Index: gcc/c/c-parser.c
===================================================================
--- gcc/c/c-parser.c	(revision 194496)
+++ gcc/c/c-parser.c	(working copy)
@@ -11918,7 +11918,7 @@
   c_cont_label = NULL_TREE;
   body = c_parser_c99_block_statement (parser);
   c_finish_cilk_loop (loc, cvar, cond, incr, body, c_cont_label, grain);
-  add_stmt (c_end_compound_stmt (UNKNOWN_LOCATION, block, true));
+  add_stmt (c_end_compound_stmt (loc, block, true));
   c_break_label = save_break;
   c_cont_label = save_cont;
 }
Index: gcc/c/c-typeck.c
===================================================================
--- gcc/c/c-typeck.c	(revision 194496)
+++ gcc/c/c-typeck.c	(working copy)
@@ -10970,7 +10970,7 @@
 }
 
 void
-c_finish_cilk_loop (location_t start_locus ATTRIBUTE_UNUSED, tree cvar,
+c_finish_cilk_loop (location_t start_locus, tree cvar,
 		    tree cond, tree incr, tree body, tree clab, tree grain)
 {
   tree init;
@@ -10982,12 +10982,12 @@
 
   if (!cond)
     {
-      error ("_Cilk_for missing condition");
+      error_at (start_locus, "_Cilk_for missing condition");
       return;
     }
   if (!incr)
     {
-      error ("_Cilk_for missing increment");
+      error_at (start_locus, "_Cilk_for missing increment");
       return;
     }
 
@@ -10999,7 +10999,7 @@
     }
   if (!cvar)
     {
-      error ("missing control variable");
+      error_at (start_locus, "missing control variable");
       return;
     }
   if (clab)
@@ -11007,7 +11007,31 @@
       error_at (EXPR_LOCATION (clab), "_Cilk_for has continue");
       return;
     }
+  
+  /* Checks if cond expr is one of the following: !=, <=, <, >=, or >.  */
+  if (TREE_CODE (cond) != NE_EXPR
+      && TREE_CODE (cond) != LT_EXPR
+      && TREE_CODE (cond) != LE_EXPR
+      && TREE_CODE (cond) != GT_EXPR
+      && TREE_CODE (cond) != GE_EXPR)
+    {
+      error_at (EXPR_LOCATION (cond), "_Cilk_for condition must be one of the "
+		"following: !=, <=, <, >= or >");
+      return;
+    }
 
+  /* Checks if the induction variable is volatile or constant.  */
+  if (TREE_THIS_VOLATILE (cvar))
+    {
+      error_at (start_locus, "_Cilk_for induction variable cannot be volatile");
+      return;
+    }
+  else if (TREE_CONSTANT (cvar) || TREE_READONLY (cvar))
+    {
+      error_at (start_locus, "_Cilk_for induction variable cannot be constant or "
+		"readonly");
+      return;
+    }
   init = DECL_INITIAL (cvar);
   
   c_tree = build_stmt (UNKNOWN_LOCATION, CILK_FOR_STMT, NULL_TREE, NULL_TREE,
Index: gcc/testsuite/gcc.dg/cilk-plus/cilk_keywords_test/errors/cilk_for_volatile_var.c
===================================================================
--- gcc/testsuite/gcc.dg/cilk-plus/cilk_keywords_test/errors/cilk_for_volatile_var.c	(revision 0)
+++ gcc/testsuite/gcc.dg/cilk-plus/cilk_keywords_test/errors/cilk_for_volatile_var.c	(revision 0)
@@ -0,0 +1,20 @@
+/* <feature>
+    The variable may not be const or volatile
+   </feature>
+*/
+
+#include "controls.h"
+
+int a[SMALL_INT_ARRAY_SIZE];
+
+int main (void)
+{
+    volatile int ii;
+    const int jj;
+
+    
+    _Cilk_for(ii = 0; ii < SMALL_INT_ARRAY_SIZE; ii++) /* { dg-error "_Cilk_for induction variable cannot be volatile." } */
+    {
+	a[ii] = ii;
+    }
+}
Index: gcc/testsuite/gcc.dg/cilk-plus/cilk_keywords_test/errors/cilk_for_invalid_compares.c
===================================================================
--- gcc/testsuite/gcc.dg/cilk-plus/cilk_keywords_test/errors/cilk_for_invalid_compares.c	(revision 0)
+++ gcc/testsuite/gcc.dg/cilk-plus/cilk_keywords_test/errors/cilk_for_invalid_compares.c	(revision 0)
@@ -0,0 +1,17 @@
+/* <feature>
+     The operator denoted OP shall be one of !=, <=, <, >=, or >
+   </feature>
+*/
+
+#define ARRAY_SIZE 10000
+
+int a[ARRAY_SIZE];
+
+int main (void)
+{
+    int ii;
+    _Cilk_for(ii = 0; ii == ARRAY_SIZE; ii++) /* { dg-error "_Cilk_for condition must be one of the following."  */
+    {
+	a[ii] = ii;
+    }
+}
Index: gcc/testsuite/ChangeLog.cilkplus
===================================================================
--- gcc/testsuite/ChangeLog.cilkplus	(revision 194496)
+++ gcc/testsuite/ChangeLog.cilkplus	(working copy)
@@ -1,3 +1,10 @@
+2012-12-14  Balaji V. Iyer  <balaji.v.iyer@intel.com>
+
+	* gcc.dg/cilk-plus/cilk_keywords_test/errors/cilk_for_invalid_compares.c: 
+	New test.
+	* gcc.dg/cilk-plus/cilk_keywords_test/errors/cilk_for_volatile_var.c:
+	Likewise.
+
 2012-12-12  Balaji V. Iyer  <balaji.v.iyer@intel.com>
 
 	* gcc.dg/cilk-plus/cilk_keywords_test/errors/goto_inside_cilkfor.c: 
Index: gcc/ChangeLog.cilkplus
===================================================================
--- gcc/ChangeLog.cilkplus	(revision 194496)
+++ gcc/ChangeLog.cilkplus	(working copy)
@@ -1,3 +1,11 @@
+2012-12-14  Balaji V. Iyer  <balaji.v.iyer@intel.com>
+
+	* c/c-parser.c (c_parser_cilk_for_statement): Replaced unknown location with the
+	correct location value.
+	* c/c-typeck.c (c_finish_cilk_loop): Checked if the increment is one of
+	the following: !=, <=, <, >=, or >.  Report error otherwise.  Also 
+	report error if the induction variable is constant or volatile.
+
 2012-12-13  Balaji V. Iyer  <balaji.v.iyer@intel.com>
 
 	* tree-vect-loop.c (vect_determine_vectorization_factor): Added a
