1 files changed, 245 insertions, 273 deletions

diff --git a/gcc/tree-ssa-structalias.c b/gcc/tree-ssa-structalias.c
index 0b8a81f..6f12a66 100644
--- a/gcc/tree-ssa-structalias.c
+++ b/gcc/tree-ssa-structalias.c
@@ -44,6 +44,9 @@
 #include "tree-ssa.h"
 #include "tree-cfg.h"
 #include "gimple-range.h"
+#include "ipa-modref-tree.h"
+#include "ipa-modref.h"
+#include "attr-fnspec.h"
 
 /* The idea behind this analyzer is to generate set constraints from the
    program, then solve the resulting constraints in order to generate the
@@ -4048,98 +4051,203 @@ get_function_part_constraint (varinfo_t fi, unsigned part)
   return c;
 }
 
-/* For non-IPA mode, generate constraints necessary for a call on the
-   RHS.  */
+/* Produce constraints for argument ARG of call STMT with eaf flags
+   FLAGS.  RESULTS is array holding constraints for return value.
+   CALLESCAPE_ID is variable where call loocal escapes are added.
+   WRITES_GLOVEL_MEMORY is true if callee may write global memory. */
 
 static void
-handle_rhs_call (gcall *stmt, vec<ce_s> *results)
-{
-  struct constraint_expr rhsc;
-  unsigned i;
-  bool returns_uses = false;
+handle_call_arg (gcall *stmt, tree arg, vec<ce_s> *results, int flags,
+		 int callescape_id, bool writes_global_memory)
+{
+  /* If the argument is not used we can ignore it.
+     Similarly argument is invisile for us if it not clobbered, does not
+     escape, is not read and can not be returned.  */
+  if ((flags & EAF_UNUSED)
+      || ((flags & (EAF_NOCLOBBER | EAF_NOESCAPE | EAF_NOREAD
+		    | EAF_NOT_RETURNED))
+	  == (EAF_NOCLOBBER | EAF_NOESCAPE | EAF_NOREAD
+	      | EAF_NOT_RETURNED)))
+    return;
+
+  varinfo_t tem = new_var_info (NULL_TREE, "callarg", true);
+  tem->is_reg_var = true;
+  make_constraint_to (tem->id, arg);
+  make_any_offset_constraints (tem);
+
+  if (!(flags & EAF_DIRECT))
+    make_transitive_closure_constraints (tem);
 
-  for (i = 0; i < gimple_call_num_args (stmt); ++i)
+  if (!(flags & EAF_NOT_RETURNED))
     {
-      tree arg = gimple_call_arg (stmt, i);
-      int flags = gimple_call_arg_flags (stmt, i);
+      struct constraint_expr cexpr;
+      cexpr.var = tem->id;
+      cexpr.type = SCALAR;
+      cexpr.offset = 0;
+      results->safe_push (cexpr);
+    }
 
-      /* If the argument is not used we can ignore it.
-	 Similarly argument is invisile for us if it not clobbered, does not
-	 escape, is not read and can not be returned.  */
-      if ((flags & EAF_UNUSED)
-	  || ((flags & (EAF_NOCLOBBER | EAF_NOESCAPE | EAF_NOREAD
-			| EAF_NOT_RETURNED))
-	      == (EAF_NOCLOBBER | EAF_NOESCAPE | EAF_NOREAD
-		  | EAF_NOT_RETURNED)))
-	continue;
+  if (!(flags & EAF_NOREAD))
+    {
+      varinfo_t uses = get_call_use_vi (stmt);
+      make_copy_constraint (uses, tem->id);
+    }
 
