/*
- * Copyright (C) 1995-2007 University of Karlsruhe. All right reserved.
+ * Copyright (C) 1995-2011 University of Karlsruhe. All right reserved.
*
* This file is part of libFirm.
*
* @file
* @brief Optimization of function calls.
* @author Michael Beck
- * @version $Id$
*/
-#ifdef HAVE_CONFIG_H
#include "config.h"
-#endif
-#include <adt/raw_bitset.h>
-
-#include "funccall_t.h"
+#include "opt_init.h"
+#include <stdbool.h>
#include "irnode_t.h"
#include "irgraph_t.h"
#include "irgmod.h"
#include "irgwalk.h"
-#include "irvrfy.h"
#include "dbginfo_t.h"
#include "irflag_t.h"
+#include "irloop_t.h"
#include "ircons.h"
+#include "iredges_t.h"
+#include "irpass_t.h"
+#include "iroptimize.h"
+#include "analyze_irg_args.h"
#include "irhooks.h"
+#include "raw_bitset.h"
#include "debug.h"
DEBUG_ONLY(static firm_dbg_module_t *dbg;)
/**
- * The walker environment for rem_mem_from_const_fkt_calls
+ * The walker environment for updating function calls.
*/
-typedef struct _env_t {
- unsigned n_calls_SymConst;
- unsigned n_calls_Sel;
- ir_node *const_call_list; /**< The list of all const function calls that will be changed. */
- ir_node *pure_call_list; /**< The list of all pure function calls that will be changed. */
- ir_node *proj_list; /**< The list of all potential Proj nodes that must be fixed. */
+typedef struct env_t {
+ ir_node *float_const_call_list; /**< The list of all floating const function calls that will be changed. */
+ ir_node *nonfloat_const_call_list; /**< The list of all non-floating const function calls that will be changed. */
+ ir_node *pure_call_list; /**< The list of all pure function calls that will be changed. */
+ ir_node *nothrow_call_list; /**< The list of all nothrow function calls that will be changed. */
+ ir_node *proj_list; /**< The list of all potential Proj nodes that must be fixed. */
} env_t;
/** Ready IRG's are marked in the ready set. */
static unsigned *busy_set;
/**
- * We misuse the mtp_temporary flag as temporary here.
- * The is ok, as we cannot set or get it anyway.
- */
-#define mtp_temporary mtp_property_inherited
-
-/**
- * Collect all calls to const and pure functions
+ * Walker: Collect all calls to const and pure functions
* to lists. Collect all Proj(Call) nodes into a Proj list.
*/
-static void collect_calls(ir_node *node, void *env) {
- env_t *ctx = env;
- ir_node *call, *ptr;
- ir_entity *ent;
- unsigned mode;
+static void collect_const_and_pure_calls(ir_node *node, void *env)
+{
+ env_t *ctx = (env_t*)env;
if (is_Call(node)) {
- call = node;
+ ir_node *call = node;
/* set the link to NULL for all non-const/pure calls */
set_irn_link(call, NULL);
- ptr = get_Call_ptr(call);
- if (is_SymConst(ptr) && get_SymConst_kind(ptr) == symconst_addr_ent) {
- ent = get_SymConst_entity(ptr);
-
- mode = get_entity_additional_properties(ent);
- if ((mode & (mtp_property_const|mtp_property_pure)) == 0)
- return;
- ++ctx->n_calls_SymConst;
- } else if (get_opt_closed_world() &&
- is_Sel(ptr) &&
- get_irg_callee_info_state(current_ir_graph) == irg_callee_info_consistent) {
- /* If all possible callees are const functions, we can remove the memory edge. */
- int i, n_callees = get_Call_n_callees(call);
- if (n_callees == 0) {
- /* This is kind of strange: dying code or a Call that will raise an exception
- when executed as there is no implementation to call. So better not
- optimize. */
- return;
- }
+ ir_node *ptr = get_Call_ptr(call);
+ if (!is_SymConst_addr_ent(ptr))
+ return;
- /* note that const function are a subset of pure ones */
- mode = mtp_property_const | mtp_property_pure;
- for (i = 0; i < n_callees; ++i) {
- ent = get_Call_callee(call, i);
- if (ent == unknown_entity) {
- /* we don't know which entity is called here */
- return;
- }
- mode &= get_entity_additional_properties(ent);
- if (mode == 0)
- return;
- }
- ++ctx->n_calls_Sel;
- } else
+ ir_entity *ent = get_SymConst_entity(ptr);
+
+ unsigned prop = get_entity_additional_properties(ent);
+ if ((prop & (mtp_property_const|mtp_property_pure)) == 0)
return;
/* ok, if we get here we found a call to a const or a pure function */
- if (mode & mtp_property_pure) {
+ if (prop & mtp_property_pure) {
set_irn_link(call, ctx->pure_call_list);
ctx->pure_call_list = call;
} else {
- set_irn_link(call, ctx->const_call_list);
- ctx->const_call_list = call;
+ if (prop & mtp_property_has_loop) {
+ set_irn_link(call, ctx->nonfloat_const_call_list);
+ ctx->nonfloat_const_call_list = call;
+ } else {
+ set_irn_link(call, ctx->float_const_call_list);
+ ctx->float_const_call_list = call;
+ }
}
} else if (is_Proj(node)) {
/*
* Collect all memory and exception Proj's from
* calls.
