fix trailing whitespaces and tabulators in the middle of a line
[libfirm] / ir / opt / ldstopt.c
index 46db2a7..628ca32 100644 (file)
@@ -35,7 +35,6 @@
 #include "ircons_t.h"
 #include "irgmod.h"
 #include "irgwalk.h"
-#include "irvrfy.h"
 #include "tv_t.h"
 #include "dbginfo_t.h"
 #include "iropt_dbg.h"
 #include "array_t.h"
 #include "irhooks.h"
 #include "iredges.h"
-#include "irtools.h"
+#include "irpass.h"
 #include "opt_polymorphy.h"
 #include "irmemory.h"
 #include "irphase_t.h"
 #include "irgopt.h"
+#include "set.h"
 #include "debug.h"
 
 /** The debug handle. */
@@ -58,9 +58,9 @@ DEBUG_ONLY(static firm_dbg_module_t *dbg;)
 #endif
 
 #undef IMAX
-#define IMAX(a,b)      ((a) > (b) ? (a) : (b))
+#define IMAX(a,b)   ((a) > (b) ? (a) : (b))
 
-#define MAX_PROJ       IMAX(IMAX(pn_Load_max, pn_Store_max), pn_Call_max)
+#define MAX_PROJ    IMAX(IMAX(pn_Load_max, pn_Store_max), pn_Call_max)
 
 enum changes_t {
        DF_CHANGED = 1,       /**< data flow changed */
@@ -70,13 +70,13 @@ enum changes_t {
 /**
  * walker environment
  */
-typedef struct _walk_env_t {
+typedef struct walk_env_t {
        struct obstack obst;          /**< list of all stores */
        unsigned changes;             /**< a bitmask of graph changes */
 } walk_env_t;
 
 /** A Load/Store info. */
-typedef struct _ldst_info_t {
+typedef struct ldst_info_t {
        ir_node  *projs[MAX_PROJ];    /**< list of Proj's of this node */
        ir_node  *exc_block;          /**< the exception block if available */
        int      exc_idx;             /**< predecessor index in the exception block */
@@ -94,7 +94,7 @@ enum block_flags_t {
 /**
  * a Block info.
  */
-typedef struct _block_info_t {
+typedef struct block_info_t {
        unsigned flags;               /**< flags for the block */
 } block_info_t;
 
@@ -108,12 +108,12 @@ static unsigned master_visited = 0;
 /**
  * get the Load/Store info of a node
  */
-static ldst_info_t *get_ldst_info(ir_node *node, struct obstack *obst) {
+static ldst_info_t *get_ldst_info(ir_node *node, struct obstack *obst)
+{
        ldst_info_t *info = get_irn_link(node);
 
        if (! info) {
-               info = obstack_alloc(obst, sizeof(*info));
-               memset(info, 0, sizeof(*info));
+               info = OALLOCZ(obst, ldst_info_t);
                set_irn_link(node, info);
        }
        return info;
@@ -122,12 +122,12 @@ static ldst_info_t *get_ldst_info(ir_node *node, struct obstack *obst) {
 /**
  * get the Block info of a node
  */
-static block_info_t *get_block_info(ir_node *node, struct obstack *obst) {
+static block_info_t *get_block_info(ir_node *node, struct obstack *obst)
+{
        block_info_t *info = get_irn_link(node);
 
        if (! info) {
-               info = obstack_alloc(obst, sizeof(*info));
-               memset(info, 0, sizeof(*info));
+               info = OALLOCZ(obst, block_info_t);
                set_irn_link(node, info);
        }
        return info;
@@ -296,7 +296,7 @@ static ir_entity *find_constant_entity(ir_node *ptr)
                                }
                        }
 
-                       if (variability_constant == get_entity_variability(ent))
+                       if (get_entity_linkage(ent) & IR_LINKAGE_CONSTANT)
                                return ent;
 
                        /* try next */
@@ -319,7 +319,7 @@ static ir_entity *find_constant_entity(ir_node *ptr)
                        ir_node *l = get_Sub_left(ptr);
                        ir_node *r = get_Sub_right(ptr);
 