-      /* As we compute ESCAPED context-insensitive we do not gain
-         any precision with just EAF_NOCLOBBER but not EAF_NOESCAPE
-	 set.  The argument would still get clobbered through the
-	 escape solution.  */
-      if ((flags & EAF_NOCLOBBER)
-	   && (flags & (EAF_NOESCAPE | EAF_NODIRECTESCAPE)))
-	{
-	  varinfo_t uses = get_call_use_vi (stmt);
-	  varinfo_t tem = new_var_info (NULL_TREE, "callarg", true);
-	  tem->is_reg_var = true;
-	  make_constraint_to (tem->id, arg);
-	  make_any_offset_constraints (tem);
-	  if (!(flags & EAF_DIRECT))
-	    make_transitive_closure_constraints (tem);
-	  make_copy_constraint (uses, tem->id);
-	  /* TODO: This is overly conservative when some parameters are
-	     returned while others are not.  */
-	  if (!(flags & EAF_NOT_RETURNED))
-	    returns_uses = true;
-	  if (!(flags & (EAF_NOESCAPE | EAF_DIRECT)))
-	    make_indirect_escape_constraint (tem);
-	}
-      else if (flags & (EAF_NOESCAPE | EAF_NODIRECTESCAPE))
+  if (!(flags & EAF_NOCLOBBER))
+    {
+      struct constraint_expr lhs, rhs;
+
+      /* *arg = callescape.  */
+      lhs.type = DEREF;
+      lhs.var = tem->id;
+      lhs.offset = 0;
+
+      rhs.type = SCALAR;
+      rhs.var = callescape_id;
+      rhs.offset = 0;
+      process_constraint (new_constraint (lhs, rhs));
+
+      /* callclobbered = arg.  */
+      make_copy_constraint (get_call_clobber_vi (stmt), tem->id);
+    }
+
+  if (!(flags & (EAF_NOESCAPE | EAF_NODIRECTESCAPE)))
+    {
+      struct constraint_expr lhs, rhs;
+
+      /* callescape = arg;  */
+      lhs.var = callescape_id;
+      lhs.offset = 0;
+      lhs.type = SCALAR;
+
+      rhs.var = tem->id;
+      rhs.offset = 0;
+      rhs.type = SCALAR;
+      process_constraint (new_constraint (lhs, rhs));
+
+      if (writes_global_memory)
+	make_escape_constraint (arg);
+    }
+  else if (!(flags & EAF_NOESCAPE))
+    {
+      struct constraint_expr lhs, rhs;
+
+      /* callescape = *(arg + UNKNOWN);  */
+      lhs.var = callescape_id;
+      lhs.offset = 0;
+      lhs.type = SCALAR;
+
+      rhs.var = tem->id;
+      rhs.offset = UNKNOWN_OFFSET;
+      rhs.type = DEREF;
+      process_constraint (new_constraint (lhs, rhs));
+
+      if (writes_global_memory)
+	make_indirect_escape_constraint (tem);
+    }
+}
+
+/* Determine global memory access of call STMT and update
+   WRITES_GLOBAL_MEMORY, READS_GLOBAL_MEMORY and USES_GLOBAL_MEMORY.  */
+
+static void
+determine_global_memory_access (gcall *stmt,
+				bool *writes_global_memory,
+				bool *reads_global_memory,
+				bool *uses_global_memory)
+{
+  tree callee;
+  cgraph_node *node;
+  modref_summary *summary;
+
+  /* We need to detrmine reads to set uses.  */
+  gcc_assert (!uses_global_memory || reads_global_memory);
+
+  if ((callee = gimple_call_fndecl (stmt)) != NULL_TREE
+      && (node = cgraph_node::get (callee)) != NULL
+      && (summary = get_modref_function_summary (node)))
+    {
+      if (writes_global_memory && *writes_global_memory)
