2007-05-20 Manuel Lopez-Ibanez <manu@gcc.gnu.org>

	
	PR middle-end/7651
	PR c++/11856
	PR c/12963
	PR c/23587
	PR other/29694
	* c.opt (Wtype-limits): New.
	* doc/invoke.texi (Wtype-limits): Document it.
	(Wextra): Enabled by -Wextra.
	* c-opts.c (c_common_post_options): Enabled by -Wextra.
	* c-common.c (shorten_compare): Warn with Wtype-limits.

testsuite/
	* gcc.dg/compare6.c: Replace Wall with Wtype-limits.
	* gcc.dg/Wtype-limits.c: New.
	* gcc.dg/Wtype-limits-Wextra.c: New.
	* gcc.dg/Wtype-limits-no.c: New.
	* g++.dg/warn/Wtype-limits.C: New.
	* g++.dg/warn/Wtype-limits-Wextra.C: New.
	* g++.dg/warn/Wtype-limits-no.C: New.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@124875 138bc75d-0d04-0410-961f-82ee72b054a4

8 files changed, 466 insertions, 1 deletions

diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 0b7b2c0583f..db0a0d5ac95 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,18 @@
+2007-05-20  Manuel Lopez-Ibanez  <manu@gcc.gnu.org>
+
+	PR middle-end/7651
+	PR c++/11856
+	PR c/12963
+	PR c/23587
+	PR other/29694
+	* gcc.dg/compare6.c: Replace Wall with Wtype-limits.
+	* gcc.dg/Wtype-limits.c: New.
+	* gcc.dg/Wtype-limits-Wextra.c: New.
+	* gcc.dg/Wtype-limits-no.c: New.
+	* g++.dg/warn/Wtype-limits.C: New.
+	* g++.dg/warn/Wtype-limits-Wextra.C: New.
+	* g++.dg/warn/Wtype-limits-no.C: New.
+
 2006-05-20  Uros Bizjak  <ubizjak@gmail.com>
 
