Add .nop assembler directive

Implement the '.nop SIZE[, CONTROL]' assembler directive, which emits
SIZE bytes filled with no-op instructions.  SIZE is absolute expression.
The optional CONTROL byte controls how no-op instructions should be
generated.  If the comma and @var{control} are omitted, CONTROL is
assumed to be zero.

For Intel 80386 and AMD x86-64 targets, CONTROL byte specifies the size
limit of a single no-op instruction.  The valid values of CONTROL byte
are between 0 and 8 for 16-bit mode, between 0 and 10 for 32-bit mode,
between 0 and 11 for 64-bit mode.  When 0 is used, the no-op size limit
is set to the maximum supported size.

2 new relax states, rs_space_nop and rs_fill_nop, are added to enum
_relax_state, which are similar to rs_space and rs_fill, respectively,
but they fill with no-op instructions, instead of a single byte.  A
target backend must override the default md_generate_nops to generate
proper no-op instructions.  Otherwise, an error of unimplemented .nop
directive will be issued whenever .nop directive is used.

	* NEWS: Mention .nop directive.
	* as.h (_relax_state): Add rs_space_nop and rs_fill_nop.
	* read.c (potable): Add .nop.
	(s_nop): New function.
	* read.h (s_nop): New prototype.
	* write.c (cvt_frag_to_fill): Handle rs_space_nop and
	rs_fill_nop.
	(md_generate_nops): New function.
	(relax_segment): Likewise.
	(write_contents): Use md_generate_nops for rs_fill_nop.
	* config/tc-i386.c (alt64_11): New.
	(alt64_patt): Likewise.
	(md_convert_frag): Handle rs_space_nop.
	(i386_output_nops): New function.
	(i386_generate_nops): Likewise.
	(i386_align_code): Call i386_output_nops.
	* config/tc-i386.h (i386_generate_nops): New.
	(md_generate_nops): Likewise.
	* doc/as.texinfo: Document .nop directive.
	* testsuite/gas/i386/i386.exp: Run .nop directive tests.
	* testsuite/gas/i386/nop-1.d: New file.
	* testsuite/gas/i386/nop-1.s: Likewise.
	* testsuite/gas/i386/nop-2.d: Likewise.
	* testsuite/gas/i386/nop-2.s: Likewise.
	* testsuite/gas/i386/nop-3.d: Likewise.
	* testsuite/gas/i386/nop-3.s: Likewise.
	* testsuite/gas/i386/nop-4.d: Likewise.
	* testsuite/gas/i386/nop-4.s: Likewise.
	* testsuite/gas/i386/nop-5.d: Likewise.
	* testsuite/gas/i386/nop-5.s: Likewise.
	* testsuite/gas/i386/nop-6.d: Likewise.
	* testsuite/gas/i386/nop-6.s: Likewise.
	* testsuite/gas/i386/nop-bad-1.l: Likewise.
	* testsuite/gas/i386/nop-bad-1.s: Likewise.
	* testsuite/gas/i386/x86-64-nop-1.d: Likewise.
	* testsuite/gas/i386/x86-64-nop-2.d: Likewise.
	* testsuite/gas/i386/x86-64-nop-3.d: Likewise.
	* testsuite/gas/i386/x86-64-nop-4.d: Likewise.
	* testsuite/gas/i386/x86-64-nop-5.d: Likewise.
	* testsuite/gas/i386/x86-64-nop-6.d: Likewise.

