* @author Michael Beck
* @version $Id$
*/
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
+#include "config.h"
#include <string.h>
#include "dbginfo_t.h"
#include "iropt_dbg.h"
#include "irflag_t.h"
-#include "array.h"
+#include "array_t.h"
#include "irhooks.h"
#include "iredges.h"
#include "irtools.h"
#include "opt_polymorphy.h"
#include "irmemory.h"
-#include "xmalloc.h"
#include "irphase_t.h"
#include "irgopt.h"
#include "debug.h"
store_mode = get_irn_mode(get_Store_value(store));
store_mode_len = get_mode_size_bytes(store_mode);
delta = load_offset - store_offset;
- if (delta < 0 || delta + load_mode_len > store_mode_len)
- return 0;
+ store_value = get_Store_value(store);
- if (get_mode_arithmetic(store_mode) != irma_twos_complement ||
- get_mode_arithmetic(load_mode) != irma_twos_complement)
- return 0;
+ if (delta != 0 || store_mode != load_mode) {
+ if (delta < 0 || delta + load_mode_len > store_mode_len)
+ return 0;
- store_value = get_Store_value(store);
+ if (get_mode_arithmetic(store_mode) != irma_twos_complement ||
+ get_mode_arithmetic(load_mode) != irma_twos_complement)
+ return 0;
- /* produce a shift to adjust offset delta */
- if (delta > 0) {
- ir_node *cnst;
- /* FIXME: only true for little endian */
- cnst = new_Const_long(mode_Iu, delta * 8);
- store_value = new_r_Shr(current_ir_graph, get_nodes_block(load),
- store_value, cnst, store_mode);
- }
+ /* produce a shift to adjust offset delta */
+ if (delta > 0) {
+ ir_node *cnst;
+
+ /* FIXME: only true for little endian */
+ cnst = new_Const_long(mode_Iu, delta * 8);
+ store_value = new_r_Shr(current_ir_graph, get_nodes_block(load),
+ store_value, cnst, store_mode);
+ }
- /* add an convert if needed */
- if (store_mode != load_mode) {
- store_value = new_r_Conv(current_ir_graph, get_nodes_block(load),
- store_value, load_mode);
+ /* add an convert if needed */
+ if (store_mode != load_mode) {
+ store_value = new_r_Conv(current_ir_graph, get_nodes_block(load),
+ store_value, load_mode);
+ }
}
DBG_OPT_RAW(load, store_value);
return get_mode_size_bits(new_mode) >= get_mode_size_bits(old_mode);
} /* is_completely_overwritten */
+/**
+ * Check whether small is a part of large (starting at same address).
+ */
+static int is_partially_same(ir_node *small, ir_node *large)
+{
+ ir_mode *sm = get_irn_mode(small);
+ ir_mode *lm = get_irn_mode(large);
+
+ /* FIXME: Check endianness */
+ return is_Conv(small) && get_Conv_op(small) == large
+ && get_mode_size_bytes(sm) < get_mode_size_bytes(lm)
+ && get_mode_arithmetic(sm) == irma_twos_complement
+ && get_mode_arithmetic(lm) == irma_twos_complement;
+} /* is_partially_same */
+
/**
* follow the memory chain as long as there are only Loads and alias free Stores.
*
* if the pointers are identical, they refer to the same object.
* This is only true in strong typed languages, not is C were the following
* is possible *(ir_type1 *)p = a; *(ir_type2 *)p = b ...
- * However, if the mode that is written have a bigger or equal size the the old
- * one, the old value is completely overwritten and can be killed ...
+ * However, if the size of the mode that is written is bigger or equal the
+ * size of the old one, the old value is completely overwritten and can be
+ * killed ...
*/
if (is_Store(pred) && get_Store_ptr(pred) == ptr &&
- get_nodes_MacroBlock(pred) == mblk &&
- is_completely_overwritten(get_irn_mode(get_Store_value(pred)), mode)) {
+ get_nodes_MacroBlock(pred) == mblk) {
/*
* a Store after a Store in the same MacroBlock -- a write after write.
- * We may remove the first Store, if it does not have an exception handler.
+ */
+
+ /*
+ * We may remove the first Store, if the old value is completely
+ * overwritten or the old value is a part of the new value,
+ * and if it does not have an exception handler.
