Commit 39c28e07 authored by Michael Beck's avatar Michael Beck
Browse files

- handle pure Calls like Load nodes

- remove unused code

[r16933]
parent ff3ff6be
......@@ -63,7 +63,7 @@ DEBUG_ONLY(static firm_dbg_module_t *dbg;)
#undef IMAX
#define IMAX(a,b) ((a) > (b) ? (a) : (b))
#define MAX_PROJ IMAX(pn_Load_max, pn_Store_max)
#define MAX_PROJ IMAX(IMAX(pn_Load_max, pn_Store_max), pn_Call_max)
enum changes_t {
DF_CHANGED = 1, /**< data flow changed */
......@@ -78,19 +78,11 @@ typedef struct _walk_env_t {
unsigned changes; /**< a bitmask of graph changes */
} walk_env_t;
/**
* flags for Load/Store
*/
enum ldst_flags_t {
LDST_VISITED = 1 /**< if set, this Load/Store is already visited */
};
/** A Load/Store info. */
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 */
unsigned flags; /**< flags */
unsigned visited; /**< visited counter for breaking loops */
} ldst_info_t;
......@@ -190,28 +182,20 @@ static unsigned update_exc(ldst_info_t *info, ir_node *block, int pos)
*/
static void collect_nodes(ir_node *node, void *env)
{
ir_op *op = get_irn_op(node);
ir_opcode opcode = get_irn_opcode(node);
ir_node *pred, *blk, *pred_blk;
ldst_info_t *ldst_info;
walk_env_t *wenv = env;
if (op == op_Proj) {
ir_node *adr;
ir_op *op;
pred = get_Proj_pred(node);
op = get_irn_op(pred);
if (opcode == iro_Proj) {
pred = get_Proj_pred(node);
opcode = get_irn_opcode(pred);
if (op == op_Load) {
if (opcode == iro_Load || opcode == iro_Store || opcode == iro_Call) {
ldst_info = get_ldst_info(pred, &wenv->obst);
wenv->changes |= update_projs(ldst_info, node);
if ((ldst_info->flags & LDST_VISITED) == 0) {
adr = get_Load_ptr(pred);
ldst_info->flags |= LDST_VISITED;
}
/*
* Place the Proj's to the same block as the
* predecessor Load. This is always ok and prevents
......@@ -224,30 +208,8 @@ static void collect_nodes(ir_node *node, void *env)
wenv->changes |= DF_CHANGED;
set_nodes_block(node, pred_blk);
}
} else if (op == op_Store) {
ldst_info = get_ldst_info(pred, &wenv->obst);
wenv->changes |= update_projs(ldst_info, node);
if ((ldst_info->flags & LDST_VISITED) == 0) {
adr = get_Store_ptr(pred);
ldst_info->flags |= LDST_VISITED;
}
/*
* Place the Proj's to the same block as the
* predecessor Store. This is always ok and prevents
* "non-SSA" form after optimizations if the Proj
* is in a wrong block.
*/
blk = get_nodes_block(node);
pred_blk = get_nodes_block(pred);
if (blk != pred_blk) {
wenv->changes |= DF_CHANGED;
set_nodes_block(node, pred_blk);
}
}
} else if (op == op_Block) {
} else if (opcode == iro_Block) {
int i;
for (i = get_Block_n_cfgpreds(node) - 1; i >= 0; --i) {
......@@ -274,7 +236,8 @@ static void collect_nodes(ir_node *node, void *env)
else if (is_irn_forking(pred))
bl_info->flags |= BLOCK_HAS_COND;
if (is_exc && (get_irn_op(pred) == op_Load || get_irn_op(pred) == op_Store)) {
opcode = get_irn_opcode(pred);
if (is_exc && (opcode == iro_Load || opcode == iro_Store || opcode == iro_Call)) {
ldst_info = get_ldst_info(pred, &wenv->obst);
wenv->changes |= update_exc(ldst_info, node, i);
......@@ -472,9 +435,30 @@ static int can_use_stored_value(ir_mode *old_mode, ir_mode *new_mode) {
} /* can_use_stored_value */
/**
* Follow the memory chain as long as there are only Loads
* and alias free Stores and try to replace current Load or Store
* by a previous ones.
* Check whether a Call is at least pure, ie. does only read memory.
*/
static unsigned is_Call_pure(ir_node *call) {
ir_type *call_tp = get_Call_type(call);
unsigned prop = get_method_additional_properties(call_tp);
/* check first the call type */
if ((prop & (mtp_property_const|mtp_property_pure)) == 0) {
/* try the called entity */
ir_node *ptr = get_Call_ptr(call);
if (is_SymConst(ptr) && get_SymConst_kind(ptr) == symconst_addr_ent) {
ir_entity *ent = get_SymConst_entity(ptr);
prop = get_entity_additional_properties(ent);
}
}
return (prop & (mtp_property_const|mtp_property_pure)) != 0;
} /* is_Call_pure */
/**
* Follow the memory chain as long as there are only Loads,
* alias free Stores, and constant Calls and try to replace the
* current Load by a previous ones.
* Note that in unreachable loops it might happen that we reach
* load again, as well as we can fall into a cycle.
* We break such cycles using a special visited flag.
......@@ -605,8 +589,17 @@ static unsigned follow_Mem_chain(ir_node *load, ir_node *curr) {
if (rel != no_alias)
break;
pred = skip_Proj(get_Store_mem(pred));
} else if (get_irn_op(pred) == op_Load) {
} else if (is_Load(pred)) {
pred = skip_Proj(get_Load_mem(pred));
} else if (is_Call(pred)) {
if (is_Call_pure(pred)) {
/* The called graph is at least pure, so there are no Store's
in it. We can handle it like a Load and skip it. */
pred = skip_Proj(get_Call_mem(pred));
} else {
/* there might be Store's in the graph, stop here */
break;
}
} else {
/* follow only Load chains */
break;
......@@ -1305,9 +1298,12 @@ struct phi_entry {
};
/**
* Move loops out of loops if possible
* Move loops out of loops if possible.
*
* @param pscc the loop described by an SCC
* @param env the loop environment
*/
static void move_loads_in_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;
......@@ -1374,6 +1370,7 @@ static void move_loads_in_loops(scc *pscc, loop_env *env) {
if (rel != no_alias)
break;
}
/* only pure Calls are allowed here, so ignore them */
}
if (other == NULL) {
ldst_info_t *ninfo;
......@@ -1414,7 +1411,7 @@ static void move_loads_in_loops(scc *pscc, loop_env *env) {
}
}
}
} /* move_loads_in_loops */
} /* move_loads_out_of_loops */
/**
* Process a loop SCC.
......@@ -1458,8 +1455,15 @@ static void process_loop(scc *pscc, loop_env *env) {
next = e->next;
switch (get_irn_opcode(irn)) {
case iro_Call:
if (is_Call_pure(irn)) {
/* pure calls can be treated like loads */
only_phi = 0;
break;
}
/* non-pure calls must be handle like may-alias Stores */
goto fail;
case iro_CopyB:
/* cannot handle Calls or CopyB yet */
/* cannot handle CopyB yet */
goto fail;
case iro_Load:
process = 1;
......@@ -1529,7 +1533,7 @@ static void process_loop(scc *pscc, loop_env *env) {
}
DB((dbg, LEVEL_2, "\n"));
move_loads_in_loops(pscc, env);
move_loads_out_of_loops(pscc, env);
fail:
;
......
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