diff --git a/gas/ChangeLog b/gas/ChangeLog
index 8b6f8f9224f..c0028075480 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,12 @@
+2017-11-23  Jan Beulich  <jbeulich@suse.com>
+
+	* testsuite/gas/i386/arch-4.s: Correct ud1 and ud2b. Add ud0.
+	* testsuite/gas/i386/intel.s: Test ud2 instead of ud2b.
+	* testsuite/gas/i386/opcode.s: Likewise.
+	* testsuite/gas/i386/arch-4.d, testsuite/gas/i386/intel.d,
+	testsuite/gas/i386/opcode.d, testsuite/gas/i386/opcode-intel.d,
+	testsuite/gas/i386/opcode-suffix.d: Adjust expectations.
+
 2017-11-23  Jan Beulich  <jbeulich@suse.com>
 
 	* config/tc-i386-intel.c (i386_intel_operand): Don't call
diff --git a/gas/testsuite/gas/i386/arch-4.d b/gas/testsuite/gas/i386/arch-4.d
index 05375d74ae3..dc2c05dfdcd 100644
--- a/gas/testsuite/gas/i386/arch-4.d
+++ b/gas/testsuite/gas/i386/arch-4.d
@@ -1,4 +1,3 @@
-#as: -march=generic32
 #objdump: -dw
 #name: i386 arch 4
 
@@ -7,8 +6,9 @@
 Disassembly of section .text:
 
 0+ <.text>:
-[ 	]*[a-f0-9]+:	0f b9                	ud1    
+[ 	]*[a-f0-9]+:	0f ff 07 [ 	]*ud0    \(%edi\),%eax
+[ 	]*[a-f0-9]+:	0f b9 07 [ 	]*ud1    \(%edi\),%eax
 [ 	]*[a-f0-9]+:	0f 0b                	ud2    
 [ 	]*[a-f0-9]+:	0f 0b                	ud2    
-[ 	]*[a-f0-9]+:	0f b9                	ud1    
+[ 	]*[a-f0-9]+:	0f b9 07 [ 	]*ud1    \(%edi\),%eax
 #pass
diff --git a/gas/testsuite/gas/i386/arch-4.s b/gas/testsuite/gas/i386/arch-4.s
index 75d53bb4a1d..cf14d736b36 100644
--- a/gas/testsuite/gas/i386/arch-4.s
+++ b/gas/testsuite/gas/i386/arch-4.s
@@ -1,5 +1,6 @@
 	.text
-	ud1
+	ud0	(%edi),%eax
+	ud1	(%edi),%eax
 	ud2
 	ud2a
-	ud2b
+	ud2b	(%edi),%eax
diff --git a/gas/testsuite/gas/i386/intel.d b/gas/testsuite/gas/i386/intel.d
index 836acd601dc..8401d10906f 100644
--- a/gas/testsuite/gas/i386/intel.d
+++ b/gas/testsuite/gas/i386/intel.d
@@ -360,7 +360,7 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	0f b5 90 90 90 90 90 [ 	]*lgs    -0x6f6f6f70\(%eax\),%edx
 [ 	]*[a-f0-9]+:	0f b6 90 90 90 90 90 [ 	]*movzbl -0x6f6f6f70\(%eax\),%edx
 [ 	]*[a-f0-9]+:	0f b7 90 90 90 90 90 [ 	]*movzwl -0x6f6f6f70\(%eax\),%edx
-[ 	]*[a-f0-9]+:	0f b9 [ 	]*ud1    
+[ 	]*[a-f0-9]+:	0f 0b [ 	]*ud2[ 	]*
 [ 	]*[a-f0-9]+:	0f bb 90 90 90 90 90 [ 	]*btc    %edx,-0x6f6f6f70\(%eax\)
 [ 	]*[a-f0-9]+:	0f bc 90 90 90 90 90 [ 	]*bsf    -0x6f6f6f70\(%eax\),%edx
 [ 	]*[a-f0-9]+:	0f bd 90 90 90 90 90 [ 	]*bsr    -0x6f6f6f70\(%eax\),%edx
diff --git a/gas/testsuite/gas/i386/intel.s b/gas/testsuite/gas/i386/intel.s
index 813daaa60df..54249d35b6b 100644
--- a/gas/testsuite/gas/i386/intel.s
+++ b/gas/testsuite/gas/i386/intel.s
@@ -353,7 +353,7 @@ foo:
  lgs    edx, 0x90909090[eax]
  movzx  edx, byte ptr 0x90909090[eax]
  movzx  edx, word ptr 0x90909090[eax]