*/
- call = get_Proj_pred(node);
- if (! is_Call(call))
+ ir_node *call = get_Proj_pred(node);
+ if (!is_Call(call))
return;
/* collect the Proj's in the Proj list */
switch (get_Proj_proj(node)) {
- case pn_Call_M_regular:
+ case pn_Call_M:
case pn_Call_X_except:
- case pn_Call_M_except:
+ case pn_Call_X_regular:
set_irn_link(node, ctx->proj_list);
ctx->proj_list = node;
break;
break;
}
}
-} /* collect_calls */
+}
/**
* Fix the list of collected Calls.
*
- * @param irg the graph that contained calls to pure functions
- * @param call_list the list of all call sites of const functions
- * @param proj_list the list of all memory/exception Proj's of this call sites
+ * @param irg the graph that contained calls to pure functions
+ * @param ctx context
*/
-static void fix_const_call_list(ir_graph *irg, ir_node *call_list, ir_node *proj_list) {
- ir_node *call, *next, *mem, *proj;
- int exc_changed = 0;
- ir_graph *rem = current_ir_graph;
-
- current_ir_graph = irg;
+static void fix_const_call_lists(ir_graph *irg, env_t *ctx)
+{
+ bool exc_changed = false;
- /* First step: fix all calls by removing it's memory input.
- It's original memory input is preserved in their link fields. */
- for (call = call_list; call; call = next) {
- next = get_irn_link(call);
- mem = get_Call_mem(call);
+ /* First step: fix all calls by removing their memory input and let
+ * them floating.
+ * The original memory input is preserved in their link fields. */
+ ir_node *next;
+ for (ir_node *call = ctx->float_const_call_list; call != NULL; call = next) {
+ next = (ir_node*)get_irn_link(call);
+ ir_node *mem = get_Call_mem(call);
set_irn_link(call, mem);
set_Call_mem(call, get_irg_no_mem(irg));
/*
- * Sorrily we cannot simply set the node to 'float'.
+ * Unfortunately we cannot simply set the node to 'float'.
* There is a reason for that:
*
* - The call might be inside a loop/if that is NOT entered
* observable states...
*/
- /* finally, this call can float
- set_irn_pinned(call, op_pin_state_floats); */
+ /* finally, this call can float */
+ set_irn_pinned(call, op_pin_state_floats);
hook_func_call(irg, call);
}
- /* Second step: fix all Proj's */
- for (proj = proj_list; proj; proj = next) {
- next = get_irn_link(proj);
- call = get_Proj_pred(proj);
- mem = get_irn_link(call);
+ /* Last step: fix all Proj's */
+ for (ir_node *proj = ctx->proj_list; proj != NULL; proj = next) {
+ next = (ir_node*)get_irn_link(proj);
+ ir_node *call = get_Proj_pred(proj);
+ ir_node *mem = (ir_node*)get_irn_link(call);
/* beware of calls in the pure call list */
- if (! mem || get_irn_op(mem) == op_Call)
+ if (!mem || is_Call(mem))
continue;
assert(get_irn_mode(mem) == mode_M);
switch (get_Proj_proj(proj)) {
- case pn_Call_M_regular: {
+ case pn_Call_M: {
/* in dead code there might be cycles where proj == mem */
if (proj != mem)
exchange(proj, mem);
- } break;
+ break;
+ }
case pn_Call_X_except:
- case pn_Call_M_except:
- exc_changed = 1;
- exchange(proj, get_irg_bad(irg));
+ exc_changed = true;
+ exchange(proj, new_r_Bad(irg, mode_X));
break;
+ case pn_Call_X_regular: {
+ ir_node *block = get_nodes_block(call);
+ exc_changed = true;
+ exchange(proj, new_r_Jmp(block));
+ break;
+ }
default:
- ;
+ break;
}
}
- /* changes were done ... */
- set_irg_outs_inconsistent(irg);
- set_irg_loopinfo_state(irg, loopinfo_cf_inconsistent);
+ if (exc_changed) {
+ /* ... including exception edges */
+ clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE
+ | IR_GRAPH_PROPERTY_CONSISTENT_LOOPINFO);
+ }
+}
+
+/**
+ * Walker: Collect all calls to nothrow functions
+ * to lists. Collect all Proj(Call) nodes into a Proj list.
