start_exp, ip->end_exp)) - { - error ("start expr and TO expr must be compatible"); - return; - } - if (step_exp != NULL_TREE) - { - if (TREE_CODE (step_exp) == ERROR_MARK) - return; - if (! discrete_type_p (TREE_TYPE (step_exp))) - { - error ("BY expr must have discrete mode"); - return; - } - if (! CH_COMPATIBLE_CLASSES (ip->start_exp, step_exp)) - { - error ("start expr and BY expr must be compatible"); - return; - } - } - - if (! flag_local_loop_counter) - { - /* In this case, it's a previously-declared VAR_DECL node. */ - tree id_node = ip->user_var; - if (TREE_CODE (ip->user_var) == IDENTIFIER_NODE) - ip->user_var = lookup_name (ip->user_var); - - /* Chill 1984 allows the name to be a defining occurrence, - but does not require it. */ - if (ip->user_var == NULL_TREE) - { - warning ("loop identifier undeclared"); - ip->user_var = id_node; - /* We declare a local name below. */ - } - else - { - if (TREE_CODE (TREE_TYPE (ip->user_var)) == REFERENCE_TYPE) - ip->user_var = convert_from_reference (ip->user_var); - - if (! CH_COMPATIBLE_CLASSES (ip->start_exp, ip->user_var)) - { - error ("loop variable incompatible with start expression"); - return; - } - class = chill_expr_class (ip->user_var); - } - } - /* Otherwise, declare a new name. */ - if (TREE_CODE (ip->user_var) == IDENTIFIER_NODE) - { - class = CH_RESULTING_CLASS (chill_expr_class (ip->start_exp), - chill_expr_class (ip->end_exp)); - if (step_exp) - class = CH_RESULTING_CLASS (class, chill_expr_class (step_exp)); - - /* Integer literals noramally have type 'long long' - (see convert_integer in lex.c). That is usually overkill. */ - if (class.kind == CH_DERIVED_CLASS - && class.mode == long_long_integer_type_node - && int_fits_type_p (ip->start_exp, integer_type_node) - && int_fits_type_p (ip->end_exp, integer_type_node)) - class.mode = integer_type_node; - } - - if (TREE_CODE (ip->start_exp) == INTEGER_CST - && TREE_CODE (ip->end_exp) == INTEGER_CST - && compare_int_csts (ip->down_flag ? LT_EXPR : GT_EXPR, - ip->start_exp, ip->end_exp)) - warning ("body of DO FOR will never execute"); - - ip->start_exp = convert_to_class (class, ip->start_exp); - ip->end_exp = convert_to_class (class, ip->end_exp); - ip->step_exp = convert_to_class (class, ip->step_exp); - - if (TREE_CODE (ip->step_exp) != INTEGER_CST) - { - /* generate runtime check for negative BY expr */ - ip->step_exp = - check_range (ip->step_exp, ip->step_exp, - integer_zero_node, NULL_TREE); - } - else if (compare_int_csts (LE_EXPR, ip->step_exp, integer_zero_node)) - { - error ("BY expression is negative or zero"); - return; - } - } - - ip->error_flag = 0; /* no errors! */ -} - -void -build_loop_start (start_label) - tree start_label; -{ - ITERATOR *firstp = loopstack->iter_list; - - if (firstp->error_flag) - return; - - maybe_skip_loop (); - - if (initialize_iter_var ()) - return; - - /* use the label as an 'exit' label, - 'goto' needs another sort of label */ - expand_start_loop (start_label != NULL_TREE); -} - -/* - * Called after the last action of the loop body - * has been parsed. - */ -void -build_loop_end () -{ - ITERATOR *ip = loopstack->iter_list; - - emit_line_note (input_filename, lineno); - - if (ip->error_flag) - return; - - if (bottom_loop_end_check ()) - return; - - if (increment_temps ()) - return; - - expand_end_loop (); - - for (; ip != NULL; ip = ip->next) - { - switch (ip->itype) - { - case DO_LOC_VARYING: - case DO_STEP: - expand_end_cond (); - break; - default: - break; - } - } -} - -/* - * Reserve space for any loop-control temporaries, initialize them - */ -static int -declare_temps () -{ - ITERATOR *firstp = loopstack->iter_list, *ip; - tree start_ptr; - - for (ip = firstp; ip != NULL; ip = ip->next) - { - switch (ip->itype) - { - case DO_FOREVER: - break; - case DO_STEP: - ip->iter_type - = type_for_size (TYPE_PRECISION (TREE_TYPE (ip->start_exp)), 1); - - /* create, initialize temporaries if expressions aren't constant */ - ip->start_temp = maybe_make_for_temp (ip->start_exp, "for_start", - TREE_TYPE (ip->start_exp)); - ip->end_temp = maybe_make_for_temp (ip->end_exp, "for_end", - TREE_TYPE (ip->end_exp)); - /* this is just the step-expression */ - ip->step_temp = maybe_make_for_temp (ip->step_exp, "for_step", - TREE_TYPE (ip->step_exp)); - if (TREE_CODE (ip->user_var) == IDENTIFIER_NODE) - { - /* (re-)declare the user's iteration variable in the - loop's scope. */ - tree id_node = ip->user_var; - ip->user_var = - decl_temp1 (id_node, TREE_TYPE (ip->start_exp), 0, NULL_TREE, - 0, 0); - CH_DERIVED_FLAG (ip->user_var) = CH_DERIVED_FLAG (ip->start_exp); - pushdecl (ip->user_var); - } - ip->iter_var = - decl_temp1 (get_unique_identifier ("iter_var"), - ip->iter_type, 0, NULL_TREE, 0, 0); - break; - - case DO_POWERSET: - /* the user's powerset-expression */ - ip->powerset_temp = save_expr (ip->start_exp); - mark_addressable (ip->powerset_temp); - - ip->iter_type = integer_type_node; - ip->iter_var = decl_temp1 (get_unique_identifier ("iter_var"), - ip->iter_type, 0, - !ip->down_flag ? integer_zero_node - : powersetlen (ip->powerset_temp), - 0, 0); - - if (flag_local_loop_counter) - { - /* declare the user's iteration variable in the loop's scope. */ - /* in this case, it's just an IDENTIFIER_NODE */ - ip->user_var = - decl_temp1 (ip->user_var, - TYPE_DOMAIN (TREE_TYPE (ip->start_exp)), - 0, NULL_TREE, 0, 0); - pushdecl (ip->user_var); - } - else - { - /* in this case, it's a previously-declared VAR_DECL node */ - ip->user_var = lookup_name (ip->user_var); - } - break; - - case DO_LOC: - case DO_LOC_VARYING: - ip->iter_type = chill_unsigned_type_node; - /* create the counter temp */ - ip->iter_var = - build_temporary_variable ("iter_var", ip->iter_type); - - if (!CH_LOCATION_P (ip->start_exp)) - ip->start_exp - = decl_temp1 (get_unique_identifier ("iter_loc"), - TREE_TYPE (ip->start_exp), 0, - ip->start_exp, 0, 0); - - if (ip->itype == DO_LOC) - { - tree array_type = TREE_TYPE (ip->start_exp); - tree ptr_type; - tree temp; - - /* FIXME: check for array type in ip->start_exp */ - - /* create pointer temporary */ - ip->base_type = TREE_TYPE (array_type); - ptr_type = build_pointer_type (ip->base_type); - ip->loc_ptr_temp = - build_temporary_variable ("loc_ptr_tmp", ptr_type); - - /* declare the user's iteration variable in - the loop's scope, as an expression, to be - passed to build_component_ref later */ - save_expr_under_name (ip->user_var, - build1 (INDIRECT_REF, ip->base_type, - ip->loc_ptr_temp)); - - /* FIXME: see stor_layout */ - ip->step_temp = size_in_bytes (ip->base_type); - - temp = TYPE_DOMAIN (array_type); - - /* pointer to first array entry to look at */ - start_ptr = build1 (ADDR_EXPR, ptr_type, ip->start_exp); - mark_addressable (ip->start_exp); - ip->start_temp = ip->down_flag ? - fold (build (PLUS_EXPR, ptr_type, - start_ptr, - fold (build (MULT_EXPR, integer_type_node, ip->step_temp, - fold (build (MINUS_EXPR, integer_type_node, - TYPE_MAX_VALUE (temp), - TYPE_MIN_VALUE (temp))))))) - : start_ptr; - } - else - { - tree array_length = - convert (integer_type_node, - build_component_ref (ip->start_exp, var_length_id)); - tree array_type = TREE_TYPE (TREE_CHAIN ( - TYPE_FIELDS (TREE_TYPE (ip->start_exp)))); - tree array_data_ptr = - build_component_ref (ip->start_exp, var_data_id); - tree ptr_type; - - if (TREE_CODE (TREE_TYPE (array_type)) == BOOLEAN_TYPE) - { - error ("Can't iterate through array of BOOL"); - firstp->error_flag = 1; - return firstp->error_flag; - } - - /* create pointer temporary */ - ip->base_type = TREE_TYPE (array_type); - ptr_type = build_pointer_type (ip->base_type); - ip->loc_ptr_temp = - build_temporary_variable ("loc_ptr_temp", ptr_type); - - - /* declare the user's iteration variable in - the loop's scope, as an expression, to be - passed to build_component_ref later */ - save_expr_under_name (ip->user_var, - build1 (INDIRECT_REF, ip->base_type, - ip->loc_ptr_temp)); - - /* FIXME: see stor_layout */ - ip->step_temp = size_in_bytes (ip->base_type); - - /* pointer to first array entry to look at */ - start_ptr = build1 (ADDR_EXPR, ptr_type, array_data_ptr); - mark_addressable (array_data_ptr); - ip->start_temp = ip->down_flag ? - fold (build (PLUS_EXPR, ptr_type, - start_ptr, - fold (build (MULT_EXPR, integer_type_node, ip->step_temp, - fold (build (MINUS_EXPR, integer_type_node, - array_length, - integer_one_node)))))) - : start_ptr; - } - default: - ; - } - } - return firstp->error_flag; -} - -/* - * Initialize the hidden iteration-control variables, - * and the user's explicit loop variable. - */ -static int -initialize_iter_var () -{ - ITERATOR *firstp = loopstack->iter_list, *ip; - - for (ip = firstp; ip != NULL; ip = ip->next) - { - switch (ip->itype) - { - tree array_type, array_length; - case DO_FOREVER: - break; - case DO_STEP: - { - tree count; - count = build (MINUS_EXPR, ip->iter_type, - convert (ip->iter_type, - ip->down_flag ? ip->start_temp : ip->end_temp), - convert (ip->iter_type, - ip->down_flag ? ip->end_temp : ip->start_temp)); - count = fold (build (TRUNC_DIV_EXPR, ip->iter_type, - fold (count), - ip->step_temp)); - /* The count in this case is actually one less than the - number of iterations, to avoid overflow problems - if we iterate *all* the values of iter_type. */ - /* initialize the loop's hidden counter variable */ - expand_expr_stmt ( - build_chill_modify_expr (ip->iter_var, count)); - - /* initialize user's variable */ - expand_expr_stmt ( - build_chill_modify_expr (ip->user_var, ip->start_temp)); - } - break; - case DO_POWERSET: - break; - case DO_LOC: - array_type = TREE_TYPE (ip->start_exp); - array_length = fold (build (TRUNC_DIV_EXPR, integer_type_node, - size_in_bytes (array_type), - size_in_bytes (TREE_TYPE (array_type)))); - goto do_loc_common; - - case DO_LOC_VARYING: - array_length - = convert (integer_type_node, - build_component_ref (ip->start_exp, var_length_id)); - - do_loc_common: - expand_expr_stmt (build_chill_modify_expr (ip->iter_var, - array_length)); - expand_expr_stmt ( - build_chill_modify_expr (ip->loc_ptr_temp, - ip->start_temp)); - break; - - default: - ; - } - } - return firstp->error_flag; -} - -/* Generate code to skip the whole loop, if start expression not - * <= end expression (or >= for DOWN loops). This comparison must - * *NOT* be done in unsigned mode, or it will fail. - * Also, skip processing an empty VARYING array. - */ -static void -maybe_skip_loop () -{ - ITERATOR *firstp = loopstack->iter_list, *ip; - - for (ip = firstp; ip != NULL; ip = ip->next) - { - switch (ip->itype) - { - case DO_STEP: - expand_start_cond ( - build_compare_discrete_expr (ip->down_flag ? GE_EXPR : LE_EXPR, - ip->start_temp, ip->end_temp), 0); - break; - - case DO_LOC_VARYING: - { tree array_length = - convert (integer_type_node, - build_component_ref (ip->start_exp, var_length_id)); - expand_start_cond ( - build (NE_EXPR, TREE_TYPE (array_length), - array_length, integer_zero_node), 0); - break; - } - default: - break; - } - } -} - -/* - * Check at the top of the loop for a termination - */ -void -top_loop_end_check (condition) - tree condition; -{ - ITERATOR *ip; - - for (ip = loopstack->iter_list; ip != NULL; ip = ip->next) - { - switch (ip->itype) - { - case DO_FOREVER: - case DO_STEP: - break; - case DO_POWERSET: - { - tree temp1; - const char *func_name; - tree user_type = TREE_TYPE (ip->user_var); - - if (ip->down_flag) - func_name = "__flsetclrpowerset"; - else - func_name = "__ffsetclrpowerset"; - - temp1 = lookup_name (get_identifier (func_name)); - if (ip->down_flag) - temp1 = build_chill_function_call (temp1, - tree_cons (NULL_TREE, force_addr_of (ip->powerset_temp), - tree_cons (NULL_TREE, ip->iter_var, - tree_cons (NULL_TREE, integer_zero_node, NULL_TREE)))); - else - temp1 = build_chill_function_call (temp1, - tree_cons (NULL_TREE, force_addr_of (ip->powerset_temp), - tree_cons (NULL_TREE, powersetlen (ip->powerset_temp), - tree_cons (NULL_TREE, ip->iter_var, NULL_TREE)))); - expand_assignment (ip->iter_var, temp1, 0, 0); - expand_exit_loop_if_false (0, build (GE_EXPR, boolean_type_node, - ip->iter_var, - integer_zero_node)); - temp1 = TYPE_MIN_VALUE - (TYPE_DOMAIN (TREE_TYPE (ip->powerset_temp))); - expand_assignment (ip->user_var, - build (PLUS_EXPR, user_type, - convert (user_type, ip->iter_var), - convert (user_type, temp1)), - 0, 0); - } - break; - case DO_LOC: - case DO_LOC_VARYING: - break; - default: - ; - } - } - emit_line_note (input_filename, lineno); - - /* now, exit the loop if the condition isn't TRUE. */ - if (condition) - expand_exit_loop_if_false (0, truthvalue_conversion (condition)); -} - -/* - * Check generated temporaries for loop's end - */ -static int -bottom_loop_end_check () -{ - ITERATOR *firstp = loopstack->iter_list, *ip; - - emit_line_note (input_filename, lineno); - - /* now, generate code to check each loop counter for termination */ - for (ip = firstp; ip != NULL; ip = ip->next) - { - switch (ip->itype) - { - case DO_FOREVER: - break; - case DO_STEP: - /* exit if it's zero */ - expand_exit_loop_if_false (0, - build (NE_EXPR, boolean_type_node, - ip->iter_var, - integer_zero_node)); - /* decrement iteration counter by one */ - chill_expand_assignment (ip->iter_var, MINUS_EXPR, integer_one_node); - break; - case DO_LOC: - case DO_LOC_VARYING: - /* decrement iteration counter