typedef struct _env_t {
int n_calls_removed_SymConst;
int n_calls_removed_Sel;
- ir_node *list; /**< The list of all Calls that will be changed. */
- ir_node *proj_list; /**< list of all potential Proj nones that must be fixed.*/
+ 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. */
} env_t;
/**
- * remove memory from const function calls by rerouting
- * it's ProjM and connection the call with a NoMem node.
- *
- * Note: By "const function" we understand a function that did neither
- * read nor write memory. Hence its result depends solely on its
- * arguments.
+ * Collect all calls to const and pure functions
+ * to lists. Collect of Proj nodes into a Proj list.
*/
-static void rem_mem_from_const_fkt_calls(ir_node *node, void *env)
+static void collect_calls(ir_node *node, void *env)
{
env_t *ctx = env;
ir_node *call, *ptr;
entity *ent;
+ unsigned mode;
if (get_irn_op(node) == op_Call) {
call = node;
if (get_irn_op(ptr) == op_SymConst && get_SymConst_kind(ptr) == symconst_addr_ent) {
ent = get_SymConst_entity(ptr);
- if ((get_entity_additional_properties(ent) & mtp_property_const) == 0)
+ mode = get_entity_additional_properties(ent);
+ if (mode & (mtp_property_const|mtp_property_pure) == 0)
return;
++ctx->n_calls_removed_SymConst;
}
else if (is_Sel(ptr) &&
get_irg_callee_info_state(current_ir_graph) == irg_callee_info_consistent) {
- /* If all possible callees are real functions, we can remove the memory edge. */
+ /* 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;
+
+ /* 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;
}
- if ((get_entity_additional_properties(ent) & mtp_property_const) == 0)
+ mode &= get_entity_additional_properties(ent);
+ if (mode == 0)
return;
}
++ctx->n_calls_removed_Sel;
else
return;
- /* ok, if we get here we found a call to a const function */
- set_irn_link(call, ctx->list);
- ctx->list = call;
+ /* ok, if we get here we found a call to a const or a pure function */
+ if (mode & 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;
+ }
}
else if (get_irn_op(node) == op_Proj) {
/*
ctx->proj_list = node;
break;
default:
- ;
+ break;
}
}
} /* rem_mem_from_const_fkt_calls */
* @param call_list the list of all call sites of pure functions
* @param proj_list the list of all memory/exception Projs of this call sites
*/
-static void fix_call_list(ir_graph *irg, ir_node *call_list, ir_node *proj_list) {
+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;
}
} /* fix_call_list */
-/*
- * optimize function calls by handling const functions
+
+/**
+ * Check if a graph represents a const function.
+ *
+ * @param irg the graph
*/
-void optimize_funccalls(int force_run)
+static int is_const_function(ir_graph *irg)
{
- int i, j;
- int change;
- unsigned num_pure = 0;
+ ir_node *end, *endbl;
+ int j, change;
- if (! get_opt_real_function_call())
- return;
+ if (get_irg_additional_properties(irg) & mtp_property_const) {
+ /* already marked as a const function */
+ return 0;
+ }
- /* first step: detect, which functions are const, i.e. do NOT touch any memory */
- for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
- ir_graph *irg = get_irp_irg(i);
- ir_node *end = get_irg_end(irg);
- ir_node *endbl = get_nodes_block(end);
+ end = get_irg_end(irg);
+ endbl = get_nodes_block(end);
+ change = 0;
- change = 0;
+ /* 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;
- if (get_irg_additional_properties(irg) & mtp_property_const) {
- /* already marked as a const function */
- ++num_pure;
+ /* Bad nodes usually do NOT produce anything, so it's ok */
+ if (op == op_Bad)
+ continue;
+
+ if (op == op_Return) {
+ mem = get_Return_mem(node);
+
+ /* Bad nodes usually do NOT produce anything, so it's ok */
+ if (is_Bad(mem))
+ continue;
+
+ change = mem != get_irg_initial_mem(irg);
