[Arm] Add CSDB instruction

CSDB is a new instruction which Arm has defined. As it shares the
encoding space with NOP instructions, it is available from Armv3 in
Arm mode, and Armv6T2 in Thumb mode.

OK? If so, please commit on my behalf as I don't have commit rights
over here.

Thanks, James

---
opcodes/

2018-01-09  James Greenhalgh  <james.greenhalgh@arm.com>

	* arm-dis.c (arm_opcodes): Add csdb.
	(thumb32_opcodes): Add csdb.

gas/

2018-01-09  James Greenhalgh  <james.greenhalgh@arm.com>

	* config/tc-arm.c (insns): Add csdb, enable for Armv3 and above
	in Arm execution state, and Armv6T2 and above in Thumb execution
	state.
	* testsuite/gas/arm/csdb.s: New.
	* testsuite/gas/arm/csdb.d: New.
	* testsuite/gas/arm/thumb2_it_bad.l: Add csdb.
	* testsuite/gas/arm/thumb2_it_bad.s: Add csdb.

6 files changed, 44 insertions, 0 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index d00ccb2..287656b 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,5 +1,15 @@
 2018-01-09  James Greenhalgh  <james.greenhalgh@arm.com>
 
+	* config/tc-arm.c (insns): Add csdb, enable for Armv3 and above
+	in Arm execution state, and Armv6T2 and above in Thumb execution
+	state.
+	* testsuite/gas/arm/csdb.s: New.
+	* testsuite/gas/arm/csdb.d: New.
+	* testsuite/gas/arm/thumb2_it_bad.l: Add csdb.
+	* testsuite/gas/arm/thumb2_it_bad.s: Add csdb.
+
+2018-01-09  James Greenhalgh  <james.greenhalgh@arm.com>
+
 	* testsuite/gas/aarch64/system.d: Update expected results to expect
 	CSDB for hint 0x14.
 
diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index 85f74a8..0b81c19 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -11275,6 +11275,12 @@ do_t_clz (void)
 }
 
 static void
+do_t_csdb (void)
+{
+  set_it_insn_type (OUTSIDE_IT_INSN);
+}
+
+static void
 do_t_cps (void)
 {
   set_it_insn_type (OUTSIDE_IT_INSN);
@@ -19984,6 +19990,15 @@ static const struct asm_opcode insns[] =
  TC3("ldrsbt",	03000d0, f9100e00, 2, (RRnpc_npcsp, ADDR), ldsttv4, t_ldstt),
  TC3("strht",	02000b0, f8200e00, 2, (RRnpc_npcsp, ADDR), ldsttv4, t_ldstt),
 
+#undef  ARM_VARIANT
+#define ARM_VARIANT    & arm_ext_v3
+#undef  THUMB_VARIANT
+#define THUMB_VARIANT  & arm_ext_v6t2
+
+ TUE("csdb",	320f014, f3af8014, 0, (), noargs, t_csdb),
+
+#undef  ARM_VARIANT
+#define ARM_VARIANT    & arm_ext_v6t2
 #undef  THUMB_VARIANT
 #define THUMB_VARIANT  & arm_ext_v6t2_v8m
  TCE("movw",	3000000, f2400000, 2, (RRnpc, HALF),		    mov16, t_mov16),
diff --git a/gas/testsuite/gas/arm/csdb.d b/gas/testsuite/gas/arm/csdb.d
new file mode 100644
index 0000000..baf5855
--- /dev/null
+++ b/gas/testsuite/gas/arm/csdb.d
@@ -0,0 +1,10 @@
+#name: CSDB
+#source: csdb.s
+#objdump: -dr --prefix-addresses --show-raw-insn
+
+.*: +file format .*arm.*
+
+Disassembly of section .text:
+0+000 <[^>]*> f3af 8014 ?	csdb
+0+004 <[^>]*> e320f014 ?	csdb
+
diff --git a/gas/testsuite/gas/arm/csdb.s b/gas/testsuite/gas/arm/csdb.s
new file mode 100644
index 0000000..133a5f0
--- /dev/null
+++ b/gas/testsuite/gas/arm/csdb.s
@@ -0,0 +1,6 @@
+.text
+.thumb
+.syntax unified
+csdb
+.arm
+csdb
diff --git a/gas/testsuite/gas/arm/thumb2_it_bad.l b/gas/testsuite/gas/arm/thumb2_it_bad.l
index aa1f658..da9341f 100644
--- a/gas/testsuite/gas/arm/thumb2_it_bad.l
+++ b/gas/testsuite/gas/arm/thumb2_it_bad.l
@@ -10,3 +10,4 @@
 [^:]*:19: Error: instruction is always unconditional -- `bkpteq 0'
 [^:]*:20: Error: instruction not allowed in IT block -- `setendeq le'
 [^:]*:22: Error: IT falling in the range of a previous IT block -- `iteq eq'
+[^:]*:25: Error: instruction not allowed in IT block -- `csdbeq'
diff --git a/gas/testsuite/gas/arm/thumb2_it_bad.s b/gas/testsuite/gas/arm/thumb2_it_bad.s
index 6add4fb..72f305d 100644
--- a/gas/testsuite/gas/arm/thumb2_it_bad.s
+++ b/gas/testsuite/gas/arm/thumb2_it_bad.s
@@ -21,4 +21,6 @@ thumb2_it_bad:
 	it	eq
 	iteq	eq
 	nop
+	it	eq
+	csdbeq
 foo: