Modify the ARM encoding and decoding of SQRSHRL and UQRSHLL MVE instructions.

This is a change to the first published specifications [1][a] but since there is no hardware
out there that uses the old instructions we do not want to support the old variant.
This changes are done based on the latest published specifications [1][b].

[1] https://developer.arm.com/architectures/cpu-architecture/m-profile/docs/ddi0553/latest/armv81-m-architecture-reference-manual
    [a] version bf
    [b] version bh

gas	* config/tc-arm.c (enum operand_parse_code): Add the entry OP_I48_I64.
	(po_imm1_or_imm2_or_fail): Marco to check the immediate is either of
        48 or 64.
	(parse_operands): Add case OP_I48_I64.
	(do_mve_scalar_shift1): Add function to encode the MVE shift
        instructions with 4 arguments.
	* testsuite/gas/arm/mve-shift-bad.l: Modify.
	* testsuite/gas/arm/mve-shift-bad.s: Likewise.
	* testsuite/gas/arm/mve-shift.d: Likewise.
	* testsuite/gas/arm/mve-shift.s: Likewise.

opcodes	* arm-dis.c (struct mopcode32 mve_opcodes): Modify the mask for
	cases MVE_SQRSHRL and MVE_UQRSHLL.
	(print_insn_mve): Add case for specifier 'k' to check
	specific bit of the instruction.

6 files changed, 76 insertions, 8 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index d7e0840..a60b9d2 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,16 @@
+2019-08-12  Srinath Parvathaneni  <srinath.parvathaneni@arm.com>
+
+	* config/tc-arm.c (enum operand_parse_code): Add the entry OP_I48_I64.
+	(po_imm1_or_imm2_or_fail): Marco to check the immediate is either of
+        48 or 64.
+	(parse_operands): Add case OP_I48_I64.
+	(do_mve_scalar_shift1): Add function to encode the MVE shift
+        instructions with 4 arguments.
+	* testsuite/gas/arm/mve-shift-bad.l: Modify.
+	* testsuite/gas/arm/mve-shift-bad.s: Likewise.
+	* testsuite/gas/arm/mve-shift.d: Likewise.
+	* testsuite/gas/arm/mve-shift.s: Likewise.
+
 2019-08-12  Barnaby Wilks  <barnaby.wilks@arm.com>
 
 	* config/tc-arm.c (enum fp_16bit_format): Add enum to represent the 2 float16 encodings.
diff --git a/gas/config/tc-arm.c b/gas/config/tc-arm.c
index 714121b..e2b21ed 100644
--- a/gas/config/tc-arm.c
+++ b/gas/config/tc-arm.c
@@ -7050,6 +7050,7 @@ enum operand_parse_code
   OP_I31w,	/*		   0 .. 31, optional trailing ! */
   OP_I32,	/*		   1 .. 32 */
   OP_I32z,	/*		   0 .. 32 */
+  OP_I48_I64,	/*		   48 or 64 */
   OP_I63,	/*		   0 .. 63 */
   OP_I63s,	/*		 -64 .. 63 */
   OP_I64,	/*		   1 .. 64 */
@@ -7201,6 +7202,25 @@ parse_operands (char *str, const unsigned int *pattern, bfd_boolean thumb)
     }								\
   while (0)
 
+#define po_imm1_or_imm2_or_fail(imm1, imm2, popt)		\
+  do								\
+    {								\
+      expressionS exp;						\
+      my_get_expression (&exp, &str, popt);			\
+      if (exp.X_op != O_constant)				\
+	{							\
+	  inst.error = _("constant expression required");	\
+	  goto failure;						\
+	}							\
+      if (exp.X_add_number != imm1 && exp.X_add_number != imm2) \
+	{							\
+	  inst.error = _("immediate value 48 or 64 expected");	\
+	  goto failure;						\
+	}							\
+      inst.operands[i].imm = exp.X_add_number;			\
+    }								\
+  while (0)
+
 #define po_scalar_or_goto(elsz, label, reg_type)			\
   do									\
     {									\
@@ -7545,6 +7565,7 @@ parse_operands (char *str, const unsigned int *pattern, bfd_boolean thumb)
 	case OP_I31:	 po_imm_or_fail (  0,	  31, FALSE);	break;
 	case OP_I32:	 po_imm_or_fail (  1,	  32, FALSE);	break;
 	case OP_I32z:	 po_imm_or_fail (  0,     32, FALSE);   break;
+	case OP_I48_I64: po_imm1_or_imm2_or_fail (48, 64, FALSE); break;
 	case OP_I63s:	 po_imm_or_fail (-64,	  63, FALSE);	break;
 	case OP_I63:	 po_imm_or_fail (  0,     63, FALSE);   break;
 	case OP_I64:	 po_imm_or_fail (  1,     64, FALSE);   break;
@@ -14345,6 +14366,24 @@ v8_1_loop_reloc (int is_le)
     }
 }
 