-                       if (get_irn_mode(l) == get_irn_mode(ptr) &&     is_Const(r))
+                       if (get_irn_mode(l) == get_irn_mode(ptr) && is_Const(r))
                                ptr = l;
                        else
                                return NULL;
@@ -334,7 +334,8 @@ static ir_entity *find_constant_entity(ir_node *ptr)
 /**
  * Return the Selection index of a Sel node from dimension n
  */
-static long get_Sel_array_index_long(ir_node *n, int dim) {
+static long get_Sel_array_index_long(ir_node *n, int dim)
+{
        ir_node *index = get_Sel_index(n, dim);
        assert(is_Const(index));
        return get_tarval_long(get_Const_tarval(index));
@@ -348,7 +349,8 @@ static long get_Sel_array_index_long(ir_node *n, int dim) {
  * @param depth  current depth in steps upward from the root
  *               of the address
  */
-static compound_graph_path *rec_get_accessed_path(ir_node *ptr, int depth) {
+static compound_graph_path *rec_get_accessed_path(ir_node *ptr, int depth)
+{
        compound_graph_path *res = NULL;
        ir_entity           *root, *field, *ent;
        int                 path_len, pos, idx;
@@ -495,7 +497,8 @@ ptr_arith:
  * Returns an access path or NULL.  The access path is only
  * valid, if the graph is in phase_high and _no_ address computation is used.
  */
-static compound_graph_path *get_accessed_path(ir_node *ptr) {
+static compound_graph_path *get_accessed_path(ir_node *ptr)
+{
        compound_graph_path *gr = rec_get_accessed_path(ptr, 0);
        return gr;
 }  /* get_accessed_path */
@@ -506,7 +509,8 @@ typedef struct path_entry {
        long              index;
 } path_entry;
 
-static ir_node *rec_find_compound_ent_value(ir_node *ptr, path_entry *next) {
+static ir_node *rec_find_compound_ent_value(ir_node *ptr, path_entry *next)
+{
        path_entry       entry, *p;
        ir_entity        *ent, *field;
        ir_initializer_t *initializer;
@@ -680,7 +684,8 @@ ptr_arith:
        return NULL;
 }
 
-static ir_node *find_compound_ent_value(ir_node *ptr) {
+static ir_node *find_compound_ent_value(ir_node *ptr)
+{
        return rec_find_compound_ent_value(ptr, NULL);
 }
 
@@ -690,7 +695,8 @@ static void reduce_adr_usage(ir_node *ptr);
 /**
  * Update a Load that may have lost its users.
  */
-static void handle_load_update(ir_node *load) {
+static void handle_load_update(ir_node *load)
+{
        ldst_info_t *info = get_irn_link(load);
 
        /* do NOT touch volatile loads for now */
@@ -704,7 +710,7 @@ static void handle_load_update(ir_node *load) {
                /* a Load whose value is neither used nor exception checked, remove it */
                exchange(info->projs[pn_Load_M], mem);
                if (info->projs[pn_Load_X_regular])
-                       exchange(info->projs[pn_Load_X_regular], new_r_Jmp(current_ir_graph, get_nodes_block(load)));
+                       exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
                kill_node(load);
                reduce_adr_usage(ptr);
        }
@@ -714,20 +720,22 @@ static void handle_load_update(ir_node *load) {
  * A use of an address node has vanished. Check if this was a Proj
  * node and update the counters.
  */
-static void reduce_adr_usage(ir_node *ptr) {
-       if (is_Proj(ptr)) {
-               if (get_irn_n_edges(ptr) <= 0) {
-                       /* this Proj is dead now */
-                       ir_node *pred = get_Proj_pred(ptr);
-
-                       if (is_Load(pred)) {
-                               ldst_info_t *info = get_irn_link(pred);
-                               info->projs[get_Proj_proj(ptr)] = NULL;
-
-                               /* this node lost its result proj, handle that */
-                               handle_load_update(pred);
-                       }
-               }
+static void reduce_adr_usage(ir_node *ptr)
+{
+       ir_node *pred;
+       if (!is_Proj(ptr))
+               return;
+       if (get_irn_n_edges(ptr) > 0)
+               return;
+
+       /* this Proj is dead now */
+       pred = get_Proj_pred(ptr);
+       if (is_Load(pred)) {
+               ldst_info_t *info = get_irn_link(pred);
+               info->projs[get_Proj_proj(ptr)] = NULL;
+
+               /* this node lost its result proj, handle that */
+               handle_load_update(pred);
        }
 }  /* reduce_adr_usage */
 
@@ -735,7 +743,8 @@ static void reduce_adr_usage(ir_node *ptr) {
  * Check, if an already existing value of mode old_mode can be converted
  * into the needed one new_mode without loss.
  */
-static int can_use_stored_value(ir_mode *old_mode, ir_mode *new_mode) {
+static int can_use_stored_value(ir_mode *old_mode, ir_mode *new_mode)
+{
        if (old_mode == new_mode)
                return 1;
 
@@ -751,7 +760,8 @@ static int can_use_stored_value(ir_mode *old_mode, ir_mode *new_mode) {
 /**
  * Check whether a Call is at least pure, ie. does only read memory.
  */
-static unsigned is_Call_pure(ir_node *call) {
+static unsigned is_Call_pure(ir_node *call)
+{
        ir_type *call_tp = get_Call_type(call);
        unsigned prop = get_method_additional_properties(call_tp);
 
@@ -870,14 +880,13 @@ static int try_load_after_store(ir_node *load,
 
                        /* 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 = new_r_Shr(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, 0);
+                       store_value = new_r_Conv(get_nodes_block(load), store_value, load_mode);
                }
        }
 