+ */
+static void collect_nothrow_calls(ir_node *node, void *env)
+{
+ env_t *ctx = (env_t*)env;
+
+ if (is_Call(node)) {
+ ir_node *call = node;
+ /* set the link to NULL for all non-const/pure calls */
+ set_irn_link(call, NULL);
+ ir_node *ptr = get_Call_ptr(call);
+ if (!is_SymConst_addr_ent(ptr))
+ return;
+
+ ir_entity *ent = get_SymConst_entity(ptr);
+
+ unsigned prop = get_entity_additional_properties(ent);
+ if ((prop & mtp_property_nothrow) == 0)
+ return;
+
+ /* ok, if we get here we found a call to a nothrow function */
+ set_irn_link(call, ctx->nothrow_call_list);
+ ctx->nothrow_call_list = call;
+ } else if (is_Proj(node)) {
+ /*
+ * Collect all memory and exception Proj's from
+ * calls.
+ */
+ ir_node *call = get_Proj_pred(node);
+ if (! is_Call(call))
+ return;
+
+ /* collect the Proj's in the Proj list */
+ switch (get_Proj_proj(node)) {
+ case pn_Call_M:
+ case pn_Call_X_except:
+ case pn_Call_X_regular:
+ set_irn_link(node, ctx->proj_list);
+ ctx->proj_list = node;
+ break;
+ default:
+ break;
+ }
+ }
+}
+
+/**
+ * Fix the list of collected nothrow Calls.
+ *
+ * @param irg the graph that contained calls to pure functions
+ * @param call_list the list of all call sites of const functions
+ * @param proj_list the list of all memory/exception Proj's of this call sites
+ */
+static void fix_nothrow_call_list(ir_graph *irg, ir_node *call_list,
+ ir_node *proj_list)
+{
+ bool exc_changed = false;
+
+ /* First step: go through the list of calls and mark them. */
+ ir_node *next;
+ for (ir_node *call = call_list; call; call = next) {
+ next = (ir_node*)get_irn_link(call);
+
+ /* current_ir_graph is in memory anyway, so it's a good marker */
+ set_irn_link(call, ¤t_ir_graph);
+ hook_func_call(irg, call);
+ }
+
+ /* Second step: Remove all exception Proj's */
+ for (ir_node *proj = proj_list; proj; proj = next) {
+ next = (ir_node*)get_irn_link(proj);
+ ir_node *call = get_Proj_pred(proj);
+
+ /* handle only marked calls */
+ if (get_irn_link(call) != ¤t_ir_graph)
+ continue;
+
+ /* kill any exception flow */
+ switch (get_Proj_proj(proj)) {
+ case pn_Call_X_except:
+ exc_changed = true;
+ exchange(proj, new_r_Bad(irg, mode_X));
+ break;
+ case pn_Call_X_regular: {
+ ir_node *block = get_nodes_block(call);
+ exc_changed = true;
+ exchange(proj, new_r_Jmp(block));
+ break;
+ }
+ default:
+ break;
+ }
+ }
+
+ /* changes were done ... */
if (exc_changed) {
/* ... including exception edges */
- set_irg_doms_inconsistent(irg);
+ clear_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_DOMINANCE
+ | IR_GRAPH_PROPERTY_CONSISTENT_LOOPINFO);
}
- current_ir_graph = rem;
-} /* fix_call_list */
+}
/* marking */
-#define SET_IRG_READY(irg) rbitset_set(ready_set, get_irg_idx(irg))
+#define SET_IRG_READY(irg) rbitset_set(ready_set, get_irg_idx(irg))
#define IS_IRG_READY(irg) rbitset_is_set(ready_set, get_irg_idx(irg))
#define SET_IRG_BUSY(irg) rbitset_set(busy_set, get_irg_idx(irg))
#define CLEAR_IRG_BUSY(irg) rbitset_clear(busy_set, get_irg_idx(irg))
#define IS_IRG_BUSY(irg) rbitset_is_set(busy_set, get_irg_idx(irg))
/* forward */
-static unsigned check_const_or_pure_function(ir_graph *irg, int top);
+static mtp_additional_properties check_const_or_pure_function(ir_graph *irg, bool top);
/**
- * Calculate the bigger mode of two. Handle the temporary flag right.
+ * Calculate the bigger property of two. Handle the temporary flag right.
*/
-static unsigned mode_max(unsigned a, unsigned b) {
- unsigned r, t = (a | b) & mtp_temporary;
+static mtp_additional_properties max_property(mtp_additional_properties a,
+ mtp_additional_properties b)
+{
+ mtp_additional_properties t = (a | b) & mtp_temporary;
a &= ~mtp_temporary;
b &= ~mtp_temporary;
if (a == mtp_no_property || b == mtp_no_property)
return mtp_no_property;
- r = a > b ? a : b;
+ mtp_additional_properties r = a > b ? a : b;
return r | t;
}
* the mtp_property.
