by the C-based front ends. The structure of gimplified, or
language-independent, trees is dictated by the grammar described in this
file.
- Copyright (C) 2002, 2003, 2004 Free Software Foundation, Inc.
+ Copyright (C) 2002, 2003, 2004, 2005, 2007, 2008
+ Free Software Foundation, Inc.
Lowering of expressions contributed by Sebastian Pop <s.pop@laposte.net>
Re-written to support lowering of whole function trees, documentation
and miscellaneous cleanups by Diego Novillo <dnovillo@redhat.com>
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 2, or (at your option) any later
+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
for more details.
You should have received a copy of the GNU General Public License
-along with GCC; see the file COPYING. If not, write to the Free
-Software Foundation, 59 Temple Place - Suite 330, Boston, MA
-02111-1307, USA. */
+along with GCC; see the file COPYING3. If not see
+<http://www.gnu.org/licenses/>. */
#include "config.h"
#include "system.h"
#include "coretypes.h"
#include "tm.h"
#include "tree.h"
-#include "errors.h"
#include "varray.h"
#include "c-tree.h"
#include "c-common.h"
-#include "tree-gimple.h"
+#include "gimple.h"
#include "hard-reg-set.h"
#include "basic-block.h"
#include "tree-flow.h"
walk back up, we check that they fit our constraints, and copy them
into temporaries if not. */
-/* Local declarations. */
-
-enum bc_t { bc_break = 0, bc_continue = 1 };
-
-static struct c_gimplify_ctx
-{
- /* For handling break and continue. */
- tree current_bc_label;
- tree bc_id[2];
-} *ctxp;
-
-static void
-push_context (void)
-{
- if (ctxp)
- abort ();
- ctxp = (struct c_gimplify_ctx *) xcalloc (1, sizeof (struct c_gimplify_ctx));
- ctxp->bc_id[bc_continue] = get_identifier ("continue");
- ctxp->bc_id[bc_break] = get_identifier ("break");
-}
-
-static void
-pop_context (void)
-{
- if (!ctxp || ctxp->current_bc_label)
- abort ();
- free (ctxp);
- ctxp = NULL;
-}
-
/* Gimplification of statement trees. */
/* Convert the tree representation of FNDECL from C frontend trees to
void
c_genericize (tree fndecl)
{
- FILE *dump_file;
+ FILE *dump_orig;
int local_dump_flags;
struct cgraph_node *cgn;
/* Dump the C-specific tree IR. */
- dump_file = dump_begin (TDI_original, &local_dump_flags);
- if (dump_file)
+ dump_orig = dump_begin (TDI_original, &local_dump_flags);
+ if (dump_orig)
{
- fprintf (dump_file, "\n;; Function %s",
+ fprintf (dump_orig, "\n;; Function %s",
lang_hooks.decl_printable_name (fndecl, 2));
- fprintf (dump_file, " (%s)\n",
- IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl)));
- fprintf (dump_file, ";; enabled by -%s\n", dump_flag_name (TDI_original));
- fprintf (dump_file, "\n");
+ fprintf (dump_orig, " (%s)\n",
+ (!DECL_ASSEMBLER_NAME_SET_P (fndecl) ? "null"
+ : IDENTIFIER_POINTER (DECL_ASSEMBLER_NAME (fndecl))));
+ fprintf (dump_orig, ";; enabled by -%s\n", dump_flag_name (TDI_original));
+ fprintf (dump_orig, "\n");
if (local_dump_flags & TDF_RAW)
dump_node (DECL_SAVED_TREE (fndecl),
- TDF_SLIM | local_dump_flags, dump_file);
+ TDF_SLIM | local_dump_flags, dump_orig);
else
- print_c_tree (dump_file, DECL_SAVED_TREE (fndecl));
- fprintf (dump_file, "\n");
+ print_c_tree (dump_orig, DECL_SAVED_TREE (fndecl));
+ fprintf (dump_orig, "\n");
- dump_end (TDI_original, dump_file);
+ dump_end (TDI_original, dump_orig);
}
/* Go ahead and gimplify for now. */
- push_context ();
gimplify_function_tree (fndecl);
- pop_context ();
- /* Dump the genericized tree IR. */
dump_function (TDI_generic, fndecl);
/* Genericize all nested functions now. We do things in this order so
static void
add_block_to_enclosing (tree block)
{
+ unsigned i;
tree enclosing;
+ gimple bind;
+ VEC(gimple, heap) *stack = gimple_bind_expr_stack ();
- for (enclosing = gimple_current_bind_expr ();
- enclosing; enclosing = TREE_CHAIN (enclosing))
- if (BIND_EXPR_BLOCK (enclosing))
+ for (i = 0; VEC_iterate (gimple, stack, i, bind); i++)
+ if (gimple_bind_block (bind))
break;
- enclosing = BIND_EXPR_BLOCK (enclosing);
+ enclosing = gimple_bind_block (bind);
BLOCK_SUBBLOCKS (enclosing) = chainon (BLOCK_SUBBLOCKS (enclosing), block);
}
body = build_empty_stmt ();
if (decls || block)
{
- bind = build (BIND_EXPR, void_type_node, decls, body, block);
+ bind = build3 (BIND_EXPR, void_type_node, decls, body, block);
TREE_SIDE_EFFECTS (bind) = 1;
}
else
return bind;
}
-/* Gimplify an EXPR_STMT node.
