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Diffstat (limited to 'gcc/fortran/trans-array.c')
| -rw-r--r-- | gcc/fortran/trans-array.c | 4158 |
1 files changed, 4158 insertions, 0 deletions
diff --git a/gcc/fortran/trans-array.c b/gcc/fortran/trans-array.c new file mode 100644 index 00000000000..452b0fec81c --- /dev/null +++ b/gcc/fortran/trans-array.c @@ -0,0 +1,4158 @@ +/* Array translation routines + Copyright (C) 2002, 2003 Free Software Foundation, Inc. + Contributed by Paul Brook <paul@nowt.org> + and Steven Bosscher <s.bosscher@student.tudelft.nl> + +This file is part of GNU G95. + +GNU G95 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 G95 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 G95; see the file COPYING. If not, write to +the Free Software Foundation, 59 Temple Place - Suite 330, +Boston, MA 02111-1307, USA. */ + +/* trans-array.c-- Various array related code, including scalarization, + allocation, initialization and other support routines. */ + +/* How the scalarizer works. + In gfortran, array expressions use the same core routines as scalar + expressions. + First, a Scalarization State (SS) chain is built. This is done by walking + the expression tree, and building a linear list of the terms in the + expression. As the tree is walked, scalar subexpressions are translated. + + The scalarization parameters are stored in a gfc_loopinfo structure. + First the start and stride of each term is calculated by + gfc_conv_ss_startstride. During this process the expressions for the array + descriptors and data pointers are also translated. + + If the expression is an assignment, we must then resolve any dependencies. + In fortran all the rhs values of an assignment must be evaluated before + any assignments take place. This can require a temporary array to store the + values. We also require a temporary when we are passing array expressions + or vector subecripts as procedure parameters. + + Array sections are passed without copying to a temporary. These use the + scalarizer to determine the shape of the section. The flag + loop->array_parameter tells the scalarizer that the actual values and loop + variables will not be required. + + The function gfc_conv_loop_setup generates the scalarization setup code. + It determines the range of the scalarizing loop variables. If a temporary + is required, this is created and initialized. Code for scalar expressions + taken outside the loop is also generated at this time. Next the offset and + scaling required to translate from loop variables to array indices for each + term is calculated. + + A call to gfc_start_scalarized_body marks the start of the scalarized + expression. This creates a scope and declares the loop variables. Before + calling this gfc_make_ss_chain_used must be used to indicate which terms + will be used inside this loop. + + The scalar gfc_conv_* functions are then used to build the main body of the + scalarization loop. Scalarization loop variables and precalculated scalar + values are automaticaly substituted. Note that gfc_advance_se_ss_chain + must be used, rather than changing the se->ss directly. + + For assignment expressions requiring a temporary two sub loops are + generated. The first stores the result of the expression in the temporary, + the second copies it to the result. A call to + gfc_trans_scalarized_loop_boundary marks the end of the main loop code and + the start of the copying loop. The temporary may be less than full rank. + + Finally gfc_trans_scalarizing_loops is called to generate the implicit do + loops. The loops are added to the pre chain of the loopinfo. The post + chain may still contain cleanup code. + + After the loop code has been added into its parent scope gfc_cleanup_loop + is called to free all the SS allocated by the scalarizer. */ + +#include "config.h" +#include "system.h" +#include "coretypes.h" +#include "tree.h" +#include "tree-simple.h" +#include <stdio.h> +#include "ggc.h" +#include "toplev.h" +#include "real.h" +#include "flags.h" +#include <assert.h> +#include <gmp.h> +#include "gfortran.h" +#include "trans.h" +#include "trans-stmt.h" +#include "trans-types.h" +#include "trans-array.h" +#include "trans-const.h" +#include "dependency.h" + +static gfc_ss *gfc_walk_subexpr (gfc_ss *, gfc_expr *); + +/* The contents of this structure aren't actualy used, just the address. */ +static gfc_ss gfc_ss_terminator_var; +gfc_ss * const gfc_ss_terminator = &gfc_ss_terminator_var; + +unsigned HOST_WIDE_INT gfc_stack_space_left; + + +/* Returns true if a variable of specified size should go on the stack. */ + +int +gfc_can_put_var_on_stack (tree size) +{ + unsigned HOST_WIDE_INT low; + + if (!INTEGER_CST_P (size)) + return 0; + + if (gfc_option.flag_max_stack_var_size < 0) + return 1; + + if (TREE_INT_CST_HIGH (size) != 0) + return 0; + + low = TREE_INT_CST_LOW (size); + if (low > (unsigned HOST_WIDE_INT) gfc_option.flag_max_stack_var_size) + return 0; + +/* TODO: Set a per-function stack size limit. */ +#if 0 + /* We should be a bit more clever with array temps. */ + if (gfc_option.flag_max_function_vars_size >= 0) + { + if (low > gfc_stack_space_left) + return 0; + + gfc_stack_space_left -= low; + } +#endif + + return 1; +} + +static tree +gfc_array_dataptr_type (tree desc) +{ + return (GFC_TYPE_ARRAY_DATAPTR_TYPE (TREE_TYPE (desc))); +} + + +/* Build expressions to access the members of an array descriptor. + It's surprisingly easy to mess up here, so never access + an array descriptor by "brute force", always use these + functions. This also avoids problems if we change the format + of an array descriptor. + + To understand these magic numbers, look at the comments + before gfc_build_array_type() in trans-types.c. + + The code within these defines should be the only code which knows the format + of an array descriptor. + + Any code just needing to read obtain the bounds of an array should use + gfc_conv_array_* rather than the following functions as these will return + know constant values, and work with arrays which do not have descriptors. + + Don't forget to #undef these! */ + +#define DATA_FIELD 0 +#define OFFSET_FIELD 1 +#define DTYPE_FIELD 2 +#define DIMENSION_FIELD 3 + +#define STRIDE_SUBFIELD 0 +#define LBOUND_SUBFIELD 1 +#define UBOUND_SUBFIELD 2 + +tree +gfc_conv_descriptor_data (tree desc) +{ + tree field; + tree type; + + type = TREE_TYPE (desc); + assert (GFC_DESCRIPTOR_TYPE_P (type)); + + field = TYPE_FIELDS (type); + assert (DATA_FIELD == 0); + assert (field != NULL_TREE + && TREE_CODE (TREE_TYPE (field)) == POINTER_TYPE + && TREE_CODE (TREE_TYPE (TREE_TYPE (field))) == ARRAY_TYPE); + + return build (COMPONENT_REF, TREE_TYPE (field), desc, field); +} + +tree +gfc_conv_descriptor_offset (tree desc) +{ + tree type; + tree field; + + type = TREE_TYPE (desc); + assert (GFC_DESCRIPTOR_TYPE_P (type)); + + field = gfc_advance_chain (TYPE_FIELDS (type), OFFSET_FIELD); + assert (field != NULL_TREE && TREE_TYPE (field) == gfc_array_index_type); + + return build (COMPONENT_REF, TREE_TYPE (field), desc, field); +} + +tree +gfc_conv_descriptor_dtype (tree desc) +{ + tree field; + tree type; + + type = TREE_TYPE (desc); + assert (GFC_DESCRIPTOR_TYPE_P (type)); + + field = gfc_advance_chain (TYPE_FIELDS (type), DTYPE_FIELD); + assert (field != NULL_TREE && TREE_TYPE (field) == gfc_array_index_type); + + return build (COMPONENT_REF, TREE_TYPE (field), desc, field); +} + +static tree +gfc_conv_descriptor_dimension (tree desc, tree dim) +{ + tree field; + tree type; + tree tmp; + + type = TREE_TYPE (desc); + assert (GFC_DESCRIPTOR_TYPE_P (type)); + + field = gfc_advance_chain (TYPE_FIELDS (type), DIMENSION_FIELD); + assert (field != NULL_TREE + && TREE_CODE (TREE_TYPE (field)) == ARRAY_TYPE + && TREE_CODE (TREE_TYPE (TREE_TYPE (field))) == RECORD_TYPE); + + tmp = build (COMPONENT_REF, TREE_TYPE (field), desc, field); + tmp = gfc_build_array_ref (tmp, dim); + return tmp; +} + +tree +gfc_conv_descriptor_stride (tree desc, tree dim) +{ + tree tmp; + tree field; + + tmp = gfc_conv_descriptor_dimension (desc, dim); + field = TYPE_FIELDS (TREE_TYPE (tmp)); + field = gfc_advance_chain (field, STRIDE_SUBFIELD); + assert (field != NULL_TREE && TREE_TYPE (field) == gfc_array_index_type); + + tmp = build (COMPONENT_REF, TREE_TYPE (field), tmp, field); + return tmp; +} + +tree +gfc_conv_descriptor_lbound (tree desc, tree dim) +{ + tree tmp; + tree field; + + tmp = gfc_conv_descriptor_dimension (desc, dim); + field = TYPE_FIELDS (TREE_TYPE (tmp)); + field = gfc_advance_chain (field, LBOUND_SUBFIELD); + assert (field != NULL_TREE && TREE_TYPE (field) == gfc_array_index_type); + + tmp = build (COMPONENT_REF, TREE_TYPE (field), tmp, field); + return tmp; +} + +tree +gfc_conv_descriptor_ubound (tree desc, tree dim) +{ + tree tmp; + tree field; + + tmp = gfc_conv_descriptor_dimension (desc, dim); + field = TYPE_FIELDS (TREE_TYPE (tmp)); + field = gfc_advance_chain (field, UBOUND_SUBFIELD); + assert (field != NULL_TREE && TREE_TYPE (field) == gfc_array_index_type); + + tmp = build (COMPONENT_REF, TREE_TYPE (field), tmp, field); + return tmp; +} + + +/* Generate an initializer for a static pointer or allocatable array. */ + +void +gfc_trans_static_array_pointer (gfc_symbol * sym) +{ + tree tmp; + tree field; + tree type; + + assert (TREE_STATIC (sym->backend_decl)); + /* Just zero the data member. */ + type = TREE_TYPE (sym->backend_decl); + assert (GFC_DESCRIPTOR_TYPE_P (type)); + assert (DATA_FIELD == 0); + field = TYPE_FIELDS (type); + + tmp = tree_cons (field, null_pointer_node, NULL_TREE); + tmp = build1 (CONSTRUCTOR, type, tmp); + TREE_CONSTANT (tmp) = 1; + TREE_INVARIANT (tmp) = 1; + DECL_INITIAL (sym->backend_decl) = tmp; +} + + +/* Cleanup those #defines. */ + +#undef DATA_FIELD +#undef OFFSET_FIELD +#undef DTYPE_FIELD +#undef DIMENSION_FIELD +#undef STRIDE_SUBFIELD +#undef LBOUND_SUBFIELD +#undef UBOUND_SUBFIELD + + +/* Mark a SS chain as used. Flags specifies in which loops the SS is used. + flags & 1 = Main loop body. + flags & 2 = temp copy loop. */ + +void +gfc_mark_ss_chain_used (gfc_ss * ss, unsigned flags) +{ + for (; ss != gfc_ss_terminator; ss = ss->next) + ss->useflags = flags; +} + +static void gfc_free_ss (gfc_ss *); + + +/* Free a gfc_ss chain. */ + +static void +gfc_free_ss_chain (gfc_ss * ss) +{ + gfc_ss *next; + + while (ss != gfc_ss_terminator) + { + assert (ss != NULL); + next = ss->next; + gfc_free_ss (ss); + ss = next; + } +} + + +/* Free a SS. */ + +static void +gfc_free_ss (gfc_ss * ss) +{ + int n; + + switch (ss->type) + { + case GFC_SS_SECTION: + case GFC_SS_VECTOR: + for (n = 0; n < GFC_MAX_DIMENSIONS; n++) + { + if (ss->data.info.subscript[n]) + gfc_free_ss_chain (ss->data.info.subscript[n]); + } + break; + + default: + break; + } + + gfc_free (ss); +} + + +/* Free all the SS associated with a loop. */ + +void +gfc_cleanup_loop (gfc_loopinfo * loop) +{ + gfc_ss *ss; + gfc_ss *next; + + ss = loop->ss; + while (ss != gfc_ss_terminator) + { + assert (ss != NULL); + next = ss->loop_chain; + gfc_free_ss (ss); + ss = next; + } +} + + +/* Associate a SS chain with a loop. */ + +void +gfc_add_ss_to_loop (gfc_loopinfo * loop, gfc_ss * head) +{ + gfc_ss *ss; + + if (head == gfc_ss_terminator) + return; + + ss = head; + for (; ss && ss != gfc_ss_terminator; ss = ss->next) + { + if (ss->next == gfc_ss_terminator) + ss->loop_chain = loop->ss; + else + ss->loop_chain = ss->next; + } + assert (ss == gfc_ss_terminator); + loop->ss = head; +} + + +/* Generate code to allocate an array temporary, or create a variable to + hold the data. */ + +static void +gfc_trans_allocate_array_storage (gfc_loopinfo * loop, gfc_ss_info * info, + tree size, tree nelem) +{ + tree tmp; + tree args; + tree desc; + tree data; + bool onstack; + + desc = info->descriptor; + data = gfc_conv_descriptor_data (desc); + onstack = gfc_can_put_var_on_stack (size); + if (onstack) + { + /* Make a temporary variable to hold the data. */ + tmp = fold (build (MINUS_EXPR, TREE_TYPE (nelem), nelem, + integer_one_node)); + tmp = build_range_type (gfc_array_index_type, integer_zero_node, tmp); + tmp = build_array_type (gfc_get_element_type (TREE_TYPE (desc)), tmp); + tmp = gfc_create_var (tmp, "A"); + tmp = gfc_build_addr_expr (TREE_TYPE (data), tmp); + gfc_add_modify_expr (&loop->pre, data, tmp); + info->data = data; + info->offset = gfc_index_zero_node; + + } + else + { + /* Allocate memory to hold the data. */ + args = gfc_chainon_list (NULL_TREE, size); + + if (gfc_index_integer_kind == 4) + tmp = gfor_fndecl_internal_malloc; + else if (gfc_index_integer_kind == 8) + tmp = gfor_fndecl_internal_malloc64; + else + abort (); + tmp = gfc_build_function_call (tmp, args); + tmp = convert (TREE_TYPE (data), tmp); + gfc_add_modify_expr (&loop->pre, data, tmp); + + info->data = data; + info->offset = gfc_index_zero_node; + } + + /* The offset is zero because we create temporaries with a zero + lower bound. */ + tmp = gfc_conv_descriptor_offset (desc); + gfc_add_modify_expr (&loop->pre, tmp, gfc_index_zero_node); + + if (!onstack) + { + /* Free the temporary. */ + tmp = convert (pvoid_type_node, info->data); + tmp = gfc_chainon_list (NULL_TREE, tmp); + tmp = gfc_build_function_call (gfor_fndecl_internal_free, tmp); + gfc_add_expr_to_block (&loop->post, tmp); + } +} + + +/* Generate code to allocate and initialize the descriptor for a temporary + array. Fills in the descriptor, data