@@ -894,7 +903,7 @@ static int try_load_after_store(ir_node *load,
                res |= CF_CHANGED;
        }
        if (info->projs[pn_Load_X_regular]) {
-               exchange( info->projs[pn_Load_X_regular], new_r_Jmp(current_ir_graph, get_nodes_block(load)));
+               exchange( info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
                res |= CF_CHANGED;
        }
 
@@ -917,7 +926,8 @@ static int try_load_after_store(ir_node *load,
  *
  * INC_MASTER() must be called before dive into
  */
-static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) {
+static unsigned follow_Mem_chain(ir_node *load, ir_node *curr)
+{
        unsigned    res = 0;
        ldst_info_t *info = get_irn_link(load);
        ir_node     *pred;
@@ -931,19 +941,19 @@ static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) {
                /*
                 * a Load immediately after a Store -- a read after write.
                 * We may remove the Load, if both Load & Store does not have an
-                * exception handler OR they are in the same MacroBlock. In the latter
+                * exception handler OR they are in the same Block. In the latter
                 * case the Load cannot throw an exception when the previous Store was
                 * quiet.
                 *
                 * Why we need to check for Store Exception? If the Store cannot
                 * be executed (ROM) the exception handler might simply jump into
-                * the load MacroBlock :-(
+                * the load Block :-(
                 * We could make it a little bit better if we would know that the
                 * exception handler of the Store jumps directly to the end...
                 */
                if (is_Store(pred) && ((pred_info->projs[pn_Store_X_except] == NULL
                                && info->projs[pn_Load_X_except] == NULL)
-                               || get_nodes_MacroBlock(load) == get_nodes_MacroBlock(pred)))
+                               || get_nodes_block(load) == get_nodes_block(pred)))
                {
                        long    load_offset;
                        ir_node *base_ptr = get_base_and_offset(ptr, &load_offset);
@@ -955,14 +965,17 @@ static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) {
                           can_use_stored_value(get_Load_mode(pred), load_mode)) {
                        /*
                         * a Load after a Load -- a read after read.
-                        * We may remove the second Load, if it does not have an exception handler
-                        * OR they are in the same MacroBlock. In the later case the Load cannot
-                        * throw an exception when the previous Load was quiet.
+                        * We may remove the second Load, if it does not have an exception
+                        * handler OR they are in the same Block. In the later case
+                        * the Load cannot throw an exception when the previous Load was
+                        * quiet.
                         *
-                        * Here, there is no need to check if the previous Load has an exception
-                        * hander because they would have exact the same exception...
+                        * Here, there is no need to check if the previous Load has an
+                        * exception hander because they would have exact the same
+                        * exception...
                         */
-                       if (info->projs[pn_Load_X_except] == NULL || get_nodes_MacroBlock(load) == get_nodes_MacroBlock(pred)) {
+                       if (info->projs[pn_Load_X_except] == NULL
+                                       || get_nodes_block(load) == get_nodes_block(pred)) {
                                ir_node *value;
 
                                DBG_OPT_RAR(load, pred);
@@ -971,13 +984,13 @@ static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) {
                                if (info->projs[pn_Load_res]) {
                                        if (pred_info->projs[pn_Load_res] == NULL) {
                                                /* create a new Proj again */
-                                               pred_info->projs[pn_Load_res] = new_r_Proj(current_ir_graph, get_nodes_block(pred), pred, get_Load_mode(pred), pn_Load_res);
+                                               pred_info->projs[pn_Load_res] = new_r_Proj(pred, get_Load_mode(pred), pn_Load_res);
                                        }
                                        value = pred_info->projs[pn_Load_res];
 
                                        /* add an convert if needed */
                                        if (get_Load_mode(pred) != load_mode) {
-                                               value = new_r_Conv(current_ir_graph, get_nodes_block(load), value, load_mode, 0);
+                                               value = new_r_Conv(get_nodes_block(load), value, load_mode);
                                        }
 
                                        exchange(info->projs[pn_Load_res], value);
@@ -992,7 +1005,7 @@ static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) {
                                        res |= CF_CHANGED;
                                }
                                if (info->projs[pn_Load_X_regular]) {
-                                       exchange( info->projs[pn_Load_X_regular], new_r_Jmp(current_ir_graph, get_nodes_block(load)));
+                                       exchange( info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
                                        res |= CF_CHANGED;
                                }
 
@@ -1053,7 +1066,8 @@ static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) {
  * Check if we can replace the load by a given const from
  * the const code irg.
  */
-ir_node *can_replace_load_by_const(const ir_node *load, ir_node *c) {
+ir_node *can_replace_load_by_const(const ir_node *load, ir_node *c)
+{
        ir_mode *c_mode = get_irn_mode(c);
        ir_mode *l_mode = get_Load_mode(load);
        ir_node *res    = NULL;
@@ -1067,7 +1081,7 @@ ir_node *can_replace_load_by_const(const ir_node *load, ir_node *c) {
 
