x86: derive mandatory prefix attribute from base opcode

Just like is already done for legacy encoded insns, record the mandatory
prefix information in the respective opcode modifier field. Do this
without changing the source table, but rather by deriving the values from
their existing source representation.

1 files changed, 41 insertions, 53 deletions

diff --git a/opcodes/i386-gen.c b/opcodes/i386-gen.c
index 2f4caba..6530a54 100644
--- a/opcodes/i386-gen.c
+++ b/opcodes/i386-gen.c
@@ -1175,12 +1175,12 @@ adjust_broadcast_modifier (char **opnd)
   return bcst_type;
 }
 
-static int
-process_i386_opcode_modifier (FILE *table, char *mod, char **opnd, int lineno)
+static void
+process_i386_opcode_modifier (FILE *table, char *mod, unsigned int prefix,
+			      char **opnd, int lineno)
 {
   char *str, *next, *last;
   bitfield modifiers [ARRAY_SIZE (opcode_modifiers)];
-  unsigned int regular_encoding = 1;
 
   active_isstring = 0;
 
@@ -1199,18 +1199,7 @@ process_i386_opcode_modifier (FILE *table, char *mod, char **opnd, int lineno)
 	    {
 	      int val = 1;
 	      if (strcasecmp(str, "Broadcast") == 0)
-		{
-		  val = adjust_broadcast_modifier (opnd);
-		  regular_encoding = 0;
-		}
-	      else if (strcasecmp(str, "Vex") == 0
-		       || strncasecmp(str, "Vex=", 4) == 0
-		       || strcasecmp(str, "EVex") == 0
-		       || strncasecmp(str, "EVex=", 5) == 0
-		       || strncasecmp(str, "Disp8MemShift=", 14) == 0
-		       || strncasecmp(str, "Masking=", 8) == 0
-		       || strcasecmp(str, "SAE") == 0)
-		regular_encoding = 0;
+		val = adjust_broadcast_modifier (opnd);
 
 	      set_bitfield (str, modifiers, val, ARRAY_SIZE (modifiers),
 			    lineno);
@@ -1231,6 +1220,19 @@ process_i386_opcode_modifier (FILE *table, char *mod, char **opnd, int lineno)
 	    }
 	}
 
+      if (prefix)
+	{
+	  if (!modifiers[OpcodePrefix].value)
+	    modifiers[OpcodePrefix].value = prefix;
+	  else if (modifiers[OpcodePrefix].value != prefix)
+	    fail (_("%s:%d: Conflicting prefix specifications\n"),
+		  filename, lineno);
+	  else
+	    fprintf (stderr,
+		     _("%s:%d: Warning: redundant prefix specification\n"),
+		     filename, lineno);
+	}
+
       if (have_w && !bwlq_suf)
 	fail ("%s: %d: stray W modifier\n", filename, lineno);
       if (have_w && !(bwlq_suf & 1))
@@ -1242,8 +1244,6 @@ process_i386_opcode_modifier (FILE *table, char *mod, char **opnd, int lineno)
 		 filename, lineno);
     }
   output_opcode_modifier (table, modifiers, ARRAY_SIZE (modifiers));
-
-  return regular_encoding;
 }
 
 enum stage {
@@ -1355,9 +1355,10 @@ static void
 output_i386_opcode (FILE *table, const char *name, char *str,
 		    char *last, int lineno)
 {
-  unsigned int i;
-  char *base_opcode, *extension_opcode, *opcode_length;
+  unsigned int i, prefix = 0;
+  char *base_opcode, *extension_opcode, *opcode_length, *end;
   char *cpu_flags, *opcode_modifier, *operand_types [MAX_OPERANDS];
+  unsigned long int opcode, length;
 
   /* Find base_opcode.  */
   base_opcode = next_field (str, ',', &str, last);
@@ -1407,46 +1408,33 @@ output_i386_opcode (FILE *table, const char *name, char *str,
 	}
     }
 
-  fprintf (table, "  { \"%s\", %s, %s, %s, %u,\n",
-	   name, base_opcode, extension_opcode, opcode_length, i);
+  length = strtoul (opcode_length, &end, 0);
+  opcode = strtoul (base_opcode, &end, 0);
 
-  if (process_i386_opcode_modifier (table, opcode_modifier,
-				    operand_types, lineno))
+  /* Transform prefixes encoded in the opcode into opcode modifier
+     representation.  */
+  if (length < 4)
     {
-      char *end;
-      unsigned long int length = strtoul (opcode_length, &end, 0);
-      unsigned long int opcode = strtoul (base_opcode, &end, 0);
-      switch (length)
+      switch (opcode >> (8 * length))
 	{
-	case 4:
-	  break;
-	case 3:
-	  if ((opcode >> 24) != 0)
-	    fail (_("%s: %s: (base_opcode >> 24) != 0: %s\n"),
-		  filename, name, base_opcode);
-	  break;
-	case 2:
-	  if ((opcode >> 16) != 0)
-	    fail (_("%s: %s: (base_opcode >> 16) != 0: %s\n"),
-		  filename, name, base_opcode);
-	  break;
-	case 1:
-	  if ((opcode >> 8) != 0)
-	    fail (_("%s: %s: (base_opcode >> 8) != 0: %s\n"),
-		  filename, name, base_opcode);
-	  break;
-	case 0:
-	  if (opcode != 0)
-	    fail (_("%s: %s: base_opcode != 0: %s\n"),
-		  filename, name, base_opcode);
-	  break;
+	case 0: break;
+	case 0x66: prefix = PREFIX_0X66; break;
+	case 0xF3: prefix = PREFIX_0XF3; break;
+	case 0xF2: prefix = PREFIX_0XF2; break;
 	default:
-	  fail (_("%s: %s: invalid opcode length: %s\n"),
-		filename, name, opcode_length);
-	  break;
+	  fail (_("%s:%d: %s: Unexpected opcode prefix %02lx\n"),
+		filename, lineno, name, opcode >> (8 * length));
 	}
+
+      opcode &= (1UL << (8 * length)) - 1;
     }
 
+  fprintf (table, "  { \"%s\", 0x%0*lx%s, %s, %lu, %u,\n",
+	   name, 2 * (int)length, opcode, end, extension_opcode, length, i);
+
+  process_i386_opcode_modifier (table, opcode_modifier, prefix,
+				operand_types, lineno);
+
   process_i386_cpu_flag (table, cpu_flags, 0, ",", "    ", lineno);
 
   fprintf (table, "    { ");
@@ -1836,7 +1824,7 @@ process_i386_opcodes (FILE *table)
 
   fprintf (table, "  { NULL, 0, 0, 0, 0,\n");
 
-  process_i386_opcode_modifier (table, "0", NULL, -1);
+  process_i386_opcode_modifier (table, "0", 0, NULL, -1);
 
   process_i386_cpu_flag (table, "0", 0, ",", "    ", -1);