/* Pass manager for Fortran front end. Copyright (C) 2010-2013 Free Software Foundation, Inc. Contributed by Thomas König. This file is part of GCC. GCC 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 3, or (at your option) any later version. GCC 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 GCC; see the file COPYING3. If not see . */ #include "config.h" #include "system.h" #include "coretypes.h" #include "gfortran.h" #include "arith.h" #include "flags.h" #include "dependency.h" #include "constructor.h" #include "opts.h" /* Forward declarations. */ static void strip_function_call (gfc_expr *); static void optimize_namespace (gfc_namespace *); static void optimize_assignment (gfc_code *); static bool optimize_op (gfc_expr *); static bool optimize_comparison (gfc_expr *, gfc_intrinsic_op); static bool optimize_trim (gfc_expr *); static bool optimize_lexical_comparison (gfc_expr *); static void optimize_minmaxloc (gfc_expr **); static bool is_empty_string (gfc_expr *e); static void doloop_warn (gfc_namespace *); /* How deep we are inside an argument list. */ static int count_arglist; /* Pointer to an array of gfc_expr ** we operate on, plus its size and counter. */ static gfc_expr ***expr_array; static int expr_size, expr_count; /* Pointer to the gfc_code we currently work on - to be able to insert a block before the statement. */ static gfc_code **current_code; /* Pointer to the block to be inserted, and the statement we are changing within the block. */ static gfc_code *inserted_block, **changed_statement; /* The namespace we are currently dealing with. */ static gfc_namespace *current_ns; /* If we are within any forall loop. */ static int forall_level; /* Keep track of whether we are within an OMP workshare. */ static bool in_omp_workshare; /* Keep track of iterators for array constructors. */ static int iterator_level; /* Keep track of DO loop levels. */ static gfc_code **doloop_list; static int doloop_size, doloop_level; /* Vector of gfc_expr * to keep track of DO loops. */ struct my_struct *evec; /* Entry point - run all passes for a namespace. */ void gfc_run_passes (gfc_namespace *ns) { /* Warn about dubious DO loops where the index might change. */ doloop_size = 20; doloop_level = 0; doloop_list = XNEWVEC(gfc_code *, doloop_size); doloop_warn (ns); XDELETEVEC (doloop_list); if (gfc_option.flag_frontend_optimize) { expr_size = 20; expr_array = XNEWVEC(gfc_expr **, expr_size); optimize_namespace (ns); if (gfc_option.dump_fortran_optimized) gfc_dump_parse_tree (ns, stdout); XDELETEVEC (expr_array); } } /* Callback for each gfc_code node invoked through gfc_code_walker from optimize_namespace. */ static int optimize_code (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED) { gfc_exec_op op; op = (*c)->op; if (op == EXEC_CALL || op == EXEC_COMPCALL || op == EXEC_ASSIGN_CALL || op == EXEC_CALL_PPC) count_arglist = 1; else count_arglist = 0; if (op == EXEC_ASSIGN) optimize_assignment (*c); return 0; } /* Callback for each gfc_expr node invoked through gfc_code_walker from optimize_namespace. */ static int optimize_expr (gfc_expr **e, int *walk_subtrees ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED) { bool function_expr; if ((*e)->expr_type == EXPR_FUNCTION) { count_arglist ++; function_expr = true; } else function_expr = false; if (optimize_trim (*e)) gfc_simplify_expr (*e, 0); if (optimize_lexical_comparison (*e)) gfc_simplify_expr (*e, 0); if ((*e)->expr_type == EXPR_OP && optimize_op (*e)) gfc_simplify_expr (*e, 0); if ((*e)->expr_type == EXPR_FUNCTION && (*e)->value.function.isym) switch ((*e)->value.function.isym->id) { case GFC_ISYM_MINLOC: case GFC_ISYM_MAXLOC: optimize_minmaxloc (e); break; default: break; } if (function_expr) count_arglist --; return 0; } /* Callback function for common function elimination, called from cfe_expr_0. Put all eligible function expressions into expr_array. */ static int cfe_register_funcs (gfc_expr **e, int *walk_subtrees ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED) { if ((*e)->expr_type != EXPR_FUNCTION) return 0; /* We don't do character functions with unknown charlens. */ if ((*e)->ts.type == BT_CHARACTER && ((*e)->ts.u.cl == NULL || (*e)->ts.u.cl->length == NULL || (*e)->ts.u.cl->length->expr_type != EXPR_CONSTANT)) return 0; /* We don't do function elimination within FORALL statements, it can lead to wrong-code in certain circumstances. */ if (forall_level > 0) return 0; /* Function elimination inside an iterator could lead to functions which depend on iterator variables being moved outside. FIXME: We should check if the functions do indeed depend on the iterator variable. */ if (iterator_level > 0) return 0; /* If we don't know the shape at compile time, we create an allocatable temporary variable to hold the intermediate result, but only if allocation on assignment is active. */ if ((*e)->rank > 0 && (*e)->shape == NULL && !gfc_option.flag_realloc_lhs) return 0; /* Skip the test for pure functions if -faggressive-function-elimination is specified. */ if ((*e)->value.function.esym) { /* Don't create an array temporary for elemental functions. */ if ((*e)->value.function.esym->attr.elemental && (*e)->rank > 0) return 0; /* Only eliminate potentially impure functions if the user specifically requested it. */ if (!gfc_option.flag_aggressive_function_elimination && !