+ if (change)
+ break;
}
else {
- /* 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;
-
- /* Bad nodes usually do NOT produce anything, so it's ok */
- if (op == op_Bad)
- continue;
-
- if (op == op_Return) {
- mem = get_Return_mem(node);
-
- /* Bad nodes usually do NOT produce anything, so it's ok */
- if (is_Bad(mem))
- continue;
-
- change = mem != get_irg_initial_mem(irg);
- if (change)
- break;
- }
- else {
- /* exception found */
- change = 1;
- break;
- }
+ /* exception found */
+ change = 1;
+ break;
+ }
+ }
+
+ if (! change) {
+ /* 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);
+
+ if (mode_M != get_irn_mode(mem))
+ continue;
+
+ change = mem != get_irg_initial_mem(irg);
+ if (change)
+ break;
+ }
+ }
+
+ if (! change) {
+ /* no memory changes found, it's a const function */
+ set_irg_additional_property(irg, mtp_property_const);
+ return 1;
+ }
+ return 0;
+} /* is_const_function */
+
+/* a marker */
+static char _mark;
+#define MARK &_mark
+
+#define UNMARK_IRG(irg) set_irg_link((irg), NULL)
+#define MARK_IRG(irg) set_irg_link((irg), MARK)
+#define IS_IRG_MARKED(irg) (get_irg_link(irg) == MARK)
+
+/* forward */
+static int is_pure_function(ir_graph *irg);
+
+#define UMAX(a,b) (a) > (b) ? (a) : (b)
+
+/**
+ * Follow the memory chain starting at node and determine
+ * 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
+ * bad_property else
+ */
+static unsigned _follow_mem(ir_node *node) {
+ unsigned m, mode = mtp_property_const;
+ ir_node *ptr;
+ int i;
+
+ for (;;) {
+ if (irn_visited(node))
+ return mode;
+
+ mark_irn_visited(node);
+
+ switch (get_irn_opcode(node)) {
+ case iro_Proj:
+ node = get_Proj_pred(node);
+ break;
+
+ case iro_NoMem:
+ /* finish here */
+ return mode;
+
+ case iro_Phi:
+ case iro_Sync:
+ for (i = get_irn_arity(node) - 1; i >= 0; --i) {
+ mode &= _follow_mem(get_irn_n(node, i));
}
+ break;
- if (! change) {
- /* 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);
+ case iro_Load:
+ /* Beware volatile Loads are NOT allowed in pure functions */
+ if (get_Load_volatility(node) == volatility_is_volatile)
+ return 0;
+ mode = mtp_property_pure;
+ node = get_Load_mem(node);
+ break;
- if (mode_M != get_irn_mode(mem))
- continue;
+ 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) {
+ entity *ent = get_SymConst_entity(ptr);
+ ir_graph *irg = get_entity_irg(ent);
- change = mem != get_irg_initial_mem(irg);
- if (change)
- break;
+ if (irg == current_ir_graph) {
+ /* A recursive call. The did not mode depend on this call */
+ }
+ else if (irg == NULL) {
+ m = get_entity_additional_properties(ent) & (mtp_property_const|mtp_property_pure);
+ if (! m)
+ return 0;
+ mode = UMAX(mode, m);
+ }
+ else if (irg != NULL) {
+ /* we have a graph. Check if it is already analyzed */
+ if (IS_IRG_MARKED(irg))
+ (void)is_pure_function(irg);
+
+ m = get_irg_additional_properties(irg) & (mtp_property_const|mtp_property_pure);
+ if (! m)
+ return 0;
+ mode = UMAX(mode, m);
}
}
+ else
+ return 0;
+ node = get_Call_mem(node);
+ break;
- if (! change) {
- /* no memory changes found, it's a const function */
- set_irg_additional_property(irg, mtp_property_const);
- ++num_pure;
- }
+ default:
+ return 0;
}
}
+} /* follow_mem */
- if (force_run || num_pure > 0) {
- env_t ctx;
+/**
+ * Follow the memory chain starting at node and determine
+ * 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
+ * 0 else
+ */
+static unsigned follow_mem(ir_graph *irg, ir_node *node, unsigned mode) {
+ unsigned m;
+
+ inc_irg_visited(irg);
+ /* mark the initial mem: recursion stops here */
+ mark_irn_visited(get_irg_initial_mem(irg));
+ m = _follow_mem(node);
+ if (! m)
+ return 0;
+ return UMAX(mode, m);
+} /* follow_mwm */
+
+/*
+ * Check if a graph represents a pure function.