                        /* copy the value from the const code irg and cast it */
                        res = copy_const_value(dbg, c);
-                       res = new_rd_Conv(dbg, current_ir_graph, block, res, l_mode, 0);
+                       res = new_rd_Conv(dbg, block, res, l_mode);
                }
        } else {
                /* copy the value from the const code irg */
@@ -1096,44 +1110,17 @@ static unsigned optimize_load(ir_node *load)
        /* the address of the load to be optimized */
        ptr = get_Load_ptr(load);
 
-       /*
-        * Check if we can remove the exception from a Load:
-        * This can be done, if the address is from an Sel(Alloc) and
-        * the Sel type is a subtype of the allocated type.
-        *
-        * This optimizes some often used OO constructs,
-        * like x = new O; x->t;
-        */
-       if (info->projs[pn_Load_X_except]) {
-               ir_node *addr = ptr;
-
-               /* find base address */
-               while (is_Sel(addr))
-                       addr = get_Sel_ptr(addr);
-               if (is_Alloc(skip_Proj(skip_Cast(addr)))) {
-                       /* simple case: a direct load after an Alloc. Firm Alloc throw
-                        * an exception in case of out-of-memory. So, there is no way for an
-                        * exception in this load.
-                        * This code is constructed by the "exception lowering" in the Jack compiler.
-                        */
-                       exchange(info->projs[pn_Load_X_except], new_Bad());
-                       info->projs[pn_Load_X_except] = NULL;
-                       exchange(info->projs[pn_Load_X_regular], new_r_Jmp(current_ir_graph, get_nodes_block(load)));
-                       info->projs[pn_Load_X_regular] = NULL;
-                       res |= CF_CHANGED;
-               }
-       }
-
        /* The mem of the Load. Must still be returned after optimization. */
        mem = get_Load_mem(load);
 
-       if (! info->projs[pn_Load_res] && ! info->projs[pn_Load_X_except]) {
-               /* a Load which value is neither used nor exception checked, remove it */
+       if (info->projs[pn_Load_res] == NULL
+                       && info->projs[pn_Load_X_except] == NULL) {
+               /* the value is never used and we don't care about exceptions, remove */
                exchange(info->projs[pn_Load_M], mem);
 
                if (info->projs[pn_Load_X_regular]) {
                        /* should not happen, but if it does, remove it */
-                       exchange(info->projs[pn_Load_X_regular], new_r_Jmp(current_ir_graph, get_nodes_block(load)));
+                       exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
                        res |= CF_CHANGED;
                }
                kill_node(load);
@@ -1148,11 +1135,11 @@ static unsigned optimize_load(ir_node *load)
                value = NULL;
                /* check if we can determine the entity that will be loaded */
                ent = find_constant_entity(ptr);
-               if (ent != NULL                                     &&
-                   allocation_static == get_entity_allocation(ent) &&
-                   visibility_external_allocated != get_entity_visibility(ent)) {
-                       /* a static allocation that is not external: there should be NO exception
-                        * when loading even if we cannot replace the load itself. */
+               if (ent != NULL
+                               && get_entity_visibility(ent) != ir_visibility_external) {
+                       /* a static allocation that is not external: there should be NO
+                        * exception when loading even if we cannot replace the load itself.
+                        */
 
                        /* no exception, clear the info field as it might be checked later again */
                        if (info->projs[pn_Load_X_except]) {
@@ -1161,22 +1148,16 @@ static unsigned optimize_load(ir_node *load)
                                res |= CF_CHANGED;
                        }
                        if (info->projs[pn_Load_X_regular]) {
-                               exchange(info->projs[pn_Load_X_regular], new_r_Jmp(current_ir_graph, get_nodes_block(load)));
+                               exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
                                info->projs[pn_Load_X_regular] = NULL;
                                res |= CF_CHANGED;
                        }
 
-                       if (variability_constant == get_entity_variability(ent)) {
-                               if (is_atomic_entity(ent)) {
-                                       /* Might not be atomic after lowering of Sels.  In this case we
-                                        * could also load, but it's more complicated. */
-                                       /* more simpler case: we load the content of a constant value:
-                                        * replace it by the constant itself */
-                                       value = get_atomic_ent_value(ent);
-                               } else if (ent->has_initializer) {
+                       if (get_entity_linkage(ent) & IR_LINKAGE_CONSTANT) {
+                               if (ent->initializer != NULL) {
                                        /* new style initializer */
                                        value = find_compound_ent_value(ptr);
-                               } else {
+                               } else if (entity_has_compound_ent_values(ent)) {
                                        /* old style initializer */
                                        compound_graph_path *path = get_accessed_path(ptr);
 