*
* @return mtp_property_const if only calls of const functions are detected
- * mtp_property_pure if only Loads and const/pure
- * calls detected
- * mtp_no_property else
+ * mtp_property_pure if only Loads and const/pure calls detected
+ * mtp_no_property else
*/
-static unsigned _follow_mem(ir_node *node) {
- unsigned m, mode = mtp_property_const;
- ir_node *ptr;
- int i;
+static mtp_additional_properties follow_mem_(ir_node *node)
+{
+ mtp_additional_properties mode = mtp_property_const;
for (;;) {
if (mode == mtp_no_property)
return mtp_no_property;
- if (irn_visited(node))
+ if (irn_visited_else_mark(node))
return mode;
- mark_irn_visited(node);
-
switch (get_irn_opcode(node)) {
case iro_Proj:
node = get_Proj_pred(node);
case iro_Phi:
case iro_Sync:
/* do a dfs search */
- for (i = get_irn_arity(node) - 1; i >= 0; --i) {
- m = _follow_mem(get_irn_n(node, i));
- mode = mode_max(mode, m);
+ for (int i = get_irn_arity(node) - 1; i >= 0; --i) {
+ mtp_additional_properties m = follow_mem_(get_irn_n(node, i));
+ mode = max_property(mode, m);
if (mode == mtp_no_property)
return mtp_no_property;
}
/* Beware volatile Loads are NOT allowed in pure functions. */
if (get_Load_volatility(node) == volatility_is_volatile)
return mtp_no_property;
- mode = mode_max(mode, mtp_property_pure);
+ mode = max_property(mode, mtp_property_pure);
node = get_Load_mem(node);
break;
- case iro_Call:
+ case iro_Call: {
/* A call is only tolerable if its either constant or pure. */
- ptr = get_Call_ptr(node);
- if (get_irn_op(ptr) == op_SymConst &&
- get_SymConst_kind(ptr) == symconst_addr_ent) {
- ir_entity *ent = get_SymConst_entity(ptr);
- ir_graph *irg = get_entity_irg(ent);
-
- if (irg == current_ir_graph) {
- /* A self-recursive call. The mode did not depend on this call. */
- } else if (irg == NULL) {
- m = get_entity_additional_properties(ent) & (mtp_property_const|mtp_property_pure);
- mode = mode_max(mode, m);
- } else if (irg != NULL) {
- /* we have a graph, analyze it. */
- m = check_const_or_pure_function(irg, /*top=*/0);
- mode = mode_max(mode, m);
- }
- } else
+ ir_node *ptr = get_Call_ptr(node);
+ if (!is_SymConst_addr_ent(ptr))
return mtp_no_property;
+
+ ir_entity *ent = get_SymConst_entity(ptr);
+ ir_graph *irg = get_entity_irg(ent);
+
+ mtp_additional_properties m;
+ if (irg == NULL) {
+ m = get_entity_additional_properties(ent) & (mtp_property_const|mtp_property_pure);
+ mode = max_property(mode, m);
+ } else {
+ /* we have a graph, analyze it. */
+ m = check_const_or_pure_function(irg, false);
+ mode = max_property(mode, m);
+ }
node = get_Call_mem(node);
break;
+ }
default:
return mtp_no_property;
}
}
-} /* _follow_mem */
+}
/**
* Follow the memory chain starting at node and determine
* mtp_property_pure if only Loads and const/pure calls detected
* mtp_no_property else
*/
-static unsigned follow_mem(ir_node *node, unsigned mode) {
- unsigned m;
-
- m = _follow_mem(node);
- return mode_max(mode, m);
-} /* follow_mem */
+static mtp_additional_properties follow_mem(ir_node *node, mtp_additional_properties mode)
+{
+ mtp_additional_properties m = follow_mem_(node);
+ return max_property(mode, m);
+}
-/*
- * Check if a graph represents a const function.
+/**
+ * Check if a graph represents a const or a pure function.
*
- * @param irg the graph
- * @param top top call
+ * @param irg the graph to check
+ * @param top if set, this is the top call
*/
-static unsigned check_const_or_pure_function(ir_graph *irg, int top) {
- ir_node *end, *endbl;
- int j;
- unsigned mode = get_irg_additional_properties(irg);
- ir_graph *rem = current_ir_graph;
+static mtp_additional_properties check_const_or_pure_function(ir_graph *irg, bool top)
+{
+ ir_entity *entity = get_irg_entity(irg);
+ ir_type *type = get_entity_type(entity);
+ size_t n_params = get_method_n_params(type);
+ mtp_additional_properties may_be_const = mtp_property_const;
+ mtp_additional_properties prop = get_entity_additional_properties(entity);
+
+ /* libfirm handles aggregate parameters by passing around pointers to
+ * stuff in memory, so if we have compound parameters we are never const */
+ for (size_t i = 0; i < n_params; ++i) {
+ ir_type *param = get_method_param_type(type, i);
+ if (is_compound_type(param)) {
+ prop &= ~mtp_property_const;
+ may_be_const = mtp_no_property;
+ }
+ }
- if (mode & mtp_property_const) {
+ if (prop & mtp_property_const) {
/* already marked as a const function */
return mtp_property_const;
}
- if (mode & mtp_property_pure) {
+ if (prop & mtp_property_pure) {
/* already marked as a pure function */
return mtp_property_pure;
}
return mtp_no_property;
}
if (IS_IRG_BUSY(irg)) {
- /* we are still evaluate this method. Be optimistic,
- return the best possible so far but mark the result as temporary. */
- return mtp_temporary | mtp_property_const;
+ /* We are still evaluate this method.