21 files changed, 459 insertions, 0 deletions

diff --git a/gas/testsuite/gas/i386/i386.exp b/gas/testsuite/gas/i386/i386.exp
index a21ef84..0ca49ea 100644
--- a/gas/testsuite/gas/i386/i386.exp
+++ b/gas/testsuite/gas/i386/i386.exp
@@ -431,6 +431,8 @@ if [expr ([istarget "i*86-*-*"] ||  [istarget "x86_64-*-*"]) && [gas_32_check]]
     run_dump_test "align-1a"
     run_dump_test "align-1b"
     run_list_test "inval-pseudo" "-al"
+    run_dump_test "nop-1"
+    run_dump_test "nop-2"
 
     # These tests require support for 8 and 16 bit relocs,
     # so we only run them for ELF and COFF targets.
@@ -494,6 +496,10 @@ if [expr ([istarget "i*86-*-*"] ||  [istarget "x86_64-*-*"]) && [gas_32_check]]
 	run_dump_test "got-no-relax"
 
 	run_dump_test "addend"
+	run_dump_test "nop-3"
+	run_dump_test "nop-4"
+	run_dump_test "nop-5"
+	run_dump_test "nop-6"
 
 	if { [gas_64_check] } then {
 	    run_dump_test "att-regs"
@@ -538,6 +544,7 @@ if [expr [istarget "i*86-*-*"] || [istarget "x86_64-*-*"]] then {
     run_list_test "space1" "-al"
     run_dump_test rept
     run_dump_test pr19498
+    run_list_test "nop-bad-1" ""
     if [is_elf_format] then {
 	run_list_test_stdin "list-1" "-al"
 	run_list_test_stdin "list-2" "-al"
@@ -904,6 +911,8 @@ if [expr ([istarget "i*86-*-*"] || [istarget "x86_64-*-*"]) && [gas_64_check]] t
     run_list_test "x86-64-notrackbad" "-al"
     run_dump_test "x86-64-movd"
     run_dump_test "x86-64-movd-intel"
+    run_dump_test "x86-64-nop-1"
+    run_dump_test "x86-64-nop-2"
 
     if { ![istarget "*-*-aix*"]
       && ![istarget "*-*-beos*"]
@@ -961,6 +970,10 @@ if [expr ([istarget "i*86-*-*"] || [istarget "x86_64-*-*"]) && [gas_64_check]] t
 	run_dump_test "x86-64-gotpcrel-no-relax"
 
 	run_dump_test "x86-64-addend"
+	run_dump_test "x86-64-nop-3"
+	run_dump_test "x86-64-nop-4"
+	run_dump_test "x86-64-nop-5"
+	run_dump_test "x86-64-nop-6"
     }
 