and offset fields of info. Also + adjusts the loop variables to be zero-based. Returns the size of the + array. */ + +tree +gfc_trans_allocate_temp_array (gfc_loopinfo * loop, gfc_ss_info * info, + tree eltype, tree string_length) +{ + tree type; + tree desc; + tree tmp; + tree size; + tree nelem; + int n; + int dim; + + assert (info->dimen > 0); + /* Set the lower bound to zero. */ + for (dim = 0; dim < info->dimen; dim++) + { + n = loop->order[dim]; + if (n < loop->temp_dim) + assert (integer_zerop (loop->from[n])); + else + { + loop->to[n] = fold (build (MINUS_EXPR, gfc_array_index_type, + loop->to[n], loop->from[n])); + loop->from[n] = integer_zero_node; + } + + info->delta[dim] = integer_zero_node; + info->start[dim] = integer_zero_node; + info->stride[dim] = integer_one_node; + info->dim[dim] = dim; + } + + /* Initialise the descriptor. */ + type = + gfc_get_array_type_bounds (eltype, info->dimen, loop->from, loop->to, 1); + desc = gfc_create_var (type, "atmp"); + GFC_DECL_PACKED_ARRAY (desc) = 1; + + info->descriptor = desc; + size = integer_one_node; + + /* Fill in the array dtype. */ + tmp = gfc_conv_descriptor_dtype (desc); + gfc_add_modify_expr (&loop->pre, tmp, + GFC_TYPE_ARRAY_DTYPE (TREE_TYPE (desc))); + + /* Fill in the bounds and stride. This is a packed array, so: + size = 1; + for (n = 0; n < rank; n++) + { + stride[n] = size + delta = ubound[n] + 1 - lbound[n]; + size = size * delta; + } + size = size * sizeof(element); */ + for (n = 0; n < info->dimen; n++) + { + /* Store the stride and bound components in the descriptor. */ + tmp = gfc_conv_descriptor_stride (desc, gfc_rank_cst[n]); + gfc_add_modify_expr (&loop->pre, tmp, size); + + tmp = gfc_conv_descriptor_lbound (desc, gfc_rank_cst[n]); + gfc_add_modify_expr (&loop->pre, tmp, integer_zero_node); + + tmp = gfc_conv_descriptor_ubound (desc, gfc_rank_cst[n]); + gfc_add_modify_expr (&loop->pre, tmp, loop->to[n]); + + tmp = fold (build (PLUS_EXPR, gfc_array_index_type, + loop->to[n], integer_one_node)); + + size = fold (build (MULT_EXPR, gfc_array_index_type, size, tmp)); + size = gfc_evaluate_now (size, &loop->pre); + } + + /* TODO: Where does the string length go? */ + if (string_length) + gfc_todo_error ("temporary arrays of strings"); + + /* Get the size of the array. */ + nelem = size; + size = fold (build (MULT_EXPR, gfc_array_index_type, size, + TYPE_SIZE_UNIT (gfc_get_element_type (type)))); + + gfc_trans_allocate_array_storage (loop, info, size, nelem); + + if (info->dimen > loop->temp_dim) + loop->temp_dim = info->dimen; + + return size; +} + + +/* Make sure offset is a variable. */ + +static void +gfc_put_offset_into_var (stmtblock_t * pblock, tree * poffset, + tree * offsetvar) +{ + /* We should have already created the offset variable. We cannot + create it here because we may be in an inner scopde. */ + assert (*offsetvar != NULL_TREE); + gfc_add_modify_expr (pblock, *offsetvar, *poffset); + *poffset = *offsetvar; + TREE_USED (*offsetvar) = 1; +} + + +/* Add the contents of an array to the constructor. */ + +static void +gfc_trans_array_constructor_subarray (stmtblock_t * pblock, + tree type ATTRIBUTE_UNUSED, + tree pointer, gfc_expr * expr, + tree * poffset, tree * offsetvar) +{ + gfc_se se; + gfc_ss *ss; + gfc_loopinfo loop; + stmtblock_t body; + tree tmp; + + /* We need this to be a variable so we can increment it. */ + gfc_put_offset_into_var (pblock, poffset, offsetvar); + + gfc_init_se (&se, NULL); + + /* Walk the array expression. */ + ss = gfc_walk_expr (expr); + assert (ss != gfc_ss_terminator); + + /* Initialize the scalarizer. */ + gfc_init_loopinfo (&loop); + gfc_add_ss_to_loop (&loop, ss); + + /* Initialize the loop. */ + gfc_conv_ss_startstride (&loop); + gfc_conv_loop_setup (&loop); + + /* Make the loop body. */ + gfc_mark_ss_chain_used (ss, 1); + gfc_start_scalarized_body (&loop, &body); + gfc_copy_loopinfo_to_se (&se, &loop); + se.ss = ss; + + gfc_conv_expr (&se, expr); + gfc_add_block_to_block (&body, &se.pre); + + /* Store the value. */ + tmp = gfc_build_indirect_ref (pointer); + tmp = gfc_build_array_ref (tmp, *poffset); + gfc_add_modify_expr (&body, tmp, se.expr); + + /* Increment the offset. */ + tmp = build (PLUS_EXPR, gfc_array_index_type, *poffset, integer_one_node); + gfc_add_modify_expr (&body, *poffset, tmp); + + /* Finish the loop. */ + gfc_add_block_to_block (&body, &se.post); + assert (se.ss == gfc_ss_terminator); + gfc_trans_scalarizing_loops (&loop, &body); + gfc_add_block_to_block (&loop.pre, &loop.post); + tmp = gfc_finish_block (&loop.pre); + gfc_add_expr_to_block (pblock, tmp); + + gfc_cleanup_loop (&loop); +} + + +/* Assign the values to the elements of an array constructor. */ + +static void +gfc_trans_array_constructor_value (stmtblock_t * pblock, tree type, + tree pointer, gfc_constructor * c, + tree * poffset, tree * offsetvar) +{ + tree tmp; + tree ref; + stmtblock_t body; + tree loopbody; + gfc_se se; + + for (; c; c = c->next) + { + /* If this is an iterator or an array, the offset must be a variable. */ + if ((c->iterator || c->expr->rank > 0) && INTEGER_CST_P (*poffset)) + gfc_put_offset_into_var (pblock, poffset, offsetvar); + + gfc_start_block (&body); + + if (c->expr->expr_type == EXPR_ARRAY) + { + /* Array constructors can be nested. */ + gfc_trans_array_constructor_value (&body, type, pointer, + c->expr->value.constructor, + poffset, offsetvar); + } + else if (c->expr->rank > 0) + { + gfc_trans_array_constructor_subarray (&body, type, pointer, + c->expr, poffset, offsetvar); + } + else + { + /* This code really upsets the gimplifier so don't bother for now. */ + gfc_constructor *p; + HOST_WIDE_INT n; + HOST_WIDE_INT size; + + p = c; + n = 0; + while (p && !(p->iterator || p->expr->expr_type != EXPR_CONSTANT)) + { + p = p->next; + n++; + } + if (n < 4) + { + /* Scalar values. */ + gfc_init_se (&se, NULL); + gfc_conv_expr (&se, c->expr); + gfc_add_block_to_block (&body, &se.pre); + + ref = gfc_build_indirect_ref (pointer); + ref = gfc_build_array_ref (ref, *poffset); + gfc_add_modify_expr (&body, ref, se.expr); + gfc_add_block_to_block (&body, &se.post); + + *poffset = fold (build (PLUS_EXPR, gfc_array_index_type, + *poffset, integer_one_node)); + } + else + { + /* Collect multiple scalar constants into a constructor. */ + tree list; + tree init; + tree bound; + tree tmptype; + + p = c; + list = NULL_TREE; + /* Count the number of consecutive scalar constants. */ + while (p && !(p->iterator + || p->expr->expr_type != EXPR_CONSTANT)) + { + gfc_init_se (&se, NULL); + gfc_conv_constant (&se, p->expr); + list = tree_cons (NULL_TREE, se.expr, list); + c = p; + p = p->next; + } + + bound = build_int_2 (n - 1, 0); + /* Create an array type to hold them. */ + tmptype = build_range_type (gfc_array_index_type, + integer_zero_node, bound); + tmptype = build_array_type (type, tmptype); + + init = build1 (CONSTRUCTOR, tmptype, nreverse (list)); + TREE_CONSTANT (init) = 1; + TREE_INVARIANT (init) = 1; + TREE_STATIC (init) = 1; + /* Create a static variable to hold the data. */ + tmp = gfc_create_var (tmptype, "data"); + TREE_STATIC (tmp) = 1; + TREE_CONSTANT (tmp) = 1; + TREE_INVARIANT (tmp) = 1; + DECL_INITIAL (tmp) = init; + init = tmp; + + /* Use BUILTIN_MEMCPY to assign the values. */ + tmp = gfc_build_indirect_ref (pointer); + tmp = gfc_build_array_ref (tmp, *poffset); + tmp = gfc_build_addr_expr (NULL, tmp); + init = gfc_build_addr_expr (NULL, init); + + size = TREE_INT_CST_LOW (TYPE_SIZE_UNIT (type)); + bound = build_int_2 (n * size, 0); + tmp = gfc_chainon_list (NULL_TREE, tmp); + tmp = gfc_chainon_list (tmp, init); + tmp = gfc_chainon_list (tmp, bound); + tmp = gfc_build_function_call (built_in_decls[BUILT_IN_MEMCPY], + tmp); + gfc_add_expr_to_block (&body, tmp); + + *poffset = fold (build (PLUS_EXPR, gfc_array_index_type, + *poffset, bound)); + } + if (!INTEGER_CST_P (*poffset)) + { + gfc_add_modify_expr (&body, *offsetvar, *poffset); + *poffset = *offsetvar; + } + } + + /* The frontend should already have done any expansions. */ + if (c->iterator) + { + tree end; + tree step; + tree loopvar; + tree exit_label; + + loopbody = gfc_finish_block (&body); + + gfc_init_se (&se, NULL); + gfc_conv_expr (&se, c->iterator->var); + gfc_add_block_to_block (pblock, &se.pre); + loopvar = se.expr; + + /* Initialize thie loop. */ + gfc_init_se (&se, NULL); + gfc_conv_expr_val (&se, c->iterator->start); + gfc_add_block_to_block (pblock, &se.pre); + gfc_add_modify_expr (pblock, loopvar, se.expr); + + gfc_init_se (&se, NULL); + gfc_conv_expr_val (&se, c->iterator->end); + gfc_add_block_to_block (pblock, &se.pre); + end = gfc_evaluate_now (se.expr, pblock); + + gfc_init_se (&se, NULL); + gfc_conv_expr_val (&se, c->iterator->step); + gfc_add_block_to_block (pblock, &se.pre); + step = gfc_evaluate_now (se.expr, pblock); + + /* Generate the loop body. */ + exit_label = gfc_build_label_decl (NULL_TREE); + gfc_start_block (&body); + + /* Generate the exit condition. */ + end = build (GT_EXPR, boolean_type_node, loopvar, end); + tmp = build1_v (GOTO_EXPR, exit_label); + TREE_USED (exit_label) = 1; + tmp = build_v (COND_EXPR, end, tmp, build_empty_stmt ()); + gfc_add_expr_to_block (&body, tmp); + + /* The main loop body. */ + gfc_add_expr_to_block (&body, loopbody); + + /* Increment the loop variable. */ + tmp = build (PLUS_EXPR, TREE_TYPE (loopvar), loopvar, step); + gfc_add_modify_expr (&body, loopvar, tmp); + + /* Finish the loop. */ + tmp = gfc_finish_block (&body); + tmp = build_v (LOOP_EXPR, tmp); + gfc_add_expr_to_block (pblock, tmp); + + /* Add the exit label. */ + tmp = build1_v (LABEL_EXPR, exit_label); + gfc_add_expr_to_block (pblock, tmp); + } + else + { + /* Pass the code as is. */ + tmp = gfc_finish_block (&body); + gfc_add_expr_to_block (pblock, tmp); + } + } +} + + +/* Get the size of an expression. Returns -1 if the size isn't constant. + Implied do loops with non-constant bounds are tricky because we must only + evaluate the bounds once. */ + +static void +gfc_get_array_cons_size (mpz_t * size, gfc_constructor * c) +{ + gfc_iterator *i; + mpz_t val; + mpz_t len; + + mpz_set_ui (*size, 0); + mpz_init (len); + mpz_init (val); + + for (; c; c = c->next) + { + if (c->expr->expr_type == EXPR_ARRAY) + { + /* A nested array constructor. */ + gfc_get_array_cons_size (&len, c->expr->value.constructor); + if (mpz_sgn (len) < 0) + { + mpz_set (*size, len); + mpz_clear (len); + mpz_clear (val); + return; + } + } + else + { + if (c->expr->rank > 0) + { + mpz_set_si (*size, -1); + mpz_clear (len); + mpz_clear (val); + return; + } + mpz_set_ui (len, 1); + } + + if (c->iterator) + { + i = c->iterator; + + if (i->start->expr_type != EXPR_CONSTANT + || i->end->expr_type != EXPR_CONSTANT + || i->step->expr_type != EXPR_CONSTANT) + { + mpz_set_si (*size, -1); + mpz_clear (len); + mpz_clear (val); + return; + } + + mpz_add (val, i->end->value.integer, i->start->value.integer); + mpz_tdiv_q (val, val, i->step->value.integer); + mpz_add_ui (val, val, 1); + mpz_mul (len, len, val); + } + mpz_add (*size, *size, len); + } + mpz_clear (len); + mpz_clear (val); +} + + +/* Array constructors are handled by constructing a temporary, then using that + within the scalarization loop. This is not optimal, but seems by far the + simplest method. */ + +static void +gfc_trans_array_constructor (gfc_loopinfo * loop, gfc_ss * ss) +{ + tree offset; + tree offsetvar; + tree desc; + tree size; + tree type; + + if (ss->expr->ts.type == BT_CHARACTER) + gfc_todo_error ("Character string array constructors"); + type = gfc_typenode_for_spec (&ss->expr->ts); + ss->data.info.dimen = loop->dimen; + size = + gfc_trans_allocate_temp_array (loop, &ss->data.info, type, NULL_TREE); + + desc = ss->data.info.descriptor; + offset = integer_zero_node; + offsetvar = gfc_create_var_np (gfc_array_index_type, "offset"); + TREE_USED (offsetvar) = 0; + gfc_trans_array_constructor_value (&loop->pre, type, + ss->data.info.data, + ss->expr->value.constructor, &offset, + &offsetvar); + + if (TREE_USED (offsetvar)) + pushdecl (offsetvar); + else + assert (INTEGER_CST_P (offset)); +#if 0 + /* Disable bound checking for now cos it's probably broken. */ + if (flag_bounds_check) + { + abort (); + } +#endif +} + + +/* Add the pre and post chains for all the scalar expressions in a SS chain + to loop. This is called after the loop parameters have been calculated, + but before the actual scalarizing loops. */ +/*GCC ARRAYS*/ + +static void +gfc_add_loop_ss_code (gfc_loopinfo * loop, gfc_ss * ss, bool subscript) +{ + gfc_se se; + int n; + + assert (ss != NULL); + + for (; ss != gfc_ss_terminator; ss = ss->loop_chain) + { + assert (ss); + + switch (ss->type) + { + case GFC_SS_SCALAR: + /* Scalar expression. Evaluate this now. This includes elemental + dimension indices, but not array section bounds. */ + gfc_init_se (&se, NULL); + gfc_conv_expr (&se, ss->expr); + gfc_add_block_to_block (&loop->pre, &se.pre); + + if (ss->expr->ts.type != BT_CHARACTER) + { + /* Move the evaluation of scalar expressions outside the + scalarization loop. */ + if (subscript) + se.expr = convert(gfc_array_index_type, se.expr); + se.expr = gfc_evaluate_now (se.expr, &loop->pre); + gfc_add_block_to_block (&loop->pre, &se.post); + } + else + gfc_add_block_to_block (&loop->post, &se.post); + + ss->data.scalar.expr = se.expr; + ss->data.scalar.string_length = se.string_length; + break; + + case GFC_SS_REFERENCE: + /* Scalar reference. Evaluate this now. */ + gfc_init_se (&se, NULL); + gfc_conv_expr_reference (&se, ss->expr); + gfc_add_block_to_block (&loop->pre, &se.pre); + gfc_add_block_to_block (&loop->post, &se.post); + + ss->data.scalar.expr = gfc_evaluate_now (se.expr, &loop->pre); + ss->data.scalar.string_length = se.string_length; + break; + + case GFC_SS_SECTION: + case GFC_SS_VECTOR: + /* Scalarized expression. Evaluate any scalar subscripts. */ + for (n = 0; n < GFC_MAX_DIMENSIONS; n++) + { + /* Add the expressions for scalar subscripts. */ + if (ss->data.info.subscript[n]) + gfc_add_loop_ss_code (loop, ss->data.info.subscript[n], true); + } + break; + + case GFC_SS_INTRINSIC: + gfc_add_intrinsic_ss_code (loop, ss); + break; + + case GFC_SS_FUNCTION: + /* Array function return value. We call the function and save its + result in a temporary for use inside the loop. */ + gfc_init_se (&se, NULL); + se.loop = loop; + se.ss = ss; + gfc_conv_expr (&se, ss->expr); + gfc_add_block_to_block (&loop->pre, &se.pre); + gfc_add_block_to_block (&loop->post, &se.post); + break; + + case GFC_SS_CONSTRUCTOR: + gfc_trans_array_constructor (loop, ss); + break; + + default: + abort (); + } + } +} + + +/* Translate expressions for the descriptor and data pointer of a SS. */ +/*GCC ARRAYS*/ + +static void +gfc_conv_ss_descriptor (stmtblock_t * block, gfc_ss * ss, int base) +{ + gfc_se se; + tree tmp; + + /* Get the descriptor for the array to be scalarized. */ + assert (ss->expr->expr_type == EXPR_VARIABLE); + gfc_init_se (&se, NULL); + se.descriptor_only = 1; + gfc_conv_expr_lhs (&se, ss->expr); + gfc_add_block_to_block (block, &se.pre); + ss->data.info.descriptor = se.expr; + + if (base) + { + /* Also the data pointer. */ + tmp = gfc_conv_array_data (se.expr); + /* If this is a variable or address of a variable we use it directly. + Otherwise we must evaluate it now to to avoid break dependency + analysis by pulling the expressions for elemental array indices + inside the loop. */ + if (!