[PATCH 1/3] x86: correct cpu_arch_isa_flags maintenance

[Jan Beulich]

These may not be set from a value derived from cpu_arch_flags: That
starts with (almost) all functionality enabled, while cpu_arch_isa_flags
is supposed to track features that were explicitly enabled (and perhaps
later disabled) by the user.

To avoid needing to do any such adjustment in two places (each),
introduce helper functions used by both command line handling and
directive processing.
---
While setting of vector_size could be moved into isa_disable() (further
reducing code duplication), the same isn't true for isa_enable().
Because of the asymmetry I didn't do so. Thoughts / opinions?

--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -2804,13 +2804,41 @@ check_cpu_arch_compatible (const char *n
 }
 
 static void
-extend_cpu_sub_arch_name (const char *name)
+extend_cpu_sub_arch_name (const char *pfx, const char *name)
 {
   if (cpu_sub_arch_name)
     cpu_sub_arch_name = reconcat (cpu_sub_arch_name, cpu_sub_arch_name,
-				  ".", name, (const char *) NULL);
+				  pfx, name, (const char *) NULL);
   else
-    cpu_sub_arch_name = concat (".", name, (const char *) NULL);
+    cpu_sub_arch_name = concat (pfx, name, (const char *) NULL);
+}
+
+static void isa_enable (unsigned int idx)
+{
+  i386_cpu_flags flags = cpu_flags_or (cpu_arch_flags, cpu_arch[idx].enable);
+
+  if (!cpu_flags_equal (&flags, &cpu_arch_flags))
+    {
+      extend_cpu_sub_arch_name (".", cpu_arch[idx].name);
+      cpu_arch_flags = flags;
+    }
+
+  cpu_arch_isa_flags = cpu_flags_or (cpu_arch_isa_flags, cpu_arch[idx].enable);
+}
+
+static void isa_disable (unsigned int idx)
+{
+  i386_cpu_flags flags
+    = cpu_flags_and_not (cpu_arch_flags, cpu_arch[idx].disable);
+
+  if (!cpu_flags_equal (&flags, &cpu_arch_flags))
+    {
+      extend_cpu_sub_arch_name (".no", cpu_arch[idx].name);
+      cpu_arch_flags = flags;
+    }
+
+  cpu_arch_isa_flags
+    = cpu_flags_and_not (cpu_arch_isa_flags, cpu_arch[idx].disable);
 }
 
 static void
@@ -2834,7 +2862,6 @@ set_cpu_arch (int dummy ATTRIBUTE_UNUSED
   int e;
   const char *string;
   unsigned int j = 0;
-  i386_cpu_flags flags;
 
   SKIP_WHITESPACE ();
 
@@ -2987,17 +3014,7 @@ set_cpu_arch (int dummy ATTRIBUTE_UNUSED
 	  if (cpu_flags_all_zero (&cpu_arch[j].enable))
 	    continue;
 
-	  flags = cpu_flags_or (cpu_arch_flags, cpu_arch[j].enable);
-
-	  if (!cpu_flags_equal (&flags, &cpu_arch_flags))
-	    {
-	      extend_cpu_sub_arch_name (string + 1);
-	      cpu_arch_flags = flags;
-	      cpu_arch_isa_flags = flags;
-	    }
-	  else
-	    cpu_arch_isa_flags
-	      = cpu_flags_or (cpu_arch_isa_flags, cpu_arch[j].enable);
+	  isa_enable (j);
 
 	  (void) restore_line_pointer (e);
 
@@ -3044,13 +3061,7 @@ set_cpu_arch (int dummy ATTRIBUTE_UNUSED
 	if (cpu_arch[j].type == PROCESSOR_NONE
 	    && strcmp (string + 3, cpu_arch[j].name) == 0)
 	  {
-	    flags = cpu_flags_and_not (cpu_arch_flags, cpu_arch[j].disable);
-	    if (!cpu_flags_equal (&flags, &cpu_arch_flags))
-	      {
-		extend_cpu_sub_arch_name (string + 1);
-		cpu_arch_flags = flags;
-		cpu_arch_isa_flags = flags;
-	      }
+	    isa_disable (j);
 