     set ASFLAGS "$old_ASFLAGS"
diff --git a/gas/testsuite/gas/i386/nop-1.d b/gas/testsuite/gas/i386/nop-1.d
new file mode 100644
index 0000000..46422c8
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-1.d
@@ -0,0 +1,31 @@
+#objdump: -drw
+#name: i386 .nop 1
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <single>:
+ +[a-f0-9]+:	90                   	nop
+
+0+1 <pseudo_1>:
+ +[a-f0-9]+:	90                   	nop
+
+0+2 <pseudo_8>:
+ +[a-f0-9]+:	0f 1f 84 00 00 00 00 00 	nopl   0x0\(%eax,%eax,1\)
+
+0+a <pseudo_8_4>:
+ +[a-f0-9]+:	0f 1f 40 00          	nopl   0x0\(%eax\)
+ +[a-f0-9]+:	0f 1f 40 00          	nopl   0x0\(%eax\)
+
+0+12 <pseudo_20>:
+ +[a-f0-9]+:	66 2e 0f 1f 84 00 00 00 00 00 	nopw   %cs:0x0\(%eax,%eax,1\)
+ +[a-f0-9]+:	66 2e 0f 1f 84 00 00 00 00 00 	nopw   %cs:0x0\(%eax,%eax,1\)
+
+0+26 <pseudo_30>:
+ +[a-f0-9]+:	66 2e 0f 1f 84 00 00 00 00 00 	nopw   %cs:0x0\(%eax,%eax,1\)
+ +[a-f0-9]+:	66 2e 0f 1f 84 00 00 00 00 00 	nopw   %cs:0x0\(%eax,%eax,1\)
+ +[a-f0-9]+:	66 2e 0f 1f 84 00 00 00 00 00 	nopw   %cs:0x0\(%eax,%eax,1\)
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+#pass
diff --git a/gas/testsuite/gas/i386/nop-1.s b/gas/testsuite/gas/i386/nop-1.s
new file mode 100644
index 0000000..891783d
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-1.s
@@ -0,0 +1,21 @@
+       .text
+single:
+	.nop 0
+	nop
+
+pseudo_1:
+	.nop 1
+
+pseudo_8:
+	.nop 8
+
+pseudo_8_4:
+	.nop 8, 4
+
+pseudo_20:
+	.nop 20
+
+pseudo_30:
+	.nop 30
+
+	xor %eax, %eax
diff --git a/gas/testsuite/gas/i386/nop-2.d b/gas/testsuite/gas/i386/nop-2.d
new file mode 100644
index 0000000..332b990
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-2.d
@@ -0,0 +1,40 @@
+#objdump: -drw -Mi8086
+#name: i386 .nop 2
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <single>:
+ +[a-f0-9]+:	90                   	nop
+
+0+1 <pseudo_1>:
+ +[a-f0-9]+:	90                   	nop
+
+0+2 <pseudo_8>:
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+
+0+a <pseudo_8_4>:
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+
+0+12 <pseudo_20>:
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+
+0+26 <pseudo_30>:
+ +[a-f0-9]+:	89 f6                	mov    %si,%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+ +[a-f0-9]+:	66 31 c0             	xor    %eax,%eax
+#pass
diff --git a/gas/testsuite/gas/i386/nop-2.s b/gas/testsuite/gas/i386/nop-2.s
new file mode 100644
index 0000000..2b71b97
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-2.s
@@ -0,0 +1,22 @@
+       .text
+       .code16
+single:
+	.nop 0
+	nop
+
+pseudo_1:
+	.nop 1
+
+pseudo_8:
+	.nop 8
+
+pseudo_8_4:
+	.nop 8, 4
+
+pseudo_20:
+	.nop 20
+
+pseudo_30:
+	.nop 30
+
+	xor %eax, %eax
diff --git a/gas/testsuite/gas/i386/nop-3.d b/gas/testsuite/gas/i386/nop-3.d
new file mode 100644
index 0000000..bebd24b
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-3.d
@@ -0,0 +1,20 @@
+#objdump: -drw
+#name: i386 .nop 3
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <_start>:
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	85 c0                	test   %eax,%eax
+ +[a-f0-9]+:	0f 1f 00             	nopl   \(%eax\)
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+
+Disassembly of section .altinstr_replacement:
+
+0+ <.altinstr_replacement>:
+ +[a-f0-9]+:	e9 fc ff ff ff       	jmp    1 <.altinstr_replacement\+0x1>	1: (R_386_PC)?(DISP)?32	foo