+	*writes_global_memory = summary->global_memory_written_p ();
+      if (reads_global_memory && *reads_global_memory)
+	*reads_global_memory = summary->global_memory_read_p ();
+      if (reads_global_memory && uses_global_memory
+	  && !*reads_global_memory && node->binds_to_current_def_p ())
+	*uses_global_memory = false;
+    }
+  if ((writes_global_memory && *writes_global_memory)
+      || (uses_global_memory && *uses_global_memory)
+      || (reads_global_memory && *reads_global_memory))
+    {
+      attr_fnspec fnspec = gimple_call_fnspec (stmt);
+      if (fnspec.known_p ())
 	{
-	  struct constraint_expr lhs, rhs;
-	  varinfo_t uses = get_call_use_vi (stmt);
-	  varinfo_t clobbers = get_call_clobber_vi (stmt);
-	  varinfo_t tem = new_var_info (NULL_TREE, "callarg", true);
-	  tem->is_reg_var = true;
-	  make_constraint_to (tem->id, arg);
-	  make_any_offset_constraints (tem);
-	  if (!(flags & EAF_DIRECT))
-	    make_transitive_closure_constraints (tem);
-	  make_copy_constraint (uses, tem->id);
-	  if (!(flags & EAF_NOT_RETURNED))
-	    returns_uses = true;
-	  make_copy_constraint (clobbers, tem->id);
-	  /* Add *tem = nonlocal, do not add *tem = callused as
-	     EAF_NOESCAPE parameters do not escape to other parameters
-	     and all other uses appear in NONLOCAL as well.  */
-	  lhs.type = DEREF;
-	  lhs.var = tem->id;
-	  lhs.offset = 0;
-	  rhs.type = SCALAR;
-	  rhs.var = nonlocal_id;
-	  rhs.offset = 0;
-	  process_constraint (new_constraint (lhs, rhs));
-	  if (!(flags & (EAF_NOESCAPE | EAF_DIRECT)))
-	    make_indirect_escape_constraint (tem);
+	  if (writes_global_memory
+	      && !fnspec.global_memory_written_p ())
+	    *writes_global_memory = false;
+	  if (reads_global_memory && !fnspec.global_memory_read_p ())
+	    {
+	      *reads_global_memory = false;
+	      if (uses_global_memory)
+		*uses_global_memory = false;
+	    }
 	}
-      else
-	make_escape_constraint (arg);
     }
+}
+
+/* For non-IPA mode, generate constraints necessary for a call on the
+   RHS and collect return value constraint to RESULTS to be used later in
+   handle_lhs_call.
+  
+   IMPLICIT_EAF_FLAGS are added to each function argument.  If
+   WRITES_GLOBAL_MEMORY is true function is assumed to possibly write to global
+   memory.  Similar for READS_GLOBAL_MEMORY.  */
+
+static void
+handle_rhs_call (gcall *stmt, vec<ce_s> *results,
+		 int implicit_eaf_flags,
+		 bool writes_global_memory,
+		 bool reads_global_memory)
+{
+  determine_global_memory_access (stmt, &writes_global_memory,
+				  &reads_global_memory,
+				  NULL);
+
+  varinfo_t callescape = new_var_info (NULL_TREE, "callescape", true);
+
+  /* If function can use global memory, add it to callescape
+     and to possible return values.  If not we can still use/return addresses
+     of global symbols.  */
+  struct constraint_expr lhs, rhs;
+
+  lhs.type = SCALAR;
+  lhs.var = callescape->id;
+  lhs.offset = 0;
+
+  rhs.type = reads_global_memory ? SCALAR : ADDRESSOF;
+  rhs.var = nonlocal_id;
+  rhs.offset = 0;
 
