re PR ipa/63838 (ipa-pure-const miscomputes can_throw)

PR ipa/63838
	* ipa-pure-const.c (propagate_nothrow): Walk w->indirect_calls
	chain instead of node->indirect_calls.  Put !can_throw into
	conditions of all the loops.

	* g++.dg/ipa/pr63838.C: New test.

From-SVN: r217449

gcc/ChangeLog

@@ -1,3 +1,10 @@
+2014-11-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR ipa/63838
+	* ipa-pure-const.c (propagate_nothrow): Walk w->indirect_calls
+	chain instead of node->indirect_calls.  Put !can_throw into
+	conditions of all the loops.
+
 2014-11-12  H.J. Lu  <hongjiu.lu@intel.com>
 
 	* config/i386/i386.c (x86_output_mi_thunk): Use gen_rtx_REG to

gcc/ipa-pure-const.c

@@ -1448,7 +1448,7 @@ propagate_nothrow (void)
 
       /* Find the worst state for any node in the cycle.  */
       w = node;
-      while (w)
+      while (w && !can_throw)
 	{
 	  struct cgraph_edge *e, *ie;
 	  funct_state w_l = get_function_state (w);
@@ -1457,10 +1457,7 @@ propagate_nothrow (void)
 	      || w->get_availability () == AVAIL_INTERPOSABLE)
 	    can_throw = true;
 
-	  if (can_throw)
+	  for (e = w->callees; e && !can_throw; e = e->next_callee)
-	    break;
-
-	  for (e = w->callees; e; e = e->next_callee)
 	    {
 	      enum availability avail;
 	      struct cgraph_node *y = e->callee->function_symbol (&avail);
@@ -1469,8 +1466,6 @@ propagate_nothrow (void)
 		{
 		  funct_state y_l = get_function_state (y);
 
-		  if (can_throw)
-		    break;
 		  if (y_l->can_throw && !TREE_NOTHROW (w->decl)
 		      && e->can_throw_external)
 		    can_throw = true;
@@ -1478,12 +1473,9 @@ propagate_nothrow (void)
 	      else if (e->can_throw_external && !TREE_NOTHROW (y->decl))
 	        can_throw = true;
 	    }
-          for (ie = node->indirect_calls; ie; ie = ie->next_callee)
+          for (ie = w->indirect_calls; ie && !can_throw; ie = ie->next_callee)
 	    if (ie->can_throw_external)
-	      {
+	      can_throw = true;
-		can_throw = true;
-		break;
-	      }
 	  w_info = (struct ipa_dfs_info *) w->aux;
 	  w = w_info->next_cycle;
 	}
@@ -1794,5 +1786,3 @@ make_pass_warn_function_noreturn (gcc::context *ctxt)
 {
   return new pass_warn_function_noreturn (ctxt);
 }
-
-

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2014-11-12  Jakub Jelinek  <jakub@redhat.com>
+
+	PR ipa/63838
+	* g++.dg/ipa/pr63838.C: New test.
+
 2014-11-12  Matthew Fortune  <matthew.fortune@imgtec.com>
 
 	* gcc.target/mips/args-1.c: Handle __mips_fpr == 0.

gcc/testsuite/g++.dg/ipa/pr63838.C

@@ -0,0 +1,56 @@
+// PR ipa/63838
+// { dg-do run }
+// { dg-options "-O2 -fdump-ipa-pure-const" }
+// { dg-final { scan-ipa-dump-not "Function found to be nothrow: void foo" "pure-const" } }
+// { dg-final { scan-ipa-dump-not "Function found to be nothrow: void bar" "pure-const" } }
+// { dg-final { cleanup-ipa-dump "pure-const" } }
+
+__attribute__((noinline, noclone)) static void bar (int);
+volatile int v;
+void (*fn) ();
+struct S { S () { v++; } ~S () { v++; } };
+
+__attribute__((noinline, noclone)) static void
+foo (int x)
+{
+  v++;
+  if (x == 5)
+    bar (x);
+}
+
+__attribute__((noinline, noclone)) static void
+bar (int x)
+{
+  v++;
+  if (x == 6)
+    foo (x);
+  else if (x == 5)
+    fn ();
+}
+
+__attribute__((noinline, noclone)) int
+baz (int x)
+{
+  S s;
+  foo (x);
+}
+
+void
+throw0 ()
+{
+  throw 0;
+}
+
+int
+main ()
+{
+  fn = throw0;
+  asm volatile ("" : : : "memory");
+  try
+    {
+      baz (5);
+    }
+  catch (int)
+    {
+    }
+}