--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/gcc/testsuite/gcc.dg/strcmpopt_6.c	Thu Feb 13 11:34:05 2020 +0900
@@ -0,0 +1,207 @@
+/* Verify that strcmp and strncmp calls with mixed constant and
+   non-constant strings are evaluated correctly.
+   { dg-do run }
+   { dg-options "-O2" } */
+
+#include "strlenopt.h"
+
+#define A(expr)                                                 \
+  ((expr)                                                       \
+   ? (void)0                                                    \
+   : (__builtin_printf ("assertion failed on line %i: %s\n",    \
+                        __LINE__, #expr),                       \
+      __builtin_abort ()))
+
+__attribute__ ((noclone, noinline)) int
+test_strlen_gt2_strcmp_abcd (const char *s)
+{
+  if (strlen (s) < 3)
+    return -1;
+
+  return strcmp (s, "abcd") == 0;
+}
+
+__attribute__ ((noclone, noinline)) int
+test_strlen_lt6_strcmp_abcd (const char *s)
+{
+  if (strlen (s) > 5)
+    return -1;
+
+  return strcmp (s, "abcd") == 0;
+}
+
+__attribute__ ((noclone, noinline)) int
+test_strcpy_strcmp_abc (const char *s)
+{
+  char a[4];
+  strcpy (a, s);
+  return strcmp (a, "abc") == 0;
+}
+
+__attribute__ ((noclone, noinline)) int
+test_strcpy_abc_strcmp (const char *s)
+{
+  char a[4], b[6];
+  strcpy (a, "abc");
+  strcpy (b, s);
+  return strcmp (a, b) == 0;
+}
+
+/* Exercise strcmp of two strings between 1 and 3 characters long
+   stored in arrays of the same known size.  */
+char ga4[4], gb4[4];
+
+__attribute__ ((noclone, noinline)) int
+test_store_0_nulterm_strcmp_same_size_arrays (void)
+{
+  ga4[0] = gb4[0] = 'x';
+  ga4[3] = gb4[3] = '\0';
+  return strcmp (ga4, gb4) == 0;
+}
+
+__attribute__ ((noclone, noinline)) int
+test_store_0_nulterm_strncmp_bound_2_same_size_arrays (void)
+{
+  ga4[0] = gb4[0] = 'x';
+  ga4[3] = gb4[3] = '\0';
+  return strncmp (ga4, gb4, 2) == 0;
+}
+
+__attribute__ ((noclone, noinline)) int
+test_store_0_nulterm_strncmp_bound_equal_same_size_arrays (void)
+{
+  ga4[0] = gb4[0] = 'x';
+  ga4[3] = gb4[3] = '\0';
+  return strncmp (ga4, gb4, 4) == 0;
+}
+
+/* Exercise strcmp of two strings between 0 and 3 characters long
+   stored in arrays of the same known size.  */
+
+__attribute__ ((noclone, noinline)) int
+test_nulterm_strcmp_same_size_arrays (void)
+{
+  ga4[3] = gb4[3] = '\0';
+  return strcmp (ga4, gb4) == 0;
+}
+
+/* Exercise strcmp of two strings between 1 and 3 and 1 and 4 characters
+   long, respectively, stored in arrays of known but different sizes.  */
+char gc5[5];
+
+__attribute__ ((noclone, noinline)) int
+test_store_0_nulterm_strcmp_arrays (void)
+{
+  ga4[0] = gc5[0] = 'x';
+  ga4[3] = gc5[4] = '\0';
+  return strcmp (ga4, gc5) == 0;
+}
+
+/* Exercise strcmp of two strings between 0 and 3 and 1 and 4 characters
+   long, respectively, stored in arrays of known but different sizes.  */
+
+__attribute__ ((noclone, noinline)) int
+test_nulterm_strcmp_arrays (void)
+{
+  ga4[3] = gc5[4] = '\0';
+  return strcmp (ga4, gc5) == 0;
+}
+
+
+__attribute__ ((noclone, noinline)) int
+test_strcpy_strncmp_abcd (const char *s)
+{
+  char a[6];
+  strcpy (a, s);
+  return strcmp (a, "abcd") == 0;
+}
+
