X-Git-Url: http://nsz.repo.hu/git/?a=blobdiff_plain;f=ir%2Fopt%2Ffunccall.c;h=bc47dc8512bffbc1ba10d04adcd585314410ea39;hb=8c89e7f37d59bcdcc21d680e1430c712c344938d;hp=82b382864d0da3e82bcb0aeea5bc064121b5eb1e;hpb=34a7a1cf3b1e1771c34367ba352798fead1d9904;p=libfirm

diff --git a/ir/opt/funccall.c b/ir/opt/funccall.c
index 82b382864..bc47dc851 100644
--- a/ir/opt/funccall.c
+++ b/ir/opt/funccall.c
@@ -1,11 +1,11 @@
 /*
  * Project:     libFIRM
- * File name:   ir/opt/ldstopt.c
+ * File name:   ir/opt/funccall.c
  * Purpose:     optimization of function calls
- * Author:
+ * Author:      Michael Beck
  * Created:
  * CVS-ID:      $Id$
- * Copyright:   (c) 1998-2004 Universität Karlsruhe
+ * Copyright:   (c) 1998-2004 Universit�t Karlsruhe
  * Licence:     This file protected by GPL -  GNU GENERAL PUBLIC LICENSE.
  */
 #include "irnode_t.h"
@@ -16,143 +16,214 @@
 #include "dbginfo_t.h"
 #include "irflag_t.h"
 #include "ircons.h"
-#include "eset.h"
 #include "funccall.h"
 #include "irhooks.h"
 
 /**
- * The walker environment for rem_mem_from_real_fkt_calls
+ * The walker environment for rem_mem_from_const_fkt_calls
  */
 typedef struct _env_t {
-  eset *pure_fkt;   /**< set containing all real functions */
-  int  changed;     /**< flag, is set if a graph was changed */
+  int  changed;                   /**< flag, is set if a graph was changed */
+  int  n_calls_removed_SymConst;
+  int  n_calls_removed_Sel;
 } env_t;
 
 /**
- * remove memory from real function calls by rerouting
+ * remove memory from const function calls by rerouting
  * it's ProjM and connection the call with a NoMem node.
  *
- * Note: By "real function" we understand a function that did neither
- * read nor write memory.
+ * Note: By "const function" we understand a function that did neither
+ * read nor write memory. Hence its result depends solely on its
+ * arguments.
  */
-static void rem_mem_from_real_fkt_calls(ir_node *node, void *env)
+static void rem_mem_from_const_fkt_calls(ir_node *node, void *env)
 {
   env_t *ctx = env;
   ir_node *call, *ptr, *mem;
   entity *ent;
 
-  if (get_irn_op(node) != op_Proj || get_irn_mode(node) != mode_M)
-    return;
-
-  /* look at Memory Proj's */
-  call = get_Proj_pred(node);
-  if (get_irn_op(call) != op_Call)
-    return;
+  if (get_irn_op(node) == op_Call) {
+    call = node;
 
-  ptr = get_Call_ptr(call);
-  if (get_irn_op(ptr) != op_SymConst || get_SymConst_kind(ptr) != symconst_addr_ent)
-    return;
+    set_irn_link(call, NULL);
 
-  ent = get_SymConst_entity(ptr);
+    ptr = get_Call_ptr(call);
+    if (get_irn_op(ptr) == op_SymConst && get_SymConst_kind(ptr) == symconst_addr_ent) {
+      ent = get_SymConst_entity(ptr);
 
-  if (! eset_contains(ctx->pure_fkt, ent))
-    return;
+      if ((get_entity_additional_properties(ent) & mtp_property_const) == 0)
+        return;
+      ++ctx->n_calls_removed_SymConst;
+    }
+    else if (get_irn_op(ptr) == op_Sel &&
+	     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. */
+      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;
+      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)
+          return;
+      }
+      ++ctx->n_calls_removed_Sel;
+    }
+    else
+      return;
 
-  /* ok, if we get here we found a call to a pure function,
-   * route the NoMem node to the call */
-  mem   = get_Call_mem(call);
+    /* ok, if we get here we found a call to a const function,
+     * route the NoMem node to the call */
+    mem   = get_Call_mem(call);
 
-  exchange(node, mem);
-  set_Call_mem(call, new_r_NoMem(current_ir_graph));
+    set_irn_link(call, mem);
+    set_Call_mem(call, new_r_NoMem(current_ir_graph));
 
-  /* finally, this call can floats */
-  set_irn_pinned(call, op_pin_state_floats);
+    /* finally, this call can float */
+    set_irn_pinned(call, op_pin_state_floats);
 
