--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -1279,6 +1279,18 @@ static const unsigned char f32_6[] =
   {0x8d,0xb6,0x00,0x00,0x00,0x00};	/* leal 0L(%esi),%esi	*/
 static const unsigned char f32_7[] =
   {0x8d,0xb4,0x26,0x00,0x00,0x00,0x00};	/* leal 0L(%esi,1),%esi */
+static const unsigned char f64_3[] =
+  {0x48,0x89,0xf6};			/* mov %rsi,%rsi	*/
+static const unsigned char f64_4[] =
+  {0x48,0x8d,0x76,0x00};		/* lea 0(%rsi),%rsi	*/
+#define f64_5 (f64_6 + 1)		/* lea 0(%rsi,%riz),%rsi	*/
+static const unsigned char f64_6[] =
+  {0x2e,0x48,0x8d,0x74,0x26,0x00};	/* lea %cs:0(%rsi,%riz),%rsi	*/
+static const unsigned char f64_7[] =
+  {0x48,0x8d,0xb6,0x00,0x00,0x00,0x00};	/* lea 0L(%rsi),%rsi	*/
+#define f64_8 (f64_9 + 1)		/* lea 0L(%rsi,%riz),%rsi */
+static const unsigned char f64_9[] =
+  {0x2e,0x48,0x8d,0xb4,0x26,0x00,0x00,0x00,0x00}; /* lea %cs:0L(%rsi,%riz),%rsi */
 static const unsigned char f16_3[] =
   {0x8d,0x74,0x00};			/* lea 0(%si),%si	*/
 static const unsigned char f16_4[] =
@@ -1293,6 +1305,10 @@ static const unsigned char jump16_disp32
 static const unsigned char *const f32_patt[] = {
   f32_1, f32_2, f32_3, f32_4, NULL, f32_6, f32_7
 };
+/* 64-bit NOPs patterns.  */
+static const unsigned char *const f64_patt[] = {
+  f32_1, f32_2, f64_3, f64_4, f64_5, f64_6, f64_7, f64_8, f64_9
+};
 /* 16-bit NOPs patterns.  */
 static const unsigned char *const f16_patt[] = {
   f32_1, f32_2, f16_3, f16_4
@@ -1428,7 +1444,7 @@ i386_generate_nops (fragS *fragP, char *
      2. For the rest, alt_patt will be used.
 
      When -mtune= isn't used, alt_patt will be used if
-     cpu_arch_isa_flags has CpuNop.  Otherwise, f32_patt will
+     cpu_arch_isa_flags has CpuNop.  Otherwise, f32_patt/f64_patt will
      be used.
 
      When -march= or .arch is used, we can't use anything beyond
@@ -1443,6 +1459,7 @@ i386_generate_nops (fragS *fragP, char *
     }
   else
     {
+      patt = fragP->tc_frag_data.code == CODE_64BIT ? f64_patt : f32_patt;
       if (fragP->tc_frag_data.isa == PROCESSOR_UNKNOWN)
 	{
 	  /* PROCESSOR_UNKNOWN means that all ISAs may be used.  */
@@ -1453,8 +1470,6 @@ i386_generate_nops (fragS *fragP, char *
 		 optimize with nops.  */
 	      if (fragP->tc_frag_data.isa_flags.bitfield.cpunop)
 		patt = alt_patt;
-	      else
-		patt = f32_patt;
 	      break;
 	    case PROCESSOR_PENTIUM4:
 	    case PROCESSOR_NOCONA:
@@ -1477,7 +1492,6 @@ i386_generate_nops (fragS *fragP, char *
 	    case PROCESSOR_PENTIUMPRO:
 	    case PROCESSOR_IAMCU:
 	    case PROCESSOR_GENERIC32:
-	      patt = f32_patt;
 	      break;
 	    case PROCESSOR_NONE:
 	      abort ();
@@ -1509,8 +1523,6 @@ i386_generate_nops (fragS *fragP, char *
 		 with nops.  */
 	      if (fragP->tc_frag_data.isa_flags.bitfield.cpunop)
 		patt = alt_patt;
-	      else
-		patt = f32_patt;
 	      break;
 	    case PROCESSOR_PENTIUMPRO:
 	    case PROCESSOR_PENTIUM4:
@@ -1520,8 +1532,6 @@ i386_generate_nops (fragS *fragP, char *
 	    case PROCESSOR_COREI7:
 	      if (fragP->tc_frag_data.isa_flags.bitfield.cpunop)
 		patt = alt_patt;
-	      else
-		patt = f32_patt;
 	      break;
 	    case PROCESSOR_GENERIC64:
 	      patt = alt_patt;
@@ -1531,9 +1541,10 @@ i386_generate_nops (fragS *fragP, char *
 	    }
 	}
 
