Index: gcc/doc/invoke.texi
===================================================================
--- gcc/doc/invoke.texi	(revision 120173)
+++ gcc/doc/invoke.texi	(working copy)
@@ -230,7 +230,7 @@ Objective-C and Objective-C++ Dialects}.
 -Werror  -Werror-* -Werror-implicit-function-declaration @gol
 -Wfatal-errors  -Wfloat-equal  -Wformat  -Wformat=2 @gol
 -Wno-format-extra-args -Wformat-nonliteral @gol
--Wformat-security  -Wformat-y2k @gol
+-Wformat-security  -Wformat-y2k  -Wfutile-unsigned-comparison @gol
 -Wimplicit  -Wimplicit-function-declaration  -Wimplicit-int @gol
 -Wimport  -Wno-import  -Winit-self  -Winline @gol
 -Wno-int-to-pointer-cast @gol
@@ -2883,7 +2883,9 @@ For example, an expression such as @samp
 but @samp{x[(void)i,j]} will not.
 
 @item
-An unsigned value is compared against zero with @samp{<} or @samp{>=}.
+An unsigned variable is compared against zero with @samp{<} or @samp{>=}.
+This warning can be independently controlled by 
+@option{-Wfutile-unsigned-comparison}.
 
 @item
 Storage-class specifiers like @code{static} are not the first things in
@@ -3177,6 +3179,11 @@ changed by the conversion like in @code{
 An empty body occurs in an @samp{if} or @samp{else} statement. 
 This warning is also enabled by @option{-Wextra}.
 
+@item -Wfutile-unsigned-comparison
+@opindex Wfutile-unsigned-comparison
+An unsigned variable is compared against zero with @samp{<} or @samp{>=}.
+This warning is also enabled by @option{-Wextra}.
+
 @item -Wsign-compare
 @opindex Wsign-compare
 @cindex warning for comparison of signed and unsigned values
Index: gcc/testsuite/gcc.dg/Wfutile-unsigned-comparison-no.c
===================================================================
--- gcc/testsuite/gcc.dg/Wfutile-unsigned-comparison-no.c	(revision 0)
+++ gcc/testsuite/gcc.dg/Wfutile-unsigned-comparison-no.c	(revision 0)
@@ -0,0 +1,11 @@
+/* Test disabling -Wfutile-unsigned-comparison */
+/* { dg-do compile } */
+/* { dg-options "-Wextra -Wno-futile-unsigned-comparison" } */
+
+void h(unsigned x)
+{
+    if (x < 0)  return;/* { dg-bogus "comparison of unsigned expression < 0 is always false" } */
+    if (x >= 0) return;/* { dg-bogus "comparison of unsigned expression >= 0 is always true" } */
+    if (1U >= 0) return;
+    if (1U < 0) return;
+}
Index: gcc/testsuite/gcc.dg/Wfutile-unsigned-comparison-Wextra.c
===================================================================
--- gcc/testsuite/gcc.dg/Wfutile-unsigned-comparison-Wextra.c	(revision 0)
+++ gcc/testsuite/gcc.dg/Wfutile-unsigned-comparison-Wextra.c	(revision 0)
@@ -0,0 +1,11 @@
+/* Test that -Wfutile-unsigned-comparison is enabled by -Wextra */
+/* { dg-do compile } */
+/* { dg-options "-Wextra" } */
+
+void h(unsigned x)
+{
+    if (x < 0)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+    if (x >= 0) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+    if (1U >= 0) return;
+    if (1U < 0) return;
+}
Index: gcc/testsuite/gcc.dg/Wfutile-unsigned-comparison.c
===================================================================
--- gcc/testsuite/gcc.dg/Wfutile-unsigned-comparison.c	(revision 0)
+++ gcc/testsuite/gcc.dg/Wfutile-unsigned-comparison.c	(revision 0)
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-Wfutile-unsigned-comparison" } */
+
+void h(unsigned x)
+{
+    if (x < 0)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+    if (x >= 0) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+    if (1U >= 0) return;
+    if (1U < 0) return;
+}
Index: gcc/testsuite/g++.dg/warn/Wfutile-unsigned-comparison.C
===================================================================
--- gcc/testsuite/g++.dg/warn/Wfutile-unsigned-comparison.C	(revision 0)
+++ gcc/testsuite/g++.dg/warn/Wfutile-unsigned-comparison.C	(revision 0)
@@ -0,0 +1,10 @@
+/* { dg-do compile } */
+/* { dg-options "-Wfutile-unsigned-comparison" } */
+
+void h(unsigned x)
+{
+    if (x < 0)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+    if (x >= 0) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+    if (1U >= 0) return;
+    if (1U < 0) return;
+}
Index: gcc/testsuite/g++.dg/warn/Wfutile-unsigned-comparison-Wextra.C
===================================================================
--- gcc/testsuite/g++.dg/warn/Wfutile-unsigned-comparison-Wextra.C	(revision 0)
+++ gcc/testsuite/g++.dg/warn/Wfutile-unsigned-comparison-Wextra.C	(revision 0)
@@ -0,0 +1,11 @@
+/* Test that -Wfutile-unsigned-comparison is enabled by -Wextra */
+/* { dg-do compile } */
+/* { dg-options "-Wextra" } */
+
+void h(unsigned x)
+{
+    if (x < 0)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+    if (x >= 0) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+    if (1U >= 0) return;
+    if (1U < 0) return;
+}
Index: gcc/testsuite/g++.dg/warn/Wfutile-unsigned-comparison-no.C
===================================================================
--- gcc/testsuite/g++.dg/warn/Wfutile-unsigned-comparison-no.C	(revision 0)
+++ gcc/testsuite/g++.dg/warn/Wfutile-unsigned-comparison-no.C	(revision 0)
@@ -0,0 +1,11 @@
+/* Test disabling -Wfutile-unsigned-comparison */
+/* { dg-do compile } */
+/* { dg-options "-Wextra -Wno-futile-unsigned-comparison" } */
+
+void h(unsigned x)
+{
+    if (x < 0)  return;/* { dg-bogus "comparison of unsigned expression < 0 is always false" } */
+    if (x >= 0) return;/* { dg-bogus "comparison of unsigned expression >= 0 is always true" } */
+    if (1U >= 0) return;
+    if (1U < 0) return;
+}
Index: gcc/c.opt
===================================================================
--- gcc/c.opt	(revision 120173)
+++ gcc/c.opt	(working copy)
@@ -224,6 +224,10 @@ Warn about zero-length formats
 Wformat=
 C ObjC C++ ObjC++ Joined
 