+ * The function (indirectly) calls itself and thus may not terminate. */
+ return mtp_no_property;
}
SET_IRG_BUSY(irg);
- end = get_irg_end(irg);
- endbl = get_nodes_block(end);
- mode = mtp_property_const;
-
- current_ir_graph = irg;
+ ir_node *end = get_irg_end(irg);
+ ir_node *endbl = get_nodes_block(end);
+ prop = may_be_const;
+ ir_reserve_resources(irg, IR_RESOURCE_IRN_VISITED);
inc_irg_visited(irg);
- /* mark the initial mem: recursion of follow_mem stops here */
+ /* mark the initial mem: recursion of follow_mem() stops here */
mark_irn_visited(get_irg_initial_mem(irg));
/* visit every Return */
- for (j = get_Block_n_cfgpreds(endbl) - 1; j >= 0; --j) {
- ir_node *node = get_Block_cfgpred(endbl, j);
- ir_op *op = get_irn_op(node);
- ir_node *mem;
+ for (int j = get_Block_n_cfgpreds(endbl) - 1; j >= 0; --j) {
+ ir_node *node = get_Block_cfgpred(endbl, j);
+ unsigned code = get_irn_opcode(node);
/* Bad nodes usually do NOT produce anything, so it's ok */
- if (op == op_Bad)
+ if (code == iro_Bad)
continue;
- if (op == op_Return) {
- mem = get_Return_mem(node);
+ if (code == iro_Return) {
+ ir_node *mem = get_Return_mem(node);
/* Bad nodes usually do NOT produce anything, so it's ok */
if (is_Bad(mem))
continue;
if (mem != get_irg_initial_mem(irg))
- mode = mode_max(mode, follow_mem(mem, mode));
+ prop = max_property(prop, follow_mem(mem, prop));
} else {
/* Exception found. Cannot be const or pure. */
- mode = mtp_no_property;
+ prop = mtp_no_property;
break;
}
- if (mode == mtp_no_property)
+ if (prop == mtp_no_property)
break;
}
- if (mode != mtp_no_property) {
+ if (prop != mtp_no_property) {
/* check, if a keep-alive exists */
- for (j = get_End_n_keepalives(end) - 1; j >= 0; --j) {
- ir_node *mem = get_End_keepalive(end, j);
+ for (int j = get_End_n_keepalives(end) - 1; j >= 0; --j) {
+ ir_node *kept = get_End_keepalive(end, j);
+
+ if (is_Block(kept)) {
+ prop = mtp_no_property;
+ break;
+ }
- if (mode_M != get_irn_mode(mem))
+ if (mode_M != get_irn_mode(kept))
continue;
- mode = mode_max(mode, follow_mem(mem, mode));
- if (mode == mtp_no_property)
+ prop = max_property(prop, follow_mem(kept, prop));
+ if (prop == mtp_no_property)
break;
}
}
- if (mode != mtp_no_property) {
- if (top || (mode & mtp_temporary) == 0) {
- /* We use the temporary flag here to mark optimistic result.
- Set the property only if we are sure that it does NOT base on
- temporary results OR if we are at top-level. */
- set_irg_additional_property(irg, mode & ~mtp_temporary);
- SET_IRG_READY(irg);
+ if (top) {
+ /* Set the property only if we are at top-level. */
+ if (prop != mtp_no_property) {
+ add_entity_additional_properties(entity, prop);
}
- }
- if (top)
SET_IRG_READY(irg);
+ }
CLEAR_IRG_BUSY(irg);
- current_ir_graph = rem;
- return mode;
-} /* check_const_or_pure_function */
+ ir_free_resources(irg, IR_RESOURCE_IRN_VISITED);
+ return prop;
+}
/**
* Handle calls to const functions.
+ *
+ * @param ctx context
*/
-static void handle_const_Calls(env_t *ctx) {
- int i;
+static void handle_const_Calls(env_t *ctx)
+{
+ /* all calls of const functions can be transformed */
+ size_t n = get_irp_n_irgs();
+ for (size_t i = 0; i < n; ++i) {
+ ir_graph *irg = get_irp_irg(i);
- ctx->n_calls_SymConst = 0;
- ctx->n_calls_Sel = 0;
+ ctx->float_const_call_list = NULL;
+ ctx->nonfloat_const_call_list = NULL;
+ ctx->pure_call_list = NULL;
+ ctx->proj_list = NULL;
+ ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
+ irg_walk_graph(irg, NULL, collect_const_and_pure_calls, ctx);
+ fix_const_call_lists(irg, ctx);
+ ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
+
+ confirm_irg_properties(irg,
+ IR_GRAPH_PROPERTIES_CONTROL_FLOW
+ | IR_GRAPH_PROPERTY_ONE_RETURN
+ | IR_GRAPH_PROPERTY_MANY_RETURNS);
+ }
+}
+
+/**
+ * Handle calls to nothrow functions.