-
- STMT is the statement node.
-
- PRE_P points to the list where side effects that must happen before
- STMT should be stored.
+/* Gimplification of expression trees. */
- POST_P points to the list where side effects that must happen after
- STMT should be stored. */
+/* Gimplify a C99 compound literal expression. This just means adding
+ the DECL_EXPR before the current statement and using its anonymous
+ decl instead. */
static enum gimplify_status
-gimplify_expr_stmt (tree *stmt_p)
+gimplify_compound_literal_expr (tree *expr_p, gimple_seq *pre_p)
{
- tree stmt = EXPR_STMT_EXPR (*stmt_p);
-
- if (stmt == error_mark_node)
- stmt = NULL;
-
- /* Gimplification of a statement expression will nullify the
- statement if all its side effects are moved to *PRE_P and *POST_P.
-
- In this case we will not want to emit the gimplified statement.
- However, we may still want to emit a warning, so we do that before
- gimplification. */
- if (stmt && (extra_warnings || warn_unused_value))
- {
- if (!TREE_SIDE_EFFECTS (stmt))
- {
- if (!IS_EMPTY_STMT (stmt)
- && !VOID_TYPE_P (TREE_TYPE (stmt))
- && !TREE_NO_WARNING (stmt))
- warning ("statement with no effect");
- }
- else if (warn_unused_value)
- warn_if_unused_value (stmt, input_location);
- }
-
- if (stmt == NULL_TREE)
- stmt = alloc_stmt_list ();
+ tree decl_s = COMPOUND_LITERAL_EXPR_DECL_STMT (*expr_p);
+ tree decl = DECL_EXPR_DECL (decl_s);
+ /* Mark the decl as addressable if the compound literal
+ expression is addressable now, otherwise it is marked too late
+ after we gimplify the initialization expression. */
+ if (TREE_ADDRESSABLE (*expr_p))
+ TREE_ADDRESSABLE (decl) = 1;
+
+ /* Preliminarily mark non-addressed complex variables as eligible
+ for promotion to gimple registers. We'll transform their uses
+ as we find them. */
+ if ((TREE_CODE (TREE_TYPE (decl)) == COMPLEX_TYPE
+ || TREE_CODE (TREE_TYPE (decl)) == VECTOR_TYPE)
+ && !TREE_THIS_VOLATILE (decl)
+ && !needs_to_live_in_memory (decl))
+ DECL_GIMPLE_REG_P (decl) = 1;
- *stmt_p = stmt;
+ /* This decl isn't mentioned in the enclosing block, so add it to the
+ list of temps. FIXME it seems a bit of a kludge to say that
+ anonymous artificial vars aren't pushed, but everything else is. */
+ if (DECL_NAME (decl) == NULL_TREE && !DECL_SEEN_IN_BIND_EXPR_P (decl))
+ gimple_add_tmp_var (decl);
+ gimplify_and_add (decl_s, pre_p);
+ *expr_p = decl;
return GS_OK;
}
-/* Begin a scope which can be exited by a break or continue statement. BC
- indicates which.