+Wfutile-unsigned-comparison
+C ObjC C++ ObjC++ Var(warn_futile_unsigned_comparison) Init(-1)
+Warn about comparison of unsigned variables against zero with < or >=
+
 Winit-self
 C ObjC C++ ObjC++ Var(warn_init_self)
 Warn about variables which are initialized to themselves
Index: gcc/c-opts.c
===================================================================
--- gcc/c-opts.c	(revision 120173)
+++ gcc/c-opts.c	(working copy)
@@ -1025,13 +1025,16 @@ c_common_post_options (const char **pfil
   if (flag_objc_exceptions && !flag_objc_sjlj_exceptions)
     flag_exceptions = 1;
 
-  /* -Wextra implies -Wclobbered, -Wempty-body, -Wsign-compare, 
+  /* -Wextra implies -Wclobbered, -Wempty-body,
+     -Wfutile-unsigned-comparison, -Wsign-compare, 
      -Wmissing-field-initializers, -Wmissing-parameter-type and -Woverride-init, 
      but not if explicitly overridden.  */
   if (warn_clobbered == -1)
     warn_clobbered = extra_warnings;
   if (warn_empty_body == -1)
     warn_empty_body = extra_warnings;
+  if (warn_futile_unsigned_comparison == -1)
+    warn_futile_unsigned_comparison = extra_warnings;
   if (warn_sign_compare == -1)
     warn_sign_compare = extra_warnings;
   if (warn_missing_field_initializers == -1)
Index: gcc/c-common.c
===================================================================
--- gcc/c-common.c	(revision 120173)
+++ gcc/c-common.c	(working copy)
@@ -2463,24 +2463,27 @@ shorten_compare (tree *op0_ptr, tree *op
 	  switch (code)
 	    {
 	    case GE_EXPR:
-	      /* All unsigned values are >= 0, so we warn if extra warnings
-		 are requested.  However, if OP0 is a constant that is
-		 >= 0, the signedness of the comparison isn't an issue,
-		 so suppress the warning.  */
-	      if (extra_warnings && !in_system_header
+	      /* All unsigned values are >= 0, so we warn if
+		 Wfutile-unsigned-comparison is requested.  However,
+		 if OP0 is a constant that is >= 0, the signedness of
+		 the comparison isn't an issue, so suppress the
+		 warning.  */
+	      if (warn_futile_unsigned_comparison && !in_system_header
 		  && !(TREE_CODE (primop0) == INTEGER_CST
 		       && !TREE_OVERFLOW (convert (c_common_signed_type (type),
 						   primop0))))
-		warning (0, "comparison of unsigned expression >= 0 is always true");
+		warning (OPT_Wfutile_unsigned_comparison, 
+			 "comparison of unsigned expression >= 0 is always true");
 	      value = truthvalue_true_node;
 	      break;
 
 	    case LT_EXPR:
-	      if (extra_warnings && !in_system_header
+	      if (warn_futile_unsigned_comparison && !in_system_header
 		  && !(TREE_CODE (primop0) == INTEGER_CST
 		       && !TREE_OVERFLOW (convert (c_common_signed_type (type),
 						   primop0))))
-		warning (0, "comparison of unsigned expression < 0 is always false");
+		warning (OPT_Wfutile_unsigned_comparison, 
+			 "comparison of unsigned expression < 0 is always false");
 	      value = truthvalue_false_node;
 	      break;