+/* For shifts with four operands in MVE.  */
+static void
+do_mve_scalar_shift1 (void)
+{
+  unsigned int value = inst.operands[2].imm;
+
+  inst.instruction |= inst.operands[0].reg << 16;
+  inst.instruction |= inst.operands[1].reg << 8;
+
+  /* Setting the bit for saturation.  */
+  inst.instruction |= ((value == 64) ? 0: 1) << 7;
+
+  /* Assuming Rm is already checked not to be 11x1.  */
+  constraint (inst.operands[3].reg == inst.operands[0].reg, BAD_OVERLAP);
+  constraint (inst.operands[3].reg == inst.operands[1].reg, BAD_OVERLAP);
+  inst.instruction |= inst.operands[3].reg << 12;
+}
+
 /* For shifts in MVE.  */
 static void
 do_mve_scalar_shift (void)
@@ -25405,8 +25444,8 @@ static const struct asm_opcode insns[] =
  ToC("lsll",	ea50010d, 3, (RRe, RRo, RRnpcsp_I32), mve_scalar_shift),
  ToC("lsrl",	ea50011f, 3, (RRe, RRo, I32),	      mve_scalar_shift),
  ToC("asrl",	ea50012d, 3, (RRe, RRo, RRnpcsp_I32), mve_scalar_shift),
- ToC("uqrshll",	ea51010d, 3, (RRe, RRo, RRnpcsp),     mve_scalar_shift),
- ToC("sqrshrl",	ea51012d, 3, (RRe, RRo, RRnpcsp),     mve_scalar_shift),
+ ToC("uqrshll",	ea51010d, 4, (RRe, RRo, I48_I64, RRnpcsp), mve_scalar_shift1),
+ ToC("sqrshrl",	ea51012d, 4, (RRe, RRo, I48_I64, RRnpcsp), mve_scalar_shift1),
  ToC("uqshll",	ea51010f, 3, (RRe, RRo, I32),	      mve_scalar_shift),
  ToC("urshrl",	ea51011f, 3, (RRe, RRo, I32),	      mve_scalar_shift),
  ToC("srshrl",	ea51012f, 3, (RRe, RRo, I32),	      mve_scalar_shift),
diff --git a/gas/testsuite/gas/arm/mve-shift-bad.l b/gas/testsuite/gas/arm/mve-shift-bad.l
index 5e7bfed..835d0e3 100644
--- a/gas/testsuite/gas/arm/mve-shift-bad.l
+++ b/gas/testsuite/gas/arm/mve-shift-bad.l
@@ -5,8 +5,14 @@
 .*: Error: Even register not allowed here -- `lsll r2,r4,#5'
 .*: Error: r15 not allowed here -- `lsll r2,r15,r5'
 .*: Warning: instruction is UNPREDICTABLE with SP operand
-.*: Error: registers may not be the same -- `sqrshrl r2,r3,r3'
+.*: Error: registers may not be the same -- `sqrshrl r2,r3,#64,r3'
+.*: Error: registers may not be the same -- `sqrshrl r2,r3,#48,r3'
+.*: Error: constant expression required -- `sqrshrl r2,r3,r3'
+.*: Error: immediate value 48 or 64 expected -- `sqrshrl r2,r3,#40,r3'
 .*: Error: registers may not be the same -- `sqrshr r2,r2'
-.*: Error: registers may not be the same -- `uqrshll r2,r3,r2'
+.*: Error: registers may not be the same -- `uqrshll r2,r3,#64,r2'
+.*: Error: registers may not be the same -- `uqrshll r2,r3,#48,r2'