-  /* If we added to the calls uses solution make sure we account for
-     pointers to it to be returned.  */
-  if (returns_uses)
+  process_constraint (new_constraint (lhs, rhs));
+  results->safe_push (rhs);
+
+  varinfo_t uses = get_call_use_vi (stmt);
+  make_copy_constraint (uses, callescape->id);
+
+  for (unsigned i = 0; i < gimple_call_num_args (stmt); ++i)
     {
-      rhsc.var = get_call_use_vi (stmt)->id;
-      rhsc.offset = UNKNOWN_OFFSET;
-      rhsc.type = SCALAR;
-      results->safe_push (rhsc);
+      tree arg = gimple_call_arg (stmt, i);
+      int flags = gimple_call_arg_flags (stmt, i);
+      handle_call_arg (stmt, arg, results,
+		       flags | implicit_eaf_flags,
+		       callescape->id, writes_global_memory);
     }
 
   /* The static chain escapes as well.  */
   if (gimple_call_chain (stmt))
-    make_escape_constraint (gimple_call_chain (stmt));
+    handle_call_arg (stmt, gimple_call_chain (stmt), results,
+		     implicit_eaf_flags,
+		     callescape->id, writes_global_memory);
 
   /* And if we applied NRV the address of the return slot escapes as well.  */
   if (gimple_call_return_slot_opt_p (stmt)
@@ -4147,20 +4255,17 @@ handle_rhs_call (gcall *stmt, vec<ce_s> *results)
       && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt))))
     {
       auto_vec<ce_s> tmpc;
-      struct constraint_expr lhsc, *c;
+      struct constraint_expr *c;
+      unsigned i;
+
       get_constraint_for_address_of (gimple_call_lhs (stmt), &tmpc);
-      lhsc.var = escaped_id;
-      lhsc.offset = 0;
-      lhsc.type = SCALAR;
+
+      make_constraints_to (callescape->id, tmpc);
+      if (writes_global_memory)
+	make_constraints_to (escaped_id, tmpc);
       FOR_EACH_VEC_ELT (tmpc, i, c)
-	process_constraint (new_constraint (lhsc, *c));
+	results->safe_push (*c);
     }
-
-  /* Regular functions return nonlocal memory.  */
-  rhsc.var = nonlocal_id;
-  rhsc.offset = 0;
-  rhsc.type = SCALAR;
-  results->safe_push (rhsc);
 }
 
 /* For non-IPA mode, generate constraints necessary for a call
@@ -4227,160 +4332,6 @@ handle_lhs_call (gcall *stmt, tree lhs, int flags, vec<ce_s> &rhsc,
     process_all_all_constraints (lhsc, rhsc);
 }
 