-
- Just creates a label and pushes it into the current context. */
-
-static tree
-begin_bc_block (enum bc_t bc)
-{
- tree label = create_artificial_label ();
- DECL_NAME (label) = ctxp->bc_id[bc];
- TREE_CHAIN (label) = ctxp->current_bc_label;
- ctxp->current_bc_label = label;
- return label;
-}
-
-/* Finish a scope which can be exited by a break or continue statement.
- LABEL was returned from the most recent call to begin_bc_block. BODY is
- an expression for the contents of the scope.
-
- If we saw a break (or continue) in the scope, append a LABEL_EXPR to
- body. Otherwise, just forget the label. */
-
-static tree
-finish_bc_block (tree label, tree body)
-{
- if (label != ctxp->current_bc_label)
- abort ();
-
- if (TREE_USED (label))
- {
- tree t, sl = NULL;
-
- /* Clear the name so flow can delete the label. */
- DECL_NAME (label) = NULL_TREE;
- t = build1 (LABEL_EXPR, void_type_node, label);
-
- append_to_statement_list (body, &sl);
- append_to_statement_list (t, &sl);
- body = sl;
- }
-
- ctxp->current_bc_label = TREE_CHAIN (label);
- TREE_CHAIN (label) = NULL_TREE;
- return body;
-}
-
-/* Build a GOTO_EXPR to represent a break or continue statement. BC
- indicates which. */
+/* Optimize embedded COMPOUND_LITERAL_EXPRs within a CONSTRUCTOR,
+ return a new CONSTRUCTOR if something changed. */
static tree
-build_bc_goto (enum bc_t bc)
+optimize_compound_literals_in_ctor (tree orig_ctor)
{
- tree label;
- tree target_name = ctxp->bc_id[bc];
-
- /* Look for the appropriate type of label. */
- for (label = ctxp->current_bc_label;
- label;
- label = TREE_CHAIN (label))
- if (DECL_NAME (label) == target_name)
- break;
+ tree ctor = orig_ctor;
+ VEC(constructor_elt,gc) *elts = CONSTRUCTOR_ELTS (ctor);
+ unsigned int idx, num = VEC_length (constructor_elt, elts);
- if (label == NULL_TREE)
+ for (idx = 0; idx < num; idx++)
{
- if (bc == bc_break)
- error ("break statement not within loop or switch");
- else
- error ("continue statement not within loop or switch");
-
- return NULL_TREE;
- }
-
- /* Mark the label used for finish_bc_block. */
- TREE_USED (label) = 1;
- return build1 (GOTO_EXPR, void_type_node, label);
-}
-
-/* Build a generic representation of one of the C loop forms. COND is the
- loop condition or NULL_TREE. BODY is the (possibly compound) statement
- controlled by the loop. INCR is the increment expression of a for-loop,
- or NULL_TREE. COND_IS_FIRST indicates whether the condition is
- evaluated before the loop body as in while and for loops, or after the
- loop body as in do-while loops. */
-
-static tree
-gimplify_c_loop (tree cond, tree body, tree incr, bool cond_is_first)
-{
- tree top, entry, exit, cont_block, break_block, stmt_list, t;
- location_t stmt_locus;
-
- stmt_locus = input_location;
-
- /* Detect do { ... } while (0) and don't generate loop construct. */
- if (!cond_is_first && cond && integer_zerop (cond))
- top = cond = NULL;
- else
- {
- /* If we use a LOOP_EXPR here, we have to feed the whole thing
- back through the main gimplifier to lower it. Given that we
- have to gimplify the loop body NOW so that we can resolve
- break/continue stmts, seems easier to just expand to gotos. */