@@ -1201,7 +1182,7 @@ static unsigned optimize_load(ir_node *load)
                        res |= CF_CHANGED;
                }
                if (info->projs[pn_Load_X_regular]) {
-                       exchange(info->projs[pn_Load_X_regular], new_r_Jmp(current_ir_graph, get_nodes_block(load)));
+                       exchange(info->projs[pn_Load_X_regular], new_r_Jmp(get_nodes_block(load)));
                        info->projs[pn_Load_X_regular] = NULL;
                        res |= CF_CHANGED;
                }
@@ -1264,7 +1245,8 @@ static int is_partially_same(ir_node *small, ir_node *large)
  *
  * INC_MASTER() must be called before dive into
  */
-static unsigned follow_Mem_chain_for_Store(ir_node *store, ir_node *curr) {
+static unsigned follow_Mem_chain_for_Store(ir_node *store, ir_node *curr)
+{
        unsigned res = 0;
        ldst_info_t *info = get_irn_link(store);
        ir_node *pred;
@@ -1273,7 +1255,6 @@ static unsigned follow_Mem_chain_for_Store(ir_node *store, ir_node *curr) {
        ir_node *value = get_Store_value(store);
        ir_mode *mode  = get_irn_mode(value);
        ir_node *block = get_nodes_block(store);
-       ir_node *mblk  = get_Block_MacroBlock(block);
 
        for (pred = curr; pred != store;) {
                ldst_info_t *pred_info = get_irn_link(pred);
@@ -1288,9 +1269,9 @@ static unsigned follow_Mem_chain_for_Store(ir_node *store, ir_node *curr) {
                 * killed ...
                 */
                if (is_Store(pred) && get_Store_ptr(pred) == ptr &&
-            get_nodes_MacroBlock(pred) == mblk) {
+            get_nodes_block(pred) == block) {
                        /*
-                        * a Store after a Store in the same MacroBlock -- a write after write.
+                        * a Store after a Store in the same Block -- a write after write.
                         */
 
                        /*
@@ -1305,7 +1286,7 @@ static unsigned follow_Mem_chain_for_Store(ir_node *store, ir_node *curr) {
                                ir_node *predvalue = get_Store_value(pred);
                                ir_mode *predmode  = get_irn_mode(predvalue);
 
-                               if(is_completely_overwritten(predmode, mode)
+                               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));
@@ -1325,7 +1306,7 @@ static unsigned follow_Mem_chain_for_Store(ir_node *store, ir_node *curr) {
                                && !info->projs[pn_Store_X_except]) {
                                ir_node *predvalue = get_Store_value(pred);
 
-                               if(is_partially_same(value, predvalue)) {
+                               if (is_partially_same(value, predvalue)) {
                                        DBG_OPT_WAW(pred, store);
                                        exchange(info->projs[pn_Store_M], mem);
                                        kill_node(store);
@@ -1396,7 +1377,7 @@ static unsigned follow_Mem_chain_for_Store(ir_node *store, ir_node *curr) {
 /** find entity used as base for an address calculation */
 static ir_entity *find_entity(ir_node *ptr)
 {
-       switch(get_irn_opcode(ptr)) {
+       switch (get_irn_opcode(ptr)) {
        case iro_SymConst:
                return get_SymConst_entity(ptr);
        case iro_Sel: {
@@ -1427,7 +1408,8 @@ static ir_entity *find_entity(ir_node *ptr)
  *
  * @param store  the Store node
  */
-static unsigned optimize_store(ir_node *store) {
+static unsigned optimize_store(ir_node *store)
+{
        ir_node   *ptr;
        ir_node   *mem;
        ir_entity *entity;
@@ -1442,6 +1424,7 @@ static unsigned optimize_store(ir_node *store) {
        if (entity != NULL && !(get_entity_usage(entity) & ir_usage_read)) {
                ldst_info_t *info = get_irn_link(store);
                if (info->projs[pn_Store_X_except] == NULL) {
+                       DB((dbg, LEVEL_1, "  Killing useless %+F to never read entity %+F\n", store, entity));
                        exchange(info->projs[pn_Store_M], get_Store_mem(store));
                        kill_node(store);
                        reduce_adr_usage(ptr);
@@ -1610,16 +1593,16 @@ static unsigned optimize_phi(ir_node *phi, walk_env_t *wenv)
        block = get_nodes_block(phi);
 
        /* second step: create a new memory Phi */
-       phiM = new_rd_Phi(get_irn_dbg_info(phi), current_ir_graph, block, n, inM, mode_M);
+       phiM = new_rd_Phi(get_irn_dbg_info(phi), block, n, inM, mode_M);
 
        /* third step: create a new data Phi */
-       phiD = new_rd_Phi(get_irn_dbg_info(phi), current_ir_graph, block, n, inD, mode);
+       phiD = new_rd_Phi(get_irn_dbg_info(phi), block, n, inD, mode);
 
        /* rewire memory and kill the node */
        for (i = n - 1; i >= 0; --i) {
                ir_node *proj  = projMs[i];
 
-               if(is_Proj(proj)) {
+               if (is_Proj(proj)) {
                        ir_node *store = get_Proj_pred(proj);
                        exchange(proj, inM[i]);
                        kill_node(store);
@@ -1627,19 +1610,19 @@ static unsigned optimize_phi(ir_node *phi, walk_env_t *wenv)
        }
 
