[PATCH 6/6] x86: don't accept base architectures as extensions

[Jan Beulich <jbeulich@suse.com>]

The -march= intentions are quite clear: A base architecture may be
followed by any number of extensions. Accepting a base architecture in
place of an extension will at best result in confusion, as the first of
the two (or more) items specified simply would not take effect, due to
being overridden by the later one(s).

--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -13263,7 +13263,7 @@ md_parse_option (int c, const char *arg)
 	    *next++ = '\0';
 	  for (j = 0; j < ARRAY_SIZE (cpu_arch); j++)
 	    {
-	      if (strcmp (arch, cpu_arch [j].name) == 0)
+	      if (arch == saved && strcmp (arch, cpu_arch [j].name) == 0)
 		{
 		  /* Processor.  */
 		  if (! cpu_arch[j].flags.bitfield.cpui386)
--- /dev/null
+++ b/gas/testsuite/gas/i386/arch-10-5.l
@@ -0,0 +1,2 @@
+Assembler messages:
+Fatal error: .*
--- /dev/null
+++ b/gas/testsuite/gas/i386/arch-10-5.s
@@ -0,0 +1 @@
+	.text
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -199,6 +199,7 @@ if [gas_32_check] then {
     run_list_test "arch-10-2" "-march=i686 -I${srcdir}/$subdir -al"
     run_list_test "arch-10-3" "-march=i686+mmx+sse4.2 -I${srcdir}/$subdir -al"
     run_list_test "arch-10-4" "-march=i686+mmx+sse4+vmx+smx -I${srcdir}/$subdir -al"
+    run_list_test "arch-10-5" "-march=generic32+i686 -al"
     run_dump_test "arch-11"
     run_dump_test "arch-12"
     run_dump_test "arch-13"