+ *
+ * @param ctx context
+ */
+static void handle_nothrow_Calls(env_t *ctx)
+{
/* all calls of const functions can be transformed */
- for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
+ size_t n = get_irp_n_irgs();
+ for (size_t i = 0; i < n; ++i) {
ir_graph *irg = get_irp_irg(i);
- ctx->const_call_list = NULL;
- ctx->pure_call_list = NULL;
- ctx->proj_list = NULL;
- irg_walk_graph(irg, NULL, collect_calls, ctx);
+ ctx->nothrow_call_list = NULL;
+ ctx->proj_list = NULL;
+
+ ir_reserve_resources(irg, IR_RESOURCE_IRN_LINK);
+ irg_walk_graph(irg, NULL, collect_nothrow_calls, ctx);
- if (ctx->const_call_list)
- fix_const_call_list(irg, ctx->const_call_list, ctx->proj_list);
+ if (ctx->nothrow_call_list)
+ fix_nothrow_call_list(irg, ctx->nothrow_call_list, ctx->proj_list);
+ ir_free_resources(irg, IR_RESOURCE_IRN_LINK);
}
-} /* handle_const_Calls */
+}
-/*
- * optimize function calls by handling const functions
+/**
+ * Check, whether a given node represents a return value of
+ * a malloc like function (ie, new heap allocated memory).
+ *
+ * @param node the node to check
+ */
+static bool is_malloc_call_result(const ir_node *node)
+{
+ if (is_Alloc(node) && get_Alloc_where(node) == heap_alloc) {
+ /* Firm style high-level allocation */
+ return true;
+ }
+ /* TODO: check mtp_malloc */
+ return false;
+}
+
+/**
+ * Update a property depending on a call property.
+ */
+static mtp_additional_properties update_property(mtp_additional_properties orig_prop, mtp_additional_properties call_prop)
+{
+ mtp_additional_properties t = (orig_prop | call_prop) & mtp_temporary;
+ mtp_additional_properties r = orig_prop & call_prop;
+ return r | t;
+}
+
+/**
+ * Check if a node is stored.
*/
-void optimize_funccalls(int force_run)
+static bool is_stored(const ir_node *n)
{
- int i, n;
- unsigned num_const = 0;
- unsigned num_pure = 0;
+ const ir_node *ptr;
+ foreach_out_edge(n, edge) {
+ const ir_node *succ = get_edge_src_irn(edge);
+
+ switch (get_irn_opcode(succ)) {
+ case iro_Return:
+ case iro_Load:
+ case iro_Cmp:
+ /* ok */
+ break;
+ case iro_Store:
+ if (get_Store_value(succ) == n)
+ return true;
+ /* ok if its only the address input */
+ break;
+ case iro_Sel:
+ case iro_Cast:
+ case iro_Confirm:
+ if (is_stored(succ))
+ return true;
+ break;
+ case iro_Call:
+ ptr = get_Call_ptr(succ);
+ if (is_SymConst_addr_ent(ptr)) {
+ ir_entity *ent = get_SymConst_entity(ptr);
+ size_t i;
+
+ /* we know the called entity */
+ for (i = get_Call_n_params(succ); i > 0;) {
+ if (get_Call_param(succ, --i) == n) {
+ /* n is the i'th param of the call */
+ if (get_method_param_access(ent, i) & ptr_access_store) {
+ /* n is store in ent */
+ return true;
+ }
+ }
+ }
+ } else {
+ /* unknown call address */
+ return true;
+ }
+ break;
+ default:
+ /* bad, potential alias */
+ return true;
+ }
+ }
+ return false;
+}
+
+/**
+ * Check that the return value of an irg is not stored anywhere.
+ *
+ * return ~mtp_property_malloc if return values are stored, ~0 else
+ */
+static mtp_additional_properties check_stored_result(ir_graph *irg)
+{
+ ir_node *end_blk = get_irg_end_block(irg);
+ mtp_additional_properties res = ~mtp_no_property;
+
+ assure_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_OUT_EDGES);
+
+ for (int i = get_Block_n_cfgpreds(end_blk) - 1; i >= 0; --i) {
+ ir_node *pred = get_Block_cfgpred(end_blk, i);
+
+ if (! is_Return(pred))
+ continue;
+ for (size_t j = get_Return_n_ress(pred); j > 0;) {
+ const ir_node *irn = get_Return_res(pred, --j);
+
+ if (is_stored(irn)) {
+ /* bad, might create an alias */
+ res = ~mtp_property_malloc;
+ goto finish;
+ }
+ }
+ }
+finish:
+ confirm_irg_properties(irg, IR_GRAPH_PROPERTIES_ALL);
+ return res;
+}
+
+/**
+ * Check if a graph represents a nothrow or a malloc function.