+ *
+ * @param irg the graph
+ */
+static int is_pure_function(ir_graph *irg) {
+ ir_node *end, *endbl;
+ int j;
+ unsigned mode = get_irg_additional_properties(irg);
+ ir_graph *rem = current_ir_graph;
+
+ if (mode & mtp_property_const) {
+ /* already marked as a const function */
+ return mtp_property_const;
+ }
+ if (mode & mtp_property_pure) {
+ /* already marked as a pure function */
+ return mtp_property_const;
+ }
- ctx.n_calls_removed_SymConst = 0;
- ctx.n_calls_removed_Sel = 0;
+ if (! IS_IRG_MARKED(irg))
+ return 0;
+ UNMARK_IRG(irg);
- /* all calls of pure functions can be transformed into FuncCalls */
- for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
- ir_graph *irg = get_irp_irg(i);
+ end = get_irg_end(irg);
+ endbl = get_nodes_block(end);
+ mode = mtp_property_const;
- /* no need to do this on const functions */
- if ((get_irg_additional_properties(irg) & mtp_property_const) == 0) {
- ctx.list = NULL;
- ctx.proj_list = NULL;
- irg_walk_graph(irg, NULL, rem_mem_from_const_fkt_calls, &ctx);
+ current_ir_graph = irg;
- if (ctx.list)
- fix_call_list(irg, ctx.list, ctx.proj_list);
- }
+ /* 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;
+
+ /* Bad nodes usually do NOT produce anything, so it's ok */
+ if (op == op_Bad)
+ continue;
+
+ if (op == op_Return) {
+ 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 = follow_mem(irg, mem, mode);
+ }
+ else {
+ /* exception found. */
+ mode = follow_mem(irg, mem, mode);
+ break;
+ }
+ if (mode == 0)
+ break;
+ }
+
+ if (mode != 0) {
+ /* 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);
+
+ if (mode_M != get_irn_mode(mem))
+ continue;
+
+ mode = follow_mem(irg, mem, mode);
+ if (mode == 0)
+ break;
}
+ }
+
+ if (mode)
+ set_irg_additional_property(irg, mode);
+ current_ir_graph = rem;
+ return mode;
+} /* is_pure_function */
+
+/**
+ * Handle calls to const functions.
+ */
+static void handle_const_Calls(env_t *ctx)
+{
+ int i;
+
+ ctx->n_calls_removed_SymConst = 0;
+ ctx->n_calls_removed_Sel = 0;
+
+ /* all calls of const functions can be transformed */
+ for (i = get_irp_n_irgs() - 1; i >= 0; --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);
+
+ if (ctx->const_call_list)
+ fix_const_call_list(irg, ctx->const_call_list, ctx->proj_list);
+ }
+} /* handle_const_Calls */
+
+/*
+ * optimize function calls by handling const functions
+ */
+void optimize_funccalls(int force_run)
+{
+ int i, n;
+ unsigned num_const = 0;
+ unsigned num_pure = 0;
+
+ if (! get_opt_function_call())
+ return;
+
+ /* prepare: mark all graphs as not analyzed */
+ n = get_irp_n_irgs();
+ for (i = n - 1; i >= 0; --i)
+ MARK_IRG(get_irp_irg(i));
+
+ /* first step: detect, which functions are const, i.e. do NOT touch any memory */
+ for (i = n - 1; i >= 0; --i) {
+ ir_graph *irg = get_irp_irg(i);
+ unsigned mode = is_pure_function(irg);
+
+ if (mode & mtp_property_const)
+ ++num_const;
+ else if (mode & mtp_property_pure)
+ ++num_pure;
+ }
+
+ if (force_run || num_const > 0) {
+ env_t ctx;
+ handle_const_Calls(&ctx);
if (get_firm_verbosity()) {
- printf("Detected %d graphs without side effects.\n", num_pure);
- printf("Optimizes %d(SymConst) + %d(Sel) calls to const functions.\n",
- ctx.n_calls_removed_SymConst, ctx.n_calls_removed_Sel);
+ printf("Detected %d graphs without side effects.\n", num_const);
+ printf("Optimizes %d(SymConst) + %d(Sel) calls to const/pure functions.\n",
+ ctx.n_calls_removed_SymConst, ctx.n_calls_removed_Sel);
}
}
else {
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