by one */ - chill_expand_assignment (ip->iter_var, MINUS_EXPR, integer_one_node); - /* exit if it's zero */ - expand_exit_loop_if_false (0, - build (NE_EXPR, boolean_type_node, - ip->iter_var, - integer_zero_node)); - break; - case DO_POWERSET: - break; - default: - ; - } - } - - return firstp->error_flag; -} - -/* - * increment the loop-control variables. - */ -static int -increment_temps () -{ - ITERATOR *firstp = loopstack->iter_list, *ip; - - for (ip = firstp; ip != NULL; ip = ip->next) - { - switch (ip->itype) - { - case DO_FOREVER: - break; - case DO_STEP: - { - tree delta = - fold (build (ip->down_flag ? MINUS_EXPR : PLUS_EXPR, - TREE_TYPE (ip->user_var), ip->user_var, - ip->step_temp)); - expand_expr_stmt ( - build_chill_modify_expr (ip->user_var, delta)); - } - break; - case DO_LOC: - case DO_LOC_VARYING: - /* This statement uses the C semantics, so that - the pointer is actually incremented by the - length of the object pointed to. */ - { - enum tree_code op = ip->down_flag ? MINUS_EXPR : PLUS_EXPR; - tree el_type = TREE_TYPE (TREE_TYPE (ip->loc_ptr_temp)); - chill_expand_assignment (ip->loc_ptr_temp, NOP_EXPR, - build (op, - TREE_TYPE (ip->loc_ptr_temp), - ip->loc_ptr_temp, - size_in_bytes (el_type))); - } - break; - case DO_POWERSET: - if (!ip->down_flag) - expand_assignment (ip->iter_var, - build (PLUS_EXPR, ip->iter_type, - ip->iter_var, - integer_one_node), - 0, 0); - break; - default: - ; - } - } - return firstp->error_flag; -} - -/* - * Generate a (temporary) unique identifier_node of - * the form "__tmp_%s_%d" - */ -tree -get_unique_identifier (lead) - const char *lead; -{ - char idbuf [256]; - static int idcount = 0; - - sprintf (idbuf, "__tmp_%s_%d", lead ? lead : "", idcount++); - return get_identifier (idbuf); -} - -/* - * build a temporary variable, given its NAME and TYPE. - * The name will have a number appended to assure uniqueness. - * return its DECL node. - */ -static tree -build_temporary_variable (name, type) - const char *name; - tree type; -{ - return decl_temp1 (get_unique_identifier (name), type, 0, NULL_TREE, 0, 0); -} - - -/* - * If the given expression isn't a constant, build a temp for it - * and evaluate the expression into the temp. Return the tree - * representing either the original constant expression or the - * temp which now contains the expression's value. - */ -static tree -maybe_make_for_temp (exp, temp_name, exp_type) - tree exp; - const char *temp_name; - tree exp_type; -{ - tree result = exp; - - if (exp != NULL_TREE) - { - /* if exp isn't constant, create a temporary for its value */ - if (TREE_CONSTANT (exp)) - { - /* FIXME: assure that TREE_TYPE (result) == ip->exp_type */ - result = convert (exp_type, exp); - } - else { - /* build temp, assign the value */ - result = decl_temp1 (get_unique_identifier (temp_name), exp_type, 0, - exp, 0, 0); - } - } - return result; -} - -#if 0 -/* - * Adapt the C unsigned_type function to CHILL - we need to - * account for any CHILL-specific integer types here. So far, - * the 16-bit integer type is the only one. - */ -static tree -chill_unsigned_type (type) - tree type; -{ - extern tree chill_unsigned_type_node; - tree type1 = TYPE_MAIN_VARIANT (type); - - if (type1 == chill_integer_type_node) - return chill_unsigned_type_node; - else - return unsigned_type (type); -} -#endif |