- top = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
- }
-
- break_block = begin_bc_block (bc_break);
-
- if (top)
- {
- /* If we have an exit condition, then we build an IF with gotos either
- out of the loop, or to the top of it. If there's no exit condition,
- then we just build a jump back to the top. */
- exit = build_and_jump (&LABEL_EXPR_LABEL (top));
- if (cond)
+ tree value = VEC_index (constructor_elt, elts, idx)->value;
+ tree newval = value;
+ if (TREE_CODE (value) == CONSTRUCTOR)
+ newval = optimize_compound_literals_in_ctor (value);
+ else if (TREE_CODE (value) == COMPOUND_LITERAL_EXPR)
{
- t = build_bc_goto (bc_break);
- exit = build (COND_EXPR, void_type_node, cond, exit, t);
- exit = fold (exit);
- gimplify_stmt (&exit);
+ tree decl_s = COMPOUND_LITERAL_EXPR_DECL_STMT (value);
+ tree decl = DECL_EXPR_DECL (decl_s);
+ tree init = DECL_INITIAL (decl);
+
+ if (!TREE_ADDRESSABLE (value)
+ && !TREE_ADDRESSABLE (decl)
+ && init)
+ newval = init;
}
- }
- else
- exit = NULL_TREE;
-
- cont_block = begin_bc_block (bc_continue);
+ if (newval == value)
+ continue;
- gimplify_stmt (&body);
- gimplify_stmt (&incr);
-
- body = finish_bc_block (cont_block, body);
-
- stmt_list = NULL;
-
- if (cond_is_first && cond)
- {
- entry = build1 (LABEL_EXPR, void_type_node, NULL_TREE);
- t = build_and_jump (&LABEL_EXPR_LABEL (entry));
- append_to_statement_list (t, &stmt_list);
+ if (ctor == orig_ctor)
+ {
+ ctor = copy_node (orig_ctor);
+ CONSTRUCTOR_ELTS (ctor) = VEC_copy (constructor_elt, gc, elts);
+ elts = CONSTRUCTOR_ELTS (ctor);
+ }
+ VEC_index (constructor_elt, elts, idx)->value = newval;
}
- else
- entry = NULL_TREE;
-
- append_to_statement_list (top, &stmt_list);
- append_to_statement_list (body, &stmt_list);
- append_to_statement_list (incr, &stmt_list);
- append_to_statement_list (entry, &stmt_list);
- append_to_statement_list (exit, &stmt_list);
-
- annotate_all_with_locus (&stmt_list, stmt_locus);
-
- return finish_bc_block (break_block, stmt_list);
-}
-
-/* Gimplify a FOR_STMT node. Move the stuff in the for-init-stmt into the
- prequeue and hand off to gimplify_c_loop. */
-
-static enum gimplify_status
-gimplify_for_stmt (tree *stmt_p, tree *pre_p)
-{
- tree stmt = *stmt_p;
-
- if (FOR_INIT_STMT (stmt))
- gimplify_and_add (FOR_INIT_STMT (stmt), pre_p);
-
- *stmt_p = gimplify_c_loop (FOR_COND (stmt), FOR_BODY (stmt),
- FOR_EXPR (stmt), 1);
-
- return GS_ALL_DONE;
+ return ctor;
}
-/* Gimplify a WHILE_STMT node. */
-
-static enum gimplify_status
-gimplify_while_stmt (tree *stmt_p)
-{
- tree stmt = *stmt_p;
- *stmt_p = gimplify_c_loop (WHILE_COND (stmt), WHILE_BODY (stmt),
- NULL_TREE, 1);
- return GS_ALL_DONE;
-}
-
-/* Gimplify a DO_STMT node. */
-
-static enum gimplify_status
-gimplify_do_stmt (tree *stmt_p)
-{
- tree stmt = *stmt_p;
- *stmt_p = gimplify_c_loop (DO_COND (stmt), DO_BODY (stmt),
- NULL_TREE, 0);
- return GS_ALL_DONE;
-}
-
-/* Genericize a SWITCH_STMT by turning it into a SWITCH_EXPR. */
-
-static enum gimplify_status
-gimplify_switch_stmt (tree *stmt_p)
-{
- tree stmt = *stmt_p;
- tree break_block, body;
- location_t stmt_locus = input_location;