(DECL_P (tmp) + || (TREE_CODE (tmp) == ADDR_EXPR + && DECL_P (TREE_OPERAND (tmp, 0))))) + tmp = gfc_evaluate_now (tmp, block); + ss->data.info.data = tmp; + + tmp = gfc_conv_array_offset (se.expr); + ss->data.info.offset = gfc_evaluate_now (tmp, block); + } +} + + +/* Initialise a gfc_loopinfo structure. */ + +void +gfc_init_loopinfo (gfc_loopinfo * loop) +{ + int n; + + memset (loop, 0, sizeof (gfc_loopinfo)); + gfc_init_block (&loop->pre); + gfc_init_block (&loop->post); + + /* Initialy scalarize in order. */ + for (n = 0; n < GFC_MAX_DIMENSIONS; n++) + loop->order[n] = n; + + loop->ss = gfc_ss_terminator; +} + + +/* Copies the loop variable info to a gfc_se sructure. Does not copy the SS + chain. */ + +void +gfc_copy_loopinfo_to_se (gfc_se * se, gfc_loopinfo * loop) +{ + se->loop = loop; +} + + +/* Return an expression for the data pointer of an array. */ + +tree +gfc_conv_array_data (tree descriptor) +{ + tree type; + + type = TREE_TYPE (descriptor); + if (GFC_ARRAY_TYPE_P (type)) + { + if (TREE_CODE (type) == POINTER_TYPE) + return descriptor; + else + { + /* Descritporless arrays. */ + return gfc_build_addr_expr (NULL, descriptor); + } + } + else + return gfc_conv_descriptor_data (descriptor); +} + + +/* Return an expression for the base offset of an array. */ + +tree +gfc_conv_array_offset (tree descriptor) +{ + tree type; + + type = TREE_TYPE (descriptor); + if (GFC_ARRAY_TYPE_P (type)) + return GFC_TYPE_ARRAY_OFFSET (type); + else + return gfc_conv_descriptor_offset (descriptor); +} + + +/* Get an expression for the array stride. */ + +tree +gfc_conv_array_stride (tree descriptor, int dim) +{ + tree tmp; + tree type; + + type = TREE_TYPE (descriptor); + + /* For descriptorless arrays use the array size. */ + tmp = GFC_TYPE_ARRAY_STRIDE (type, dim); + if (tmp != NULL_TREE) + return tmp; + + tmp = gfc_conv_descriptor_stride (descriptor, gfc_rank_cst[dim]); + return tmp; +} + + +/* Like gfc_conv_array_stride, but for the lower bound. */ + +tree +gfc_conv_array_lbound (tree descriptor, int dim) +{ + tree tmp; + tree type; + + type = TREE_TYPE (descriptor); + + tmp = GFC_TYPE_ARRAY_LBOUND (type, dim); + if (tmp != NULL_TREE) + return tmp; + + tmp = gfc_conv_descriptor_lbound (descriptor, gfc_rank_cst[dim]); + return tmp; +} + + +/* Like gfc_conv_array_stride, but for the upper bound. */ + +tree +gfc_conv_array_ubound (tree descriptor, int dim) +{ + tree tmp; + tree type; + + type = TREE_TYPE (descriptor); + + tmp = GFC_TYPE_ARRAY_UBOUND (type, dim); + if (tmp != NULL_TREE) + return tmp; + + /* This should only ever happen when passing an assumed shape array + as an actual parameter. The value will never be used. */ + if (GFC_ARRAY_TYPE_P (TREE_TYPE (descriptor))) + return integer_zero_node; + + tmp = gfc_conv_descriptor_ubound (descriptor, gfc_rank_cst[dim]); + return tmp; +} + + +/* Translate an array reference. The descriptor should be in se->expr. + Do not use this function, it wil be removed soon. */ +/*GCC ARRAYS*/ + +static void +gfc_conv_array_index_ref (gfc_se * se, tree pointer, tree * indices, + tree offset, int dimen) +{ + tree array; + tree tmp; + tree index; + int n; + + array = gfc_build_indirect_ref (pointer); + + index = offset; + for (n = 0; n < dimen; n++) + { + /* index = index + stride[n]*indices[n] */ + tmp = gfc_conv_array_stride (se->expr, n); + tmp = fold (build (MULT_EXPR, gfc_array_index_type, indices[n], tmp)); + + index = fold (build (PLUS_EXPR, gfc_array_index_type, index, tmp)); + } + + /* Result = data[index]. */ + tmp = gfc_build_array_ref (array, index); + + /* Check we've used the correct number of dimensions. */ + assert (TREE_CODE (TREE_TYPE (tmp)) != ARRAY_TYPE); + + se->expr = tmp; +} + + +/* Generate code to perform an array index bound check. */ + +static tree +gfc_trans_array_bound_check (gfc_se * se, tree descriptor, tree index, int n) +{ + tree cond; + tree fault; + tree tmp; + + if (!flag_bounds_check) + return index; + + index = gfc_evaluate_now (index, &se->pre); + /* Check lower bound. */ + tmp = gfc_conv_array_lbound (descriptor, n); + fault = fold (build (LT_EXPR, boolean_type_node, index, tmp)); + /* Check upper bound. */ + tmp = gfc_conv_array_ubound (descriptor, n); + cond = fold (build (GT_EXPR, boolean_type_node, index, tmp)); + fault = fold (build (TRUTH_OR_EXPR, boolean_type_node, fault, cond)); + + gfc_trans_runtime_check (fault, gfc_strconst_fault, &se->pre); + + return index; +} + + +/* A reference to an array vector subscript. Uses recursion to handle nested + vector subscripts. */ + +static tree +gfc_conv_vector_array_index (gfc_se * se, tree index, gfc_ss * ss) +{ + tree descsave; + tree indices[GFC_MAX_DIMENSIONS]; + gfc_array_ref *ar; + gfc_ss_info *info; + int n; + + assert (ss && ss->type == GFC_SS_VECTOR); + + /* Save the descriptor. */ + descsave = se->expr; + info = &ss->data.info; + se->expr = info->descriptor; + + ar = &info->ref->u.ar; + for (n = 0; n < ar->dimen; n++) + { + switch (ar->dimen_type[n]) + { + case DIMEN_ELEMENT: + assert (info->subscript[n] != gfc_ss_terminator + && info->subscript[n]->type == GFC_SS_SCALAR); + indices[n] = info->subscript[n]->data.scalar.expr; + break; + + case DIMEN_RANGE: + indices[n] = index; + break; + + case DIMEN_VECTOR: + index = gfc_conv_vector_array_index (se, index, info->subscript[n]); + + indices[n] = + gfc_trans_array_bound_check (se, info->descriptor, index, n); + break; + + default: + abort (); + } + } + /* Get the index from the vector. */ + gfc_conv_array_index_ref (se, info->data, indices, info->offset, ar->dimen); + index = se->expr; + /* Put the descriptor back. */ + se->expr = descsave; + + return index; +} + + +/* Return the offset for an index. Performs bound checking for elemental + dimensions. Single element references are processed seperately. */ + +static tree +gfc_conv_array_index_offset (gfc_se * se, gfc_ss_info * info, int dim, int i, + gfc_array_ref * ar, tree stride) +{ + tree index; + + /* Get the index into the array for this dimension. */ + if (ar) + { + assert (ar->type != AR_ELEMENT); + if (ar->dimen_type[dim] == DIMEN_ELEMENT) + { + assert (i == -1); + /* Elemental dimension. */ + assert (info->subscript[dim] + && info->subscript[dim]->type == GFC_SS_SCALAR); + /* We've already translated this value outside the loop. */ + index = info->subscript[dim]->data.scalar.expr; + + index = + gfc_trans_array_bound_check (se, info->descriptor, index, dim); + } + else + { + /* Scalarized dimension. */ + assert (info && se->loop); + + /* Multiply the loop variable by the stride and dela. */ + index = se->loop->loopvar[i]; + index = fold (build (MULT_EXPR, gfc_array_index_type, index, + info->stride[i])); + index = fold (build (PLUS_EXPR, gfc_array_index_type, index, + info->delta[i])); + + if (ar->dimen_type[dim] == DIMEN_VECTOR) + { + /* Handle vector subscripts. */ + index = gfc_conv_vector_array_index (se, index, + info->subscript[dim]); + index = + gfc_trans_array_bound_check (se, info->descriptor, index, + dim); + } + else + assert (ar->dimen_type[dim] == DIMEN_RANGE); + } + } + else + { + /* Temporary array. */ + assert (se->loop); + index = se->loop->loopvar[se->loop->order[i]]; + } + + /* Multiply by the stride. */ + index = fold (build (MULT_EXPR, gfc_array_index_type, index, stride)); + + return index; +} + + +/* Build a scalarized reference to an array. */ + +static void +gfc_conv_scalarized_array_ref (gfc_se * se, gfc_array_ref * ar) +{ + gfc_ss_info *info; + tree index; + tree tmp; + int n; + + info = &se->ss->data.info; + if (ar) + n = se->loop->order[0]; + else + n = 0; + + index = gfc_conv_array_index_offset (se, info, info->dim[n], n, ar, + info->stride0); + /* Add the offset for this dimension to the stored offset for all other + dimensions. */ + index = fold (build (PLUS_EXPR, gfc_array_index_type, index, info->offset)); + + tmp = gfc_build_indirect_ref (info->data); + se->expr = gfc_build_array_ref (tmp, index); +} + + +/* Translate access of temporary array. */ + +void +gfc_conv_tmp_array_ref (gfc_se * se) +{ + tree desc; + + desc = se->ss->data.info.descriptor; + /* TODO: We need the string length for string variables. */ + + gfc_conv_scalarized_array_ref (se, NULL); +} + + +/* Build an array reference. se->expr already holds the array descriptor. + This should be either a variable, indirect variable reference or component + reference. For arrays which do not have a descriptor, se->expr will be + the data pointer. + a(i, j, k) = base[offset + i * stride[0] + j * stride[1] + k * stride[2]]*/ + +void +gfc_conv_array_ref (gfc_se * se, gfc_array_ref * ar) +{ + int n; + tree index; + tree tmp; + tree stride; + tree fault; + gfc_se indexse; + + /* Handle scalarized references seperately. */ + if (ar->type != AR_ELEMENT) + { + gfc_conv_scalarized_array_ref (se, ar); + return; + } + + index = integer_zero_node; + + fault = integer_zero_node; + + /* Calculate the offsets from all the dimensions. */ + for (n = 0; n < ar->dimen; n++) + { + /* Calculate the index for this demension. */ + gfc_init_se (&indexse, NULL); + gfc_conv_expr_type (&indexse, ar->start[n], gfc_array_index_type); + gfc_add_block_to_block (&se->pre, &indexse.pre); + + if (flag_bounds_check) + { + /* Check array bounds. */ + tree cond; + + indexse.expr = gfc_evaluate_now (indexse.expr, &se->pre); + + tmp = gfc_conv_array_lbound (se->expr, n); + cond = fold (build (LT_EXPR, boolean_type_node, indexse.expr, tmp)); + fault = + fold (build (TRUTH_OR_EXPR, boolean_type_node, fault, cond)); + + tmp = gfc_conv_array_ubound (se->expr, n); + cond = fold (build (GT_EXPR, boolean_type_node, indexse.expr, tmp)); + fault = + fold (build (TRUTH_OR_EXPR, boolean_type_node, fault, cond)); + } + + /* Multiply the index by the stride. */ + stride = gfc_conv_array_stride (se->expr, n); + tmp = fold (build (MULT_EXPR, gfc_array_index_type, indexse.expr, + stride)); + + /* And add it to the total. */ + index = fold (build (PLUS_EXPR, gfc_array_index_type, index, tmp)); + } + + if (flag_bounds_check) + gfc_trans_runtime_check (fault, gfc_strconst_fault, &se->pre); + + tmp = gfc_conv_array_offset (se->expr); + if (!integer_zerop (tmp)) + index = fold (build (PLUS_EXPR, gfc_array_index_type, index, tmp)); + + /* Access the calculated element. */ + tmp = gfc_conv_array_data (se->expr); + tmp = gfc_build_indirect_ref (tmp); + se->expr = gfc_build_array_ref (tmp, index); +} + + +/* Generate the code to be executed immediately before entering a + scalarization loop. */ + +static void +gfc_trans_preloop_setup (gfc_loopinfo * loop, int dim, int flag, + stmtblock_t * pblock) +{ + tree index; + tree stride; + gfc_ss_info *info; + gfc_ss *ss; + gfc_se se; + int i; + + /* This code will be executed before entering the scalarization loop + for this dimension. */ + for (ss = loop->ss; ss != gfc_ss_terminator; ss = ss->loop_chain) + { + if ((ss->useflags & flag) == 0) + continue; + + if (ss->type != GFC_SS_SECTION + && ss->type != GFC_SS_FUNCTION && ss->type != GFC_SS_CONSTRUCTOR) + continue; + + info = &ss->data.info; + + if (dim >= info->dimen) + continue; + + if (dim == info->dimen - 1) + { + /* For the outermost loop calculate the offset due to any + elemental dimensions. It will have been initialized with the + base offset of the array. */ + if (info->ref) + { + for (i = 0; i < info->ref->u.ar.dimen; i++) + { + if (info->ref->u.ar.dimen_type[i] != DIMEN_ELEMENT) + continue; + + gfc_init_se (&se, NULL); + se.loop = loop; + se.expr = info->descriptor; + stride = gfc_conv_array_stride (info->descriptor, i); + index = gfc_conv_array_index_offset (&se, info, i, -1, + &info->ref->u.ar, + stride); + gfc_add_block_to_block (pblock, &se.pre); + + info->offset = fold (build (PLUS_EXPR, gfc_array_index_type, + info->offset, index)); + info->offset = gfc_evaluate_now (info->offset, pblock); + } + + i = loop->order[0]; + stride = gfc_conv_array_stride (info->descriptor, info->dim[i]); + } + else + stride = gfc_conv_array_stride (info->descriptor, 0); + + /* Calculate the stride of the innermost loop. Hopefully this will + allow the backend optimizers to do their stuff more effectively. + */ + info->stride0 = gfc_evaluate_now (stride, pblock); + } + else + { + /* Add the offset for the previous loop dimension. */ + gfc_array_ref *ar; + + if (info->ref) + { + ar = &info->ref->u.ar; + i = loop->order[dim + 1]; + } + else + { + ar = NULL; + i = dim + 1; + } + + gfc_init_se (&se, NULL); + se.loop = loop; + se.expr = info->descriptor; + stride = gfc_conv_array_stride (info->descriptor, info->dim[i]); + index = gfc_conv_array_index_offset (&se, info, info->dim[i], i, + ar, stride); + gfc_add_block_to_block (pblock, &se.pre); + info->offset = fold (build (PLUS_EXPR, gfc_array_index_type, + info->offset, index)); + info->offset = gfc_evaluate_now (info->offset, pblock); + } + + /* Remeber this offset for the second loop. */ + if (dim == loop->temp_dim - 1) + info->saved_offset = info->offset; + } +} + + +/* Start a scalarized expression. Creates a scope and declares loop + variables. */ + +void +gfc_start_scalarized_body (gfc_loopinfo * loop, stmtblock_t * pbody) +{ + int dim; + int n; + int flags; + + assert (!loop->array_parameter); + + for (dim = loop->dimen - 1; dim >= 0; dim--) + { + n = loop->order[dim]; + + gfc_start_block (&loop->code[n]); + + /* Create the loop variable. */ + loop->loopvar[n] = gfc_create_var (gfc_array_index_type, "S"); + + if (dim < loop->temp_dim) + flags = 3; + else + flags = 1; + /* Calculate values that will be constant within this loop. */ + gfc_trans_preloop_setup (loop, dim, flags, &loop->code[n]); + } + gfc_start_block (pbody); +} + + +/* Generates the actual loop code for a scalarization loop. */ + +static void +gfc_trans_scalarized_loop_end (gfc_loopinfo * loop, int n, + stmtblock_t * pbody) +{ + stmtblock_t block; + tree cond; + tree tmp; + tree loopbody; + tree exit_label; + + loopbody = gfc_finish_block (pbody); + + /* Initialize the loopvar. */ + gfc_add_modify_expr (&loop->code[n], loop->loopvar[n], loop->from[n]); + + exit_label = gfc_build_label_decl (NULL_TREE); + + /* Generate the loop body. */ + gfc_init_block (&block); + + /* The exit condition. */ + cond = build (GT_EXPR, boolean_type_node, loop->loopvar[n], loop->to[n]); + tmp = build1_v (GOTO_EXPR, exit_label); + TREE_USED (exit_label) = 1; + tmp = build_v (COND_EXPR, cond, tmp, build_empty_stmt ()); + gfc_add_expr_to_block (&block, tmp); + + /* The main body. */ + gfc_add_expr_to_block (&block, loopbody); + + /* Increment the loopvar. */ + tmp = build (PLUS_EXPR, gfc_array_index_type, + loop->loopvar[n], integer_one_node); + gfc_add_modify_expr (&block, loop->loopvar[n], tmp); + + /* Build the loop. */ + tmp = gfc_finish_block (&block); + tmp = build_v (LOOP_EXPR, tmp); + gfc_add_expr_to_block (&loop->code[n], tmp); + + /* Add the exit label. */ + tmp = build1_v (LABEL_EXPR, exit_label); + gfc_add_expr_to_block (&loop->code[n], tmp); +} + + +/* Finishes and generates the loops for a scalarized expression. */ + +void +gfc_trans_scalarizing_loops (gfc_loopinfo * loop, stmtblock_t * body) +{ + int dim; + int n; + gfc_ss *ss; + stmtblock_t *pblock; + tree tmp; + + pblock = body; + /* Generate the loops. */ + for (dim = 0; dim < loop->dimen; dim++) + { + n = loop->order[dim]; + gfc_trans_scalarized_loop_end (loop, n, pblock); + loop->loopvar[n] = NULL_TREE; + pblock = &loop->code[n]; + } + + tmp = gfc_finish_block (pblock); + gfc_add_expr_to_block (&loop->pre, tmp); + + /* Clear all the used flags. */ + for (ss = loop->ss; ss; ss = ss->loop_chain) + ss->useflags = 0; +} + + +/* Finish the main body of a scalarized expression, and start the secondary + copying body. */ + +void +gfc_trans_scalarized_loop_boundary (gfc_loopinfo * loop, stmtblock_t * body) +{ + int dim; + int n; + stmtblock_t *pblock; + gfc_ss *ss; + + pblock = body; + /* We finish as many loops as are used by the temporary. */ + for (dim = 0; dim < loop->temp_dim - 1; dim++) + { + n = loop->order[dim]; + gfc_trans_scalarized_loop_end (loop, n, pblock); + loop->loopvar[n] = NULL_TREE; + pblock = &loop->code[n]; + } + + /* We don't want to finish the outermost loop entirely. */ + n = loop->order[loop->temp_dim - 1]; + gfc_trans_scalarized_loop_end (loop, n, pblock); + + /* Restore the initial offsets. */ + for (ss = loop->ss; ss != gfc_ss_terminator; ss = ss->loop_chain) + { + if ((ss->useflags & 2) == 0) + continue; + + if (ss->type != GFC_SS_SECTION + && ss->type != GFC_SS_FUNCTION && ss->type != GFC_SS_CONSTRUCTOR) + continue; + + ss->data.info.offset = ss->data.info.saved_offset; + } + + /* Restart all the inner loops we just finished. */ + for (dim = loop->temp_dim - 2; dim >= 0; dim--) + { + n = loop->order[dim]; + + gfc_start_block (&loop->code[n]); + + loop->loopvar[n] = gfc_create_var (gfc_array_index_type, "Q"); + + gfc_trans_preloop_setup (loop, dim, 2, &loop->code[n]); + } + + /* Start a block for the secondary copying code. */ + gfc_start_block (body); +} + + +/* Calculate the upper bound of an array section. */ + +static tree +gfc_conv_section_upper_bound (gfc_ss * ss, int n, stmtblock_t * pblock) +{ + int dim; + gfc_ss *vecss; + gfc_expr *end; + tree desc; + tree bound; + gfc_se se; + + assert (ss->type == GFC_SS_SECTION); + + /* For vector array subscripts we want the size of the vector. */ + dim = ss->data.info.dim[n]; + vecss = ss; + while (vecss->data.info.ref->u.ar.dimen_type[dim] == DIMEN_VECTOR) + { + vecss = vecss->data.info.subscript[dim]; + assert (vecss && vecss->type == GFC_SS_VECTOR); + dim = vecss->data.info.dim[0]; + } + + assert (vecss->data.info.ref->u.ar.dimen_type[dim] == DIMEN_RANGE); + end = vecss->data.info.ref->u.ar.end[dim]; + desc = vecss->data.info.descriptor; + + if (end) + { + /* The upper bound was specified. */ + gfc_init_se (&se, NULL); + gfc_conv_expr_type (&se, end, gfc_array_index_type); + gfc_add_block_to_block (pblock, &se.pre); + bound = se.expr; + } + else + { + /* No upper bound was specified, so use the bound of the array. */ + bound = gfc_conv_array_ubound (desc, dim); + } + + return bound; +} + + +/* Calculate the lower bound of an array section. */ + +static void +gfc_conv_section_startstride (gfc_loopinfo * loop, gfc_ss * ss, int n) +{ + gfc_expr *start; + gfc_expr *stride; + gfc_ss *vecss; + tree desc; + gfc_se se; + gfc_ss_info *info; + int dim; + + info = &ss->data.info; + + dim = info->dim[n]; + + /* For vector array subscripts we want the size of the vector. */ + vecss = ss; + while (vecss->data.info.ref->u.ar.dimen_type[dim] == DIMEN_VECTOR) + { + vecss = vecss->data.info.subscript[dim]; + assert (vecss && vecss->type == GFC_SS_VECTOR); + /* Get the descriptors for the vector subscripts as well. */ + if (!vecss->data.info.descriptor) + gfc_conv_ss_descriptor (&loop->pre, vecss, !loop->array_parameter); + dim = vecss->data.info.dim[0]; + } + + assert (vecss->data.info.ref->u.ar.dimen_type[dim] == DIMEN_RANGE); + start = vecss->data.info.ref->u.ar.start[dim]; + stride = vecss->data.info.ref->u.ar.stride[dim]; + desc = vecss->data.info.descriptor; + + /* Calculate the start of the range. For vector subscripts this will + be the range of the vector. */ + if (start) + { + /* Specified section start. */ + gfc_init_se (&se, NULL); + gfc_conv_expr_type (&se, start, gfc_array_index_type); + gfc_add_block_to_block (&loop->pre, &se.pre); + info->start[n] = se.expr; + } + else + { + /* No lower bound specified so use the bound of the array. */ + info->start[n] = gfc_conv_array_lbound (desc, dim); + } + info->start[n] = gfc_evaluate_now (info->start[n], &loop->pre); + + /* Calculate the stride. */ + if (stride == NULL) + info->stride[n] = integer_one_node; + else + { + gfc_init_se (&se, NULL); + gfc_conv_expr_type (&se, stride, gfc_array_index_type); + gfc_add_block_to_block (&loop->pre, &se.pre); + info->stride[n] = gfc_evaluate_now (se.expr, &loop->pre); + } +} + + +/* Calculates the range start and stride for a SS chain. Also gets the + descriptor and data pointer. The range of vector subscripts is the size + of the vector. Array bounds are also checked. */ + +void +gfc_conv_ss_startstride (gfc_loopinfo * loop) +{ + int n; + tree tmp; + gfc_ss *ss; + gfc_ss *vecss; + tree desc; + + loop->dimen = 0; + /* Determine the rank of the loop. */ + for (ss = loop->ss; + ss != gfc_ss_terminator && loop->dimen == 0; ss = ss->loop_chain) + { + switch (ss->type) + { + case GFC_SS_SECTION: + case GFC_SS_CONSTRUCTOR: + case GFC_SS_FUNCTION: + loop->dimen = ss->data.info.dimen; + break; + + default: + break; + } + } + + if (loop->dimen == 0) + gfc_todo_error ("Unable to determine rank of expression"); + + + /* loop over all the SS in the chain. */ + for (ss = loop->ss; ss != gfc_ss_terminator; ss = ss->loop_chain) + { + switch (ss->type) + { + case GFC_SS_SECTION: + /* Get the descriptor for the array. */ + gfc_conv_ss_descriptor (&loop->pre, ss, !loop->array_parameter); + + for (n = 0; n < ss->data.info.dimen; n++) + gfc_conv_section_startstride (loop, ss, n); + break; + + case GFC_SS_CONSTRUCTOR: + case GFC_SS_FUNCTION: + for (n = 0; n < ss->data.info.dimen; n++) + { + ss->data.info.start[n] = integer_zero_node; + ss->data.info.stride[n] = integer_one_node; + } + break; + + default: + break; + } + } + + /* The rest is just runtime bound checking. */ + if (flag_bounds_check) + { + stmtblock_t block; + tree fault; + tree bound; + tree end; + tree size[GFC_MAX_DIMENSIONS]; + gfc_ss_info *info; + int dim; + + gfc_start_block (&block); + + fault = integer_zero_node; + for (n = 0; n < loop->dimen; n++) + size[n] = NULL_TREE; + + for (ss = loop->ss; ss != gfc_ss_terminator; ss = ss->loop_chain) + { + if (ss->type != GFC_SS_SECTION) + continue; + + /* TODO: range checking for mapped dimensions. */ + info = &ss->data.info; + + /* This only checks scalarized dimensions, elemental dimensions are + checked later. */ + for (n = 0; n < loop->dimen; n++) + { + dim = info->dim[n]; + vecss = ss; + while (vecss->data.info.ref->u.ar.dimen_type[dim] + == DIMEN_VECTOR) + { + vecss = vecss->data.info.subscript[dim]; + assert (vecss && vecss->type == GFC_SS_VECTOR); + dim = vecss->data.info.dim[0]; + } + assert (vecss->data.info.ref->u.ar.dimen_type[dim] + == DIMEN_RANGE); + desc = vecss->data.info.descriptor; + + /* Check lower bound. */ + bound = gfc_conv_array_lbound (desc, dim); + tmp = info->start[n]; + tmp = fold (build (LT_EXPR, boolean_type_node, tmp, bound)); + fault = fold (build (TRUTH_OR_EXPR, boolean_type_node, fault, + tmp)); + + /* Check the upper bound. */ + bound = gfc_conv_array_ubound (desc, dim); + end = gfc_conv_section_upper_bound (ss, n, &block); + tmp = fold (build (GT_EXPR, boolean_type_node, end, bound)); + fault = fold (build (TRUTH_OR_EXPR, boolean_type_node, fault, + tmp)); + + /* Check the section sizes match. */ + tmp = fold (build (MINUS_EXPR, gfc_array_index_type, end, + info->start[n])); + tmp = fold (build (FLOOR_DIV_EXPR, gfc_array_index_type, tmp, + info->stride[n])); + /* We remember the size of the first section, and check all the + others against this. */ + if (size[n]) + { + tmp = + fold (build (NE_EXPR, boolean_type_node, tmp, size[n])); + fault = + build (TRUTH_OR_EXPR, boolean_type_node, fault, tmp); + } + else + size[n] = gfc_evaluate_now (tmp, &block); + } + } + gfc_trans_runtime_check (fault, gfc_strconst_bounds, &block); + + tmp = gfc_finish_block (&block); + gfc_add_expr_to_block (&loop->pre, tmp); + } +} + + +/* Return true if the two SS could be aliased, ie. both point to the same data + object. */ +/* TODO: resolve aliases based on frontend expressions. */ + +static int +gfc_could_be_alias (gfc_ss * lss, gfc_ss * rss) +{ + gfc_ref *lref; + gfc_ref *rref; + gfc_symbol *lsym; + gfc_symbol *rsym; + + lsym = lss->expr->symtree->n.sym; + rsym = rss->expr->symtree->n.sym; + if (gfc_symbols_could_alias (lsym, rsym)) + return 1; + + if (rsym->ts.type != BT_DERIVED + && lsym->ts.type != BT_DERIVED) + return 0; + + /* For Derived types we must check all the component types. We can ignore + array references as these will have the same base type as the previous + component ref. */ + for (lref = lss->expr->ref; lref != lss->data.info.ref; lref = lref->next) + { + if (lref->type != REF_COMPONENT) + continue; + + if (gfc_symbols_could_alias (lref->u.c.sym, rsym)) + return 1; + + for (rref = rss->expr->ref; rref != rss->data.info.ref; + rref = rref->next) + { + if (rref->type != REF_COMPONENT) + continue; + + if (gfc_symbols_could_alias (lref->u.c.sym, rref->u.c.sym)) + return 1; + } + } + + for (rref = rss->expr->ref; rref != rss->data.info.ref; rref = rref->next) + { + if (rref->type != REF_COMPONENT) + break; + + if (gfc_symbols_could_alias (rref->u.c.sym, lsym)) + return 1; + } + + return 0; +} + + +/* Resolve array data dependencies. Creates a temporary if required. */ +/* TODO: Calc dependencies with gfc_expr rather than gfc_ss, and move to + dependency.c. */ + +void +gfc_conv_resolve_dependencies (gfc_loopinfo * loop, gfc_ss * dest, + gfc_ss * rss) +{ + gfc_ss *ss; + gfc_ref *lref; + gfc_ref *rref; + gfc_ref *aref; + int nDepend = 0; + int temp_dim = 0; + + loop->temp_ss = NULL; + aref = dest->data.info.ref; + temp_dim = 0; + + for (ss = rss; ss != gfc_ss_terminator; ss = ss->next) + { + if (ss->type != GFC_SS_SECTION) + continue; + + if (gfc_could_be_alias (dest, ss)) + { + nDepend = 1; + break; + } + + if (dest->expr->symtree->n.sym == ss->expr->symtree->n.sym) + { + lref = dest->expr->ref; + rref = ss->expr->ref; + + nDepend = gfc_dep_resolver (lref, rref); +#if 0 + /* TODO : loop shifting. */ + if (nDepend == 1) + { + /* Mark the dimensions for LOOP SHIFTING */ + for (n = 0; n < loop->dimen; n++) + { + int dim = dest->data.info.dim[n]; + + if (lref->u.ar.dimen_type[dim] == DIMEN_VECTOR) + depends[n] = 2; + else if (! gfc_is_same_range (&lref->u.ar, + &rref->u.ar, dim, 0)) + depends[n] = 1; + } + + /* Put all the dimensions with dependancies in the + innermost loops. */ + dim = 0; + for (n = 0; n < loop->dimen; n++) + { + assert (loop->order[n] == n); + if (depends[n]) + loop->order[dim++] = n; + } + temp_dim = dim; + for (n = 0; n < loop->dimen; n++) + { + if (! depends[n]) + loop->order[dim++] = n; + } + + assert (dim == loop->dimen); + break; + } +#endif + } + } + + if (nDepend == 1) + { + loop->temp_ss = gfc_get_ss (); + loop->temp_ss->type = GFC_SS_TEMP; + loop->temp_ss->data.temp.type = + gfc_get_element_type (TREE_TYPE (dest->data.info.descriptor)); + loop->temp_ss->data.temp.string_length = NULL_TREE; + loop->temp_ss->data.temp.dimen = loop->dimen; + loop->temp_ss->next = gfc_ss_terminator; + gfc_add_ss_to_loop (loop, loop->temp_ss); + } + else + loop->temp_ss = NULL; +} + + +/* Initialise the scalarization loop. Creates the loop variables. Determines + the range of the loop variables. Creates a temporary if required. + Calculates how to transform from loop variables to array indices for each + expression. Also generates code for scalar expressions which have been + moved outside the loop. */ + +void +gfc_conv_loop_setup (gfc_loopinfo * loop) +{ + int n; + int dim; + gfc_ss_info *info; + gfc_ss_info *specinfo; + gfc_ss *ss; + tree tmp; + tree len; + gfc_ss *loopspec[GFC_MAX_DIMENSIONS]; + mpz_t *cshape; + mpz_t i; + + mpz_init (i); + for (n = 0; n < loop->dimen; n++) + { + loopspec[n] = NULL; + /* We use one SS term, and use that to determine the bounds of the + loop for this dimension. We try to pick the simplest term. */ + for (ss = loop->ss; ss != gfc_ss_terminator; ss = ss->loop_chain) + { + if (ss->expr && ss->expr->shape) + { + /* The frontend has worked out the size for us. */ + loopspec[n] = ss; + continue; + } + + if (ss->type == GFC_SS_CONSTRUCTOR) + { + /* Try to figure out the size of the constructior. */ + /* TODO: avoid this by making the prontend set the shape. */ + gfc_get_array_cons_size (&i, ss->expr->value.constructor); + /* A negative value meens we failed. */ + if (mpz_sgn (i) > 0) + { + mpz_sub_ui (i, i, 1); + loop->to[n] = + gfc_conv_mpz_to_tree (i, gfc_index_integer_kind); + loopspec[n] = ss; + } + continue; + } + + /* We don't know how to handle functions yet. + This may not be possible in all cases. */ + if (ss->type != GFC_SS_SECTION) + continue; + + info = &ss->data.info; + + if (loopspec[n]) + specinfo = &loopspec[n]->data.info; + else + specinfo = NULL; + info = &ss->data.info; + + /* Criteria for choosing a loop specifier (most important first): + stride of one + known stride + known lower bound + known upper bound + */ + if (!specinfo) + loopspec[n] = ss; + else if (loopspec[n]->type != GFC_SS_CONSTRUCTOR) + { + if (integer_onep (info->stride[n]) + && !integer_onep (specinfo->stride[n])) + loopspec[n] = ss; + else if (INTEGER_CST_P (info->stride[n]) + && !INTEGER_CST_P (specinfo->stride[n])) + loopspec[n] = ss; + else if (INTEGER_CST_P (info->start[n]) + && !INTEGER_CST_P (specinfo->start[n])) + loopspec[n] = ss; + /* We don't work out the upper bound. + else if (INTEGER_CST_P (info->finish[n]) + && ! INTEGER_CST_P (specinfo->finish[n])) + loopspec[n] = ss; */ + } + } + + if (!loopspec[n]) + gfc_todo_error ("Unable to find scalarization loop specifier"); + + info = &loopspec[n]->data.info; + + /* Set the extents of this range. */ + cshape = loopspec[n]->expr->shape; + if (cshape && INTEGER_CST_P (info->start[n]) + && INTEGER_CST_P (info->stride[n])) + { + loop->from[n] = info->start[n]; + mpz_set (i, cshape[n]); + mpz_sub_ui (i, i, 1); + /* To = from + (size - 1) * stride. */ + tmp = gfc_conv_mpz_to_tree (i, gfc_index_integer_kind); + if (!integer_onep (info->stride[n])) + { + tmp = fold (build (MULT_EXPR, gfc_array_index_type, + tmp, info->stride[n])); + } + loop->to[n] = fold (build (PLUS_EXPR, gfc_array_index_type, + loop->from[n], tmp)); + } + else + { + loop->from[n] = info->start[n]; + switch (loopspec[n]->type) + { + case GFC_SS_CONSTRUCTOR: + assert (info->dimen == 1); + assert (loop->to[n]); + break; + + case GFC_SS_SECTION: + loop->to[n] = gfc_conv_section_upper_bound (loopspec[n], n, + &loop->pre); + break; + + default: + abort (); + } + } + + /* Transform everything so we have a simple incrementing variable. */ + if (integer_onep (info->stride[n])) + info->delta[n] = integer_zero_node; + else + { + /* Set the delta for this section. */ + info->delta[n] = gfc_evaluate_now (loop->from[n], &loop->pre); + /* Number of iterations is (end - start + step) / step. + with start = 0, this simplifies to + last = end / step; + for (i = 0; i<=last; i++){...}; */ + tmp = fold (build (MINUS_EXPR, gfc_array_index_type, loop->to[n], + loop->from[n])); + tmp = fold (build (TRUNC_DIV_EXPR, gfc_array_index_type, tmp, + info->stride[n])); + loop->to[n] = gfc_evaluate_now (tmp, &loop->pre); + /* Make the loop variable start at 0. */ + loop->from[n] = integer_zero_node; + } + } + + /* If we want a temporary then create it. */ + if (loop->temp_ss != NULL) + { + assert (loop->temp_ss->type == GFC_SS_TEMP); + tmp = loop->temp_ss->data.temp.type; + len = loop->temp_ss->data.temp.string_length; + n = loop->temp_ss->data.temp.dimen; + memset (&loop->temp_ss->data.info, 0, sizeof (gfc_ss_info)); + loop->temp_ss->type = GFC_SS_SECTION; + loop->temp_ss->data.info.dimen = n; + gfc_trans_allocate_temp_array (loop, &loop->temp_ss->data.info, + tmp, len); + } + + /* Add all the scalar code that can be taken out of the loops. */ + gfc_add_loop_ss_code (loop, loop->ss, false); + + for (n = 0; n < loop->temp_dim; n++) + loopspec[loop->order[n]] = NULL; + + mpz_clear (i); + + /* For array parameters we don't have loop variables, so don't calculate the + translations. */ + if (loop->array_parameter) + return; + + /* Calculate the translation from loop variables to array indices. */ + for (ss = loop->ss; ss != gfc_ss_terminator; ss = ss->loop_chain) + { + if (ss->type != GFC_SS_SECTION) + continue; + + info = &ss->data.info; + + for (n = 0; n < info->dimen; n++) + { + dim = info->dim[n]; + + /* If we are specifying the range the delta may already be set. */ + if (loopspec[n] != ss) + { + /* Calculate the offset relative to the loop variable. + First multiply by the stride. */ + tmp = fold (build (MULT_EXPR, gfc_array_index_type, + loop->from[n], info->stride[n])); + + /* Then subtract this from our starting value. */ + tmp = fold (build (MINUS_EXPR, gfc_array_index_type, + info->start[n], tmp)); + + info->delta[n] = gfc_evaluate_now (tmp, &loop->pre); + } + } + } +} + + +/* Fills in an array descriptor, and returns the size of the array. The size + will be a simple_val, ie a variable or a constant. Also calculates the + offset of the base. Returns the size of the arrary. + { + stride = 1; + offset = 0; + for (n = 0; n < rank; n++) + { + a.lbound[n] = specified_lower_bound; + offset = offset + a.lbond[n] * stride; + size = 1 - lbound; + a.ubound[n] = specified_upper_bound; + a.stride[n] = stride; + size = ubound + size; //size = ubound + 1 - lbound + stride = stride * size; + } + return (stride); + } */ +/*GCC ARRAYS*/ + +static tree +gfc_array_init_size (tree descriptor, int rank, tree * poffset, + gfc_expr ** lower, gfc_expr ** upper, + stmtblock_t * pblock) +{ + tree type; + tree tmp; + tree size; + tree offset; + tree stride; + gfc_expr *ubound; + gfc_se se; + int n; + + type = TREE_TYPE (descriptor); + + stride = integer_one_node; + offset = integer_zero_node; + + /* Set the dtype. */ + tmp = gfc_conv_descriptor_dtype (descriptor); + gfc_add_modify_expr (pblock, tmp, + GFC_TYPE_ARRAY_DTYPE (TREE_TYPE (descriptor))); + + for (n = 0; n < rank; n++) + { + /* We have 3 possibilities for determining the size of the array: + lower == NULL => lbound = 1, ubound = upper[n] + upper[n] = NULL => lbound = 1, ubound = lower[n] + upper[n] != NULL => lbound = lower[n], ubound = upper[n] */ + ubound = upper[n]; + + /* Set lower bound. */ + gfc_init_se (&se, NULL); + if (lower == NULL) + se.expr = integer_one_node; + else + { + assert (lower[n]); + if (ubound) + { + gfc_conv_expr_type (&se, lower[n], gfc_array_index_type); + gfc_add_block_to_block (pblock, &se.pre); + } + else + { + se.expr = integer_one_node; + ubound = lower[n]; + } + } + tmp = gfc_conv_descriptor_lbound (descriptor, gfc_rank_cst[n]); + gfc_add_modify_expr (pblock, tmp, se.expr); + + /* Work out the offset for this component. */ + tmp = fold (build (MULT_EXPR, gfc_array_index_type, se.expr, stride)); + offset = fold (build (MINUS_EXPR, gfc_array_index_type, offset, tmp)); + + /* Start the calculation for the size of this dimension. */ + size = build (MINUS_EXPR, gfc_array_index_type, + integer_one_node, se.expr); + + /* Set upper bound. */ + gfc_init_se (&se, NULL); + assert (ubound); + gfc_conv_expr_type (&se, ubound, gfc_array_index_type); + gfc_add_block_to_block (pblock, &se.pre); + + tmp = gfc_conv_descriptor_ubound (descriptor, gfc_rank_cst[n]); + gfc_add_modify_expr (pblock, tmp, se.expr); + + /* Store the stride. */ + tmp = gfc_conv_descriptor_stride (descriptor, gfc_rank_cst[n]); + gfc_add_modify_expr (pblock, tmp, stride); + + /* Calculate the size of this dimension. */ + size = fold (build (PLUS_EXPR, gfc_array_index_type, se.expr, size)); + + /* Multiply the stride by the number of elements in this dimension. */ + stride = fold (build (MULT_EXPR, gfc_array_index_type, stride, size)); + stride = gfc_evaluate_now (stride, pblock); + } + + /* The stride is the number of elements in the array, so multiply by the + size of an element to get the total size. */ + tmp = TYPE_SIZE_UNIT (gfc_get_element_type (type)); + size = fold (build (MULT_EXPR, gfc_array_index_type, stride, tmp)); + + if (poffset != NULL) + { + offset = gfc_evaluate_now (offset, pblock); + *poffset = offset; + } + + size = gfc_evaluate_now (size, pblock); + return size; +} + + +/* Initialises the descriptor and generates a call to _gfor_allocate. Does + the work for an ALLOCATE statement. */ +/*GCC ARRAYS*/ + +void +gfc_array_allocate (gfc_se * se, gfc_ref * ref, tree pstat) +{ + tree tmp; + tree pointer; + tree allocate; + tree offset; + tree size; + gfc_expr **lower; + gfc_expr **upper; + + /* Figure out the size of the array. */ + switch (ref->u.ar.type) + { + case AR_ELEMENT: + lower = NULL; + upper = ref->u.ar.start; + break; + + case AR_FULL: + assert (ref->u.ar.as->type == AS_EXPLICIT); + + lower = ref->u.ar.as->lower; + upper = ref->u.ar.as->upper; + break; + + case AR_SECTION: + lower = ref->u.ar.start; + upper = ref->u.ar.end; + break; + + default: + abort (); + break; + } + + size = gfc_array_init_size (se->expr, ref->u.ar.as->rank, &offset, + lower, upper, &se->pre); + + /* Allocate memory to store the data. */ + tmp = gfc_conv_descriptor_data (se->expr); + pointer = gfc_build_addr_expr (NULL, tmp); + pointer = gfc_evaluate_now (pointer, &se->pre); + + if (gfc_array_index_type == gfc_int4_type_node) + allocate = gfor_fndecl_allocate; + else if (gfc_array_index_type == gfc_int8_type_node) + allocate = gfor_fndecl_allocate64; + else + abort (); + + tmp = gfc_chainon_list (NULL_TREE, pointer); + tmp = gfc_chainon_list (tmp, size); + tmp = gfc_chainon_list (tmp, pstat); + tmp = gfc_build_function_call (allocate, tmp); + gfc_add_expr_to_block (&se->pre, tmp); + + pointer = gfc_conv_descriptor_data (se->expr); + + tmp = gfc_conv_descriptor_offset (se->expr); + gfc_add_modify_expr (&se->pre, tmp, offset); +} + + +/* Deallocate an array variable. Also used when an allocated variable goes + out of scope. */ +/*GCC ARRAYS*/ + +tree +gfc_array_deallocate (tree descriptor) +{ + tree var; + tree tmp; + stmtblock_t block; + + gfc_start_block (&block); + /* Get a pointer to the data. */ + tmp = gfc_conv_descriptor_data (descriptor); + tmp = gfc_build_addr_expr (NULL, tmp); + var = gfc_create_var (TREE_TYPE (tmp), "ptr"); + gfc_add_modify_expr (&block, var, tmp); + + /* Parameter is the address of the data component. */ + tmp = gfc_chainon_list (NULL_TREE, var); + tmp = gfc_chainon_list (tmp, integer_zero_node); + tmp = gfc_build_function_call (gfor_fndecl_deallocate, tmp); + gfc_add_expr_to_block (&block, tmp); + + return gfc_finish_block (&block); +} + + +/* Create an array constructor from an initialization expression. + We assume the frontend already did any expansions and conversions. */ + +tree +gfc_conv_array_initializer (tree type, gfc_expr * expr) +{ + gfc_constructor *c; + tree list; + tree tmp; + mpz_t maxval; + gfc_se se; + HOST_WIDE_INT hi; + unsigned HOST_WIDE_INT lo; + tree index, range; + + list = NULL_TREE; + switch (expr->expr_type) + { + case EXPR_CONSTANT: + case EXPR_STRUCTURE: + /* A single scalar or derived type value. Create an array with all + elements equal to that value. */ + gfc_init_se (&se, NULL); + gfc_conv_expr (&se, expr); + + tmp = TYPE_MAX_VALUE (TYPE_DOMAIN (type)); + assert (tmp && INTEGER_CST_P (tmp)); + hi = TREE_INT_CST_HIGH (tmp); + lo = TREE_INT_CST_LOW (tmp); + lo++; + if (lo == 0) + hi++; + /* This will probably eat buckets of memory for large arrays. */ + while (hi != 0 || lo != 0) + { + list = tree_cons (NULL_TREE, se.expr, list); + if (lo == 0) + hi--; + lo--; + } + break; + + case EXPR_ARRAY: + /* Create a list of all the elements. */ + for (c = expr->value.constructor; c; c = c->next) + { + if (c->iterator) + { + /* Problems occur when we get something like + integer :: a(lots) = (/(i, i=1,lots)/) */ + /* TODO: Unexpanded array initializers. */ + internal_error + ("Possible frontend bug: array constructor not expanded"); + } + if (mpz_cmp_si (c->n.offset, 0) != 0) + index = gfc_conv_mpz_to_tree (c->n.offset, gfc_index_integer_kind); + else + index = NULL_TREE; + mpz_init (maxval); + if (mpz_cmp_si (c->repeat, 0) != 0) + { + tree tmp1, tmp2; + + mpz_set (maxval, c->repeat); + mpz_add (maxval, c->n.offset, maxval); + mpz_sub_ui (maxval, maxval, 1); + tmp2 = gfc_conv_mpz_to_tree (maxval, gfc_index_integer_kind); + if (mpz_cmp_si (c->n.offset, 0) != 0) + { + mpz_add_ui (maxval, c->n.offset, 1); + tmp1 = gfc_conv_mpz_to_tree (maxval, gfc_index_integer_kind); + } + else + tmp1 = gfc_conv_mpz_to_tree (c->n.offset, gfc_index_integer_kind); + + range = build (RANGE_EXPR, integer_type_node, tmp1, tmp2); + } + else + range = NULL; + mpz_clear (maxval); + + gfc_init_se (&se, NULL); + switch (c->expr->expr_type) + { + case EXPR_CONSTANT: + gfc_conv_constant (&se, c->expr); + if (range == NULL_TREE) + list = tree_cons (index, se.expr, list); + else + { + if (index != NULL_TREE) + list = tree_cons (index, se.expr, list); + list = tree_cons (range, se.expr, list); + } + break; + + case EXPR_STRUCTURE: + gfc_conv_structure (&se, c->expr, 1); + list = tree_cons (index, se.expr, list); + break; + + default: + abort(); + } + } + /* We created the list in reverse order. */ + list = nreverse (list); + break; + + default: + abort(); + } + + /* Create a constructor from the list of elements. */ + tmp = build1 (CONSTRUCTOR, type, list); + TREE_CONSTANT (tmp) = 1; + TREE_INVARIANT (tmp) = 1; + return tmp; +} + + +/* Generate code to evaluate non-constant array bounds. Sets *poffset and + returns the size (in elements) of the array. */ + +static tree +gfc_trans_array_bounds (tree type, gfc_symbol * sym, tree * poffset, + stmtblock_t * pblock) +{ + gfc_array_spec *as; + tree size; + tree stride; + tree offset; + tree ubound; + tree lbound; + tree tmp; + gfc_se se; + + int dim; + + as = sym->as; + + size = integer_one_node; + offset = integer_zero_node; + for (dim = 0; dim < as->rank; dim++) + { + /* Evaluate non-constant array bound expressions. */ + lbound = GFC_TYPE_ARRAY_LBOUND (type, dim); + if (as->lower[dim] && !INTEGER_CST_P (lbound)) + { + gfc_init_se (&se, NULL); + gfc_conv_expr_type (&se, as->lower[dim], gfc_array_index_type); + gfc_add_block_to_block (pblock, &se.pre); + gfc_add_modify_expr (pblock, lbound, se.expr); + } + ubound = GFC_TYPE_ARRAY_UBOUND (type, dim); + if (as->upper[dim] && !INTEGER_CST_P (ubound)) + { + gfc_init_se (&se, NULL); + gfc_conv_expr_type (&se, as->upper[dim], gfc_array_index_type); + gfc_add_block_to_block (pblock, &se.pre); + gfc_add_modify_expr (pblock, ubound, se.expr); + } + /* The offset of this dimension. offset = offset - lbound * stride. */ + tmp = fold (build (MULT_EXPR, gfc_array_index_type, lbound, size)); + offset = fold (build (MINUS_EXPR, gfc_array_index_type, offset, tmp)); + + /* The size of this dimension, and the stride of the next. */ + if (dim + 1 < as->rank) + stride = GFC_TYPE_ARRAY_STRIDE (type, dim + 1); + else + stride = NULL_TREE; + + if (ubound != NULL_TREE && !(stride && INTEGER_CST_P (stride))) + { + /* Calculate stride = size * (ubound + 1 - lbound). */ + tmp = fold (build (MINUS_EXPR, gfc_array_index_type, + integer_one_node, lbound)); + tmp = fold (build (PLUS_EXPR, gfc_array_index_type, ubound, tmp)); + tmp = fold (build (MULT_EXPR, gfc_array_index_type, size, tmp)); + if (stride) + gfc_add_modify_expr (pblock, stride, tmp); + else + stride = gfc_evaluate_now (tmp, pblock); + } + + size = stride; + } + + *poffset = offset; + return size; +} + + +/* Generate code to initialize/allocate an array variable. */ + +tree +gfc_trans_auto_array_allocation (tree decl, gfc_symbol * sym, tree fnbody) +{ + stmtblock_t block; + tree type; + tree tmp; + tree fndecl; + tree size; + tree offset; + tree args; + bool onstack; + + assert (!(sym->attr.pointer || sym->attr.allocatable)); + + /* Do nothing for USEd variables. */ + if (sym->attr.use_assoc) + return fnbody; + + type = TREE_TYPE (decl); + assert (GFC_ARRAY_TYPE_P (type)); + onstack = TREE_CODE (type) != POINTER_TYPE; + + /* We never generate initialization code of module variables. */ + if (fnbody == NULL_TREE) + { + assert (onstack); + + /* Generate static initializer. */ + if (sym->value) + { + DECL_INITIAL (decl) = + gfc_conv_array_initializer (TREE_TYPE (decl), sym->value); + } + return fnbody; + } + + gfc_start_block (&block); + + /* Evaluate character string length. */ + if (sym->ts.type == BT_CHARACTER + && onstack && !INTEGER_CST_P (sym->ts.cl->backend_decl)) + { + gfc_trans_init_string_length (sym->ts.cl, &block); + + DECL_DEFER_OUTPUT (decl) = 1; + + /* Generate code to allocate the automatic variable. It will be + freed automatically. */ + tmp = gfc_build_addr_expr (NULL, decl); + args = gfc_chainon_list (NULL_TREE, tmp); + args = gfc_chainon_list (args, sym->ts.cl->backend_decl); + tmp = gfc_build_function_call (built_in_decls[BUILT_IN_STACK_ALLOC], + args); + gfc_add_expr_to_block (&block, tmp); + } + + if (onstack) + { + if (sym->value) + { + DECL_INITIAL (decl) = + gfc_conv_array_initializer (TREE_TYPE (decl), sym->value); + } + + gfc_add_expr_to_block (&block, fnbody); + return gfc_finish_block (&block); + } + + type = TREE_TYPE (type); + + assert (!sym->attr.use_assoc); + assert (!TREE_STATIC (decl)); + assert (!sym->module[0]); + + if (sym->ts.type == BT_CHARACTER + && !INTEGER_CST_P (sym->ts.cl->backend_decl)) + gfc_trans_init_string_length (sym->ts.cl, &block); + + size = gfc_trans_array_bounds (type, sym, &offset, &block); + + /* The size is the number of elements in the array, so multiply by the + size of an element to get the total size. */ + tmp = TYPE_SIZE_UNIT (gfc_get_element_type (type)); + size = fold (build (MULT_EXPR, gfc_array_index_type, size, tmp)); + + /* Allocate memory to hold the data. */ + tmp = gfc_chainon_list (NULL_TREE, size); + + if (gfc_index_integer_kind == 4) + fndecl = gfor_fndecl_internal_malloc; + else if (gfc_index_integer_kind == 8) + fndecl = gfor_fndecl_internal_malloc64; + else + abort (); + tmp = gfc_build_function_call (fndecl, tmp); + tmp = fold (convert (TREE_TYPE (decl), tmp)); + gfc_add_modify_expr (&block, decl, tmp); + + /* Set offset of the array. */ + if (TREE_CODE (GFC_TYPE_ARRAY_OFFSET (type)) == VAR_DECL) + gfc_add_modify_expr (&block, GFC_TYPE_ARRAY_OFFSET (type), offset); + + + /* Automatic arrays should not have initializers. */ + assert (!sym->value); + + gfc_add_expr_to_block (&block, fnbody); + + /* Free the temporary. */ + tmp = convert (pvoid_type_node, decl); + tmp = gfc_chainon_list (NULL_TREE, tmp); + tmp = gfc_build_function_call (gfor_fndecl_internal_free, tmp); + gfc_add_expr_to_block (&block, tmp); + + return gfc_finish_block (&block); +} + + +/* Generate entry and exit code for g77 calling convention arrays. */ + +tree +gfc_trans_g77_array (gfc_symbol * sym, tree body) +{ + tree parm; + tree type; + locus loc; + tree offset; + tree tmp; + stmtblock_t block; + + gfc_get_backend_locus (&loc); + gfc_set_backend_locus (&sym->declared_at); + + /* Descriptor type. */ + parm = sym->backend_decl; + type = TREE_TYPE (parm); + assert (GFC_ARRAY_TYPE_P (type)); + + gfc_start_block (&block); + + if (sym->ts.type == BT_CHARACTER + && !INTEGER_CST_P (sym->ts.cl->backend_decl)) + gfc_trans_init_string_length (sym->ts.cl, &block); + + /* Evaluate the bounds of the array. */ + gfc_trans_array_bounds (type, sym, &offset, &block); + + /* Set the offset. */ + if (TREE_CODE (GFC_TYPE_ARRAY_OFFSET (type)) == VAR_DECL) + gfc_add_modify_expr (&block, GFC_TYPE_ARRAY_OFFSET (type), offset); + + /* Set the pointer itself if we aren't using the parameter dirtectly. */ + if (TREE_CODE (parm) != PARM_DECL) + { + tmp = convert (TREE_TYPE (parm), GFC_DECL_SAVED_DESCRIPTOR (parm)); + gfc_add_modify_expr (&block, parm, tmp); + } + tmp = gfc_finish_block (&block); + + gfc_set_backend_locus (&loc); + + gfc_start_block (&block); + /* Add the initialization code to the start of the function. */ + gfc_add_expr_to_block (&block, tmp); + gfc_add_expr_to_block (&block, body); + + return gfc_finish_block (&block); +} + + +/* Modify the descriptor of an array parameter so that it has the + correct lower bound. Also move the upper bound accordingly. + If the array is not packed, it will be copied into a temporary. + For each dimension we set the new lower and upper bounds. Then we copy the + stride and calculate the offset for this dimension. We also work out + what the stride of a packed array would be, and see it the two match. + If the array need repacking, we set the stride to the values we just + calculated, recalculate the offset and copy the array data. + Code is also added to copy the data back at the end of the function. + */ + +tree +gfc_trans_dummy_array_bias (gfc_symbol * sym, tree tmpdesc, tree body) +{ + tree size; + tree type; + tree offset; + locus loc; + stmtblock_t block; + stmtblock_t cleanup; + tree lbound; + tree ubound; + tree dubound; + tree dlbound; + tree dumdesc; + tree tmp; + tree stmt; + tree stride; + tree stmt_packed; + tree stmt_unpacked; + tree partial; + gfc_se se; + int n; + int checkparm; + int no_repack; + + if (sym->attr.dummy && gfc_is_nodesc_array (sym)) + return gfc_trans_g77_array (sym, body); + + gfc_get_backend_locus (&loc); + gfc_set_backend_locus (&sym->declared_at); + + /* Descriptor type. */ + type = TREE_TYPE (tmpdesc); + assert (GFC_ARRAY_TYPE_P (type)); + dumdesc = GFC_DECL_SAVED_DESCRIPTOR (tmpdesc); + dumdesc = gfc_build_indirect_ref (dumdesc); + gfc_start_block (&block); + + if (sym->ts.type == BT_CHARACTER + && !INTEGER_CST_P (sym->ts.cl->backend_decl)) + gfc_trans_init_string_length (sym->ts.cl, &block); + + checkparm = (sym->as->type == AS_EXPLICIT && flag_bounds_check); + + no_repack = !(GFC_DECL_PACKED_ARRAY (tmpdesc) + || GFC_DECL_PARTIAL_PACKED_ARRAY (tmpdesc)); + + if (GFC_DECL_PARTIAL_PACKED_ARRAY (tmpdesc)) + { + /* For non-constant shape arrays we only check if the first dimension + is contiguous. Repacking higher dimensions wouldn't gain us + anything as we still don't know the array stride. */ + partial = gfc_create_var (boolean_type_node, "partial"); + TREE_USED (partial) = 1; + tmp = gfc_conv_descriptor_stride (dumdesc, gfc_rank_cst[0]); + tmp = fold (build (EQ_EXPR, boolean_type_node, tmp, integer_one_node)); + gfc_add_modify_expr (&block, partial, tmp); + } + else + { + partial = NULL_TREE; + } + + /* The naming of stmt_unpacked and stmt_packed may be counter-intuitive + here, however I think it does the right thing. */ + if (no_repack) + { + /* Set the first stride. */ + stride = gfc_conv_descriptor_stride (dumdesc, gfc_rank_cst[0]); + stride = gfc_evaluate_now (stride, &block); + + tmp = build (EQ_EXPR, boolean_type_node, stride, integer_zero_node); + tmp = build (COND_EXPR, gfc_array_index_type, tmp, + integer_one_node, stride); + stride = GFC_TYPE_ARRAY_STRIDE (type, 0); + gfc_add_modify_expr (&block, stride, tmp); + + /* Allow the user to disable array repacking. */ + stmt_unpacked = NULL_TREE; + } + else + { + assert (integer_onep (GFC_TYPE_ARRAY_STRIDE (type, 0))); + /* A library call to repack the array if neccessary. */ + tmp = GFC_DECL_SAVED_DESCRIPTOR (tmpdesc); + tmp = gfc_chainon_list (NULL_TREE, tmp); + stmt_unpacked = gfc_build_function_call (gfor_fndecl_in_pack, tmp); + + stride = integer_one_node; + } + + /* This is for the case where the array data is used directly without + calling the repack function. */ + if (no_repack || partial != NULL_TREE) + stmt_packed = gfc_conv_descriptor_data (dumdesc); + else + stmt_packed = NULL_TREE; + + /* Assign the data pointer. */ + if (stmt_packed != NULL_TREE && stmt_unpacked != NULL_TREE) + { + /* Don't repack unknown shape arrays when the first stride is 1. */ + tmp = build (COND_EXPR, TREE_TYPE (stmt_packed), partial, + stmt_packed, stmt_unpacked); + } + else + tmp = stmt_packed != NULL_TREE ? stmt_packed : stmt_unpacked; + gfc_add_modify_expr (&block, tmpdesc, tmp); + + offset = integer_zero_node; + size = integer_one_node; + + /* Evaluate the bounds of the array. */ + for (n = 0; n < sym->as->rank; n++) + { + if (checkparm || !sym->as->upper[n]) + { + /* Get the bounds of the actual parameter. */ + dubound = gfc_conv_descriptor_ubound (dumdesc, gfc_rank_cst[n]); + dlbound = gfc_conv_descriptor_lbound (dumdesc, gfc_rank_cst[n]); + } + else + { + dubound = NULL_TREE; + dlbound = NULL_TREE; + } + + lbound = GFC_TYPE_ARRAY_LBOUND (type, n); + if (!INTEGER_CST_P (lbound)) + { + gfc_init_se (&se, NULL); + gfc_conv_expr_type (&se, sym->as->upper[n], + gfc_array_index_type); + gfc_add_block_to_block (&block, &se.pre); + gfc_add_modify_expr (&block, lbound, se.expr); + } + + ubound = GFC_TYPE_ARRAY_UBOUND (type, n); + /* Set the desired upper bound. */ + if (sym->as->upper[n]) + { + /* We know what we want the upper bound to be. */ + if (!INTEGER_CST_P (ubound)) + { + gfc_init_se (&se, NULL); + gfc_conv_expr_type (&se, sym->as->upper[n], + gfc_array_index_type); + gfc_add_block_to_block (&block, &se.pre); + gfc_add_modify_expr (&block, ubound, se.expr); + } + + /* Check the sizes match. */ + if (checkparm) + { + /* Check (ubound(a) - lbound(a) == ubound(b) - lbound(b)). */ + + tmp = fold (build (MINUS_EXPR, gfc_array_index_type, ubound, + lbound)); + stride = build (MINUS_EXPR, gfc_array_index_type, dubound, + dlbound); + tmp = fold (build (NE_EXPR, gfc_array_index_type, tmp, stride)); + gfc_trans_runtime_check (tmp, gfc_strconst_bounds, &block); + } + } + else + { + /* For assumed shape arrays move the upper bound by the same amount + as the lower bound. */ + tmp = build (MINUS_EXPR, gfc_array_index_type, dubound, dlbound); + tmp = fold (build (PLUS_EXPR, gfc_array_index_type, tmp, lbound)); + gfc_add_modify_expr (&block, ubound, tmp); + } + /* The offset of this dimension. offset = offset - lbound * stride. */ + tmp = fold (build (MULT_EXPR, gfc_array_index_type, lbound, stride)); + offset = fold (build (MINUS_EXPR, gfc_array_index_type, offset, tmp)); + + /* The size of this dimension, and the stride of the next. */ + if (n + 1 < sym->as->rank) + { + stride = GFC_TYPE_ARRAY_STRIDE (type, n + 1); + + if (no_repack || partial != NULL_TREE) + { + stmt_unpacked = + gfc_conv_descriptor_stride (dumdesc, gfc_rank_cst[n+1]); + } + + /* Figure out the stride if not a known constant. */ + if (!INTEGER_CST_P (stride)) + { + if (no_repack) + stmt_packed = NULL_TREE; + else + { + /* Calculate stride = size * (ubound + 1 - lbound). */ + tmp = fold (build (MINUS_EXPR, gfc_array_index_type, + integer_one_node, lbound)); + tmp = fold (build (PLUS_EXPR, gfc_array_index_type, + ubound, tmp)); + size = fold (build (MULT_EXPR, gfc_array_index_type, + size, tmp)); + stmt_packed = size; + } + + /* Assign the stride. */ + if (stmt_packed != NULL_TREE && stmt_unpacked != NULL_TREE) + { + tmp = build (COND_EXPR, gfc_array_index_type, partial, + stmt_unpacked, stmt_packed); + } + else + tmp = (stmt_packed != NULL_TREE) ? stmt_packed : stmt_unpacked; + gfc_add_modify_expr (&block, stride, tmp); + } + } + } + + /* Set the offset. */ + if (TREE_CODE (GFC_TYPE_ARRAY_OFFSET (type)) == VAR_DECL) + gfc_add_modify_expr (&block, GFC_TYPE_ARRAY_OFFSET (type), offset); + + stmt = gfc_finish_block (&block); + + gfc_start_block (&block); + + /* Only do the entry/initialization code if the arg is present. */ + dumdesc = GFC_DECL_SAVED_DESCRIPTOR (tmpdesc); + if (sym->attr.optional) + { + tmp = gfc_conv_expr_present (sym); + stmt = build_v (COND_EXPR, tmp, stmt, build_empty_stmt ()); + } + gfc_add_expr_to_block (&block, stmt); + + /* Add the main function body. */ + gfc_add_expr_to_block (&block, body); + + /* Cleanup code. */ + if (!no_repack) + { + gfc_start_block (&cleanup); + + if (sym->attr.intent != INTENT_IN) + { + /* Copy the data back. */ + tmp = gfc_chainon_list (NULL_TREE, dumdesc); + tmp = gfc_chainon_list (tmp, tmpdesc); + tmp = gfc_build_function_call (gfor_fndecl_in_unpack, tmp); + gfc_add_expr_to_block (&cleanup, tmp); + } + + /* Free the temporary. */ + tmp = gfc_chainon_list (NULL_TREE, tmpdesc); + tmp = gfc_build_function_call (gfor_fndecl_internal_free, tmp); + gfc_add_expr_to_block (&cleanup, tmp); + + stmt = gfc_finish_block (&cleanup); + + /* Only do the cleanup if the array was repacked. */ + tmp = gfc_build_indirect_ref (dumdesc); + tmp = gfc_conv_descriptor_data (tmp); + tmp = build (NE_EXPR, boolean_type_node, tmp, tmpdesc); + stmt = build_v (COND_EXPR, tmp, stmt, build_empty_stmt ()); + + if (sym->attr.optional) + { + tmp = gfc_conv_expr_present (sym); + stmt = build_v (COND_EXPR, tmp, stmt, build_empty_stmt ()); + } + gfc_add_expr_to_block (&block, stmt); + } + /* We don't need to free any memory allocated by internal_pack as it will + be freed at the end of the function by pop_context. */ + return gfc_finish_block (&block); +} + + +/* Convert an array for passing as an actual parameter. Expressions + and vector subscripts are evaluated and stored in a teporary, which is then + passed. For whole arrays the descriptor is passed. For array sections + a modified copy of the descriptor is passed, but using the original data. + Also used for array pointer assignments by setting se->direct_byref. */ + +void +gfc_conv_expr_descriptor (gfc_se * se, gfc_expr * expr, gfc_ss * ss) +{ + gfc_loopinfo loop; + gfc_ss *secss; + gfc_ss_info *info; + int need_tmp; + int n; + tree tmp; + tree desc; + stmtblock_t block; + tree start; + tree offset; + int full; + + assert (ss != gfc_ss_terminator); + + /* TODO: Pass constant array constructors without a temporary. */ + /* If we have a linear array section, we can pass it directly. Otherwise + we need to copy it into a temporary. */ + if (expr->expr_type == EXPR_VARIABLE) + { + gfc_ss *vss; + + /* Find the SS for the array section. */ + secss = ss; + while (secss != gfc_ss_terminator && secss->type != GFC_SS_SECTION) + secss = secss->next; + + assert (secss != gfc_ss_terminator); + + need_tmp = 0; + for (n = 0; n < secss->data.info.dimen; n++) + { + vss = secss->data.info.subscript[secss->data.info.dim[n]]; + if (vss && vss->type == GFC_SS_VECTOR) + need_tmp = 1; + } + + info = &secss->data.info; + + /* Get the descriptor for the array. */ + gfc_conv_ss_descriptor (&se->pre, secss, 0); + desc = info->descriptor; + if (GFC_ARRAY_TYPE_P (TREE_TYPE (desc))) + { + /* Create a new descriptor if the array doesn't have one. */ + full = 0; + } + else if (info->ref->u.ar.type == AR_FULL) + full = 1; + else if (se->direct_byref) + full = 0; + else + { + assert (info->ref->u.ar.type == AR_SECTION); + + full = 1; + for (n = 0; n < info->ref->u.ar.dimen; n++) + { + /* Detect passing the full array as a section. This could do + even more checking, but it doesn't seem worth it. */ + if (info->ref->u.ar.start[n] + || info->ref->u.ar.end[n] + || (info->ref->u.ar.stride[n] + && !gfc_expr_is_one (info->ref->u.ar.stride[n], 0))) + { + full = 0; + break; + } + } + } + if (full) + { + if (se->direct_byref) + { + /* Copy the descriptor for pointer assignments. */ + gfc_add_modify_expr (&se->pre, se->expr, desc); + } + else if (se->want_pointer) + { + /* We pass full arrays directly. This means that pointers and + allocatable arrays should also work. */ + se->expr = gfc_build_addr_expr (NULL, desc); + } + else + { + se->expr = desc; + } + return; + } + } + else + { + need_tmp = 1; + secss = NULL; + info = NULL; + } + + gfc_init_loopinfo (&loop); + + /* Associate the SS with the loop. */ + gfc_add_ss_to_loop (&loop, ss); + + /* Tell the scalarizer not to bother creating loop varliables, etc. */ + if (!need_tmp) + loop.array_parameter = 1; + else + assert (se->want_pointer && !se->direct_byref); + + /* Setup the scalarizing loops and bounds. */ + gfc_conv_ss_startstride (&loop); + + if (need_tmp) + { + /* Tell the scalarizer to make a temporary. */ + loop.temp_ss = gfc_get_ss (); + loop.temp_ss->type = GFC_SS_TEMP; + loop.temp_ss->next = gfc_ss_terminator; + loop.temp_ss->data.temp.type = gfc_typenode_for_spec (&expr->ts); + loop.temp_ss->data.temp.string_length = NULL; + loop.temp_ss->data.temp.dimen = loop.dimen; + gfc_add_ss_to_loop (&loop, loop.temp_ss); + } + + gfc_conv_loop_setup (&loop); + + if (need_tmp) + { + /* Copy into a temporary and pass that. We don't need to copy the data + back because expressions and vector subscripts must be INTENT_IN. */ + /* TODO: Optimize passing function return values. */ + gfc_se lse; + gfc_se rse; + + /* Start the copying loops. */ + gfc_mark_ss_chain_used (loop.temp_ss, 1); + gfc_mark_ss_chain_used (ss, 1); + gfc_start_scalarized_body (&loop, &block); + + /* Copy each data element. */ + gfc_init_se (&lse, NULL); + gfc_copy_loopinfo_to_se (&lse, &loop); + gfc_init_se (&rse, NULL); + gfc_copy_loopinfo_to_se (&rse, &loop); + + lse.ss = loop.temp_ss; + rse.ss = ss; + + gfc_conv_scalarized_array_ref (&lse, NULL); + gfc_conv_expr_val (&rse, expr); + + gfc_add_block_to_block (&block, &rse.pre); + gfc_add_block_to_block (&block, &lse.pre); + + gfc_add_modify_expr (&block, lse.expr, rse.expr); + + /* Finish the copying loops. */ + gfc_trans_scalarizing_loops (&loop, &block); + + /* Set the first stride component to zero to indicate a temporary. */ + desc = loop.temp_ss->data.info.descriptor; + tmp = gfc_conv_descriptor_stride (desc, gfc_rank_cst[0]); + gfc_add_modify_expr (&loop.pre, tmp, integer_zero_node); + + assert (is_gimple_lvalue (desc)); + se->expr = gfc_build_addr_expr (NULL, desc); + } + else + { + /* We pass sections without copying to a temporary. A function may + decide to repack the array to speed up access, but we're not + bothered about that here. */ + int dim; + tree parm; + tree parmtype; + tree stride; + tree from; + tree to; + tree base; + + /* Otherwise make a new descriptor and point it at the section we + want. The loop variable limits will be the limits of the section. + */ + desc = info->descriptor; + assert (secss && secss != gfc_ss_terminator); + if (se->direct_byref) + { + /* For pointer assignments we fill in the destination. */ + parm = se->expr; + parmtype = TREE_TYPE (parm); + } + else + { + /* Otherwise make a new one. */ + parmtype = gfc_get_element_type (TREE_TYPE (desc)); + parmtype = gfc_get_array_type_bounds (parmtype, loop.dimen, + loop.from, loop.to, 0); + parm = gfc_create_var (parmtype, "parm"); + } + + offset = integer_zero_node; + dim = 0; + + /* The following can be somewhat confusing. We have two + descriptors, a new one and the original array. + {parm, parmtype, dim} refer to the new one. + {desc, type, n, secss, loop} refer to the original, which maybe + a descriptorless array. + The bounds of the scaralization are the bounds of the section. + We don't have to worry about numeric overflows when calculating + the offsets because all elements are within the array data. */ + + /* Set the dtype. */ + tmp = gfc_conv_descriptor_dtype (parm); + gfc_add_modify_expr (&loop.pre, tmp, GFC_TYPE_ARRAY_DTYPE (parmtype)); + + if (se->direct_byref) + base = integer_zero_node; + else + base = NULL_TREE; + + for (n = 0; n < info->ref->u.ar.dimen; n++) + { + stride = gfc_conv_array_stride (desc, n); + + /* Work out the offset. */ + if (info->ref->u.ar.dimen_type[n] == DIMEN_ELEMENT) + { + assert (info->subscript[n] + && info->subscript[n]->type == GFC_SS_SCALAR); + start = info->subscript[n]->data.scalar.expr; + } + else + { + /* Check we haven't somehow got out of sync. */ + assert (info->dim[dim] == n); + + /* Evaluate and remember the start of the section. */ + start = info->start[dim]; + stride = gfc_evaluate_now (stride, &loop.pre); + } + + tmp = gfc_conv_array_lbound (desc, n); + tmp = fold (build (MINUS_EXPR, TREE_TYPE (tmp), start, tmp)); + + tmp = fold (build (MULT_EXPR, TREE_TYPE (tmp), tmp, stride)); + offset = fold (build (PLUS_EXPR, TREE_TYPE (tmp), offset, tmp)); + + if (info->ref->u.ar.dimen_type[n] == DIMEN_ELEMENT) + { + /* For elemental dimensions, we only need the offset. */ + continue; + } + + /* Vector subscripts need copying and are handled elsewhere. */ + assert (info->ref->u.ar.dimen_type[n] == DIMEN_RANGE); + + /* Set the new lower bound. */ + from = loop.from[dim]; + to = loop.to[dim]; + if (!integer_onep (from)) + { + /* Make sure the new section starts at 1. */ + tmp = fold (build (MINUS_EXPR, TREE_TYPE (from), + integer_one_node, from)); + to = fold (build (PLUS_EXPR, TREE_TYPE (to), to, tmp)); + from = integer_one_node; + } + tmp = gfc_conv_descriptor_lbound (parm, gfc_rank_cst[dim]); + gfc_add_modify_expr (&loop.pre, tmp, from); + + /* Set the new upper bound. */ + tmp = gfc_conv_descriptor_ubound (parm, gfc_rank_cst[dim]); + gfc_add_modify_expr (&loop.pre, tmp, to); + + /* Multiply the stride by the section stride to get the + total stride. */ + stride = fold (build (MULT_EXPR, gfc_array_index_type, stride, + info->stride[dim])); + + if (se->direct_byref) + { + base = fold (build (MINUS_EXPR, TREE_TYPE (base), + base, stride)); + } + + /* Store the new stride. */ + tmp = gfc_conv_descriptor_stride (parm, gfc_rank_cst[dim]); + gfc_add_modify_expr (&loop.pre, tmp, stride); + + dim++; + } + + /* Point the data pointer at the first element in the section. */ + tmp = gfc_conv_array_data (desc); + tmp = gfc_build_indirect_ref (tmp); + tmp = gfc_build_array_ref (tmp, offset); + offset = gfc_build_addr_expr (gfc_array_dataptr_type (desc), tmp); + + tmp = gfc_conv_descriptor_data (parm); + gfc_add_modify_expr (&loop.pre, tmp, offset); + + if (se->direct_byref) + { + /* Set the offset. */ + tmp = gfc_conv_descriptor_offset (parm); + gfc_add_modify_expr (&loop.pre, tmp, base); + } + else + { + /* Only the callee knows what the correct offset it, so just set + it to zero here. */ + tmp = gfc_conv_descriptor_offset (parm); + gfc_add_modify_expr (&loop.pre, tmp, gfc_index_zero_node); + } + + if (!se->direct_byref) + { + /* Get a pointer to the new descriptor. */ + if (se->want_pointer) + se->expr = gfc_build_addr_expr (NULL, parm); + else + se->expr = parm; + } + } + + gfc_add_block_to_block (&se->pre, &loop.pre); + gfc_add_block_to_block (&se->post, &loop.post); + + /* Cleanup the scalarizer. */ + gfc_cleanup_loop (&loop); +} + + +/* Convert an array for passing as an actual parameter. */ +/* TODO: Optimize passing g77 arrays. */ + +void +gfc_conv_array_parameter (gfc_se * se, gfc_expr * expr, gfc_ss * ss, int g77) +{ + tree ptr; + tree desc; + tree tmp; + tree stmt; + gfc_symbol *sym; + stmtblock_t block; + + /* Passing address of the array if it is not pointer or assumed-shape. */ + if (expr->expr_type == EXPR_VARIABLE + && expr->ref->u.ar.type == AR_FULL && g77) + { + sym = expr->symtree->n.sym; + tmp = gfc_get_symbol_decl (sym); + if (!sym->attr.pointer && sym->as->type != AS_ASSUMED_SHAPE + && !sym->attr.allocatable) + { + if (!sym->attr.dummy) + se->expr = gfc_build_addr_expr (NULL, tmp); + else + se->expr = tmp; + return; + } + if (sym->attr.allocatable) + { + se->expr = gfc_conv_array_data (tmp); + return; + } + } + + se->want_pointer = 1; + gfc_conv_expr_descriptor (se, expr, ss); + + if (g77) + { + desc = se->expr; + /* Repack the array. */ + tmp = gfc_chainon_list (NULL_TREE, desc); + ptr = gfc_build_function_call (gfor_fndecl_in_pack, tmp); + ptr = gfc_evaluate_now (ptr, &se->pre); + se->expr = ptr; + + gfc_start_block (&block); + + /* Copy the data back. */ + tmp = gfc_chainon_list (NULL_TREE, desc); + tmp = gfc_chainon_list (tmp, ptr); + tmp = gfc_build_function_call (gfor_fndecl_in_unpack, tmp); + gfc_add_expr_to_block (&block, tmp); + + /* Free the temporary. */ + tmp = convert (pvoid_type_node, ptr); + tmp = gfc_chainon_list (NULL_TREE, tmp); + tmp = gfc_build_function_call (gfor_fndecl_internal_free, tmp); + gfc_add_expr_to_block (&block, tmp); + + stmt = gfc_finish_block (&block); + + gfc_init_block (&block); + /* Only if it was repacked. This code needs to be executed before the + loop cleanup code. */ + tmp = gfc_build_indirect_ref (desc); + tmp = gfc_conv_array_data (tmp); + tmp = build (NE_EXPR, boolean_type_node, ptr, tmp); + tmp = build_v (COND_EXPR, tmp, stmt, build_empty_stmt ()); + + gfc_add_expr_to_block (&block, tmp); + gfc_add_block_to_block (&block, &se->post); + + gfc_init_block (&se->post); + gfc_add_block_to_block (&se->post, &block); + } +} + + +/* NULLIFY an allocated/pointer array on function entry, free it on exit. */ + +tree +gfc_trans_deferred_array (gfc_symbol * sym, tree body) +{ + tree type; + tree tmp; + tree descriptor; + tree deallocate; + stmtblock_t block; + stmtblock_t fnblock; + locus loc; + + /* Make sure the frontend gets these right. */ + if (!(sym->attr.pointer || sym->attr.allocatable)) + fatal_error + ("Possible frontend bug: Deferred array size without pointer or allocatable attribute."); + + gfc_init_block (&fnblock); + + assert (TREE_CODE (sym->backend_decl) == VAR_DECL); + if (sym->ts.type == BT_CHARACTER + && !INTEGER_CST_P (sym->ts.cl->backend_decl)) + gfc_trans_init_string_length (sym->ts.cl, &fnblock); + + /* Parameter variables don't need anything special. */ + if (sym->attr.dummy) + { + gfc_add_expr_to_block (&fnblock, body); + + return gfc_finish_block (&fnblock); + } + + gfc_get_backend_locus (&loc); + gfc_set_backend_locus (&sym->declared_at); + descriptor = sym->backend_decl; + + if (TREE_STATIC (descriptor)) + { + /* SAVEd variables are not freed on exit. */ + gfc_trans_static_array_pointer (sym); + return body; + } + + /* Get the descriptor type. */ + type = TREE_TYPE (sym->backend_decl); + assert (GFC_DESCRIPTOR_TYPE_P (type)); + + /* NULLIFY the data pointer. */ + tmp = gfc_conv_descriptor_data (descriptor); + gfc_add_modify_expr (&fnblock, tmp, integer_zero_node); + + gfc_add_expr_to_block (&fnblock, body); + + gfc_set_backend_locus (&loc); + /* Allocatable arrays need to be freed when they go out of scope. */ + if (sym->attr.allocatable) + { + gfc_start_block (&block); + + /* Deallocate if still allocated at the end of the procedure. */ + deallocate = gfc_array_deallocate (descriptor); + + tmp = gfc_conv_descriptor_data (descriptor); + tmp = build (NE_EXPR, boolean_type_node, tmp, integer_zero_node); + tmp = build_v (COND_EXPR, tmp, deallocate, build_empty_stmt ()); + gfc_add_expr_to_block (&block, tmp); + + tmp = gfc_finish_block (&block); + gfc_add_expr_to_block (&fnblock, tmp); + } + + return gfc_finish_block (&fnblock); +} + +/************ Expression Walking Functions ******************/ + +/* Walk a variable reference. + + Possible extension - multiple component subscripts. + x(:,:) = foo%a(:)%b(:) + Transforms to + forall (i=..., j=...) + x(i,j) = foo%a(j)%b(i) + end forall + This adds a fair amout of complexity because you need to deal with more + than one ref. Maybe handle in a similar manner to vector subscripts. + Maybe not worth the effort. */ + + +static gfc_ss * +gfc_walk_variable_expr (gfc_ss * ss, gfc_expr * expr) +{ + gfc_ref *ref; + gfc_array_ref *ar; + gfc_ss *newss; + gfc_ss *head; + int n; + + for (ref = expr->ref; ref; ref = ref->next) + { + /* We're only interested in array sections. */ + if (ref->type != REF_ARRAY) + continue; + + ar = &ref->u.ar; + switch (ar->type) + { + case AR_ELEMENT: + /* TODO: Take elemental array references out of scalarization + loop. */ + break; + + case AR_FULL: + newss = gfc_get_ss (); + newss->type = GFC_SS_SECTION; + newss->expr = expr; + newss->next = ss; + newss->data.info.dimen = ar->as->rank; + newss->data.info.ref = ref; + + /* Make sure array is the same as array(:,:), this way + we don't need to special case all the time. */ + ar->dimen = ar->as->rank; + for (n = 0; n < ar->dimen; n++) + { + newss->data.info.dim[n] = n; + ar->dimen_type[n] = DIMEN_RANGE; + + assert (ar->start[n] == NULL); + assert (ar->end[n] == NULL); + assert (ar->stride[n] == NULL); + } + return newss; + + case AR_SECTION: + newss = gfc_get_ss (); + newss->type = GFC_SS_SECTION; + newss->expr = expr; + newss->next = ss; + newss->data.info.dimen = 0; + newss->data.info.ref = ref; + + head = newss; + + /* We add SS chains for all the subscripts in the section. */ + for (n = 0; n < ar->dimen; n++) + { + gfc_ss *indexss; + + switch (ar->dimen_type[n]) + { + case DIMEN_ELEMENT: + /* Add SS for elemental (scalar) subscripts. */ + assert (ar->start[n]); + indexss = gfc_get_ss (); + indexss->type = GFC_SS_SCALAR; + indexss->expr = ar->start[n]; + indexss->next = gfc_ss_terminator; + indexss->loop_chain = gfc_ss_terminator; + newss->data.info.subscript[n] = indexss; + break; + + case DIMEN_RANGE: + /* We don't add anything for sections, just remember this + dimension for later. */ + newss->data.info.dim[newss->data.info.dimen] = n; + newss->data.info.dimen++; + break; + + case DIMEN_VECTOR: + /* Get a SS for the vector. This will not be added to the + chain directly. */ + indexss = gfc_walk_expr (ar->start[n]); + if (indexss == gfc_ss_terminator) + internal_error ("scalar vector subscript???"); + + /* We currently only handle really simple vector + subscripts. */ + if (indexss->next != gfc_ss_terminator) + gfc_todo_error ("vector subscript expressions"); + indexss->loop_chain = gfc_ss_terminator; + + /* Mark this as a vector subscript. We don't add this + directly into the chain, but as a subscript of the + existing SS for this term. */ + indexss->type = GFC_SS_VECTOR; + newss->data.info.subscript[n] = indexss; + /* Also remember this dimension. */ + newss->data.info.dim[newss->data.info.dimen] = n; + newss->data.info.dimen++; + break; + + default: + /* We should know what sort of section it is by now. */ + abort (); + } + } + /* We should have at least one non-elemental dimension. */ + assert (newss->data.info.dimen > 0); + return head; + break; + + default: + /* We should know what sort of section it is by now. */ + abort (); + } + + } + return ss; +} + + +/* Walk an expression operator. If only one operand of a binary expression is + scalar, we must also add the scalar term to the SS chain. */ + +static gfc_ss * +gfc_walk_op_expr (gfc_ss * ss, gfc_expr * expr) +{ + gfc_ss *head; + gfc_ss *head2; + gfc_ss *newss; + + head = gfc_walk_subexpr (ss, expr->op1); + if (expr->op2 == NULL) + head2 = head; + else + head2 = gfc_walk_subexpr (head, expr->op2); + + /* All operands are scalar. Pass back and let the caller deal with it. */ + if (head2 == ss) + return head2; + + /* All operands require scalarization. */ + if (head != ss && (expr->op2 == NULL || head2 != head)) + return head2; + + /* One of the operands needs scalarization, the other is scalar. + Create a gfc_ss for the scalar expression. */ + newss = gfc_get_ss (); + newss->type = GFC_SS_SCALAR; + if (head == ss) + { + /* First operand is scalar. We build the chain in reverse order, so + add the scarar SS after the second operand. */ + head = head2; + while (head && head->next != ss) + head = head->next; + /* Check we haven't somehow broken the chain. */ + assert (head); + newss->next = ss; + head->next = newss; + newss->expr = expr->op1; + } + else /* head2 == head */ + { + assert (head2 == head); + /* Second operand is scalar. */ + newss->next = head2; + head2 = newss; + newss->expr = expr->op2; + } + + return head2; +} + + +/* Reverse a SS chain. */ + +static gfc_ss * +gfc_reverse_ss (gfc_ss * ss) +{ + gfc_ss *next; + gfc_ss *head; + + assert (ss != NULL); + + head = gfc_ss_terminator; + while (ss != gfc_ss_terminator) + { + next = ss->next; + assert (next != NULL); /* Check we didn't somehow break the chain. */ + ss->next = head; + head = ss; + ss = next; + } + + return (head); +} + + +/* Walk the arguments of an elemental function. */ + +gfc_ss * +gfc_walk_elemental_function_args (gfc_ss * ss, gfc_expr * expr, + gfc_ss_type type) +{ + gfc_actual_arglist *arg; + int scalar; + gfc_ss *head; + gfc_ss *tail; + gfc_ss *newss; + + head = gfc_ss_terminator; + tail = NULL; + scalar = 1; + for (arg = expr->value.function.actual; arg; arg = arg->next) + { + if (!arg->expr) + continue; + + newss = gfc_walk_subexpr (head, arg->expr); + if (newss == head) + { + /* Scalar argumet. */ + newss = gfc_get_ss (); + newss->type = type; + newss->expr = arg->expr; + newss->next = head; + } + else + scalar = 0; + + head = newss; + if (!tail) + { + tail = head; + while (tail->next != gfc_ss_terminator) + tail = tail->next; + } + } + + if (scalar) + { + /* If all the arguments are scalar we don't need the argument SS. */ + gfc_free_ss_chain (head); + /* Pass it back. */ + return ss; + } + + /* Add it onto the existing chain. */ + tail->next = ss; + return head; +} + + +/* Walk a function call. Scalar functions are passed back, and taken out of + scalarization loops. For elemental functions we walk their arguments. + The result of functions returning arrays is stored in a temporary outside + the loop, so that the function is only called once. Hence we do not need + to walk their arguments. */ + +static gfc_ss * +gfc_walk_function_expr (gfc_ss * ss, gfc_expr * expr) +{ + gfc_ss *newss; + gfc_intrinsic_sym *isym; + gfc_symbol *sym; + + isym = expr->value.function.isym; + + /* Handle intrinsic functions seperately. */ + if (isym) + return gfc_walk_intrinsic_function (ss, expr, isym); + + sym = expr->value.function.esym; + if (!sym) + sym = expr->symtree->n.sym; + + /* A function that returns arrays. */ + if (gfc_return_by_reference (sym) && sym->result->attr.dimension) + { + newss = gfc_get_ss (); + newss->type = GFC_SS_FUNCTION; + newss->expr = expr; + newss->next = ss; + newss->data.info.dimen = expr->rank; + return newss; + } + + /* Walk the parameters of an elemental function. For now we always pass + by reference. */ + if (sym->attr.elemental) + return gfc_walk_elemental_function_args (ss, expr, GFC_SS_REFERENCE); + + /* Scalar functions are OK as these are evaluated outside the scalarisation + loop. Pass back and let the caller deal with it. */ + return ss; +} + + +/* An array temporary is constructed for array constructors. */ + +static gfc_ss * +gfc_walk_array_constructor (gfc_ss * ss, gfc_expr * expr) +{ + gfc_ss *newss; + int n; + + newss = gfc_get_ss (); + newss->type = GFC_SS_CONSTRUCTOR; + newss->expr = expr; + newss->next = ss; + newss->data.info.dimen = expr->rank; + for (n = 0; n < expr->rank; n++) + newss->data.info.dim[n] = n; + + return newss; +} + + +/* Walk an expresson. Add walked expressions to the head of the SS chain. + A wholy scalar expression will not be added. */ + +static gfc_ss * +gfc_walk_subexpr (gfc_ss * ss, gfc_expr * expr) +{ + gfc_ss *head; + + switch (expr->expr_type) + { + case EXPR_VARIABLE: + head = gfc_walk_variable_expr (ss, expr); + return head; + + case EXPR_OP: + head = gfc_walk_op_expr (ss, expr); + return head; + + case EXPR_FUNCTION: + head = gfc_walk_function_expr (ss, expr); + return head; + + case EXPR_CONSTANT: + case EXPR_NULL: + case EXPR_STRUCTURE: + /* Pass back and let the caller deal with it. */ + break; + + case EXPR_ARRAY: + head = gfc_walk_array_constructor (ss, expr); + return head; + + case EXPR_SUBSTRING: + /* Pass back and let the caller deal with it. */ + break; + + default: + internal_error ("bad expression type during walk (%d)", + expr->expr_type); + } + return ss; +} + + +/* Entry point for expression walking. + A return value equal to the passed chain means this is + a scalar expression. It is up to the caller to take whatever action is + neccessary to translate these. */ + +gfc_ss * +gfc_walk_expr (gfc_expr * expr) +{ + gfc_ss *res; + + res = gfc_walk_subexpr (gfc_ss_terminator, expr); + return gfc_reverse_ss (res); +} + |