+#pass
diff --git a/gas/testsuite/gas/i386/nop-3.s b/gas/testsuite/gas/i386/nop-3.s
new file mode 100644
index 0000000..57370ff
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-3.s
@@ -0,0 +1,15 @@
+	.text
+_start:
+	xor %eax, %eax
+140:
+	testl %eax, %eax
+141:
+	.nop -(((144f-143f)-(141b-140b)) > 0)*((144f-143f)-(141b-140b)),7
+142:
+	xor %eax, %eax
+	.pushsection .altinstr_replacement,"ax"
+143:
+	jmp foo
+144:
+	.popsection
+	xor %eax, %eax
diff --git a/gas/testsuite/gas/i386/nop-4.d b/gas/testsuite/gas/i386/nop-4.d
new file mode 100644
index 0000000..99ddcd3
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-4.d
@@ -0,0 +1,23 @@
+#objdump: -drw
+#name: i386 .nop 4
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <_start>:
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	85 c0                	test   %eax,%eax
+ +[a-f0-9]+:	66 0f 1f 84 00 00 00 00 00 	nopw   0x0\(%eax,%eax,1\)
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+
+Disassembly of section .altinstr_replacement:
+
+0+ <.altinstr_replacement>:
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	e9 fc ff ff ff       	jmp    7 <.altinstr_replacement\+0x7>	7: (R_386_PC)?(DISP)?32	foo
+#pass
diff --git a/gas/testsuite/gas/i386/nop-4.s b/gas/testsuite/gas/i386/nop-4.s
new file mode 100644
index 0000000..f7aa111
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-4.s
@@ -0,0 +1,18 @@
+	.text
+_start:
+	xor %eax, %eax
+140:
+	testl %eax, %eax
+141:
+	.nop -(((144f-143f)-(141b-140b)) > 0)*((144f-143f)-(141b-140b))
+142:
+	xor %eax, %eax
+	.pushsection .altinstr_replacement,"ax"
+143:
+	mov %eax, %eax
+	mov %eax, %eax
+	mov %eax, %eax
+	jmp foo
+144:
+	.popsection
+	xor %eax, %eax
diff --git a/gas/testsuite/gas/i386/nop-5.d b/gas/testsuite/gas/i386/nop-5.d
new file mode 100644
index 0000000..aab4258
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-5.d
@@ -0,0 +1,25 @@
+#objdump: -drw
+#name: i386 .nop 5
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <_start>:
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	85 c0                	test   %eax,%eax
+ +[a-f0-9]+:	0f 1f 44 00 00       	nopl   0x0\(%eax,%eax,1\)
+ +[a-f0-9]+:	66 0f 1f 44 00 00    	nopw   0x0\(%eax,%eax,1\)
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+
+Disassembly of section .altinstr_replacement:
+
+0+ <.altinstr_replacement>:
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	e9 fc ff ff ff       	jmp    9 <.altinstr_replacement\+0x9>	9: (R_386_PC)?(DISP)?32	foo
+#pass
diff --git a/gas/testsuite/gas/i386/nop-5.s b/gas/testsuite/gas/i386/nop-5.s
new file mode 100644
index 0000000..4f563ce
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-5.s
@@ -0,0 +1,19 @@
+	.text
+_start:
+	xor %eax, %eax
+140:
+	testl %eax, %eax
+141:
+	.nop -(((144f-143f)-(141b-140b)) > 0)*((144f-143f)-(141b-140b)),6
+142:
+	xor %eax, %eax
+	.pushsection .altinstr_replacement,"ax"
+143:
+	mov %eax, %eax
+	mov %eax, %eax
+	mov %eax, %eax
+	mov %eax, %eax
+	jmp foo
+144:
+	.popsection
+	xor %eax, %eax
diff --git a/gas/testsuite/gas/i386/nop-6.d b/gas/testsuite/gas/i386/nop-6.d
new file mode 100644
index 0000000..93ee8de
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-6.d
@@ -0,0 +1,17 @@
+#objdump: -drw
+#name: i386 .nop 6
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <_start>:
+ +[a-f0-9]+:	0f 1f 40 00          	nopl   0x0\(%eax\)
+