        /* fourth step: create the Store */
-       store = new_rd_Store(db, current_ir_graph, block, phiM, ptr, phiD, 0);
+       store = new_rd_Store(db, block, phiM, ptr, phiD, 0);
 #ifdef DO_CACHEOPT
        co_set_irn_name(store, co_get_irn_ident(old_store));
 #endif
 
-       projM = new_rd_Proj(NULL, current_ir_graph, block, store, mode_M, pn_Store_M);
+       projM = new_rd_Proj(NULL, store, mode_M, pn_Store_M);
 
        info = get_ldst_info(store, &wenv->obst);
        info->projs[pn_Store_M] = projM;
 
        /* fifths step: repair exception flow */
        if (exc) {
-               ir_node *projX = new_rd_Proj(NULL, current_ir_graph, block, store, mode_X, pn_Store_X_except);
+               ir_node *projX = new_rd_Proj(NULL, store, mode_X, pn_Store_X_except);
 
                info->projs[pn_Store_X_except] = projX;
                info->exc_block                = exc;
@@ -1665,7 +1648,8 @@ static unsigned optimize_phi(ir_node *phi, walk_env_t *wenv)
 /**
  * walker, do the optimizations
  */
-static void do_load_store_optimize(ir_node *n, void *env) {
+static void do_load_store_optimize(ir_node *n, void *env)
+{
        walk_env_t *wenv = env;
 
        switch (get_irn_opcode(n)) {
@@ -1689,14 +1673,13 @@ static void do_load_store_optimize(ir_node *n, void *env) {
 
 /** A scc. */
 typedef struct scc {
-       ir_node *head;          /**< the head of the list */
+       ir_node *head;      /**< the head of the list */
 } scc;
 
 /** A node entry. */
 typedef struct node_entry {
        unsigned DFSnum;    /**< the DFS number of this node */
        unsigned low;       /**< the low number of this node */
-       ir_node  *header;   /**< the header of this node */
        int      in_stack;  /**< flag, set if the node is on the stack */
        ir_node  *next;     /**< link to the next node the the same scc */
        scc      *pscc;     /**< the scc of this node */
@@ -1717,7 +1700,8 @@ typedef struct loop_env {
 /**
 * Gets the node_entry of a node
 */
-static node_entry *get_irn_ne(ir_node *irn, loop_env *env) {
+static node_entry *get_irn_ne(ir_node *irn, loop_env *env)
+{
        ir_phase   *ph = &env->ph;
        node_entry *e  = phase_get_irn_data(&env->ph, irn);
 
@@ -1735,7 +1719,8 @@ static node_entry *get_irn_ne(ir_node *irn, loop_env *env) {
  * @param env   the loop environment
  * @param n     the node to push
  */
-static void push(loop_env *env, ir_node *n) {
+static void push(loop_env *env, ir_node *n)
+{
        node_entry *e;
 
        if (env->tos == ARR_LEN(env->stack)) {
@@ -1754,7 +1739,8 @@ static void push(loop_env *env, ir_node *n) {
  *
  * @return  The topmost node
  */
-static ir_node *pop(loop_env *env) {
+static ir_node *pop(loop_env *env)
+{
        ir_node *n = env->stack[--env->tos];
        node_entry *e = get_irn_ne(n, env);
 
@@ -1769,7 +1755,8 @@ static ir_node *pop(loop_env *env) {
  * @param irn           the node to check
  * @param header_block  the header block of the induction variable
  */
-static int is_rc(ir_node *irn, ir_node *header_block) {
+static int is_rc(ir_node *irn, ir_node *header_block)
+{
        ir_node *block = get_nodes_block(irn);
 
        return (block != header_block) && block_dominates(block, header_block);
@@ -1783,17 +1770,50 @@ struct phi_entry {
        phi_entry *next;
 };
 
+/**
+ * An entry in the avail set.
+ */
+typedef struct avail_entry_t {
+       ir_node *ptr;   /**< the address pointer */
+       ir_mode *mode;  /**< the load mode */
+       ir_node *load;  /**< the associated Load */
+} avail_entry_t;
+
+/**
+ * Compare two avail entries.
+ */
+static int cmp_avail_entry(const void *elt, const void *key, size_t size)
+{
+       const avail_entry_t *a = elt;
+       const avail_entry_t *b = key;
+       (void) size;
+
+       return a->ptr != b->ptr || a->mode != b->mode;
+}  /* cmp_avail_entry */
+
+/**
+ * Calculate the hash value of an avail entry.
+ */
+static unsigned hash_cache_entry(const avail_entry_t *entry)
+{
+       return get_irn_idx(entry->ptr) * 9 + HASH_PTR(entry->mode);
+}  /* hash_cache_entry */
+
 /**
  * Move loops out of loops if possible.
  *
  * @param pscc   the loop described by an SCC
  * @param env    the loop environment
  */
-static void move_loads_out_of_loops(scc *pscc, loop_env *env) {
+static void move_loads_out_of_loops(scc *pscc, loop_env *env)
+{
        ir_node   *phi, *load, *next, *other, *next_other;
        ir_entity *ent;
        int       j;
        phi_entry *phi_list = NULL;
+       set       *avail;
+
+       avail = new_set(cmp_avail_entry, 8);
 