 	    if (cpu_arch[j].vsz == vsz_set)
 	      vector_size = VSZ_DEFAULT;
@@ -14598,21 +14609,7 @@ md_parse_option (int c, const char *arg)
 		       && !cpu_flags_all_zero (&cpu_arch[j].enable))
 		{
 		  /* ISA extension.  */
-		  i386_cpu_flags flags;
-
-		  flags = cpu_flags_or (cpu_arch_flags,
-					cpu_arch[j].enable);
-
-		  if (!cpu_flags_equal (&flags, &cpu_arch_flags))
-		    {
-		      extend_cpu_sub_arch_name (arch);
-		      cpu_arch_flags = flags;
-		      cpu_arch_isa_flags = flags;
-		    }
-		  else
-		    cpu_arch_isa_flags
-		      = cpu_flags_or (cpu_arch_isa_flags,
-				      cpu_arch[j].enable);
+		  isa_enable (j);
 
 		  switch (cpu_arch[j].vsz)
 		    {
@@ -14655,16 +14652,7 @@ md_parse_option (int c, const char *arg)
 		if (cpu_arch[j].type == PROCESSOR_NONE
 		    && strcmp (arch + 2, cpu_arch[j].name) == 0)
 		  {
-		    i386_cpu_flags flags;
-
-		    flags = cpu_flags_and_not (cpu_arch_flags,
-					       cpu_arch[j].disable);
-		    if (!cpu_flags_equal (&flags, &cpu_arch_flags))
-		      {
-			extend_cpu_sub_arch_name (arch);
-			cpu_arch_flags = flags;
-			cpu_arch_isa_flags = flags;
-		      }
+		    isa_disable (j);
 		    if (cpu_arch[j].vsz == vsz_set)
 		      vector_size = VSZ_DEFAULT;
 		    break;
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -147,6 +147,7 @@ if [gas_32_check] then {
     run_dump_test "nops-6"
     run_dump_test "nops-7"
     run_dump_test "nops-8"
+    run_dump_test "nops-9"
     run_dump_test "noreg16"
     run_list_test "noreg16"
     run_dump_test "noreg16-data32"
--- /dev/null
+++ b/gas/testsuite/gas/i386/nops-9.d
@@ -0,0 +1,28 @@
+#objdump: -drw
+#name: i386 nops 9
+
+.*: +file format .*
+
+Disassembly of section .text:
+
+0+ <default>:
+[ 	]*[a-f0-9]+:	0f be f0             	movsbl %al,%esi
+[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%esi,%eiz,1\),%esi
+[ 	]*[a-f0-9]+:	8d b6 00 00 00 00    	lea    0x0\(%esi\),%esi
+
+0+10 <nopopcnt>:
+[ 	]*[a-f0-9]+:	0f be f0             	movsbl %al,%esi
+[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%esi,%eiz,1\),%esi
+[ 	]*[a-f0-9]+:	8d b6 00 00 00 00    	lea    0x0\(%esi\),%esi
+
+0+20 <popcnt>:
+[ 	]*[a-f0-9]+:	f3 0f b8 f0          	popcnt %eax,%esi
+[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%esi,%eiz,1\),%esi
+[ 	]*[a-f0-9]+:	8d 74 26 00          	lea    0x0\(%esi,%eiz,1\),%esi
+[ 	]*[a-f0-9]+:	90                   	nop
+
+0+30 <nop>:
+[ 	]*[a-f0-9]+:	0f be f0             	movsbl %al,%esi
+[ 	]*[a-f0-9]+:	66 66 2e 0f 1f 84 00 00 00 00 00 	data16 nopw %cs:0x0\(%eax,%eax,1\)
+[ 	]*[a-f0-9]+:	66 90                	xchg   %ax,%ax
+#pass
--- /dev/null
+++ b/gas/testsuite/gas/i386/nops-9.s
@@ -0,0 +1,19 @@
+	.text
+default:
+	movsbl %al,%esi
+	.p2align 4
+
+	.arch .nopopcnt
+nopopcnt:
+	movsbl %al,%esi
+	.p2align 4
+
+	.arch .popcnt
+popcnt:
+	popcnt %eax,%esi
+	.p2align 4
+
+	.arch .nop
+nop:
+	movsbl %al,%esi
+	.p2align 4