(*e)->value.function.esym->attr.pure && !(*e)->value.function.esym->attr.implicit_pure) return 0; } if ((*e)->value.function.isym) { /* Conversions are handled on the fly by the middle end, transpose during trans-* stages and TRANSFER by the middle end. */ if ((*e)->value.function.isym->id == GFC_ISYM_CONVERSION || (*e)->value.function.isym->id == GFC_ISYM_TRANSFER || gfc_inline_intrinsic_function_p (*e)) return 0; /* Don't create an array temporary for elemental functions, as this would be wasteful of memory. FIXME: Create a scalar temporary during scalarization. */ if ((*e)->value.function.isym->elemental && (*e)->rank > 0) return 0; if (!(*e)->value.function.isym->pure) return 0; } if (expr_count >= expr_size) { expr_size += expr_size; expr_array = XRESIZEVEC(gfc_expr **, expr_array, expr_size); } expr_array[expr_count] = e; expr_count ++; return 0; } /* Returns a new expression (a variable) to be used in place of the old one, with an assignment statement before the current statement to set the value of the variable. Creates a new BLOCK for the statement if that hasn't already been done and puts the statement, plus the newly created variables, in that block. */ static gfc_expr* create_var (gfc_expr * e) { char name[GFC_MAX_SYMBOL_LEN +1]; static int num = 1; gfc_symtree *symtree; gfc_symbol *symbol; gfc_expr *result; gfc_code *n; gfc_namespace *ns; int i; /* If the block hasn't already been created, do so. */ if (inserted_block == NULL) { inserted_block = XCNEW (gfc_code); inserted_block->op = EXEC_BLOCK; inserted_block->loc = (*current_code)->loc; ns = gfc_build_block_ns (current_ns); inserted_block->ext.block.ns = ns; inserted_block->ext.block.assoc = NULL; ns->code = *current_code; /* If the statement has a label, make sure it is transferred to the newly created block. */ if ((*current_code)->here) { inserted_block->here = (*current_code)->here; (*current_code)->here = NULL; } inserted_block->next = (*current_code)->next; changed_statement = &(inserted_block->ext.block.ns->code); (*current_code)->next = NULL; /* Insert the BLOCK at the right position. */ *current_code = inserted_block; ns->parent = current_ns; } else ns = inserted_block->ext.block.ns; sprintf(name, "__var_%d",num++); if (gfc_get_sym_tree (name, ns, &symtree, false) != 0) gcc_unreachable (); symbol = symtree->n.sym; symbol->ts = e->ts; if (e->rank > 0) { symbol->as = gfc_get_array_spec (); symbol->as->rank = e->rank; if (e->shape == NULL) { /* We don't know the shape at compile time, so we use an allocatable. */ symbol->as->type = AS_DEFERRED; symbol->attr.allocatable = 1; } else { symbol->as->type = AS_EXPLICIT; /* Copy the shape. */ for (i=0; irank; i++) { gfc_expr *p, *q; p = gfc_get_constant_expr (BT_INTEGER, gfc_default_integer_kind, &(e->where)); mpz_set_si (p->value.integer, 1); symbol->as->lower[i] = p; q = gfc_get_constant_expr (BT_INTEGER, gfc_index_integer_kind, &(e->where)); mpz_set (q->value.integer, e->shape[i]); symbol->as->upper[i] = q; } } } symbol->attr.flavor = FL_VARIABLE; symbol->attr.referenced = 1; symbol->attr.dimension = e->rank > 0; gfc_commit_symbol (symbol); result = gfc_get_expr (); result->expr_type = EXPR_VARIABLE; result->ts = e->ts; result->rank = e->rank; result->shape = gfc_copy_shape (e->shape, e->rank); result->symtree = symtree; result->where = e->where; if (e->rank > 0) { result->ref = gfc_get_ref (); result->ref->type = REF_ARRAY; result->ref->u.ar.type = AR_FULL; result->ref->u.ar.where = e->where; result->ref->u.ar.as = symbol->ts.type == BT_CLASS ? CLASS_DATA (symbol)->as : symbol->as; if (gfc_option.warn_array_temp) gfc_warning ("Creating array temporary at %L", &(e->where)); } /* Generate the new assignment. */ n = XCNEW (gfc_code); n->op = EXEC_ASSIGN; n->loc = (*current_code)->loc; n->next = *changed_statement; n->expr1 = gfc_copy_expr (result); n->expr2 = e; *changed_statement = n; return result; } /* Warn about function elimination. */ static void warn_function_elimination (gfc_expr *e) { if (e->expr_type != EXPR_FUNCTION) return; if (e->value.function.esym) gfc_warning ("Removing call to function '%s' at %L", e->value.function.esym->name, &(e->where)); else if (e->value.function.isym) gfc_warning ("Removing call to function '%s' at %L", e->value.function.isym->name, &(e->where)); } /* Callback function for the code walker for doing common function elimination. This builds up the list of functions in the expression and goes through them to detect duplicates, which it then replaces by variables. */ static int cfe_expr_0 (gfc_expr **e, int *walk_subtrees, void *data ATTRIBUTE_UNUSED) { int i,j; gfc_expr *newvar; /* Don't do this optimization within OMP workshare. */ if (in_omp_workshare) { *walk_subtrees = 0; return 0; } expr_count = 0; gfc_expr_walker (e, cfe_register_funcs, NULL); /* Walk through all the functions. */ for (i=1; iexpr_type == EXPR_VARIABLE) continue; newvar = NULL; for (j=0; jop != EXEC_DO_WHILE) return 0; if (co->expr1 == NULL || co->expr1->expr_type == EXPR_CONSTANT) return 0; e_cond = co->expr1; /* Generate the condition of the if statement, which is .not. the original statement. */ e_not = gfc_get_expr (); e_not->ts = e_cond->ts; e_not->where = e_cond->where; e_not->expr_type = EXPR_OP; e_not->value.op.op = INTRINSIC_NOT; e_not->value.op.op1 = e_cond; /* Generate the EXIT statement. */ c_exit = XCNEW (gfc_code); c_exit->op = EXEC_EXIT; c_exit->ext.which_construct = co; c_exit->loc = co->loc; /* Generate the IF statement. */ c_if2 = XCNEW (gfc_code); c_if2->op = EXEC_IF; c_if2->expr1 = e_not; c_if2->next = c_exit; c_if2->loc = co->loc; /* ... plus the one to chain it to. */ c_if1 = XCNEW (gfc_code); c_if1->op = EXEC_IF; c_if1->block = c_if2; c_if1->loc = co->loc; /* Make the DO WHILE loop into a DO block by replacing the condition with a true constant. */ co->expr1 = gfc_get_logical_expr (gfc_default_integer_kind, &co->loc, true); /* Hang the generated if statement into the loop body. */ loopblock = co->block->next; co->block->next = c_if1; c_if1->next = loopblock; return 0; } /* Code callback function for converting if (a) then ... else if (b) then end if into if (a) then else if (b) then end if end if because otherwise common function elimination would place the BLOCKs into the wrong place. */ static int convert_elseif (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED) { gfc_code *co = *c; gfc_code *c_if1, *c_if2, *else_stmt; if (co->op != EXEC_IF) return 0; /* This loop starts out with the first ELSE statement. */ else_stmt = co->block->block; while (else_stmt != NULL) { gfc_code *next_else; /* If there is no condition, we're done. */ if (else_stmt->expr1 == NULL) break; next_else = else_stmt->block; /* Generate the new IF statement. */ c_if2 = XCNEW (gfc_code); c_if2->op = EXEC_IF; c_if2->expr1 = else_stmt->expr1; c_if2->next = else_stmt->next; c_if2->loc = else_stmt->loc; c_if2->block = next_else; /* ... plus the one to chain it to. */ c_if1 = XCNEW (gfc_code); c_if1->op = EXEC_IF; c_if1->block = c_if2; c_if1->loc = else_stmt->loc; /* Insert the new IF after the ELSE. */ else_stmt->expr1 = NULL; else_stmt->next = c_if1; else_stmt->block = NULL; else_stmt = next_else; } /* Don't walk subtrees. */ return 0; } /* Optimize a namespace, including all contained namespaces. */ static void optimize_namespace (gfc_namespace *ns) { current_ns = ns; forall_level = 0; iterator_level = 0; in_omp_workshare = false; gfc_code_walker (&ns->code, convert_do_while, dummy_expr_callback, NULL); gfc_code_walker (&ns->code, convert_elseif, dummy_expr_callback, NULL); gfc_code_walker (&ns->code, cfe_code, cfe_expr_0, NULL); gfc_code_walker (&ns->code, optimize_code, optimize_expr, NULL); /* BLOCKs are handled in the expression walker below. */ for (ns = ns->contained; ns; ns = ns->sibling) { if (ns->code == NULL || ns->code->op != EXEC_BLOCK) optimize_namespace (ns); } } /* Replace code like a = matmul(b,c) + d with a = matmul(b,c) ; a = a + d where the array function is not elemental and not allocatable and does not depend on the left-hand side. */ static bool optimize_binop_array_assignment (gfc_code *c, gfc_expr **rhs, bool seen_op) { gfc_expr *e; e = *rhs; if (e->expr_type == EXPR_OP) { switch (e->value.op.op) { /* Unary operators and exponentiation: Only look at a single operand. */ case INTRINSIC_NOT: case INTRINSIC_UPLUS: case INTRINSIC_UMINUS: case INTRINSIC_PARENTHESES: case INTRINSIC_POWER: if (optimize_binop_array_assignment (c, &e->value.op.op1, seen_op)) return true; break; default: /* Binary operators. */ if (optimize_binop_array_assignment (c, &e->value.op.op1, true)) return true; if (optimize_binop_array_assignment (c, &e->value.op.op2, true)) return true; break; } } else if (seen_op && e->expr_type == EXPR_FUNCTION && e->rank > 0 && ! (e->value.function.esym && (e->value.function.esym->attr.elemental || e->value.function.esym->attr.allocatable || e->value.function.esym->ts.type != c->expr1->ts.type || e->value.function.esym->ts.kind != c->expr1->ts.kind)) && ! (e->value.function.isym && (e->value.function.isym->elemental || e->ts.type != c->expr1->ts.type || e->ts.kind != c->expr1->ts.kind)) && ! gfc_inline_intrinsic_function_p (e)) { gfc_code *n; gfc_expr *new_expr; /* Insert a new assignment statement after the current one. */ n = XCNEW (gfc_code); n->op = EXEC_ASSIGN; n->loc = c->loc; n->next = c->next; c->next = n; n->expr1 = gfc_copy_expr (c->expr1); n->expr2 = c->expr2; new_expr = gfc_copy_expr (c->expr1); c->expr2 = e; *rhs = new_expr; return true; } /* Nothing to optimize. */ return false; } /* Remove unneeded TRIMs at the end of expressions. */ static bool remove_trim (gfc_expr *rhs) { bool ret; ret = false; /* Check for a // b // trim(c). Looping is probably not necessary because the parser usually generates (// (// a b ) trim(c) ) , but better safe than sorry. */ while (rhs->expr_type == EXPR_OP && rhs->value.op.op == INTRINSIC_CONCAT) rhs = rhs->value.op.op2; while (rhs->expr_type == EXPR_FUNCTION && rhs->value.function.isym && rhs->value.function.isym->id == GFC_ISYM_TRIM) { strip_function_call (rhs); /* Recursive call to catch silly stuff like trim ( a // trim(b)). */ remove_trim (rhs); ret = true; } return ret; } /* Optimizations for an assignment. */ static void optimize_assignment (gfc_code * c) { gfc_expr *lhs, *rhs; lhs = c->expr1; rhs = c->expr2; if (lhs->ts.type == BT_CHARACTER && !lhs->ts.deferred) { /* Optimize a = trim(b) to a = b. */ remove_trim (rhs); /* Replace a = ' ' by a = '' to optimize away a memcpy. */ if (is_empty_string(rhs)) rhs->value.character.length = 0; } if (lhs->rank > 0 && gfc_check_dependency (lhs, rhs, true) == 0) optimize_binop_array_assignment (c, &rhs, false); } /* Remove an unneeded function call, modifying the expression. This replaces the function call with the value of its first argument. The rest of the argument list is freed. */ static void strip_function_call (gfc_expr *e) { gfc_expr *e1; gfc_actual_arglist *a; a = e->value.function.actual; /* We should have at least one argument. */ gcc_assert (a->expr != NULL); e1 = a->expr; /* Free the remaining arglist, if any. */ if (a->next) gfc_free_actual_arglist (a->next); /* Graft the argument expression onto the original function. */ *e = *e1; free (e1); } /* Optimization of lexical comparison functions. */ static bool optimize_lexical_comparison (gfc_expr *e) { if (e->expr_type != EXPR_FUNCTION || e->value.function.isym == NULL) return false; switch (e->value.function.isym->id) { case GFC_ISYM_LLE: return optimize_comparison (e, INTRINSIC_LE); case GFC_ISYM_LGE: return optimize_comparison (e, INTRINSIC_GE); case GFC_ISYM_LGT: return optimize_comparison (e, INTRINSIC_GT); case GFC_ISYM_LLT: return optimize_comparison (e, INTRINSIC_LT); default: break; } return false; } /* Recursive optimization of operators. */ static bool optimize_op (gfc_expr *e) { gfc_intrinsic_op op = e->value.op.op; /* Only use new-style comparisons. */ switch(op) { case INTRINSIC_EQ_OS: op = INTRINSIC_EQ; break; case INTRINSIC_GE_OS: op = INTRINSIC_GE; break; case INTRINSIC_LE_OS: op = INTRINSIC_LE; break; case INTRINSIC_NE_OS: op = INTRINSIC_NE; break; case INTRINSIC_GT_OS: op = INTRINSIC_GT; break; case INTRINSIC_LT_OS: op = INTRINSIC_LT; break; default: break; } switch (op) { case INTRINSIC_EQ: case INTRINSIC_GE: case INTRINSIC_LE: case INTRINSIC_NE: case INTRINSIC_GT: case INTRINSIC_LT: return optimize_comparison (e, op); default: break; } return false; } /* Return true if a constant string contains only blanks. */ static bool is_empty_string (gfc_expr *e) { int i; if (e->ts.type != BT_CHARACTER || e->expr_type != EXPR_CONSTANT) return false; for (i=0; i < e->value.character.length; i++) { if (e->value.character.string[i] != ' ') return false; } return true; } /* Insert a call to the intrinsic len_trim. Use a different name for the symbol tree so we don't run into trouble when the user has renamed len_trim for some reason. */ static gfc_expr* get_len_trim_call (gfc_expr *str, int kind) { gfc_expr *fcn; gfc_actual_arglist *actual_arglist, *next; fcn = gfc_get_expr (); fcn->expr_type = EXPR_FUNCTION; fcn->value.function.isym = gfc_intrinsic_function_by_id (GFC_ISYM_LEN_TRIM); actual_arglist = gfc_get_actual_arglist (); actual_arglist->expr = str; next = gfc_get_actual_arglist (); next->expr = gfc_get_int_expr (gfc_default_integer_kind, NULL, kind); actual_arglist->next = next; fcn->value.function.actual = actual_arglist; fcn->where = str->where; fcn->ts.type = BT_INTEGER; fcn->ts.kind = gfc_charlen_int_kind; gfc_get_sym_tree ("__internal_len_trim", current_ns, &fcn->symtree, false); fcn->symtree->n.sym->ts = fcn->ts; fcn->symtree->n.sym->attr.flavor = FL_PROCEDURE; fcn->symtree->n.sym->attr.function = 1; fcn->symtree->n.sym->attr.elemental = 1; fcn->symtree->n.sym->attr.referenced = 1; fcn->symtree->n.sym->attr.access = ACCESS_PRIVATE; gfc_commit_symbol (fcn->symtree->n.sym); return fcn; } /* Optimize expressions for equality. */ static bool optimize_comparison (gfc_expr *e, gfc_intrinsic_op op) { gfc_expr *op1, *op2; bool change; int eq; bool result; gfc_actual_arglist *firstarg, *secondarg; if (e->expr_type == EXPR_OP) { firstarg = NULL; secondarg = NULL; op1 = e->value.op.op1; op2 = e->value.op.op2; } else if (e->expr_type == EXPR_FUNCTION) { /* One of the lexical comparison functions. */ firstarg = e->value.function.actual; secondarg = firstarg->next; op1 = firstarg->expr; op2 = secondarg->expr; } else gcc_unreachable (); /* Strip off unneeded TRIM calls from string comparisons. */ change = remove_trim (op1); if (remove_trim (op2)) change = true; /* An expression of type EXPR_CONSTANT is only valid for scalars. */ /* TODO: A scalar constant may be acceptable in some cases (the scalarizer handles them well). However, there are also cases that need a non-scalar argument. For example the any intrinsic. See PR 45380. */ if (e->rank > 0) return change; /* Replace a == '' with len_trim(a) == 0 and a /= '' with len_trim(a) != 0 */ if (op1->ts.type == BT_CHARACTER && op2->ts.type == BT_CHARACTER && (op == INTRINSIC_EQ || op == INTRINSIC_NE)) { bool empty_op1, empty_op2; empty_op1 = is_empty_string (op1); empty_op2 = is_empty_string (op2); if (empty_op1 || empty_op2) { gfc_expr *fcn; gfc_expr *zero; gfc_expr *str; /* This can only happen when an error for comparing characters of different kinds has already been issued. */ if (empty_op1 && empty_op2) return false; zero = gfc_get_int_expr (gfc_charlen_int_kind, &e->where, 0); str = empty_op1 ? op2 : op1; fcn = get_len_trim_call (str, gfc_charlen_int_kind); if (empty_op1) gfc_free_expr (op1); else gfc_free_expr (op2); op1 = fcn; op2 = zero; e->value.op.op1 = fcn; e->value.op.op2 = zero; } } /* Don't compare REAL or COMPLEX expressions when honoring NaNs. */ if (flag_finite_math_only || (op1->ts.type != BT_REAL && op2->ts.type != BT_REAL && op1->ts.type != BT_COMPLEX && op2->ts.type != BT_COMPLEX)) { eq = gfc_dep_compare_expr (op1, op2); if (eq <= -2) { /* Replace A // B < A // C with B < C, and A // B < C // B with A < C. */ if (op1->ts.type == BT_CHARACTER && op2->ts.type == BT_CHARACTER && op1->value.op.op == INTRINSIC_CONCAT && op2->value.op.op == INTRINSIC_CONCAT) { gfc_expr *op1_left = op1->value.op.op1; gfc_expr *op2_left = op2->value.op.op1; gfc_expr *op1_right = op1->value.op.op2; gfc_expr *op2_right = op2->value.op.op2; if (gfc_dep_compare_expr (op1_left, op2_left) == 0) { /* Watch out for 'A ' // x vs. 'A' // x. */ if (op1_left->expr_type == EXPR_CONSTANT && op2_left->expr_type == EXPR_CONSTANT && op1_left->value.character.length != op2_left->value.character.length) return change; else { free (op1_left); free (op2_left); if (firstarg) { firstarg->expr = op1_right; secondarg->expr = op2_right; } else { e->value.op.op1 = op1_right; e->value.op.op2 = op2_right; } optimize_comparison (e, op); return true; } } if (gfc_dep_compare_expr (op1_right, op2_right) == 0) { free (op1_right); free (op2_right); if (firstarg) { firstarg->expr = op1_left; secondarg->expr = op2_left; } else { e->value.op.op1 = op1_left; e->value.op.op2 = op2_left; } optimize_comparison (e, op); return true; } } } else { /* eq can only be -1, 0 or 1 at this point. */ switch (op) { case INTRINSIC_EQ: result = eq == 0; break; case INTRINSIC_GE: result = eq >= 0; break; case INTRINSIC_LE: result = eq <= 0; break; case INTRINSIC_NE: result = eq != 0; break; case INTRINSIC_GT: result = eq > 0; break; case INTRINSIC_LT: result = eq < 0; break; default: gfc_internal_error ("illegal OP in optimize_comparison"); break; } /* Replace the expression by a constant expression. The typespec and where remains the way it is. */ free (op1); free (op2); e->expr_type = EXPR_CONSTANT; e->value.logical = result; return true; } } return change; } /* Optimize a trim function by replacing it with an equivalent substring involving a call to len_trim. This only works for expressions where variables are trimmed. Return true if anything was modified. */ static bool optimize_trim (gfc_expr *e) { gfc_expr *a; gfc_ref *ref; gfc_expr *fcn; gfc_ref **rr = NULL; /* Don't do this optimization within an argument list, because