+.*: Error: constant expression required -- `uqrshll r2,r3,r2'
+.*: Error: immediate value 48 or 64 expected -- `uqrshll r2,r3,#40,r2'
 .*: Error: thumb conditional instruction should be in IT block -- `uqshlgt r2,#32'
 .*: Error: constant expression required -- `urshrlle r2,r3,r5'
diff --git a/gas/testsuite/gas/arm/mve-shift-bad.s b/gas/testsuite/gas/arm/mve-shift-bad.s
index 7b38359..0470487 100644
--- a/gas/testsuite/gas/arm/mve-shift-bad.s
+++ b/gas/testsuite/gas/arm/mve-shift-bad.s
@@ -8,8 +8,14 @@ foo:
 	lsll	r2, r4, #5
 	lsll	r2, r15, r5
 	lsrl	r2, r13, #5
+	sqrshrl	r2, r3, #64, r3
+	sqrshrl	r2, r3, #48, r3
 	sqrshrl	r2, r3, r3
+	sqrshrl	r2, r3, #40,r3
 	sqrshr	r2, r2
+	uqrshll	r2, r3, #64, r2
+	uqrshll	r2, r3, #48, r2
 	uqrshll	r2, r3, r2
+	uqrshll	r2, r3, #40, r2
 	uqshlgt		r2, #32
 	urshrlle	r2, r3, r5
diff --git a/gas/testsuite/gas/arm/mve-shift.d b/gas/testsuite/gas/arm/mve-shift.d
index be5cd46..94172ad 100644
--- a/gas/testsuite/gas/arm/mve-shift.d
+++ b/gas/testsuite/gas/arm/mve-shift.d
@@ -11,13 +11,15 @@ Disassembly of section .text:
 0[0-9a-f]+ <[^>]+> ea52 134f 	lsll	r2, r3, #5
 0[0-9a-f]+ <[^>]+> ea52 530d 	lsll	r2, r3, r5
 0[0-9a-f]+ <[^>]+> ea52 135f 	lsrl	r2, r3, #5
-0[0-9a-f]+ <[^>]+> ea53 532d 	sqrshrl	r2, r3, r5
+0[0-9a-f]+ <[^>]+> ea53 53ad 	sqrshrl	r2, r3, #48, r5
+0[0-9a-f]+ <[^>]+> ea53 532d 	sqrshrl	r2, r3, #64, r5
 0[0-9a-f]+ <[^>]+> ea52 5f2d 	sqrshr	r2, r5
 0[0-9a-f]+ <[^>]+> ea53 137f 	sqshll	r2, r3, #5
 0[0-9a-f]+ <[^>]+> ea52 1f7f 	sqshl	r2, #5
 0[0-9a-f]+ <[^>]+> ea53 73ef 	srshrl	r2, r3, #31
 0[0-9a-f]+ <[^>]+> ea52 7fef 	srshr	r2, #31
-0[0-9a-f]+ <[^>]+> ea53 530d 	uqrshll	r2, r3, r5
+0[0-9a-f]+ <[^>]+> ea53 538d 	uqrshll	r2, r3, #48, r5
+0[0-9a-f]+ <[^>]+> ea53 530d 	uqrshll	r2, r3, #64, r5
 0[0-9a-f]+ <[^>]+> ea52 5f0d 	uqrshl	r2, r5
 0[0-9a-f]+ <[^>]+> ea53 73cf 	uqshll	r2, r3, #31
 0[0-9a-f]+ <[^>]+> bfce      	itee	gt
diff --git a/gas/testsuite/gas/arm/mve-shift.s b/gas/testsuite/gas/arm/mve-shift.s
index 267e3fb..3038a0d 100644
--- a/gas/testsuite/gas/arm/mve-shift.s
+++ b/gas/testsuite/gas/arm/mve-shift.s
@@ -6,13 +6,15 @@ foo:
 	lsll	r2, r3, #5
 	lsll	r2, r3, r5
 	lsrl	r2, r3, #5
-	sqrshrl	r2, r3, r5
+	sqrshrl	r2, r3, #48, r5
+	sqrshrl	r2, r3, #64, r5
 	sqrshr	r2, r5
 	sqshll	r2, r3, #5
 	sqshl	r2, #5
 	srshrl	r2, r3, #31
 	srshr	r2, #31
-	uqrshll	r2, r3, r5
+	uqrshll	r2, r3, #48, r5
+	uqrshll	r2, r3, #64, r5
 	uqrshl	r2, r5
 	uqshll	r2, r3, #31
 	itee	gt