 	* gcc.target/i386/sse-vect-types.c: Revert 'Use "-msse"
diff --git a/gcc/testsuite/g++.dg/warn/Wtype-limits-Wextra.C b/gcc/testsuite/g++.dg/warn/Wtype-limits-Wextra.C
new file mode 100644
index 00000000000..9cbdbe54783
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wtype-limits-Wextra.C
@@ -0,0 +1,84 @@
+/* Test that -Wtype-limits is enabled by -Wextra.  */
+/* { dg-do compile } */
+/* { dg-options "-Wextra" } */
+extern void assert (int);
+
+void a (unsigned char x)
+{
+  if (x < 0)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (x <= 255) /* { dg-warning "comparison is always true due to limited range of data type" } */
+    return;
+  if (255 >= x) /* { dg-warning "comparison is always true due to limited range of data type" } */
+    return;
+  if ((int)x <= 255) /* { dg-bogus "comparison is always true due to limited range of data type" "" { xfail *-*-* } 16 } */
+    return;
+  if (255 >= (unsigned char) 1)
+    return;
+
+}
+
+void b (unsigned short x)
+{
+  if (x < 0)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+}
+
+void c (unsigned int 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+  if (1U >= 0) return;
+  if (1U < 0) return;
+  if (0 <= 1U) return;
+  if (0 > 1U) return;
+}
+
+void d (unsigned long 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+}
+
+void e (unsigned long long 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+}
+
+int test (int x) 
+{
+  if ((long long)x <= 0x123456789ABCLL) /* { dg-bogus "comparison is always true due to limited range of data type" "" { xfail *-*-* } 61 } */
+    return 1;
+  else 
+    return 0;
+}
+
+template <typename Int, Int D>
+void f(Int x) {
+  assert(0 <= x and x <= D); // { dg-warning "comparison is always true due to limited range of data type" }
+}
+
+int ff(void) {
+  f<unsigned char, 2>(5);
+  f<signed char, 2>(5);
+}
+
+template <typename Int, Int D>
+void g(void) {
+  assert(0 <= D);
+}
+int gg(void) {
+  g<unsigned char, 2>();
+}
+
diff --git a/gcc/testsuite/g++.dg/warn/Wtype-limits-no.C b/gcc/testsuite/g++.dg/warn/Wtype-limits-no.C
new file mode 100644
index 00000000000..5040e2657ba
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wtype-limits-no.C
@@ -0,0 +1,84 @@
+/* Test disabling -Wtype-limits.  */
+/* { dg-do compile } */
+/* { dg-options "-Wextra -Wno-type-limits" } */
+extern void assert (int);
+
+void a (unsigned char x)
+{
+  if (x < 0)  return;/* { dg-bogus "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-bogus "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-bogus "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-bogus "comparison is always true due to limited range of data type" } */
+  if (x <= 255) /* { dg-bogus "comparison is always true due to limited range of data type" } */
+    return;
+  if (255 >= x) /* { dg-bogus "comparison is always true due to limited range of data type" } */
+    return;
+  if ((int)x <= 255) 
+    return;
+  if (255 >= (unsigned char) 1)
+    return;
+
+}
+
+void b (unsigned short x)
+{
+  if (x < 0)  return;/* { dg-bogus "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-bogus "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-bogus "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-bogus "comparison is always true due to limited range of data type" } */
+}
+
+void c (unsigned int 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 (0 > x)  return;/* { dg-bogus "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-bogus "comparison of unsigned expression >= 0 is always true" } */
+  if (1U >= 0) return;
+  if (1U < 0) return;
+  if (0 <= 1U) return;
+  if (0 > 1U) return;
+}
+
+void d (unsigned long 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 (0 > x)  return;/* { dg-bogus "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-bogus "comparison of unsigned expression >= 0 is always true" } */
+}
+
+void e (unsigned long long 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 (0 > x)  return;/* { dg-bogus "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-bogus "comparison of unsigned expression >= 0 is always true" } */
+}
+
+int test (int x) 
+{
+  if ((long long)x <= 0x123456789ABCLL) /* { dg-bogus "comparison is always true due to limited range of data type" } */
+    return 1;
+  else 
+    return 0;
+}
+
+template <typename Int, Int D>
+void f(Int x) {
+  assert(0 <= x and x <= D); // { dg-bogus "comparison is always true due to limited range of data type" }
+}
+
+int ff(void) {
+  f<unsigned char, 2>(5);
+  f<signed char, 2>(5);
+}
+
+template <typename Int, Int D>
+void g(void) {
+  assert(0 <= D);
+}
+int gg(void) {
+  g<unsigned char, 2>();
+}
+
diff --git a/gcc/testsuite/g++.dg/warn/Wtype-limits.C b/gcc/testsuite/g++.dg/warn/Wtype-limits.C
new file mode 100644
index 00000000000..814c2a8826e
--- /dev/null
+++ b/gcc/testsuite/g++.dg/warn/Wtype-limits.C
@@ -0,0 +1,84 @@
+/* { dg-do compile } */
+/* { dg-options "-Wtype-limits" } */
+
+extern void assert (int);
+
+void a (unsigned char x)
+{
+  if (x < 0)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (x <= 255) /* { dg-warning "comparison is always true due to limited range of data type" } */
+    return;
+  if (255 >= x) /* { dg-warning "comparison is always true due to limited range of data type" } */
+    return;
+  if ((int)x <= 255) /* { dg-bogus "comparison is always true due to limited range of data type" "" { xfail *-*-* } 16 } */
+    return;
+  if (255 >= (unsigned char) 1)
+    return;
+
+}
+
+void b (unsigned short x)
+{
+  if (x < 0)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+}
+
+void c (unsigned int 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+  if (1U >= 0) return;
+  if (1U < 0) return;
+  if (0 <= 1U) return;
+  if (0 > 1U) return;
+}
+
+void d (unsigned long 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+}
+
+void e (unsigned long long 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+}
+
+int test (int x) 
+{
+  if ((long long)x <= 0x123456789ABCLL) /* { dg-bogus "comparison is always true due to limited range of data type" "" { xfail *-*-* } 61 } */
+    return 1;
+  else 
+    return 0;
+}
+
+template <typename Int, Int D>
+void f(Int x) {
+  assert(0 <= x and x <= D); // { dg-warning "comparison is always true due to limited range of data type" }