otherwise aliasing issues may occur. */ if (count_arglist != 1) return false; if (e->ts.type != BT_CHARACTER || e->expr_type != EXPR_FUNCTION || e->value.function.isym == NULL || e->value.function.isym->id != GFC_ISYM_TRIM) return false; a = e->value.function.actual->expr; if (a->expr_type != EXPR_VARIABLE) return false; /* Follow all references to find the correct place to put the newly created reference. FIXME: Also handle substring references and array references. Array references cause strange regressions at the moment. */ if (a->ref) { for (rr = &(a->ref); *rr; rr = &((*rr)->next)) { if ((*rr)->type == REF_SUBSTRING || (*rr)->type == REF_ARRAY) return false; } } strip_function_call (e); if (e->ref == NULL) rr = &(e->ref); /* Create the reference. */ ref = gfc_get_ref (); ref->type = REF_SUBSTRING; /* Set the start of the reference. */ ref->u.ss.start = gfc_get_int_expr (gfc_default_integer_kind, NULL, 1); /* Build the function call to len_trim(x, gfc_default_integer_kind). */ fcn = get_len_trim_call (gfc_copy_expr (e), gfc_default_integer_kind); /* Set the end of the reference to the call to len_trim. */ ref->u.ss.end = fcn; gcc_assert (rr != NULL && *rr == NULL); *rr = ref; return true; } /* Optimize minloc(b), where b is rank 1 array, into (/ minloc(b, dim=1) /), and similarly for maxloc, as the latter forms are expanded inline. */ static void optimize_minmaxloc (gfc_expr **e) { gfc_expr *fn = *e; gfc_actual_arglist *a; char *name, *p; if (fn->rank != 1 || fn->value.function.actual == NULL || fn->value.function.actual->expr == NULL || fn->value.function.actual->expr->rank != 1) return; *e = gfc_get_array_expr (fn->ts.type, fn->ts.kind, &fn->where); (*e)->shape = fn->shape; fn->rank = 0; fn->shape = NULL; gfc_constructor_append_expr (&(*e)->value.constructor, fn, &fn->where); name = XALLOCAVEC (char, strlen (fn->value.function.name) + 1); strcpy (name, fn->value.function.name); p = strstr (name, "loc0"); p[3] = '1'; fn->value.function.name = gfc_get_string (name); if (fn->value.function.actual->next) { a = fn->value.function.actual->next; gcc_assert (a->expr == NULL); } else { a = gfc_get_actual_arglist (); fn->value.function.actual->next = a; } a->expr = gfc_get_constant_expr (BT_INTEGER, gfc_default_integer_kind, &fn->where); mpz_set_ui (a->expr->value.integer, 1); } /* Callback function for code checking that we do not pass a DO variable to an INTENT(OUT) or INTENT(INOUT) dummy variable. */ static int doloop_code (gfc_code **c, int *walk_subtrees ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED) { gfc_code *co; int i; gfc_formal_arglist *f; gfc_actual_arglist *a; co = *c; switch (co->op) { case EXEC_DO: /* Grow the temporary storage if necessary. */ if (doloop_level >= doloop_size) { doloop_size = 2 * doloop_size; doloop_list = XRESIZEVEC (gfc_code *, doloop_list, doloop_size); } /* Mark the DO loop variable if there is one. */ if (co->ext.iterator && co->ext.iterator->var) doloop_list[doloop_level] = co; else doloop_list[doloop_level] = NULL; break; case EXEC_CALL: if (co->resolved_sym == NULL) break; f = co->resolved_sym->formal; /* Withot a formal arglist, there is only unknown INTENT, which we don't check for. */ if (f == NULL) break; a = co->ext.actual; while (a && f) { for (i=0; iext.iterator->var->symtree->n.sym; if (a->expr && a->expr->symtree && a->expr->symtree->n.sym == do_sym) { if (f->sym->attr.intent == INTENT_OUT) gfc_error_now("Variable '%s' at %L set to undefined value " "inside loop beginning at %L as INTENT(OUT) " "argument to subroutine '%s'", do_sym->name, &a->expr->where, &doloop_list[i]->loc, co->symtree->n.sym->name); else if (f->sym->attr.intent == INTENT_INOUT) gfc_error_now("Variable '%s' at %L not definable inside loop " "beginning at %L as INTENT(INOUT) argument to " "subroutine '%s'", do_sym->name, &a->expr->where, &doloop_list[i]->loc, co->symtree->n.sym->name); } } a = a->next; f = f->next; } break; default: break; } return 0; } /* Callback function for functions checking that we do not pass a DO variable to an INTENT(OUT) or INTENT(INOUT) dummy variable. */ static int do_function (gfc_expr **e, int *walk_subtrees ATTRIBUTE_UNUSED, void *data ATTRIBUTE_UNUSED) { gfc_formal_arglist *f; gfc_actual_arglist *a; gfc_expr *expr; int i; expr = *e; if (expr->expr_type != EXPR_FUNCTION) return 0; /* Intrinsic functions don't modify their arguments. */ if (expr->value.function.isym) return 0; f = expr->symtree->n.sym->formal; /* Without a formal arglist, there is only unknown INTENT, which we don't check for. */ if (f == NULL) return 0; a = expr->value.function.actual; while (a && f) { for (i=0; iext.iterator->var->symtree->n.sym; if (a->expr && a->expr->symtree && a->expr->symtree->n.sym == do_sym) { if (f->sym->attr.intent == INTENT_OUT) gfc_error_now("Variable '%s' at %L set to undefined value " "inside loop beginning at %L as INTENT(OUT) " "argument to function '%s'", do_sym->name, &a->expr->where, &doloop_list[i]->loc, expr->symtree->n.sym->name); else if (f->sym->attr.intent == INTENT_INOUT) gfc_error_now("Variable '%s' at %L not definable inside loop " "beginning at %L as INTENT(INOUT) argument to " "function '%s'", do_sym->name, &a->expr->where, &doloop_list[i]->loc, expr->symtree->n.sym->name); } } a = a->next; f = f->next; } return 0; } static void doloop_warn (gfc_namespace *ns) { gfc_code_walker (&ns->code, doloop_code, do_function, NULL); } #define WALK_SUBEXPR(NODE) \ do \ { \ result = gfc_expr_walker (&(NODE), exprfn, data); \ if (result) \ return result; \ } \ while (0) #define WALK_SUBEXPR_TAIL(NODE) e = &(NODE); continue /* Walk expression *E, calling EXPRFN on each expression in it. */ int gfc_expr_walker (gfc_expr **e, walk_expr_fn_t exprfn, void *data) { while (*e) { int walk_subtrees = 1; gfc_actual_arglist *a; gfc_ref *r; gfc_constructor *c; int result = exprfn (e, &walk_subtrees, data); if (result) return result; if (walk_subtrees) switch ((*e)->expr_type) { case EXPR_OP: WALK_SUBEXPR ((*e)->value.op.op1); WALK_SUBEXPR_TAIL ((*e)->value.op.op2); break; case EXPR_FUNCTION: for (a = (*e)->value.function.actual; a; a = a->next) WALK_SUBEXPR (a->expr); break; case EXPR_COMPCALL: case EXPR_PPC: WALK_SUBEXPR ((*e)->value.compcall.base_object); for (a = (*e)->value.compcall.actual; a; a = a->next) WALK_SUBEXPR (a->expr); break; case EXPR_STRUCTURE: case EXPR_ARRAY: for (c = gfc_constructor_first ((*e)->value.constructor); c; c = gfc_constructor_next (c)) { if (c->iterator == NULL) WALK_SUBEXPR (c->expr); else { iterator_level ++; WALK_SUBEXPR (c->expr); iterator_level --; WALK_SUBEXPR (c->iterator->var); WALK_SUBEXPR (c->iterator->start); WALK_SUBEXPR (c->iterator->end); WALK_SUBEXPR (c->iterator->step); } } if ((*e)->expr_type != EXPR_ARRAY) break; /* Fall through to the variable case in order to walk the reference. */ case EXPR_SUBSTRING: case EXPR_VARIABLE: for (r = (*e)->ref; r; r = r->next) { gfc_array_ref *ar; int i; switch (r->type) { case REF_ARRAY: ar = &r->u.ar; if (ar->type == AR_SECTION || ar->type == AR_ELEMENT) { for (i=0; i< ar->dimen; i++) { WALK_SUBEXPR (ar->start[i]); WALK_SUBEXPR (ar->end[i]); WALK_SUBEXPR (ar->stride[i]); } } break; case REF_SUBSTRING: WALK_SUBEXPR (r->u.ss.start); WALK_SUBEXPR (r->u.ss.end); break; case REF_COMPONENT: break; } } default: break; } return 0; } return 0; } #define WALK_SUBCODE(NODE) \ do \ { \ result = gfc_code_walker (&(NODE), codefn, exprfn, data); \ if (result) \ return result; \ } \ while (0) /* Walk code *C, calling CODEFN on each gfc_code node in it and calling EXPRFN on each expression in it. If any of the hooks returns non-zero, that value is immediately returned. If the hook sets *WALK_SUBTREES to 0, no subcodes or subexpressions are traversed. */ int gfc_code_walker (gfc_code **c, walk_code_fn_t codefn, walk_expr_fn_t exprfn, void *data) { for (; *c; c = &(*c)->next) { int walk_subtrees = 1; int result = codefn (c, &walk_subtrees, data); if (result) return result; if (walk_subtrees) { gfc_code *b; gfc_actual_arglist *a; gfc_code *co; gfc_association_list *alist; bool saved_in_omp_workshare; /* There might be statement insertions before the current code, which must not affect the expression walker. */ co = *c; saved_in_omp_workshare = in_omp_workshare; switch (co->op) { case EXEC_BLOCK: WALK_SUBCODE (co->ext.block.ns->code); for (alist = co->ext.block.assoc; alist; alist = alist->next) WALK_SUBEXPR (alist->target); break; case EXEC_DO: doloop_level ++; WALK_SUBEXPR (co->ext.iterator->var); WALK_SUBEXPR (co->ext.iterator->start); WALK_SUBEXPR (co->ext.iterator->end); WALK_SUBEXPR (co->ext.iterator->step); break; case EXEC_CALL: case EXEC_ASSIGN_CALL: for (a = co->ext.actual; a; a = a->next) WALK_SUBEXPR (a->expr); break; case EXEC_CALL_PPC: WALK_SUBEXPR (co->expr1); for (a = co->ext.actual; a; a = a->next) WALK_SUBEXPR (a->expr); break; case EXEC_SELECT: WALK_SUBEXPR (co->expr1); for (b = co->block; b; b = b->block) { gfc_case *cp; for (cp = b->ext.block.case_list; cp; cp = cp->next) { WALK_SUBEXPR (cp->low); WALK_SUBEXPR (cp->high); } WALK_SUBCODE (b->next); } continue; case EXEC_ALLOCATE: case EXEC_DEALLOCATE: { gfc_alloc *a; for (a = co->ext.alloc.list; a; a = a->next) WALK_SUBEXPR (a->expr); break; } case EXEC_FORALL: case EXEC_DO_CONCURRENT: { gfc_forall_iterator *fa; for (fa = co->ext.forall_iterator; fa; fa = fa->next) { WALK_SUBEXPR (fa->var); WALK_SUBEXPR (fa->start); WALK_SUBEXPR (fa->end); WALK_SUBEXPR (fa->stride); } if (co->op == EXEC_FORALL) forall_level ++; break; } case EXEC_OPEN: WALK_SUBEXPR (co->ext.open->unit); WALK_SUBEXPR (co->ext.open->file); WALK_SUBEXPR (co->ext.open->status); WALK_SUBEXPR (co->ext.open->access); WALK_SUBEXPR (co->ext.open->form); WALK_SUBEXPR (co->ext.open->recl); WALK_SUBEXPR (co->ext.open->blank); WALK_SUBEXPR (co->ext.open->position); WALK_SUBEXPR (co->ext.open->action); WALK_SUBEXPR (co->ext.open->delim); WALK_SUBEXPR (co->ext.open->pad); WALK_SUBEXPR (co->ext.open->iostat); WALK_SUBEXPR (co->ext.open->iomsg); WALK_SUBEXPR (co->ext.open->convert); WALK_SUBEXPR (co->ext.open->decimal); WALK_SUBEXPR (co->ext.open->encoding); WALK_SUBEXPR (co->ext.open->round); WALK_SUBEXPR (co->ext.open->sign); WALK_SUBEXPR (co->ext.open->asynchronous); WALK_SUBEXPR (co->ext.open->id); WALK_SUBEXPR (co->ext.open->newunit); break; case EXEC_CLOSE: WALK_SUBEXPR (co->ext.close->unit); WALK_SUBEXPR (co->ext.close->status); WALK_SUBEXPR (co->ext.close->iostat); WALK_SUBEXPR (co->ext.close->iomsg); break; case EXEC_BACKSPACE: case EXEC_ENDFILE: case EXEC_REWIND: case EXEC_FLUSH: WALK_SUBEXPR (co->ext.filepos->unit); WALK_SUBEXPR (co->ext.filepos->iostat); WALK_SUBEXPR (co->ext.filepos->iomsg); break; case EXEC_INQUIRE: WALK_SUBEXPR (co->ext.inquire->unit); WALK_SUBEXPR (co->ext.inquire->file); WALK_SUBEXPR (co->ext.inquire->iomsg); WALK_SUBEXPR (co->ext.inquire->iostat); WALK_SUBEXPR (co->ext.inquire->exist); WALK_SUBEXPR (co->ext.inquire->opened); WALK_SUBEXPR (co->ext.inquire->number); WALK_SUBEXPR (co->ext.inquire->named); WALK_SUBEXPR (co->ext.inquire->name); WALK_SUBEXPR (co->ext.inquire->access); WALK_SUBEXPR (co->ext.inquire->sequential); WALK_SUBEXPR (co->ext.inquire->direct); WALK_SUBEXPR (co->ext.inquire->form); WALK_SUBEXPR (co->ext.inquire->formatted); WALK_SUBEXPR (co->ext.inquire->unformatted); WALK_SUBEXPR (co->ext.inquire->recl); WALK_SUBEXPR (co->ext.inquire->nextrec); WALK_SUBEXPR (co->ext.inquire->blank); WALK_SUBEXPR (co->ext.inquire->position); WALK_SUBEXPR (co->ext.inquire->action); WALK_SUBEXPR (co->ext.inquire->read); WALK_SUBEXPR (co->ext.inquire->write); WALK_SUBEXPR (co->ext.inquire->readwrite); WALK_SUBEXPR (co->ext.inquire->delim); WALK_SUBEXPR (co->ext.inquire->encoding); WALK_SUBEXPR (co->ext.inquire->pad); WALK_SUBEXPR (co->ext.inquire->iolength); WALK_SUBEXPR (co->ext.inquire->convert); WALK_SUBEXPR (co->ext.inquire->strm_pos); WALK_SUBEXPR (co->ext.inquire->asynchronous); WALK_SUBEXPR (co->ext.inquire->decimal); WALK_SUBEXPR (co->ext.inquire->pending); WALK_SUBEXPR (co->ext.inquire->id); WALK_SUBEXPR (co->ext.inquire->sign); WALK_SUBEXPR (co->ext.inquire->size); WALK_SUBEXPR (co->ext.inquire->round); break; case EXEC_WAIT: WALK_SUBEXPR (co->ext.wait->unit); WALK_SUBEXPR (co->ext.wait->iostat); WALK_SUBEXPR (co->ext.wait->iomsg); WALK_SUBEXPR (co->ext.wait->id); break; case EXEC_READ: case EXEC_WRITE: WALK_SUBEXPR (co->ext.dt->io_unit); WALK_SUBEXPR (co->ext.dt->format_expr); WALK_SUBEXPR (co->ext.dt->rec); WALK_SUBEXPR (co->ext.dt->advance); WALK_SUBEXPR (co->ext.dt->iostat); WALK_SUBEXPR (co->ext.dt->size); WALK_SUBEXPR (co->ext.dt->iomsg); WALK_SUBEXPR (co->ext.dt->id); WALK_SUBEXPR (co->ext.dt->pos); WALK_SUBEXPR (co->ext.dt->asynchronous); WALK_SUBEXPR (co->ext.dt->blank); WALK_SUBEXPR (co->ext.dt->decimal); WALK_SUBEXPR (co->ext.dt->delim); WALK_SUBEXPR (co->ext.dt->pad); WALK_SUBEXPR (co->ext.dt->round); WALK_SUBEXPR (co->ext.dt->sign); WALK_SUBEXPR (co->ext.dt->extra_comma); break; case EXEC_OMP_PARALLEL: case EXEC_OMP_PARALLEL_DO: case EXEC_OMP_PARALLEL_SECTIONS: in_omp_workshare = false; /* This goto serves as a shortcut to avoid code duplication or a larger if or switch statement. */ goto check_omp_clauses; case EXEC_OMP_WORKSHARE: case EXEC_OMP_PARALLEL_WORKSHARE: in_omp_workshare = true; /* Fall through */ case EXEC_OMP_DO: case EXEC_OMP_SECTIONS: case EXEC_OMP_SINGLE: case EXEC_OMP_END_SINGLE: case EXEC_OMP_TASK: /* Come to this label only from the EXEC_OMP_PARALLEL_* cases above. */ check_omp_clauses: if (co->ext.omp_clauses) { WALK_SUBEXPR (co->ext.omp_clauses->if_expr); WALK_SUBEXPR (co->ext.omp_clauses->final_expr); WALK_SUBEXPR (co->ext.omp_clauses->num_threads); WALK_SUBEXPR (co->ext.omp_clauses->chunk_size); } break; default: break; } WALK_SUBEXPR (co->expr1); WALK_SUBEXPR (co->expr2); WALK_SUBEXPR (co->expr3); WALK_SUBEXPR (co->expr4); for (b = co->block; b; b = b->block) { WALK_SUBEXPR (b->expr1); WALK_SUBEXPR (b->expr2); WALK_SUBCODE (b->next); } if (co->op == EXEC_FORALL) forall_level --; if (co->op == EXEC_DO) doloop_level --; in_omp_workshare = saved_in_omp_workshare; } } return 0; }