+ *
+ * @param irg the graph to check
+ * @param top if set, this is the top call
+ */
+static mtp_additional_properties check_nothrow_or_malloc(ir_graph *irg, bool top)
+{
+ mtp_additional_properties curr_prop
+ = mtp_property_malloc | mtp_property_nothrow;
+
+ ir_entity *ent = get_irg_entity(irg);
+ if (IS_IRG_READY(irg)) {
+ /* already checked */
+ return get_entity_additional_properties(ent);
+ }
+ if (IS_IRG_BUSY(irg)) {
+ /* we are still evaluate this method. Be optimistic,
+ return the best possible so far but mark the result as temporary. */
+ return mtp_temporary | mtp_property_malloc | mtp_property_nothrow;
+ }
+ SET_IRG_BUSY(irg);
+
+ ir_type *mtp = get_entity_type(ent);
+ if (get_method_n_ress(mtp) <= 0)
+ curr_prop &= ~mtp_property_malloc;
+
+ ir_node *end_blk = get_irg_end_block(irg);
+ for (int i = get_Block_n_cfgpreds(end_blk) - 1; i >= 0; --i) {
+ ir_node *pred = get_Block_cfgpred(end_blk, i);
+
+ if (is_Return(pred)) {
+ if (curr_prop & mtp_property_malloc) {
+ /* check, if malloc is called here */
+ for (size_t j = get_Return_n_ress(pred); j > 0;) {
+ ir_node *res = get_Return_res(pred, --j);
+
+ /* skip Confirms and Casts */
+ res = skip_HighLevel_ops(res);
+ /* skip Proj's */
+ while (is_Proj(res))
+ res = get_Proj_pred(res);
+ if (is_malloc_call_result(res)) {
+ /* ok, this is a malloc */
+ } else if (is_Call(res)) {
+ ir_node *ptr = get_Call_ptr(res);
+
+ if (is_SymConst_addr_ent(ptr)) {
+ /* a direct call */
+ ir_entity *ent = get_SymConst_entity(ptr);
+ ir_graph *callee = get_entity_irg(ent);
+
+ if (callee == irg) {
+ /* A self-recursive call. The property did not depend on this call. */
+ } else if (callee != NULL) {
+ mtp_additional_properties prop = check_nothrow_or_malloc(callee, false);
+ curr_prop = update_property(curr_prop, prop);
+ } else {
+ curr_prop = update_property(curr_prop, get_entity_additional_properties(ent));
+ }
+ } else {
+ /* unknown call */
+ curr_prop &= ~mtp_property_malloc;
+ }
+ } else {
+ /* unknown return value */
+ curr_prop &= ~mtp_property_malloc;
+ }
+ }
+ }
+ } else if (curr_prop & mtp_property_nothrow) {
+ /* exception flow detected */
+ pred = skip_Proj(pred);
+
+ if (is_Call(pred)) {
+ ir_node *ptr = get_Call_ptr(pred);
+
+ if (is_SymConst_addr_ent(ptr)) {
+ /* a direct call */
+ ir_entity *ent = get_SymConst_entity(ptr);
+ ir_graph *callee = get_entity_irg(ent);
+
+ if (callee == irg) {
+ /* A self-recursive call. The property did not depend on this call. */
+ } else if (callee != NULL) {
+ /* Note: we check here for nothrow only, so do NOT reset the malloc property */
+ mtp_additional_properties prop = check_nothrow_or_malloc(callee, false) | mtp_property_malloc;
+ curr_prop = update_property(curr_prop, prop);
+ } else {
+ if ((get_entity_additional_properties(ent) & mtp_property_nothrow) == 0)
+ curr_prop &= ~mtp_property_nothrow;
+ }
+ } else {
+ /* unknown call */
+ curr_prop &= ~mtp_property_nothrow;
+ }
+ } else {
+ /* real exception flow possible. */
+ curr_prop &= ~mtp_property_nothrow;
+ }
+ }
+ if ((curr_prop & ~mtp_temporary) == mtp_no_property) {
+ /* no need to search further */
+ break;
+ }
+ }
+
+ if (curr_prop & mtp_property_malloc) {
+ /* Note that the malloc property means not only return newly allocated
+ * memory, but also that this memory is ALIAS FREE.
+ * To ensure that, we do NOT allow that the returned memory is somewhere
+ * stored. */
+ curr_prop &= check_stored_result(irg);
+ }
+
+ if (curr_prop != mtp_no_property
+ && (top || (curr_prop & mtp_temporary) == 0)) {
+ /* We use the temporary flag here to mark an optimistic result.