- ud2b
+ ud2
  btc    0x90909090[eax], edx
  bsf    edx, 0x90909090[eax]
  bsr    edx, 0x90909090[eax]
diff --git a/gas/testsuite/gas/i386/opcode-intel.d b/gas/testsuite/gas/i386/opcode-intel.d
index 404758c2bfc..434b0e39701 100644
--- a/gas/testsuite/gas/i386/opcode-intel.d
+++ b/gas/testsuite/gas/i386/opcode-intel.d
@@ -358,7 +358,7 @@ Disassembly of section .text:
  *[0-9a-f]+:	0f b5 90 90 90 90 90[ 	]+lgs[ 	]+edx,(FWORD PTR )?\[eax-0x6f6f6f70\]
  *[0-9a-f]+:	0f b6 90 90 90 90 90[ 	]+movzx[ 	]+edx,BYTE PTR \[eax-0x6f6f6f70\]
  *[0-9a-f]+:	0f b7 90 90 90 90 90[ 	]+movzx[ 	]+edx,WORD PTR \[eax-0x6f6f6f70\]
- *[0-9a-f]+:	0f b9[ 	]+ud1[ 	]*
+ *[0-9a-f]+:	0f 0b[ 	]+ud2[ 	]*
  *[0-9a-f]+:	0f bb 90 90 90 90 90[ 	]+btc[ 	]+(DWORD PTR )?\[eax-0x6f6f6f70\],edx
  *[0-9a-f]+:	0f bc 90 90 90 90 90[ 	]+bsf[ 	]+edx,(DWORD PTR )?\[eax-0x6f6f6f70\]
  *[0-9a-f]+:	0f bd 90 90 90 90 90[ 	]+bsr[ 	]+edx,(DWORD PTR )?\[eax-0x6f6f6f70\]
diff --git a/gas/testsuite/gas/i386/opcode-suffix.d b/gas/testsuite/gas/i386/opcode-suffix.d
index 1fdd58fcfae..059a10cd470 100644
--- a/gas/testsuite/gas/i386/opcode-suffix.d
+++ b/gas/testsuite/gas/i386/opcode-suffix.d
@@ -358,7 +358,7 @@ Disassembly of section .text:
  *[0-9a-f]+:	0f b5 90 90 90 90 90[ 	]+lgsl[ 	]+-0x6f6f6f70\(%eax\),%edx
  *[0-9a-f]+:	0f b6 90 90 90 90 90[ 	]+movzbl -0x6f6f6f70\(%eax\),%edx
  *[0-9a-f]+:	0f b7 90 90 90 90 90[ 	]+movzwl -0x6f6f6f70\(%eax\),%edx
- *[0-9a-f]+:	0f b9[ 	]+ud1[ 	]+
+ *[0-9a-f]+:	0f 0b[ 	]+ud2[ 	]*
  *[0-9a-f]+:	0f bb 90 90 90 90 90[ 	]+btcl[ 	]+%edx,-0x6f6f6f70\(%eax\)
  *[0-9a-f]+:	0f bc 90 90 90 90 90[ 	]+bsfl[ 	]+-0x6f6f6f70\(%eax\),%edx
  *[0-9a-f]+:	0f bd 90 90 90 90 90[ 	]+bsrl[ 	]+-0x6f6f6f70\(%eax\),%edx
diff --git a/gas/testsuite/gas/i386/opcode.d b/gas/testsuite/gas/i386/opcode.d
index b80a78cd4b6..f2897ff38d8 100644
--- a/gas/testsuite/gas/i386/opcode.d
+++ b/gas/testsuite/gas/i386/opcode.d
@@ -357,7 +357,7 @@ Disassembly of section .text:
  57e:	0f b5 90 90 90 90 90 [ 	]*lgs    -0x6f6f6f70\(%eax\),%edx
  585:	0f b6 90 90 90 90 90 [ 	]*movzbl -0x6f6f6f70\(%eax\),%edx
  58c:	0f b7 90 90 90 90 90 [ 	]*movzwl -0x6f6f6f70\(%eax\),%edx
- 593:	0f b9 [ 	]*ud1    
+ 593:	0f 0b [ 	]*ud2[ 	]*
  595:	0f bb 90 90 90 90 90 [ 	]*btc    %edx,-0x6f6f6f70\(%eax\)
  59c:	0f bc 90 90 90 90 90 [ 	]*bsf    -0x6f6f6f70\(%eax\),%edx
  5a3:	0f bd 90 90 90 90 90 [ 	]*bsr    -0x6f6f6f70\(%eax\),%edx
diff --git a/gas/testsuite/gas/i386/opcode.s b/gas/testsuite/gas/i386/opcode.s
index db47446dfa9..ca521116f74 100644
--- a/gas/testsuite/gas/i386/opcode.s
+++ b/gas/testsuite/gas/i386/opcode.s
@@ -350,7 +350,7 @@ foo:
  lgs    0x90909090(%eax),%edx
  movzbl 0x90909090(%eax),%edx
  movzwl 0x90909090(%eax),%edx