-
- break_block = begin_bc_block (bc_break);
-
- body = SWITCH_BODY (stmt);
- if (!body)
- body = build_empty_stmt ();
-
- *stmt_p = build (SWITCH_EXPR, SWITCH_TYPE (stmt), SWITCH_COND (stmt),
- body, NULL_TREE);
- SET_EXPR_LOCATION (*stmt_p, stmt_locus);
- gimplify_stmt (stmt_p);
-
- *stmt_p = finish_bc_block (break_block, *stmt_p);
- return GS_ALL_DONE;
-}
-
-/* Gimplification of expression trees. */
-
-/* Gimplify a C99 compound literal expression. This just means adding the
- DECL_EXPR before the current EXPR_STMT and using its anonymous decl
- instead. */
-
-static enum gimplify_status
-gimplify_compound_literal_expr (tree *expr_p, tree *pre_p)
-{
- tree decl_s = COMPOUND_LITERAL_EXPR_DECL_STMT (*expr_p);
- tree decl = DECL_EXPR_DECL (decl_s);
-
- /* This decl isn't mentioned in the enclosing block, so add it to the
- list of temps. FIXME it seems a bit of a kludge to say that
- anonymous artificial vars aren't pushed, but everything else is. */
- if (DECL_NAME (decl) == NULL_TREE)
- gimple_add_tmp_var (decl);
-
- gimplify_and_add (decl_s, pre_p);
- *expr_p = decl;
- return GS_OK;
-}
-
-/* Do C-specific gimplification. Args are as for gimplify_expr. */
+/* Do C-specific gimplification on *EXPR_P. PRE_P and POST_P are as in
+ gimplify_expr. */
int
-c_gimplify_expr (tree *expr_p, tree *pre_p, tree *post_p ATTRIBUTE_UNUSED)
+c_gimplify_expr (tree *expr_p, gimple_seq *pre_p,
+ gimple_seq *post_p ATTRIBUTE_UNUSED)
{
enum tree_code code = TREE_CODE (*expr_p);
&& !warn_init_self)
TREE_NO_WARNING (DECL_EXPR_DECL (*expr_p)) = 1;
return GS_UNHANDLED;
-
+
case COMPOUND_LITERAL_EXPR:
return gimplify_compound_literal_expr (expr_p, pre_p);
- case FOR_STMT:
- return gimplify_for_stmt (expr_p, pre_p);
-
- case WHILE_STMT:
- return gimplify_while_stmt (expr_p);
-
- case DO_STMT:
- return gimplify_do_stmt (expr_p);
-
- case SWITCH_STMT:
- return gimplify_switch_stmt (expr_p);
-
- case EXPR_STMT:
- return gimplify_expr_stmt (expr_p);
-
- case CONTINUE_STMT:
- *expr_p = build_bc_goto (bc_continue);
- return GS_ALL_DONE;
-
- case BREAK_STMT:
- *expr_p = build_bc_goto (bc_break);
- return GS_ALL_DONE;
+ case INIT_EXPR:
+ case MODIFY_EXPR:
+ if (TREE_CODE (TREE_OPERAND (*expr_p, 1)) == COMPOUND_LITERAL_EXPR)
+ {
+ tree complit = TREE_OPERAND (*expr_p, 1);
+ tree decl_s = COMPOUND_LITERAL_EXPR_DECL_STMT (complit);
+ tree decl = DECL_EXPR_DECL (decl_s);
+ tree init = DECL_INITIAL (decl);
+
+ /* struct T x = (struct T) { 0, 1, 2 } can be optimized
+ into struct T x = { 0, 1, 2 } if the address of the
+ compound literal has never been taken. */
+ if (!TREE_ADDRESSABLE (complit)
+ && !TREE_ADDRESSABLE (decl)
+ && init)
+ {
+ *expr_p = copy_node (*expr_p);
+ TREE_OPERAND (*expr_p, 1) = init;
+ return GS_OK;
+ }
+ }
+ else if (TREE_CODE (TREE_OPERAND (*expr_p, 1)) == CONSTRUCTOR)
+ {
+ tree ctor
+ = optimize_compound_literals_in_ctor (TREE_OPERAND (*expr_p, 1));
+
+ if (ctor != TREE_OPERAND (*expr_p, 1))
+ {
+ *expr_p = copy_node (*expr_p);
+ TREE_OPERAND (*expr_p, 1) = ctor;
+ return GS_OK;
+ }
+ }
+ return GS_UNHANDLED;
default:
return GS_UNHANDLED;
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