* Licence: This file protected by GPL - GNU GENERAL PUBLIC LICENSE.
*/
-/** @file escape_ana.c
+/**
+ * @file escape_ana.c
*
- * escape analysis.
+ * A fast and simple Escape analysis.
*/
#ifdef HAVE_CONFIG_H
#include "irgraph_t.h"
#include "irnode_t.h"
+#include "type_t.h"
+#include "irgwalk.h"
#include "irouts.h"
#include "analyze_irg_args.h"
#include "irgmod.h"
#include "ircons.h"
#include "escape_ana.h"
+#include "debug.h"
/**
* walker environment
typedef struct _walk_env {
ir_node *found_allocs; /**< list of all found non-escaped allocs */
ir_node *dead_allocs; /**< list of all found dead alloc */
- unsigned nr_changed; /**< number of changed allocs */
+ unsigned nr_removed; /**< number of removed allocs (placed of frame) */
+ unsigned nr_changed; /**< number of changed allocs (allocated on stack now) */
unsigned nr_deads; /**< number of dead allocs */
/* these fields are only used in the global escape analysis */
} walk_env_t;
+/** debug handle */
+DEBUG_ONLY(firm_dbg_module_t *dbgHandle;)
+
/**
* checks whether a Raise leaves a method
*/
* determine if a value calculated by n "escape", ie
* is stored somewhere we could not track
*/
-static int do_escape(ir_node *n) {
+static int can_escape(ir_node *n) {
int i, j, k;
/* should always be pointer mode or we made some mistake */
}
}
}
- else {
+ else if (get_irn_op(ptr) == op_Sel) {
/* go through all possible callees */
for (k = get_Call_n_callees(succ) - 1; k >= 0; --k) {
ent = get_Call_callee(succ, k);
+ if (ent == unknown_entity) {
+ /* we don't know what will be called, a possible escape */
+ return 1;
+ }
+
for (j = get_Call_n_params(succ) - 1; j >= 0; --j) {
if (get_Call_param(succ, j) == n) {
/* n is the j'th param of the call */
}
}
}
+ else /* we don't know want will called */
+ return 1;
+
break;
}
if (! mode_is_reference(get_irn_mode(succ)))
continue;
- if (do_escape(succ))
+ if (can_escape(succ))
return 1;
}
return 0;
return;
}
- if (! do_escape(adr)) {
+ if (! can_escape(adr)) {
set_irn_link(alloc, env->found_allocs);
env->found_allocs = alloc;
}
*/
static void transform_allocs(ir_graph *irg, walk_env_t *env)
{
- ir_node *alloc, *next, *mem, *sel;
- type *ftp;
+ ir_node *alloc, *next, *mem, *sel, *size;
+ ir_type *ftp, *atp, *tp;
entity *ent;
- char name[32];
+ char name[128];
unsigned nr = 0;
dbg_info *dbg;
for (alloc = env->dead_allocs; alloc; alloc = next) {
next = get_irn_link(alloc);
+ DBG((dbgHandle, LEVEL_1, "%+F allocation of %+F unused, deleted.\n", irg, alloc));
+
mem = get_Alloc_mem(alloc);
turn_into_tuple(alloc, pn_Alloc_max);
set_Tuple_pred(alloc, pn_Alloc_M, mem);
ftp = get_irg_frame_type(irg);
for (alloc = env->found_allocs; alloc; alloc = next) {
next = get_irn_link(alloc);
- dbg = get_irn_dbg_info(alloc);
+ size = get_Alloc_size(alloc);
+ atp = get_Alloc_type(alloc);
+
+ tp = NULL;
+ if (get_irn_op(size) == op_SymConst && get_SymConst_kind(size) == symconst_type_size) {
+ /* if the size is a type size and the types matched */
+ assert(atp == get_SymConst_type(size));
+ tp = atp;
+ }
+ else if (is_Const(size)) {
+ tarval *tv = get_Const_tarval(size);
+
+ if (tv != tarval_bad && tarval_is_long(tv) &&
+ get_type_state(atp) == layout_fixed &&
+ get_tarval_long(tv) == get_type_size_bytes(atp)) {
+ /* a already lowered type size */
+ tp = atp;
+ }
+ }
- snprintf(name, sizeof(name), "_not_escaped_%u", nr++);
- ent = new_d_entity(ftp, new_id_from_str(name), get_Alloc_type(alloc), dbg);
+ if (tp && tp != firm_unknown_type) {
+ /* we could determine the type, so we could place it on the frame */
+ dbg = get_irn_dbg_info(alloc);
- sel = new_rd_simpleSel(dbg, irg, get_nodes_block(alloc),
- get_irg_no_mem(irg), get_irg_frame(irg), ent);
- mem = get_Alloc_mem(alloc);
+ DBG((dbgHandle, LEVEL_DEFAULT, "%+F allocation of %+F type %+F placed on frame\n", irg, alloc, tp));
- turn_into_tuple(alloc, pn_Alloc_max);
- set_Tuple_pred(alloc, pn_Alloc_M, mem);
- set_Tuple_pred(alloc, pn_Alloc_X_except, new_r_Bad(irg));
- set_Tuple_pred(alloc, pn_Alloc_res, sel);
+ snprintf(name, sizeof(name), "%s_NE_%u", get_entity_name(get_irg_entity(irg)), nr++);
+ ent = new_d_entity(ftp, new_id_from_str(name), get_Alloc_type(alloc), dbg);
+
+ sel = new_rd_simpleSel(dbg, irg, get_nodes_block(alloc),
+ get_irg_no_mem(irg), get_irg_frame(irg), ent);
+ mem = get_Alloc_mem(alloc);
- ++env->nr_changed;
+ turn_into_tuple(alloc, pn_Alloc_max);
+ set_Tuple_pred(alloc, pn_Alloc_M, mem);
+ set_Tuple_pred(alloc, pn_Alloc_X_except, new_r_Bad(irg));
+ set_Tuple_pred(alloc, pn_Alloc_res, sel);
+
+ ++env->nr_removed;
+ }
+ else {
+ /*
+ * We could not determine the type or it is variable size.
+ * At least, we could place it on the stack
+ */
+ DBG((dbgHandle, LEVEL_DEFAULT, "%+F allocation of %+F type %+F placed on stack\n", irg, alloc));
+ set_Alloc_where(alloc, stack_alloc);
+
+ ++env->nr_changed;
+ }
}
- if (env->nr_changed | env->nr_deads) {
+ /* if allocs were removed somehow */
+ if (env->nr_removed | env->nr_deads) {
set_irg_outs_inconsistent(irg);
- if (env->nr_deads)
- set_irg_dom_inconsistent(irg);
+ if (env->nr_deads) {
+ /* exception control flow might have been changed */
+ set_irg_doms_inconsistent(irg);
+ }
}
}
env.found_allocs = NULL;
env.dead_allocs = NULL;
+ env.nr_removed = 0;
env.nr_changed = 0;
env.nr_deads = 0;
return;
}
+ FIRM_DBG_REGISTER(dbgHandle, "firm.opt.escape_ana");
+
/*
* We treat memory for speed: we first collect all info in a
* list of environments, than do the transformation.
irg_walk_graph(irg, NULL, find_allocations, env);
if (env->found_allocs || env->dead_allocs) {
- env->nr_changed = 0;
+ env->nr_removed = 0;
env->nr_deads = 0;
env->irg = irg;
env->next = elist;
projects / libfirm / blobdiff