*
* TODO: What, if both have the same exception handler ???
*/
- if (get_Store_volatility(pred) != volatility_is_volatile && !pred_info->projs[pn_Store_X_except]) {
- DBG_OPT_WAW(pred, store);
- exchange(pred_info->projs[pn_Store_M], get_Store_mem(pred));
- kill_node(pred);
- reduce_adr_usage(ptr);
- return DF_CHANGED;
+ if (get_Store_volatility(pred) != volatility_is_volatile
+ && !pred_info->projs[pn_Store_X_except]) {
+ ir_node *predvalue = get_Store_value(pred);
+ ir_mode *predmode = get_irn_mode(predvalue);
+
+ if(is_completely_overwritten(predmode, mode)
+ || is_partially_same(predvalue, value)) {
+ DBG_OPT_WAW(pred, store);
+ exchange(pred_info->projs[pn_Store_M], get_Store_mem(pred));
+ kill_node(pred);
+ reduce_adr_usage(ptr);
+ return DF_CHANGED;
+ }
+ }
+
+ /*
+ * We may remove the Store, if the old value already contains
+ * the new value, and if it does not have an exception handler.
+ *
+ * TODO: What, if both have the same exception handler ???
+ */
+ if (get_Store_volatility(store) != volatility_is_volatile
+ && !info->projs[pn_Store_X_except]) {
+ ir_node *predvalue = get_Store_value(pred);
+
+ if(is_partially_same(value, predvalue)) {
+ DBG_OPT_WAW(pred, store);
+ exchange(info->projs[pn_Store_M], mem);
+ kill_node(store);
+ reduce_adr_usage(ptr);
+ return DF_CHANGED;
+ }
}
} else if (is_Load(pred) && get_Load_ptr(pred) == ptr &&
value == pred_info->projs[pn_Load_res]) {
}
/* fourth step: create the Store */
- store = new_rd_Store(db, current_ir_graph, block, phiM, ptr, phiD);
+ store = new_rd_Store(db, current_ir_graph, block, phiM, ptr, phiD, 0);
#ifdef DO_CACHEOPT
co_set_irn_name(store, co_get_irn_ident(old_store));
#endif
ir_node *pred = get_Block_cfgpred_block(blk, pos);
ir_node *irn, *mem;
- pe->load = irn = new_rd_Load(db, current_ir_graph, pred, get_Phi_pred(phi, pos), ptr, load_mode);
+ pe->load = irn = new_rd_Load(db, current_ir_graph, pred, get_Phi_pred(phi, pos), ptr, load_mode, 0);
ninfo = get_ldst_info(irn, phase_obst(&env->ph));
ninfo->projs[pn_Load_M] = mem = new_r_Proj(current_ir_graph, pred, irn, mode_M, pn_Load_M);
ir_node *pred = get_irn_n(irn, i);
node_entry *o = get_irn_ne(pred, env);
- if (irn_not_visited(pred)) {
+ if (!irn_visited(pred)) {
dfs(pred, env);
node->low = MIN(node->low, o->low);
}
ir_node *pred = get_fragile_op_mem(irn);
node_entry *o = get_irn_ne(pred, env);
- if (irn_not_visited(pred)) {
+ if (!irn_visited(pred)) {
dfs(pred, env);
node->low = MIN(node->low, o->low);
}
ir_node *pred = get_Proj_pred(irn);
node_entry *o = get_irn_ne(pred, env);
- if (irn_not_visited(pred)) {
+ if (!irn_visited(pred)) {
dfs(pred, env);
node->low = MIN(node->low, o->low);
}
for (i = get_End_n_keepalives(end) - 1; i >= 0; --i) {
ir_node *ka = get_End_keepalive(end, i);
- if (is_Phi(ka) && irn_not_visited(ka))
+ if (is_Phi(ka) && !irn_visited(ka))
dfs(ka, env);
}
current_ir_graph = rem;
/*
* do the load store optimization
*/
-void optimize_load_store(ir_graph *irg) {
+int optimize_load_store(ir_graph *irg) {
walk_env_t env;
FIRM_DBG_REGISTER(dbg, "firm.opt.ldstopt");
have Bad() predecessors. */
set_irg_doms_inconsistent(irg);
}
+ return env.changes != 0;
} /* optimize_load_store */
projects / libfirm / blobdiff