- ud2b
+ ud2
  btc    %edx,0x90909090(%eax)
  bsf    0x90909090(%eax),%edx
  bsr    0x90909090(%eax),%edx
diff --git a/opcodes/ChangeLog b/opcodes/ChangeLog
index 9ca089c27f6..57624662036 100644
--- a/opcodes/ChangeLog
+++ b/opcodes/ChangeLog
@@ -1,3 +1,11 @@
+2017-11-23  Jan Beulich  <jbeulich@suse.com>
+
+	* i386-dis.c (dis386_twobyte): Correct ud1. Add ud0.
+	(twobyte_has_modrm): Set flag for index 0xb9 and 0xff.
+	* i386-opc.tbl (ud1, ud2b): Add operands.
+	(ud0): New.
+	* i386-tbl.h: Re-generate.
+
 2017-11-22  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>
 
 	* i386-opc.tbl: Remove Vec_Disp8 from vgf2p8mulb.
diff --git a/opcodes/i386-dis.c b/opcodes/i386-dis.c
index 64b47028fd4..12b723a4056 100644
--- a/opcodes/i386-dis.c
+++ b/opcodes/i386-dis.c
@@ -3067,7 +3067,7 @@ static const struct dis386 dis386_twobyte[] = {
   { "movz{wR|x}",	{ Gv, Ew }, 0 }, /* yes, there really is movzww ! */
   /* b8 */
   { PREFIX_TABLE (PREFIX_0FB8) },
-  { "ud1",		{ XX }, 0 },
+  { "ud1S",		{ Gv, Ev }, 0 },
   { REG_TABLE (REG_0FBA) },
   { "btcS",		{ Evh1, Gv }, 0 },
   { PREFIX_TABLE (PREFIX_0FBC) },
@@ -3145,7 +3145,7 @@ static const struct dis386 dis386_twobyte[] = {
   { "paddb",		{ MX, EM }, PREFIX_OPCODE },
   { "paddw",		{ MX, EM }, PREFIX_OPCODE },
   { "paddd",		{ MX, EM }, PREFIX_OPCODE },
-  { Bad_Opcode },
+  { "ud0S",		{ Gv, Ev }, 0 },
 };
 
 static const unsigned char onebyte_has_modrm[256] = {
@@ -3185,11 +3185,11 @@ static const unsigned char twobyte_has_modrm[256] = {
   /* 80 */ 0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0, /* 8f */
   /* 90 */ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* 9f */
   /* a0 */ 0,0,0,1,1,1,1,1,0,0,0,1,1,1,1,1, /* af */
-  /* b0 */ 1,1,1,1,1,1,1,1,1,0,1,1,1,1,1,1, /* bf */
+  /* b0 */ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* bf */
   /* c0 */ 1,1,1,1,1,1,1,1,0,0,0,0,0,0,0,0, /* cf */
   /* d0 */ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* df */
   /* e0 */ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1, /* ef */
-  /* f0 */ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,0  /* ff */
+  /* f0 */ 1,1,1,1,1,1,1,1,1,1,1,1,1,1,1,1  /* ff */
   /*       -------------------------------        */
   /*       0 1 2 3 4 5 6 7 8 9 a b c d e f        */
 };
diff --git a/opcodes/i386-opc.tbl b/opcodes/i386-opc.tbl
index ec478d7e825..eb4d62f008f 100644
--- a/opcodes/i386-opc.tbl
+++ b/opcodes/i386-opc.tbl
@@ -861,9 +861,11 @@ ud2, 0, 0xf0b, None, 2, Cpu186, No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf
 // alias for ud2
 ud2a, 0, 0xf0b, None, 2, Cpu186, No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
 // 2nd. official undefined instr.
