x86: Accept Intel64 only instruction by default

Commit d835a58baae720 disabled sysenter/sysenter in 64-bit mode by
default.  By default, assembler should accept common, Intel64 only
and AMD64 ISAs since there are no conflicts.

gas/

	PR gas/25516
	* config/tc-i386.c (intel64): Renamed to ...
	(isa64): This.
	(match_template): Accept Intel64 only instruction by default.
	(i386_displacement): Updated.
	(md_parse_option): Updated.
	* c-i386.texi: Update -mamd64/-mintel64 documentation.
	* testsuite/gas/i386/i386.exp: Run x86-64-sysenter.  Pass
	-mamd64 to x86-64-sysenter-amd.
	* testsuite/gas/i386/x86-64-sysenter.d: New file.

opcodes/

	PR gas/25516
	* i386-gen.c (opcode_modifiers): Replace AMD64 and Intel64
	with ISA64.
	* i386-opc.h (AMD64): Removed.
	(Intel64): Likewose.
	(AMD64): New.
	(INTEL64): Likewise.
	(INTEL64ONLY): Likewise.
	(i386_opcode_modifier): Replace amd64 and intel64 with isa64.
	* i386-opc.tbl (Amd64): New.
	(Intel64): Likewise.
	(Intel64Only): Likewise.
	Replace AMD64 with Amd64.  Update sysenter/sysenter with
	Cpu64 and Intel64Only.  Remove AMD64 from sysenter/sysenter.
	* i386-tbl.h: Regenerated.

5 files changed, 52 insertions, 12 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index a07d9b7..d7d91a4 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,16 @@
+2020-02-10  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR gas/25516
+	* config/tc-i386.c (intel64): Renamed to ...
+	(isa64): This.
+	(match_template): Accept Intel64 only instruction by default.
+	(i386_displacement): Updated.
+	(md_parse_option): Updated.
+	* c-i386.texi: Update -mamd64/-mintel64 documentation.
+	* testsuite/gas/i386/i386.exp: Run x86-64-sysenter.  Pass
+	-mamd64 to x86-64-sysenter-amd.
+	* testsuite/gas/i386/x86-64-sysenter.d: New file.
+
 2020-02-10  Alan Modra  <amodra@gmail.com>
 
 	* config/obj-elf.c (obj_elf_change_section): Error for section
diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index 945ceb2..543fe25 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -598,9 +598,11 @@ static int shared = 0;
    0 if att syntax.  */
 static int intel_syntax = 0;
 
-/* 1 for Intel64 ISA,
-   0 if AMD64 ISA.  */
-static int intel64;
+static enum x86_64_isa
+{
+  amd64 = 1,	/* AMD64 ISA.  */
+  intel64	/* Intel64 ISA.  */
+} isa64;
 
 /* 1 for intel mnemonic,
    0 if att mnemonic.  */
@@ -5805,14 +5807,32 @@ match_template (char mnem_suffix)
       if (intel_mnemonic && t->opcode_modifier.attmnemonic)
 	continue;
 
-      /* Check AT&T/Intel syntax and Intel64/AMD64 ISA.   */
+      /* Check AT&T/Intel syntax.  */
       i.error = unsupported_syntax;
       if ((intel_syntax && t->opcode_modifier.attsyntax)
-	  || (!intel_syntax && t->opcode_modifier.intelsyntax)
-	  || (intel64 && t->opcode_modifier.amd64)
-	  || (!intel64 && t->opcode_modifier.intel64))
+	  || (!intel_syntax && t->opcode_modifier.intelsyntax))
 	continue;
 
+      /* Check Intel64/AMD64 ISA.   */
+      switch (isa64)
+	{
+	default:
+	  /* Default: Don't accept Intel64.  */
+	  if (t->opcode_modifier.isa64 == INTEL64)
+	    continue;
+	  break;
+	case amd64:
+	  /* -mamd64: Don't accept Intel64 and Intel64 only.  */
+	  if (t->opcode_modifier.isa64 >= INTEL64)
+	    continue;
+	  break;
+	case intel64:
+	  /* -mintel64: Don't accept AMD64.  */
+	  if (t->opcode_modifier.isa64 == AMD64)
+	    continue;
+	  break;
+	}
+
       /* Check the suffix.  */
       i.error = invalid_instruction_suffix;
       if ((t->opcode_modifier.no_bsuf && suffix_check.no_bsuf)
@@ -9963,7 +9983,7 @@ i386_displacement (char *disp_start, char *disp_end)
 	  if (t->opcode_modifier.jump
 	      != current_templates->start->opcode_modifier.jump)
 	    break;
-	  if (t->opcode_modifier.intel64)
+	  if ((t->opcode_modifier.isa64 >= INTEL64))
 	    has_intel64 = TRUE;
 	}
       if (t < current_templates->end)
@@ -12525,11 +12545,11 @@ md_parse_option (int c, const char *arg)
       break;
 
     case OPTION_MAMD64:
-      intel64 = 0;
+      isa64 = amd64;
       break;
 
     case OPTION_MINTEL64:
-      intel64 = 1;
+      isa64 = intel64;
       break;
 
     case 'O':
diff --git a/gas/doc/c-i386.texi b/gas/doc/c-i386.texi
index 9fb681e..f0189cc 100644
--- a/gas/doc/c-i386.texi
+++ b/gas/doc/c-i386.texi
@@ -488,7 +488,8 @@ with 01, 10 and 11 RC bits, respectively.
 @item -mamd64
 @itemx -mintel64
 This option specifies that the assembler should accept only AMD64 or
-Intel64 ISA in 64-bit mode.  The default is to accept both.
+Intel64 ISA in 64-bit mode.  The default is to accept common, Intel64
+only and AMD64 ISAs.
 
 @cindex @samp{-O0} option, i386
 @cindex @samp{-O0} option, x86-64
diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index 59b1415..c428041 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -728,10 +728,11 @@ if [expr ([istarget "i*86-*-*"] || [istarget "x86_64-*-*"]) && [gas_64_check]] t
     run_dump_test "x86-64-nops-5"
     run_dump_test "x86-64-nops-5-k8"
     run_dump_test "x86-64-nops-7"
+    run_dump_test "x86-64-sysenter"
     run_dump_test "x86-64-sysenter-intel"
     run_dump_test "x86-64-sysenter-mixed"
     run_dump_test "x86-64-sysenter-amd"
-    run_list_test "x86-64-sysenter-amd"
+    run_list_test "x86-64-sysenter-amd" "-mamd64"
     run_dump_test "noreg64"
     run_list_test "noreg64"
     run_list_test "cvtsi2sX"
diff --git a/gas/testsuite/gas/i386/x86-64-sysenter.d b/gas/testsuite/gas/i386/x86-64-sysenter.d
new file mode 100644
index 0000000..65d21a0
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-sysenter.d
@@ -0,0 +1,5 @@
+#as:
+#objdump: -dw
+#name: x86-64 sysenter (Default)
+#source: x86-64-sysenter-amd.s
+#dump: x86-64-sysenter-intel.d