+ * Set the property only if we are sure that it does NOT base on
+ * temporary results OR if we are at top-level. */
+ add_entity_additional_properties(ent, curr_prop & ~mtp_temporary);
+ SET_IRG_READY(irg);
+ }
+ if (top)
+ SET_IRG_READY(irg);
+ CLEAR_IRG_BUSY(irg);
+ return curr_prop;
+}
+
+/**
+ * When a function was detected as "const", it might be moved out of loops.
+ * This might be dangerous if the graph can contain endless loops.
+ */
+static void check_for_possible_endless_loops(ir_graph *irg)
+{
+ assure_irg_properties(irg, IR_GRAPH_PROPERTY_CONSISTENT_LOOPINFO);
+
+ ir_loop *root_loop = get_irg_loop(irg);
+ if (root_loop->flags & loop_outer_loop) {
+ ir_entity *ent = get_irg_entity(irg);
+ add_entity_additional_properties(ent, mtp_property_has_loop);
+ }
+
+ confirm_irg_properties(irg, IR_GRAPH_PROPERTIES_ALL);
+}
+
+void optimize_funccalls(void)
+{
/* prepare: mark all graphs as not analyzed */
- n = get_irp_last_idx();
- ready_set = rbitset_malloc(n);
- busy_set = rbitset_malloc(n);
+ size_t last_idx = get_irp_last_idx();
+ ready_set = rbitset_malloc(last_idx);
+ busy_set = rbitset_malloc(last_idx);
- /* first step: detect, which functions are const, i.e. do NOT touch any memory */
- DBG((dbg, LEVEL_2, "Detecting const and pure properties ...\n"));
- for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
- ir_graph *irg = get_irp_irg(i);
- unsigned mode = check_const_or_pure_function(irg, /*top=*/1);
-
- if (mode & mtp_property_const) {
- ++num_const;
- DBG((dbg, LEVEL_2, "%+F has the const property\n", irg));
- } else if (mode & mtp_property_pure) {
- ++num_pure;
- DBG((dbg, LEVEL_2, "%+F has the pure property\n", irg));
+ /* first step: detect, which functions are nothrow or malloc */
+ DB((dbg, LEVEL_2, "Detecting nothrow and malloc properties ...\n"));
+ for (size_t i = 0, n = get_irp_n_irgs(); i < n; ++i) {
+ ir_graph *irg = get_irp_irg(i);
+ unsigned prop = check_nothrow_or_malloc(irg, true);
+
+ if (prop & mtp_property_nothrow) {
+ DB((dbg, LEVEL_2, "%+F has the nothrow property\n", irg));
+ } else if (prop & mtp_property_malloc) {
+ DB((dbg, LEVEL_2, "%+F has the malloc property\n", irg));
}
}
- if (force_run || num_const > 0) {
- env_t ctx;
+ /* second step: remove exception edges: this must be done before the
+ detection of const and pure functions take place. */
+ env_t ctx;
+ handle_nothrow_Calls(&ctx);
+
+ rbitset_clear_all(ready_set, last_idx);
+ rbitset_clear_all(busy_set, last_idx);
+
+ /* third step: detect, which functions are const or pure */
+ DB((dbg, LEVEL_2, "Detecting const and pure properties ...\n"));
+ for (size_t i = 0, n = get_irp_n_irgs(); i < n; ++i) {
+ ir_graph *irg = get_irp_irg(i);
+ unsigned prop = check_const_or_pure_function(irg, true);
- handle_const_Calls(&ctx);
- if (get_firm_verbosity()) {
- DBG((dbg, LEVEL_1, "Detected %u const graphs, %u pure graphs.\n", num_const, num_pure));
- DBG((dbg, LEVEL_1, "Optimizes %u(SymConst) + %u(Sel) calls to const functions.\n",
- ctx.n_calls_SymConst, ctx.n_calls_Sel));
+ if (prop & mtp_property_const) {
+ DB((dbg, LEVEL_2, "%+F has the const property\n", irg));
+ check_for_possible_endless_loops(irg);
+ } else if (prop & mtp_property_pure) {
+ DB((dbg, LEVEL_2, "%+F has the pure property\n", irg));
}
- } else {
- DBG((dbg, LEVEL_1, "No graphs without side effects detected\n"));
}
+
+ handle_const_Calls(&ctx);
+
xfree(busy_set);
xfree(ready_set);
-} /* optimize_funccalls */
+}
-/* initialize the funccall optimization */
void firm_init_funccalls(void)
{
FIRM_DBG_REGISTER(dbg, "firm.opt.funccalls");
-} /* firm_init_funccalls */
+}
+
+ir_prog_pass_t *optimize_funccalls_pass(const char *name)
+{
+ return def_prog_pass(name ? name : "funccall", optimize_funccalls);
+}
projects / libfirm / blobdiff