-      if (patt == f32_patt)
+      if (patt != alt_patt)
 	{
-	  max_single_nop_size = sizeof (f32_patt) / sizeof (f32_patt[0]);
+	  max_single_nop_size = patt == f32_patt ? ARRAY_SIZE (f32_patt)
+						 : ARRAY_SIZE (f64_patt);
 	  /* Limit number of NOPs to 2 for older processors.  */
 	  max_number_of_nops = 2;
 	}
--- a/gas/testsuite/gas/i386/ilp32/x86-64-nops-1-pentium.d
+++ b/gas/testsuite/gas/i386/ilp32/x86-64-nops-1-pentium.d
@@ -2,166 +2,4 @@
 #as: -mtune=pentium
 #objdump: -drw
 #name: x86-64 (ILP32) -mtune=pentium nops 1
-
-.*: +file format .*
-
-Disassembly of section .text:
-
-0+ <nop15>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	90                   	nop
-
-0+10 <nop14>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-
-0+20 <nop13>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d b6 00 00 00 00    	lea    0x0\(%rsi\),%esi
-
-0+30 <nop12>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d 74 26 00          	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	90                   	nop
-
-0+40 <nop11>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d 74 26 00          	lea    0x0\(%rsi,%riz,1\),%esi
-
-0+50 <nop10>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d 76 00             	lea    0x0\(%rsi\),%esi
-
-0+60 <nop9>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	66 90                	xchg   %ax,%ax
-
-0+70 <nop8>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	90                   	nop
-
-0+80 <nop7>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-
-0+90 <nop6>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b6 00 00 00 00    	lea    0x0\(%rsi\),%esi
-
-0+a0 <nop5>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d 74 26 00          	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	90                   	nop
-
-0+b0 <nop4>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d 74 26 00          	lea    0x0\(%rsi,%riz,1\),%esi
-
-0+c0 <nop3>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d 76 00             	lea    0x0\(%rsi\),%esi
-
-0+d0 <nop2>:
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	66 90                	xchg   %ax,%ax
-#pass
+#dump: ../x86-64-nops-1-pentium.d
--- a/gas/testsuite/gas/i386/x86-64-nops-1-pentium.d
+++ b/gas/testsuite/gas/i386/x86-64-nops-1-pentium.d
@@ -9,31 +9,29 @@ Disassembly of section .text:
 
 0+ <nop15>:
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	90                   	nop
+[ 	]*[a-f0-9]+:	2e 48 8d b4 26 00 00 00 00 	cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ 	]*[a-f0-9]+:	2e 48 8d 74 26 00    	cs lea (0x)?0\(%rsi,%riz,1\),%rsi
 
 0+10 <nop14>:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
+[ 	]*[a-f0-9]+:	2e 48 8d b4 26 00 00 00 00 	cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ 	]*[a-f0-9]+:	48 8d 74 26 00       	lea    (0x)?0\(%rsi,%riz,1\),%rsi
 
 0+20 <nop13>:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d b6 00 00 00 00    	lea    0x0\(%rsi\),%esi
+[ 	]*[a-f0-9]+:	2e 48 8d b4 26 00 00 00 00 	cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ 	]*[a-f0-9]+:	48 8d 76 00          	lea    (0x)?0\(%rsi\),%rsi
 
