x86: Don't enable APX_F in 32-bit mode

gcc/ChangeLog:

	PR target/115978
	* config/i386/driver-i386.cc (host_detect_local_cpu):  Enable
	APX_F only for 64-bit codegen.
	* config/i386/i386-options.cc (DEF_PTA):  Skip PTA_APX_F if
	not in 64-bit mode.

gcc/testsuite/ChangeLog:

	PR target/115978
	* gcc.target/i386/pr115978-1.c: New test.
	* gcc.target/i386/pr115978-2.c: Ditto.

gcc/config/i386/driver-i386.cc

@@ -893,7 +893,8 @@ const char *host_detect_local_cpu (int argc, const char **argv)
 	    if (has_feature (isa_names_table[i].feature))
 	      {
 		if (codegen_x86_64
-		    || isa_names_table[i].feature != FEATURE_UINTR)
+		    || (isa_names_table[i].feature != FEATURE_UINTR
+			&& isa_names_table[i].feature != FEATURE_APX_F))
 		  options = concat (options, " ",
 				    isa_names_table[i].option, NULL);
 	      }

gcc/config/i386/i386-options.cc

@@ -2385,7 +2385,8 @@ ix86_option_override_internal (bool main_args_p,
 #define DEF_PTA(NAME) \
 	if (((processor_alias_table[i].flags & PTA_ ## NAME) != 0) \
 	    && PTA_ ## NAME != PTA_64BIT \
-	    && (TARGET_64BIT || PTA_ ## NAME != PTA_UINTR) \
+	    && (TARGET_64BIT || (PTA_ ## NAME != PTA_UINTR \
+				 && PTA_ ## NAME != PTA_APX_F))\
 	    && !TARGET_EXPLICIT_ ## NAME ## _P (opts)) \
 	  SET_TARGET_ ## NAME (opts);
 #include "i386-isa.def"

gcc/testsuite/gcc.target/i386/pr115978-1.c

@@ -0,0 +1,22 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -march=native" } */
+
+int
+main ()
+{
+  if (__builtin_cpu_supports ("apxf"))
+    {
+#ifdef __x86_64__
+# ifndef __APX_F__
+      __builtin_abort ();
+# endif
+#else
+# ifdef __APX_F__
+      __builtin_abort ();
+# endif
+#endif
+      return 0;
+    }
+
+  return 0;
+}

gcc/testsuite/gcc.target/i386/pr115978-2.c

@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=native -mno-apxf" } */
+
+#ifdef __APX_F__
+# error APX_F should be disabled
+#endif