-/* For non-IPA mode, generate constraints necessary for a call of a
-   const function that returns a pointer in the statement STMT.  */
-
-static void
-handle_const_call (gcall *stmt, vec<ce_s> *results)
-{
-  struct constraint_expr rhsc;
-  unsigned int k;
-  bool need_uses = false;
-
-  /* Treat nested const functions the same as pure functions as far
-     as the static chain is concerned.  */
-  if (gimple_call_chain (stmt))
-    {
-      varinfo_t uses = get_call_use_vi (stmt);
-      make_constraint_to (uses->id, gimple_call_chain (stmt));
-      need_uses = true;
-    }
-
-  /* And if we applied NRV the address of the return slot escapes as well.  */
-  if (gimple_call_return_slot_opt_p (stmt)
-      && gimple_call_lhs (stmt) != NULL_TREE
-      && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt))))
-    {
-      varinfo_t uses = get_call_use_vi (stmt);
-      auto_vec<ce_s> tmpc;
-      get_constraint_for_address_of (gimple_call_lhs (stmt), &tmpc);
-      make_constraints_to (uses->id, tmpc);
-      need_uses = true;
-    }
-
-  if (need_uses)
-    {
-      varinfo_t uses = get_call_use_vi (stmt);
-      make_any_offset_constraints (uses);
-      make_transitive_closure_constraints (uses);
-      rhsc.var = uses->id;
-      rhsc.offset = 0;
-      rhsc.type = SCALAR;
-      results->safe_push (rhsc);
-    }
-
-  /* May return offsetted arguments.  */
-  varinfo_t tem = NULL;
-  for (k = 0; k < gimple_call_num_args (stmt); ++k)
-    {
-      int flags = gimple_call_arg_flags (stmt, k);
-
-      /* If the argument is not used or not returned we can ignore it.  */
-      if (flags & (EAF_UNUSED | EAF_NOT_RETURNED))
-	continue;
-      if (!tem)
-	{
-	  tem = new_var_info (NULL_TREE, "callarg", true);
-	  tem->is_reg_var = true;
-	}
-      tree arg = gimple_call_arg (stmt, k);
-      auto_vec<ce_s> argc;
-      get_constraint_for_rhs (arg, &argc);
-      make_constraints_to (tem->id, argc);
-    }
-  if (tem)
-    {
-      ce_s ce;
-      ce.type = SCALAR;
-      ce.var = tem->id;
-      ce.offset = UNKNOWN_OFFSET;
-      results->safe_push (ce);
-    }
-
-  /* May return addresses of globals.  */
-  rhsc.var = nonlocal_id;
-  rhsc.offset = 0;
-  rhsc.type = ADDRESSOF;
-  results->safe_push (rhsc);
-}
-
-/* For non-IPA mode, generate constraints necessary for a call to a
-   pure function in statement STMT.  */
-
-static void
-handle_pure_call (gcall *stmt, vec<ce_s> *results)
-{
-  struct constraint_expr rhsc;
-  unsigned i;
-  varinfo_t uses = NULL;
-  bool record_uses = false;
-
-  /* Memory reached from pointer arguments is call-used.  */
-  for (i = 0; i < gimple_call_num_args (stmt); ++i)
-    {
-      tree arg = gimple_call_arg (stmt, i);
-      int flags = gimple_call_arg_flags (stmt, i);
-
-      /* If the argument is not used we can ignore it.  */
-      if ((flags & EAF_UNUSED)
-	  || (flags & (EAF_NOT_RETURNED | EAF_NOREAD))
-	     == (EAF_NOT_RETURNED | EAF_NOREAD))
-	continue;
-      if (!uses)
-	{
-	  uses = get_call_use_vi (stmt);
-	  make_any_offset_constraints (uses);
-	  make_transitive_closure_constraints (uses);
-	}
-      make_constraint_to (uses->id, arg);
-      if (!(flags & EAF_NOT_RETURNED))
-	record_uses = true;
-    }
-
-  /* The static chain is used as well.  */
-  if (gimple_call_chain (stmt))
-    {
-      if (!uses)
-	{
-	  uses = get_call_use_vi (stmt);
-	  make_any_offset_constraints (uses);
-	  make_transitive_closure_constraints (uses);
-	}
-      make_constraint_to (uses->id, gimple_call_chain (stmt));
-      record_uses = true;
-    }
-
-  /* And if we applied NRV the address of the return slot.  */
-  if (gimple_call_return_slot_opt_p (stmt)
-      && gimple_call_lhs (stmt) != NULL_TREE
-      && TREE_ADDRESSABLE (TREE_TYPE (gimple_call_lhs (stmt))))
-    {
-      if (!uses)
-	{
-	  uses = get_call_use_vi (stmt);
-	  make_any_offset_constraints (uses);
-	  make_transitive_closure_constraints (uses);
-	}
-      auto_vec<ce_s> tmpc;
-      get_constraint_for_address_of (gimple_call_lhs (stmt), &tmpc);
-      make_constraints_to (uses->id, tmpc);
-      record_uses = true;
-    }
-
-  /* Pure functions may return call-used and nonlocal memory.  */
-  if (record_uses)
-    {
-      rhsc.var = uses->id;
-      rhsc.offset = 0;
-      rhsc.type = SCALAR;
-      results->safe_push (rhsc);
-    }
-  rhsc.var = nonlocal_id;
-  rhsc.offset = 0;
-  rhsc.type = SCALAR;
-  results->safe_push (rhsc);
-}
-
 
