x86: correct cpu_arch_isa_flags maintenance

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.

4 files changed, 83 insertions, 47 deletions

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index fa813aa..9f5522b 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -2808,13 +2808,41 @@ check_cpu_arch_compatible (const char *name ATTRIBUTE_UNUSED,
 }
 
 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
@@ -2838,7 +2866,6 @@ set_cpu_arch (int dummy ATTRIBUTE_UNUSED)
   int e;
   const char *string;
   unsigned int j = 0;
-  i386_cpu_flags flags;
 
   SKIP_WHITESPACE ();
 
@@ -2991,17 +3018,7 @@ 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);
 
@@ -3048,13 +3065,7 @@ 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;
@@ -14611,21 +14622,7 @@ 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)
 		    {
@@ -14668,16 +14665,7 @@ 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;
diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index d16eb88..aa9f9a4 100644
--- 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"
diff --git a/gas/testsuite/gas/i386/nops-9.d b/gas/testsuite/gas/i386/nops-9.d
new file mode 100644
index 0000000..a073a58
--- /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
diff --git a/gas/testsuite/gas/i386/nops-9.s b/gas/testsuite/gas/i386/nops-9.s
new file mode 100644
index 0000000..db2eebb
--- /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