+Disassembly of section .altinstr_replacement:
+
+0+ <.altinstr_replacement>:
+ +[a-f0-9]+:	75 fe                	jne    0 <_start>
+ +[a-f0-9]+:	89 c4                	mov    %eax,%esp
+#pass
diff --git a/gas/testsuite/gas/i386/nop-6.s b/gas/testsuite/gas/i386/nop-6.s
new file mode 100644
index 0000000..c7b1e2c
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-6.s
@@ -0,0 +1,25 @@
+.macro mknops nr_bytes
+    .nop \nr_bytes, 9
+.endm
+
+.macro ALTERNATIVE
+.L\@_orig_s:
+.L\@_orig_e:
+     mknops (-(((.L\@_repl_e\()1 - .L\@_repl_s\()1) - (.L\@_orig_e - .L\@_orig_s)) > 0) * ((.L\@_repl_e\()1 - .L\@_repl_s\()1) - (.L\@_orig_e - .L\@_orig_s)))
+.L\@_orig_p:
+
+    .section .discard, "a", @progbits
+    .byte (.L\@_orig_p - .L\@_orig_s)
+    .byte 0xff + (.L\@_repl_e\()1 - .L\@_repl_s\()1) - (.L\@_orig_p - .L\@_orig_s)
+
+    .section .altinstr_replacement, "ax", @progbits
+.L\@_repl_s\()1:
+.L\@_fill_rsb_loop:
+    jnz .L\@_fill_rsb_loop
+    mov %eax, %esp
+.L\@_repl_e\()1:
+.endm
+
+	.text
+_start:
+ALTERNATIVE
diff --git a/gas/testsuite/gas/i386/nop-bad-1.l b/gas/testsuite/gas/i386/nop-bad-1.l
new file mode 100644
index 0000000..34be496
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-bad-1.l
@@ -0,0 +1,4 @@
+.*: Assembler messages:
+.*:2: Warning: negative nop control byte, ignored
+.*:4: Warning: \.space, \.nop or \.fill with negative value, ignored
+.*:3: Error: invalide single nop size: 20 \(expect within \[0, [0-9]+\]\)
diff --git a/gas/testsuite/gas/i386/nop-bad-1.s b/gas/testsuite/gas/i386/nop-bad-1.s
new file mode 100644
index 0000000..53cc7d5
--- /dev/null
+++ b/gas/testsuite/gas/i386/nop-bad-1.s
@@ -0,0 +1,4 @@
+	.text
+        .nop 100, -2
+        .nop 100, 20
+        .nop -1
diff --git a/gas/testsuite/gas/i386/x86-64-nop-1.d b/gas/testsuite/gas/i386/x86-64-nop-1.d
new file mode 100644
index 0000000..f3edc7d
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-nop-1.d
@@ -0,0 +1,32 @@
+#source: nop-1.s
+#objdump: -drw
+#name: x86-64 .nop 1
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <single>:
+ +[a-f0-9]+:	90                   	nop
+
+0+1 <pseudo_1>:
+ +[a-f0-9]+:	90                   	nop
+
+0+2 <pseudo_8>:
+ +[a-f0-9]+:	0f 1f 84 00 00 00 00 00 	nopl   0x0\(%rax,%rax,1\)
+
+0+a <pseudo_8_4>:
+ +[a-f0-9]+:	0f 1f 40 00          	nopl   0x0\(%rax\)
+ +[a-f0-9]+:	0f 1f 40 00          	nopl   0x0\(%rax\)
+
+0+12 <pseudo_20>:
+ +[a-f0-9]+:	66 0f 1f 84 00 00 00 00 00 	nopw   0x0\(%rax,%rax,1\)
+ +[a-f0-9]+:	67 66 2e 0f 1f 84 00 00 00 00 00 	nopw   %cs:0x0\(%eax,%eax,1\)
+
+0+26 <pseudo_30>:
+ +[a-f0-9]+:	0f 1f 84 00 00 00 00 00 	nopl   0x0\(%rax,%rax,1\)
+ +[a-f0-9]+:	67 66 2e 0f 1f 84 00 00 00 00 00 	nopw   %cs:0x0\(%eax,%eax,1\)
+ +[a-f0-9]+:	67 66 2e 0f 1f 84 00 00 00 00 00 	nopw   %cs:0x0\(%eax,%eax,1\)
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-nop-2.d b/gas/testsuite/gas/i386/x86-64-nop-2.d
new file mode 100644
index 0000000..e894d2c
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-nop-2.d
@@ -0,0 +1,41 @@
+#source: nop-2.s
+#objdump: -drw -Mi8086
+#name: x86-64 .nop 2
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <single>:
+ +[a-f0-9]+:	90                   	nop
+
+0+1 <pseudo_1>:
+ +[a-f0-9]+:	90                   	nop
+
+0+2 <pseudo_8>:
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+
+0+a <pseudo_8_4>:
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+