 /* Return the varinfo for the callee of CALL.  */
 
@@ -4931,13 +4882,13 @@ find_func_aliases_for_call (struct function *fn, gcall *t)
       if (flags & (ECF_CONST|ECF_NOVOPS))
 	{
 	  if (gimple_call_lhs (t))
-	    handle_const_call (t, &rhsc);
+	    handle_rhs_call (t, &rhsc, implicit_const_eaf_flags, false, false);
 	}
       /* Pure functions can return addresses in and of memory
 	 reachable from their arguments, but they are not an escape
 	 point for reachable memory of their arguments.  */
       else if (flags & (ECF_PURE|ECF_LOOPING_CONST_OR_PURE))
-	handle_pure_call (t, &rhsc);
+	handle_rhs_call (t, &rhsc, implicit_pure_eaf_flags, true, false);
       /* If the call is to a replaceable operator delete and results
 	 from a delete expression as opposed to a direct call to
 	 such operator, then the effects for PTA (in particular
@@ -4947,7 +4898,7 @@ find_func_aliases_for_call (struct function *fn, gcall *t)
 	       && gimple_call_from_new_or_delete (t))
 	;
       else
-	handle_rhs_call (t, &rhsc);
+	handle_rhs_call (t, &rhsc, 0, true, true);
       if (gimple_call_lhs (t))
 	handle_lhs_call (t, gimple_call_lhs (t),
 			 gimple_call_return_flags (t), rhsc, fndecl);
@@ -7582,43 +7533,64 @@ compute_points_to_sets (void)
 	  pt = gimple_call_use_set (stmt);
 	  if (gimple_call_flags (stmt) & ECF_CONST)
 	    memset (pt, 0, sizeof (struct pt_solution));
-	  else if ((vi = lookup_call_use_vi (stmt)) != NULL)
-	    {
-	      *pt = find_what_var_points_to (cfun->decl, vi);
-	      /* Escaped (and thus nonlocal) variables are always
-	         implicitly used by calls.  */
-	      /* ???  ESCAPED can be empty even though NONLOCAL
-		 always escaped.  */
-	      pt->nonlocal = 1;
-	      pt->escaped = 1;
-	    }
 	  else
 	    {
-	      /* If there is nothing special about this call then
-		 we have made everything that is used also escape.  */
-	      *pt = cfun->gimple_df->escaped;
-	      pt->nonlocal = 1;
+	      bool uses_global_memory = true;
+	      bool reads_global_memory = true;
+
+	      determine_global_memory_access (stmt, NULL,
+					      &reads_global_memory,
+					      &uses_global_memory);
+	      if (!uses_global_memory)
+		;
+	      else if ((vi = lookup_call_use_vi (stmt)) != NULL)
+		{
+		  *pt = find_what_var_points_to (cfun->decl, vi);
+		  /* Escaped (and thus nonlocal) variables are always
+		     implicitly used by calls.  */
+		  /* ???  ESCAPED can be empty even though NONLOCAL
+		     always escaped.  */
+		  pt->nonlocal = uses_global_memory;
+		  pt->escaped = uses_global_memory;
+		}
+	      else if (uses_global_memory)
+		{
+		  /* If there is nothing special about this call then
+		     we have made everything that is used also escape.  */
+		  *pt = cfun->gimple_df->escaped;
+		  pt->nonlocal = 1;
+		}
 	    }
 
 	  pt = gimple_call_clobber_set (stmt);
 	  if (gimple_call_flags (stmt) & (ECF_CONST|ECF_PURE|ECF_NOVOPS))
 	    memset (pt, 0, sizeof (struct pt_solution));
-	  else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
-	    {
-	      *pt = find_what_var_points_to (cfun->decl, vi);
-	      /* Escaped (and thus nonlocal) variables are always
-	         implicitly clobbered by calls.  */
-	      /* ???  ESCAPED can be empty even though NONLOCAL
-		 always escaped.  */
-	      pt->nonlocal = 1;
-	      pt->escaped = 1;
-	    }
 	  else
 	    {
-	      /* If there is nothing special about this call then
-		 we have made everything that is used also escape.  */
-	      *pt = cfun->gimple_df->escaped;
-	      pt->nonlocal = 1;
+	      bool writes_global_memory = true;
+
+	      determine_global_memory_access (stmt, &writes_global_memory,
+					      NULL, NULL);
+
+	      if (!writes_global_memory)
+		;
+	      else if ((vi = lookup_call_clobber_vi (stmt)) != NULL)
+		{
+		  *pt = find_what_var_points_to (cfun->decl, vi);
+		  /* Escaped (and thus nonlocal) variables are always
+		     implicitly clobbered by calls.  */
+		  /* ???  ESCAPED can be empty even though NONLOCAL
+		     always escaped.  */
+		  pt->nonlocal = writes_global_memory;
+		  pt->escaped = writes_global_memory;
+		}
+	      else if (writes_global_memory)
+		{
+		  /* If there is nothing special about this call then
+		     we have made everything that is used also escape.  */
+		  *pt = cfun->gimple_df->escaped;
+		  pt->nonlocal = 1;
+		}
 	    }
 	}
     }