-ud1, 0, 0xfb9, None, 2, Cpu186, No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
+ud1, 2, 0xfb9, None, 2, Cpu186, Modrm|No_bSuf|No_sSuf|No_ldSuf, { Reg16|Reg32|Reg64|Word|Dword|Qword|Unspecified|BaseIndex|Disp8|Disp16|Disp32|Disp32S, Reg16|Reg32|Reg64 }
 // alias for ud1
-ud2b, 0, 0xfb9, None, 2, Cpu186, No_bSuf|No_wSuf|No_lSuf|No_sSuf|No_qSuf|No_ldSuf, { 0 }
+ud2b, 2, 0xfb9, None, 2, Cpu186, Modrm|No_bSuf|No_sSuf|No_ldSuf, { Reg16|Reg32|Reg64|Word|Dword|Qword|Unspecified|BaseIndex|Disp8|Disp16|Disp32|Disp32S, Reg16|Reg32|Reg64 }
+// 3rd official undefined instr (older CPUs don't take a ModR/M byte)
+ud0, 2, 0xfff, None, 2, Cpu186, Modrm|No_bSuf|No_sSuf|No_ldSuf, { Reg16|Reg32|Reg64|Word|Dword|Qword|Unspecified|BaseIndex|Disp8|Disp16|Disp32|Disp32S, Reg16|Reg32|Reg64 }
 
 cmovo, 2, 0xf40, None, 2, Cpu686, Modrm|CheckRegSize|No_bSuf|No_sSuf|No_ldSuf, { Reg16|Reg32|Reg64|Word|Dword|Qword|Unspecified|BaseIndex|Disp8|Disp16|Disp32|Disp32S, Reg16|Reg32|Reg64 }
 cmovno, 2, 0xf41, None, 2, Cpu686, Modrm|CheckRegSize|No_bSuf|No_sSuf|No_ldSuf, { Reg16|Reg32|Reg64|Word|Dword|Qword|Unspecified|BaseIndex|Disp8|Disp16|Disp32|Disp32S, Reg16|Reg32|Reg64 }
diff --git a/opcodes/i386-tbl.h b/opcodes/i386-tbl.h
index da12e2837ad..33a885088b6 100644
--- a/opcodes/i386-tbl.h
+++ b/opcodes/i386-tbl.h
@@ -9579,32 +9579,55 @@ const insn_template i386_optab[] =
     { { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } } } },
-  { "ud1", 0, 0xfb9, None, 2,
+  { "ud1", 2, 0xfb9, None, 2,
     { { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0 } },
-    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
-      1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0,
+      0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0 },
-    { { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    { { { 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+	  1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 } },
+      { { 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } } } },
-  { "ud2b", 0, 0xfb9, None, 2,
+  { "ud2b", 2, 0xfb9, None, 2,
     { { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
         0, 0, 0 } },
-    { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 1,
-      1, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0,
+      0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
       0, 0, 0, 0, 0, 0 },
-    { { { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+    { { { 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+	  1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 } },
+      { { 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } } } },
+  { "ud0", 2, 0xfff, None, 2,
+    { { 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+        0, 0, 0 } },
+    { 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 0,
+      0, 1, 0, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+      0, 0, 0, 0, 0, 0 },
+    { { { 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+	  0, 0, 1, 1, 1, 1, 0, 0, 0, 1, 0, 0, 0, 0, 0, 0, 0, 1, 1, 0,
+	  1, 0, 0, 0, 0, 1, 0, 0, 0, 0, 0 } },
+      { { 0, 1, 1, 1, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
 	  0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 } } } },
   { "cmovo", 2, 0xf40, None, 2,