        /* collect all outer memories */
        for (phi = pscc->head; phi != NULL; phi = next) {
@@ -1804,7 +1824,7 @@ static void move_loads_out_of_loops(scc *pscc, loop_env *env) {
                if (! is_Phi(phi))
                        continue;
 
-               assert(get_irn_mode(phi) == mode_M && "DFS geturn non-memory Phi");
+               assert(get_irn_mode(phi) == mode_M && "DFS return non-memory Phi");
 
                for (j = get_irn_arity(phi) - 1; j >= 0; --j) {
                        ir_node    *pred = get_irn_n(phi, j);
@@ -1824,6 +1844,10 @@ static void move_loads_out_of_loops(scc *pscc, loop_env *env) {
        /* no Phis no fun */
        assert(phi_list != NULL && "DFS found a loop without Phi");
 
+       /* for now, we cannot handle more than one input (only reducible cf) */
+       if (phi_list->next != NULL)
+               return;
+
        for (load = pscc->head; load; load = next) {
                ir_mode *load_mode;
                node_entry *ne = get_irn_ne(load, env);
@@ -1837,10 +1861,10 @@ static void move_loads_out_of_loops(scc *pscc, loop_env *env) {
                        if (info->projs[pn_Load_res] == NULL || info->projs[pn_Load_X_regular] != NULL || info->projs[pn_Load_X_except] != NULL)
                                continue;
 
-                       /* for now, we can only handle Load(Global) */
+                       /* for now, we can only move Load(Global) */
                        if (! is_Global(ptr))
                                continue;
-                       ent = get_Global_entity(ptr);
+                       ent       = get_Global_entity(ptr);
                        load_mode = get_Load_mode(load);
                        for (other = pscc->head; other != NULL; other = next_other) {
                                node_entry *ne = get_irn_ne(other, env);
@@ -1856,17 +1880,13 @@ static void move_loads_out_of_loops(scc *pscc, loop_env *env) {
                                        if (rel != ir_no_alias)
                                                break;
                                }
-                               /* only pure Calls are allowed here, so ignore them */
+                               /* only Phis and pure Calls are allowed here, so ignore them */
                        }
                        if (other == NULL) {
-                               ldst_info_t *ninfo;
+                               ldst_info_t *ninfo = NULL;
                                phi_entry   *pe;
                                dbg_info    *db;
 
-                               /* for now, we cannot handle more than one input */
-                               if (phi_list->next != NULL)
-                                       return;
-
                                /* yep, no aliasing Store found, Load can be moved */
                                DB((dbg, LEVEL_1, "  Found a Load that could be moved: %+F\n", load));
 
@@ -1877,16 +1897,26 @@ static void move_loads_out_of_loops(scc *pscc, loop_env *env) {
                                        ir_node *blk  = get_nodes_block(phi);
                                        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, 0);
+                                       avail_entry_t entry, *res;
+
+                                       entry.ptr  = ptr;
+                                       entry.mode = load_mode;
+                                       res = set_find(avail, &entry, sizeof(entry), hash_cache_entry(&entry));
+                                       if (res != NULL) {
+                                               irn = res->load;
+                                       } else {
+                                               irn = new_rd_Load(db, pred, get_Phi_pred(phi, pos), ptr, load_mode, 0);
+                                               entry.load = irn;
+                                               set_insert(avail, &entry, sizeof(entry), hash_cache_entry(&entry));
+                                               DB((dbg, LEVEL_1, "  Created %+F in %+F\n", irn, pred));
+                                       }
+                                       pe->load = irn;
                                        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);
+                                       ninfo->projs[pn_Load_M] = mem = new_r_Proj(irn, mode_M, pn_Load_M);
                                        set_Phi_pred(phi, pos, mem);
 
-                                       ninfo->projs[pn_Load_res] = new_r_Proj(current_ir_graph, pred, irn, load_mode, pn_Load_res);
-
-                                       DB((dbg, LEVEL_1, "  Created %+F in %+F\n", irn, pred));
+                                       ninfo->projs[pn_Load_res] = new_r_Proj(irn, load_mode, pn_Load_res);
                                }
 
                                /* now kill the old Load */
@@ -1897,6 +1927,7 @@ static void move_loads_out_of_loops(scc *pscc, loop_env *env) {
                        }
                }
        }
+       del_set(avail);
 }  /* move_loads_out_of_loops */
 
