Add support to AArch64 disassembler for verifying instructions. Add verifier for LDPSW.

	PR target/19722
opcodes	* aarch64-dis.c (aarch64_opcode_decode): Run verifier if present.
	* aarch64-opc.c (verify_ldpsw): New function.
	* aarch64-opc.h (verify_ldpsw): New prototype.
	* aarch64-tbl.h: Add initialiser for verifier field.
	(LDPSW): Set verifier to verify_ldpsw.

binutils* testsuite/binutils-all/aarch64/illegal.s: New test.
	* testsuite/binutils-all/aarch64/illegal.d: New test driver.

include	* opcode/aarch64.h (struct aarch64_opcode): Add verifier field.

1 files changed, 28 insertions, 0 deletions

diff --git a/opcodes/aarch64-opc.c b/opcodes/aarch64-opc.c
index 76992df..8fbea46 100644
--- a/opcodes/aarch64-opc.c
+++ b/opcodes/aarch64-opc.c
@@ -3417,6 +3417,34 @@ aarch64_sys_ins_reg_supported_p (const aarch64_feature_set features,
 #undef C14
 #undef C15
 
+#define BIT(INSN,BT)     (((INSN) >> (BT)) & 1)
+#define BITS(INSN,HI,LO) (((INSN) >> (LO)) & ((1 << (((HI) - (LO)) + 1)) - 1))
+
+bfd_boolean
+verify_ldpsw (const struct aarch64_opcode * opcode ATTRIBUTE_UNUSED,
+	      const aarch64_insn insn)
+{
+  int t  = BITS (insn, 4, 0);
+  int n  = BITS (insn, 9, 5);
+  int t2 = BITS (insn, 14, 10);
+
+  if (BIT (insn, 23))
+    {
+      /* Write back enabled.  */
+      if ((t == n || t2 == n) && n != 31)
+	return FALSE;
+    }
+
+  if (BIT (insn, 22))
+    {
+      /* Load */
+      if (t == t2)
+	return FALSE;
+    }
+
+  return TRUE;
+}
+
 /* Include the opcode description table as well as the operand description
    table.  */
 #include "aarch64-tbl.h"