+0+12 <pseudo_20>:
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+
+0+26 <pseudo_30>:
+ +[a-f0-9]+:	89 f6                	mov    %si,%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+ +[a-f0-9]+:	8d b4 00 00          	lea    0x0\(%si\),%si
+ +[a-f0-9]+:	8d bd 00 00          	lea    0x0\(%di\),%di
+ +[a-f0-9]+:	66 31 c0             	xor    %eax,%eax
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-nop-3.d b/gas/testsuite/gas/i386/x86-64-nop-3.d
new file mode 100644
index 0000000..b43239a
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-nop-3.d
@@ -0,0 +1,21 @@
+#source: nop-3.s
+#objdump: -drw
+#name: x86-64 .nop 3
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <_start>:
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	85 c0                	test   %eax,%eax
+ +[a-f0-9]+:	0f 1f 00             	nopl   \(%rax\)
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+
+Disassembly of section .altinstr_replacement:
+
+0+ <.altinstr_replacement>:
+ +[a-f0-9]+:	e9 00 00 00 00       	jmpq   5 <_start\+0x5>	1: R_X86_64_PLT32	foo-0x4
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-nop-4.d b/gas/testsuite/gas/i386/x86-64-nop-4.d
new file mode 100644
index 0000000..a910171
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-nop-4.d
@@ -0,0 +1,24 @@
+#source: nop-4.s
+#objdump: -drw
+#name: x86-64 .nop 4
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <_start>:
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	85 c0                	test   %eax,%eax
+ +[a-f0-9]+:	66 0f 1f 84 00 00 00 00 00 	nopw   0x0\(%rax,%rax,1\)
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+
+Disassembly of section .altinstr_replacement:
+
+0+ <.altinstr_replacement>:
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	e9 00 00 00 00       	jmpq   b <_start\+0xb>	7: R_X86_64_PLT32	foo-0x4
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-nop-5.d b/gas/testsuite/gas/i386/x86-64-nop-5.d
new file mode 100644
index 0000000..57493cf
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-nop-5.d
@@ -0,0 +1,26 @@
+#source: nop-5.s
+#objdump: -drw
+#name: x86-64 .nop 5
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <_start>:
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	85 c0                	test   %eax,%eax
+ +[a-f0-9]+:	0f 1f 44 00 00       	nopl   0x0\(%rax,%rax,1\)
+ +[a-f0-9]+:	66 0f 1f 44 00 00    	nopw   0x0\(%rax,%rax,1\)
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+ +[a-f0-9]+:	31 c0                	xor    %eax,%eax
+
+Disassembly of section .altinstr_replacement:
+
+0+ <.altinstr_replacement>:
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	89 c0                	mov    %eax,%eax
+ +[a-f0-9]+:	e9 00 00 00 00       	jmpq   d <_start\+0xd>	9: R_X86_64_PLT32	foo-0x4
+#pass
diff --git a/gas/testsuite/gas/i386/x86-64-nop-6.d b/gas/testsuite/gas/i386/x86-64-nop-6.d
new file mode 100644
index 0000000..520f590
--- /dev/null
+++ b/gas/testsuite/gas/i386/x86-64-nop-6.d
@@ -0,0 +1,18 @@
+#source: nop-6.s
+#objdump: -drw
+#name: x86-64 .nop 6
+
+.*: +file format .*
+
+
+Disassembly of section .text:
+
+0+ <_start>:
+ +[a-f0-9]+:	0f 1f 40 00          	nopl   0x0\(%rax\)
+
+Disassembly of section .altinstr_replacement:
+
+0+ <.altinstr_replacement>:
+ +[a-f0-9]+:	75 fe                	jne    0 <_start>
+ +[a-f0-9]+:	89 c4                	mov    %eax,%esp
+#pass