-  hook_func_call(current_ir_graph, call);
+    hook_func_call(current_ir_graph, call);
 
-  ctx->changed = 1;
+    ctx->changed = 1;
+  }
+  else if (get_irn_op(node) == op_Proj) {
+    /*
+     * Remove memory and exception Proj's from
+     * const function calls.
+     */
+    call = get_Proj_pred(node);
+    if ((get_irn_op(call) != op_Call) ||
+        (get_irn_op(get_Call_mem(call)) != op_NoMem))
+      return;
+
+    switch (get_Proj_proj(node)) {
+    case pn_Call_M_regular: {
+      ir_node *old_mem = get_irn_link(call);
+      if (old_mem)
+        exchange(node, old_mem);
+    } break;
+    case pn_Call_X_except:
+    case pn_Call_M_except:
+      exchange(node, new_Bad());
+      break;
+    default: ;
+    }
+  }
 }
 
 /*
- * optimize function calls by handling real functions
+ * optimize function calls by handling const functions
  */
-void optimize_funccalls(void)
+void optimize_funccalls(int force_run)
 {
-  int i, n, j, k;
+  int i, j;
   int change;
   unsigned num_pure = 0;
-  eset *pure_fkt = eset_create();
 
-  if (! get_opt_real_func_call())
+  if (! get_opt_real_function_call())
     return;
 
-  /* first step: detect, which functions are pure, ie do NOT change any memory */
-  for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
+  /* 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);
 
     change = 0;
 
-    /* visit every Return */
-    for (j = 0, k = get_Block_n_cfgpreds(endbl); j < k; ++j) {
-      ir_node *ret = get_Block_cfgpred(endbl, j);
-      ir_node *mem;
-
-      /* Bad nodes usually do NOT produce anything, so it's ok */
-      if (is_Bad(ret))
-        continue;
+    if (get_irg_additional_properties(irg) & mtp_property_const) {
+      /* already marked as a const function */
+      ++num_pure;
+    }
+    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;
 
-      mem = get_Return_mem(ret);
+        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;
+          /* 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;
-    }
+          change = mem != get_irg_initial_mem(irg);
+          if (change)
+            break;
+        }
+        else {
+          /* exception found */
+          change = 1;
+          break;
+        }
+      }
 
-    if (! change) {
-      /* check, if a keep-alive exists */
-      for (j = 0, k = get_End_n_keepalives(end); j < k; ++j) {
-        ir_node *mem = get_End_keepalive(end, j);
+      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;
+          if (mode_M != get_irn_mode(mem))
+            continue;
 
-        change = mem != get_irg_initial_mem(irg);
-        if (change)
-          break;
+          change = mem != get_irg_initial_mem(irg);
+          if (change)
+            break;
+        }
       }
-    }
 
-    if (! change) {
-      eset_insert(pure_fkt, get_irg_entity(irg));
-      ++num_pure;
+      if (! change) {
+        /* no memory changes found, it's a const function */
+        set_irg_additional_property(irg, mtp_property_const);
+        ++num_pure;
+      }
     }
   }
 
-  if (num_pure > 0) {
+  if (force_run || num_pure > 0) {
     env_t ctx;
 
-    ctx.pure_fkt = pure_fkt;
+    ctx.n_calls_removed_SymConst = 0;
+    ctx.n_calls_removed_Sel = 0;
 
     /* all calls of pure functions can be transformed into FuncCalls */
-    for (i = 0, n = get_irp_n_irgs(); i < n; ++i) {
+    for (i = get_irp_n_irgs() - 1; i >= 0; --i) {
       ir_graph *irg  = get_irp_irg(i);
 
-      ctx.changed = 0;
-      irg_walk_graph(irg, NULL, rem_mem_from_real_fkt_calls, &ctx);
+      /* no need to do this on const functions */
+      if ((get_irg_additional_properties(irg) & mtp_property_const) == 0) {
+        ctx.changed = 0;
+        irg_walk_graph(irg, NULL, rem_mem_from_const_fkt_calls, &ctx);
 
-      if (ctx.changed) {
-        /* changes were done */
-        set_irg_outs_inconsistent(irg);
-        set_irg_loopinfo_state(current_ir_graph, loopinfo_cf_inconsistent);
+        if (ctx.changed) {
+          /* changes were done */
+          set_irg_outs_inconsistent(irg);
+          set_irg_loopinfo_state(current_ir_graph, loopinfo_cf_inconsistent);
+        }
       }
     }
-  }
 
-  eset_destroy(pure_fkt);
+    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);
+    }
+  }
+  else {
+    if (get_firm_verbosity()) {
+      printf("No graphs without side effects detected\n");
+    }
+  }
 }