 0+30 <nop12>:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d 74 26 00          	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	90                   	nop
+[ 	]*[a-f0-9]+:	2e 48 8d b4 26 00 00 00 00 	cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ 	]*[a-f0-9]+:	48 89 f6             	mov    %rsi,%rsi
 
 0+40 <nop11>:
 [ 	]*[a-f0-9]+:	90                   	nop
@@ -41,8 +39,8 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d 74 26 00          	lea    0x0\(%rsi,%riz,1\),%esi
+[ 	]*[a-f0-9]+:	2e 48 8d b4 26 00 00 00 00 	cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ 	]*[a-f0-9]+:	66 90                	xchg   %ax,%ax
 
 0+50 <nop10>:
 [ 	]*[a-f0-9]+:	90                   	nop
@@ -51,8 +49,8 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	8d 76 00             	lea    0x0\(%rsi\),%esi
+[ 	]*[a-f0-9]+:	2e 48 8d b4 26 00 00 00 00 	cs lea (0x)?0\(%rsi,%riz,1\),%rsi
+[ 	]*[a-f0-9]+:	90                   	nop
 
 0+60 <nop9>:
 [ 	]*[a-f0-9]+:	90                   	nop
@@ -62,8 +60,7 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	66 90                	xchg   %ax,%ax
+[ 	]*[a-f0-9]+:	2e 48 8d b4 26 00 00 00 00 	cs lea (0x)?0\(%rsi,%riz,1\),%rsi
 
 0+70 <nop8>:
 [ 	]*[a-f0-9]+:	90                   	nop
@@ -74,8 +71,7 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	90                   	nop
+[ 	]*[a-f0-9]+:	48 8d b4 26 00 00 00 00 	lea    (0x)?0\(%rsi,%riz,1\),%rsi
 
 0+80 <nop7>:
 [ 	]*[a-f0-9]+:	90                   	nop
@@ -87,7 +83,7 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b4 26 00 00 00 00 	lea    0x0\(%rsi,%riz,1\),%esi
+[ 	]*[a-f0-9]+:	48 8d b6 00 00 00 00 	lea    (0x)?0\(%rsi\),%rsi
 
 0+90 <nop6>:
 [ 	]*[a-f0-9]+:	90                   	nop
@@ -100,7 +96,7 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d b6 00 00 00 00    	lea    0x0\(%rsi\),%esi
+[ 	]*[a-f0-9]+:	2e 48 8d 74 26 00    	cs lea (0x)?0\(%rsi,%riz,1\),%rsi
 
 0+a0 <nop5>:
 [ 	]*[a-f0-9]+:	90                   	nop
@@ -114,8 +110,7 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d 74 26 00          	lea    0x0\(%rsi,%riz,1\),%esi
-[ 	]*[a-f0-9]+:	90                   	nop
+[ 	]*[a-f0-9]+:	48 8d 74 26 00       	lea    (0x)?0\(%rsi,%riz,1\),%rsi
 
 0+b0 <nop4>:
 [ 	]*[a-f0-9]+:	90                   	nop
@@ -130,7 +125,7 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d 74 26 00          	lea    0x0\(%rsi,%riz,1\),%esi
+[ 	]*[a-f0-9]+:	48 8d 76 00          	lea    (0x)?0\(%rsi\),%rsi
 
 0+c0 <nop3>:
 [ 	]*[a-f0-9]+:	90                   	nop
@@ -146,7 +141,7 @@ Disassembly of section .text:
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
 [ 	]*[a-f0-9]+:	90                   	nop
-[ 	]*[a-f0-9]+:	8d 76 00             	lea    0x0\(%rsi\),%esi
+[ 	]*[a-f0-9]+:	48 89 f6             	mov    %rsi,%rsi
 
 0+d0 <nop2>:
 [ 	]*[a-f0-9]+:	90                   	nop