 /**
@@ -1905,7 +1936,8 @@ static void move_loads_out_of_loops(scc *pscc, loop_env *env) {
  * @param pscc  the SCC
  * @param env   the loop environment
  */
-static void process_loop(scc *pscc, loop_env *env) {
+static void process_loop(scc *pscc, loop_env *env)
+{
        ir_node *irn, *next, *header = NULL;
        node_entry *b, *h = NULL;
        int j, only_phi, num_outside, process = 0;
@@ -1919,13 +1951,12 @@ static void process_loop(scc *pscc, loop_env *env) {
                next = e->next;
                b = get_irn_ne(block, env);
 
-               if (header) {
+               if (header != NULL) {
                        if (h->POnum < b->POnum) {
                                header = block;
                                h      = b;
                        }
-               }
-               else {
+               } else {
                        header = block;
                        h      = b;
                }
@@ -1980,10 +2011,12 @@ static void process_loop(scc *pscc, loop_env *env) {
                                                /* not a memory loop */
                                                goto fail;
                                        }
-                                       if (! out_rc) {
+                                       if (out_rc == NULL) {
+                                               /* first region constant */
                                                out_rc = pred;
                                                ++num_outside;
                                        } else if (out_rc != pred) {
+                                               /* another region constant */
                                                ++num_outside;
                                        }
                                }
@@ -2003,22 +2036,20 @@ static void process_loop(scc *pscc, loop_env *env) {
                for (irn = pscc->head; irn; irn = next) {
                        node_entry *e = get_irn_ne(irn, env);
                        next = e->next;
-                       e->header = NULL;
                        exchange(irn, out_rc);
                }
                env->changes |= DF_CHANGED;
                return;
        }
 
-       /* set the header for every node in this scc */
+#ifdef DEBUG_libfirm
        for (irn = pscc->head; irn; irn = next) {
                node_entry *e = get_irn_ne(irn, env);
-               e->header = header;
                next = e->next;
                DB((dbg, LEVEL_2, " %+F,", irn));
        }
        DB((dbg, LEVEL_2, "\n"));
-
+#endif
        move_loads_out_of_loops(pscc, env);
 
 fail:
@@ -2031,7 +2062,8 @@ fail:
  * @param pscc  the SCC
  * @param env   the loop environment
  */
-static void process_scc(scc *pscc, loop_env *env) {
+static void process_scc(scc *pscc, loop_env *env)
+{
        ir_node *head = pscc->head;
        node_entry *e = get_irn_ne(head, env);
 
@@ -2138,7 +2170,8 @@ static void dfs(ir_node *irn, loop_env *env)
  * @param irg  the graph to process
  * @param env  the loop environment
  */
-static void do_dfs(ir_graph *irg, loop_env *env) {
+static void do_dfs(ir_graph *irg, loop_env *env)
+{
        ir_graph *rem = current_ir_graph;
        ir_node  *endblk, *end;
        int      i;
@@ -2174,22 +2207,13 @@ static void do_dfs(ir_graph *irg, loop_env *env) {
        current_ir_graph = rem;
 }  /* do_dfs */
 
-/**
- * Initialize new phase data. We do this always explicit, so return NULL here
- */
-static void *init_loop_data(ir_phase *ph, const ir_node *irn, void *data) {
-       (void)ph;
-       (void)irn;
-       (void)data;
-       return NULL;
-}  /* init_loop_data */
-
 /**
  * Optimize Loads/Stores in loops.
  *
  * @param irg  the graph
  */
-static int optimize_loops(ir_graph *irg) {
+static int optimize_loops(ir_graph *irg)
+{
        loop_env env;
 
        env.stack         = NEW_ARR_F(ir_node *, 128);
@@ -2197,13 +2221,13 @@ static int optimize_loops(ir_graph *irg) {
        env.nextDFSnum    = 0;
        env.POnum         = 0;
        env.changes       = 0;
-       phase_init(&env.ph, "ldstopt", irg, PHASE_DEFAULT_GROWTH, init_loop_data, NULL);
+       phase_init(&env.ph, irg, phase_irn_init_default);
 
        /* calculate the SCC's and drive loop optimization. */
        do_dfs(irg, &env);
 
        DEL_ARR_F(env.stack);
-       phase_free(&env.ph);
+       phase_deinit(&env.ph);
 
        return env.changes;
 }  /* optimize_loops */
@@ -2211,7 +2235,8 @@ static int optimize_loops(ir_graph *irg) {
 /*
  * do the load store optimization
  */
-int optimize_load_store(ir_graph *irg) {
+int optimize_load_store(ir_graph *irg)
+{
        walk_env_t env;
 
        FIRM_DBG_REGISTER(dbg, "firm.opt.ldstopt");
@@ -2260,3 +2285,8 @@ int optimize_load_store(ir_graph *irg) {
        }
        return env.changes != 0;
 }  /* optimize_load_store */
+
+ir_graph_pass_t *optimize_load_store_pass(const char *name)
+{
+       return def_graph_pass_ret(name ? name : "ldst", optimize_load_store);
+}  /* optimize_load_store_pass */