+}
+
+int ff(void) {
+  f<unsigned char, 2>(5);
+  f<signed char, 2>(5);
+}
+
+template <typename Int, Int D>
+void g(void) {
+  assert(0 <= D);
+}
+int gg(void) {
+  g<unsigned char, 2>();
+}
+
diff --git a/gcc/testsuite/gcc.dg/Wtype-limits-Wextra.c b/gcc/testsuite/gcc.dg/Wtype-limits-Wextra.c
new file mode 100644
index 00000000000..ae13e73ef8b
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wtype-limits-Wextra.c
@@ -0,0 +1,66 @@
+/* Test that -Wtype-limits is enabled by -Wextra */
+/* { dg-do compile } */
+/* { dg-options "-Wextra" } */
+
+
+void a (unsigned char x)
+{
+  if (x < 0)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (x <= 255) /* { dg-warning "comparison is always true due to limited range of data type" } */
+    return;
+  if (255 >= x) /* { dg-warning "comparison is always true due to limited range of data type" } */
+    return;
+  if ((int)x <= 255) /* { dg-bogus "comparison is always true due to limited range of data type" "" { xfail *-*-* } 16 } */
+    return;
+  if (255 >= (unsigned char) 1)
+    return;
+
+}
+
+void b (unsigned short x)
+{
+  if (x < 0)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+}
+
+void c (unsigned int 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+  if (1U >= 0) return;
+  if (1U < 0) return;
+  if (0 <= 1U) return;
+  if (0 > 1U) return;
+}
+
+void d (unsigned long 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+}
+
+void e (unsigned long long 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+}
+
+int test (int x) 
+{
+  if ((long long)x <= 0x123456789ABCLL) /* { dg-bogus "comparison is always true due to limited range of data type" "" { xfail *-*-* } 61 } */
+    return 1;
+  else 
+    return 0;
+}
+
diff --git a/gcc/testsuite/gcc.dg/Wtype-limits-no.c b/gcc/testsuite/gcc.dg/Wtype-limits-no.c
new file mode 100644
index 00000000000..2af909abfa6
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wtype-limits-no.c
@@ -0,0 +1,66 @@
+/* Test disabling -Wtype-limits */
+/* { dg-do compile } */
+/* { dg-options "-Wextra -Wno-type-limits" } */
+
+
+void a (unsigned char x)
+{
+  if (x < 0)  return;/* { dg-bogus "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-bogus "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-bogus "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-bogus "comparison is always true due to limited range of data type" } */
+  if (x <= 255) /* { dg-bogus "comparison is always true due to limited range of data type" } */
+    return;
+  if (255 >= x) /* { dg-bogus "comparison is always true due to limited range of data type" } */
+    return;
+  if ((int)x <= 255)
+    return;
+  if (255 >= (unsigned char) 1)
+    return;
+
+}
+
+void b (unsigned short x)
+{
+  if (x < 0)  return;/* { dg-bogus "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-bogus "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-bogus "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-bogus "comparison is always true due to limited range of data type" } */
+}
+
+void c (unsigned int 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 (0 > x)  return;/* { dg-bogus "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-bogus "comparison of unsigned expression >= 0 is always true" } */
+  if (1U >= 0) return;
+  if (1U < 0) return;
+  if (0 <= 1U) return;
+  if (0 > 1U) return;
+}
+
+void d (unsigned long 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 (0 > x)  return;/* { dg-bogus "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-bogus "comparison of unsigned expression >= 0 is always true" } */
+}
+
+void e (unsigned long long 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 (0 > x)  return;/* { dg-bogus "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-bogus "comparison of unsigned expression >= 0 is always true" } */
+}
+
+int test (int x) 
+{
+  if ((long long)x <= 0x123456789ABCLL) 
+    return 1;
+  else 
+    return 0;
+}
+
diff --git a/gcc/testsuite/gcc.dg/Wtype-limits.c b/gcc/testsuite/gcc.dg/Wtype-limits.c
new file mode 100644
index 00000000000..64e7da61c9a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/Wtype-limits.c
@@ -0,0 +1,66 @@
+/* { dg-do compile } */
+/* { dg-options "-Wtype-limits" } */
+
+
+
+void a (unsigned char x)
+{
+  if (x < 0)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (x <= 255) /* { dg-warning "comparison is always true due to limited range of data type" } */
+    return;
+  if (255 >= x) /* { dg-warning "comparison is always true due to limited range of data type" } */
+    return;
+  if ((int)x <= 255) /* { dg-bogus "comparison is always true due to limited range of data type" "" { xfail *-*-* } 16 } */
+    return;
+  if (255 >= (unsigned char) 1)
+    return;
+
+}
+
+void b (unsigned short x)
+{
+  if (x < 0)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (x >= 0) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+  if (0 > x)  return;/* { dg-warning "comparison is always false due to limited range of data type" } */
+  if (0 <= x) return;/* { dg-warning "comparison is always true due to limited range of data type" } */
+}
+
+void c (unsigned int 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+  if (1U >= 0) return;
+  if (1U < 0) return;
+  if (0 <= 1U) return;
+  if (0 > 1U) return;
+}
+
+void d (unsigned long 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+}
+
+void e (unsigned long long 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 (0 > x)  return;/* { dg-warning "comparison of unsigned expression < 0 is always false" } */
+  if (0 <= x) return;/* { dg-warning "comparison of unsigned expression >= 0 is always true" } */
+}
+
+int test (int x) 
+{
+  if ((long long)x <= 0x123456789ABCLL) /* { dg-bogus "comparison is always true due to limited range of data type" "" { xfail *-*-* } 61 } */
+    return 1;
+  else 
+    return 0;
+}
+
diff --git a/gcc/testsuite/gcc.dg/compare6.c b/gcc/testsuite/gcc.dg/compare6.c
index fbeb6a0aedd..72f50207b03 100644
--- a/gcc/testsuite/gcc.dg/compare6.c
+++ b/gcc/testsuite/gcc.dg/compare6.c
@@ -1,7 +1,7 @@
 /* PR c/2098 */
 /* Test for a warning on comparison on out-of-range data.  */
 /* { dg-do compile { xfail c4x-*-* } } */
-/* { dg-options "-Wall" } */
+/* { dg-options "-Wtype-limits" } */
 
 signed char sc;
 unsigned char uc;