+__attribute__ ((noclone, noinline)) int
+test_strcpy_abcd_strncmp_3 (const char *s)
+{
+  char a[6], b[8];
+  strcpy (a, "abcd");
+  strcpy (b, s);
+  return strncmp (a, b, 3) == 0;
+}
+
+__attribute__ ((noclone, noinline)) int
+test_strcpy_abcd_strncmp_4 (const char *s)
+{
+  char a[6], b[8];
+  strcpy (a, "abcd");
+  strcpy (b, s);
+  return strncmp (a, b, 4) == 0;
+}
+
+
+int main (void)
+{
+  test_strlen_gt2_strcmp_abcd ("abcd");
+  test_strlen_lt6_strcmp_abcd ("abcd");
+
+  A (0 == test_strcpy_strcmp_abc ("ab"));
+  A (0 != test_strcpy_strcmp_abc ("abc"));
+  A (0 == test_strcpy_strcmp_abc ("abcd"));
+
+  A (0 == test_strcpy_abc_strcmp ("ab"));
+  A (0 != test_strcpy_abc_strcmp ("abc"));
+  A (0 == test_strcpy_abc_strcmp ("abcd"));
+
+  strcpy (ga4, "abc"); strcpy (gb4, "abd");
+  A (0 == test_store_0_nulterm_strcmp_same_size_arrays ());
+  strcpy (ga4, "abd"); strcpy (gb4, "abc");
+  A (0 == test_store_0_nulterm_strcmp_same_size_arrays ());
+  strcpy (ga4, "abc"); strcpy (gb4, "abc");
+  A (0 != test_store_0_nulterm_strcmp_same_size_arrays ());
+
+  strcpy (ga4, "abc"); strcpy (gb4, "acd");
+  A (0 == test_store_0_nulterm_strncmp_bound_2_same_size_arrays ());
+  strcpy (ga4, "acd"); strcpy (gb4, "abc");
+  A (0 == test_store_0_nulterm_strncmp_bound_2_same_size_arrays ());
+  strcpy (ga4, "abc"); strcpy (gb4, "abc");
+  A (0 != test_store_0_nulterm_strncmp_bound_2_same_size_arrays ());
+
+  strcpy (ga4, "abc"); strcpy (gb4, "abd");
+  A (0 == test_store_0_nulterm_strncmp_bound_equal_same_size_arrays ());
+  strcpy (ga4, "abd"); strcpy (gb4, "abc");
+  A (0 == test_store_0_nulterm_strncmp_bound_equal_same_size_arrays ());
+  strcpy (ga4, "abc"); strcpy (gb4, "abc");
+  A (0 != test_store_0_nulterm_strncmp_bound_equal_same_size_arrays ());
+
+  strcpy (ga4, "abc"); strcpy (gb4, "abd");
+  A (0 == test_nulterm_strcmp_same_size_arrays ());
+  strcpy (ga4, "abd"); strcpy (gb4, "abc");
+  A (0 == test_nulterm_strcmp_same_size_arrays ());
+  strcpy (ga4, "abc"); strcpy (gb4, "abc");
+  A (0 != test_nulterm_strcmp_same_size_arrays ());
+
+  strcpy (ga4, "abc"); strcpy (gc5, "abcd");
+  A (0 == test_store_0_nulterm_strcmp_arrays ());
+  strcpy (ga4, "abd"); strcpy (gc5, "abcd");
+  A (0 == test_store_0_nulterm_strcmp_arrays ());
+  strcpy (ga4, "abc"); strcpy (gc5, "abc");
+  A (0 != test_store_0_nulterm_strcmp_arrays ());
+
+  strcpy (ga4, "abc"); strcpy (gc5, "abcd");
+  A (0 == test_nulterm_strcmp_arrays ());
+  strcpy (ga4, "abd"); strcpy (gc5, "abc");
+  A (0 == test_nulterm_strcmp_arrays ());
+  strcpy (ga4, "abc"); strcpy (gc5, "abc");
+  A (0 != test_nulterm_strcmp_arrays ());
+
+  A (0 == test_strcpy_strncmp_abcd ("ab"));
+  A (0 == test_strcpy_strncmp_abcd ("abc"));
+  A (0 != test_strcpy_strncmp_abcd ("abcd"));
+  A (0 == test_strcpy_strncmp_abcd ("abcde"));
+
+  A (0 == test_strcpy_abcd_strncmp_3 ("ab"));
+  A (0 != test_strcpy_abcd_strncmp_3 ("abc"));
+  A (0 != test_strcpy_abcd_strncmp_3 ("abcd"));
+  A (0 != test_strcpy_abcd_strncmp_3 ("abcde"));
+
+  A (0 == test_strcpy_abcd_strncmp_4 ("ab"));
+  A (0 == test_strcpy_abcd_strncmp_4 ("abc"));
+  A (0 != test_strcpy_abcd_strncmp_4 ("abcd"));
+  A (0 != test_strcpy_abcd_strncmp_4 ("abcde"));
+}