[MIPS] Add load-link, store-conditional paired instructions

Add several baseline MIPS32R6[1] and MIPS64R6[2] instructions
that were omitted from the initial spec.  These instructions
are optional in implementations but not associated with any
ASE or pseudo-ASE.  Their presence is indicated by the XNP bit
in the Config5 register.

[1] "MIPS Architecture for Programmers Volume II-A: The MIPS32
     Instruction Set Manual", Imagination Technologies Ltd., Document
     Number: MD00086, Revision 6.06, December 15, 2016, Section 3.2
     "Alphabetical List of Instructions", pp. 228-229, pp. 354-357.

[2] "MIPS Architecture for Programmers Volume II-A: The MIPS64
     Instruction Set Manual", Imagination Technologies Ltd., Document
     Number: MD00087, Revision 6.06, December 15, 2016, Section 3.2
     "Alphabetical List of Instructions", pp. 289-290 and pp. 458-460.

gas/
	* config/tc-mips.c (macro) <M_LLWP_AB, M_LLDP_AB, M_SCWP_AB,
	M_SCDP_AB>: New cases and expansions for paired instructions.
	* testsuite/gas/mips/llpscp-32.s: New test source.
	* testsuite/gas/mips/llpscp-64.s: Likewise.
	* testsuite/gas/mips/llpscp-32.d: New test.
	* testsuite/gas/mips/llpscp-64.d: Likewise.
	* testsuite/gas/mips/mips.exp: Run the new tests.
	* testsuite/gas/mips/r6.s: Add new instructions to test source.
	* testsuite/gas/mips/r6-64.s: Likewise.
	* testsuite/gas/mips/r6-64-n32.d: Check new instructions.
	* testsuite/gas/mips/r6-64-n64.d: Likewise.
	* testsuite/gas/mips/r6-n32.d: Likewise.
	* testsuite/gas/mips/r6-n64.d: Likwwise.
	* testsuite/gas/mips/r6.d: Likewise.

include/
	* opcode/mips.h (M_LLWP_AB, M_LLDP_AB): New enum values.
	(M_SCWP_AB, M_SCDP_AB): Likewise.

opcodes/
	* mips-opc.c (mips_builtin_opcodes): Add llwp, lldp, scwp, scdp.

gas/ChangeLog

@@ -1,3 +1,21 @@
+2019-04-26  Andrew Bennett  <andrew.bennett@imgtec.com>
+	    Faraz Shahbazker  <fshahbazker@wavecomp.com>
+
+	* config/tc-mips.c (macro) <M_LLWP_AB, M_LLDP_AB, M_SCWP_AB,
+	M_SCDP_AB>: New cases and expansions for paired instructions.
+	* testsuite/gas/mips/llpscp-32.s: New test source.
+	* testsuite/gas/mips/llpscp-64.s: Likewise.
+	* testsuite/gas/mips/llpscp-32.d: New test.
+	* testsuite/gas/mips/llpscp-64.d: Likewise.
+	* testsuite/gas/mips/mips.exp: Run the new tests.
+	* testsuite/gas/mips/r6.s: Add new instructions to test source.
+	* testsuite/gas/mips/r6-64.s: Likewise.
+	* testsuite/gas/mips/r6-64-n32.d: Check new instructions.
+	* testsuite/gas/mips/r6-64-n64.d: Likewise.
+	* testsuite/gas/mips/r6-n32.d: Likewise.
+	* testsuite/gas/mips/r6-n64.d: Likwwise.
+	* testsuite/gas/mips/r6.d: Likewise.
+
 2019-04-26  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR gas/24485

gas/config/tc-mips.c

@@ -10279,6 +10279,7 @@ macro (struct mips_cl_insn *ip, char *str)
   int imm = 0;
   int ust = 0;
   int lp = 0;
+  int ll_sc_paired = 0;
   bfd_boolean large_offset;
   int off;
   int hold_mips_optimize;
@@ -12014,6 +12015,13 @@ macro (struct mips_cl_insn *ip, char *str)
       offbits = 12;
       lp = 1;
       goto ld;
+    case M_LLDP_AB:
+    case M_LLWP_AB:
+      s = ip->insn_mo->name;
+      fmt = "t,d,s";
+      ll_sc_paired = 1;
+      offbits = 0;
+      goto ld;
     case M_LWM_AB:
       gas_assert (mips_opts.micromips);
       s = "lwm";
@@ -12028,11 +12036,26 @@ macro (struct mips_cl_insn *ip, char *str)
       goto ld_st;
 
     ld:
-      /* We don't want to use $0 as tempreg.  */
+      /* Try to use one the the load registers to compute the base address.
-      if (op[2] == op[0] + lp || op[0] + lp == ZERO)
+	 We don't want to use $0 as tempreg.  */
-	goto ld_st;
+      if (ll_sc_paired)
+	{
+	  if ((op[0] == ZERO && op[3] == op[1])
+	      || (op[1] == ZERO && op[3] == op[0])
+	      || (op[0] == ZERO && op[1] == ZERO))
+	    goto ld_st;
+	  else if (op[0] != op[3] && op[0] != ZERO)
+	    tempreg = op[0];
+	  else
+	    tempreg = op[1];
+	}
       else
-	tempreg = op[0] + lp;
+        {
+	  if (op[2] == op[0] + lp || op[0] + lp == ZERO)
+	    goto ld_st;
+	  else
+	    tempreg = op[0] + lp;
+	}
       goto ld_noat;
 
     case M_SB_AB:
@@ -12100,6 +12123,13 @@ macro (struct mips_cl_insn *ip, char *str)
 		 : ISA_IS_R6 (mips_opts.isa) ? 9
 		 : 16);
       goto ld_st;
+    case M_SCDP_AB:
+    case M_SCWP_AB:
+      s = ip->insn_mo->name;
+      fmt = "t,d,s";
+      ll_sc_paired = 1;
+      offbits = 0;
+      goto ld_st;
     case M_CACHE_AB:
       s = "cache";
       fmt = (mips_opts.micromips ? "k,~(b)"
@@ -12193,7 +12223,7 @@ macro (struct mips_cl_insn *ip, char *str)
     ld_st:
       tempreg = AT;
     ld_noat:
-      breg = op[2];
+      breg = ll_sc_paired ? op[3] : op[2];
       if (small_offset_p (0, align, 16))
 	{
 	  /* The first case exists for M_LD_AB and M_SD_AB, which are
@@ -12205,7 +12235,12 @@ macro (struct mips_cl_insn *ip, char *str)
 	  else if (small_offset_p (0, align, offbits))
 	    {
 	      if (offbits == 0)
-		macro_build (NULL, s, fmt, op[0], breg);
+		{
+		  if (ll_sc_paired)
+		   macro_build (NULL, s, fmt, op[0], op[1], breg);
+		  else
+		   macro_build (NULL, s, fmt, op[0], breg);
+		}
 	      else
 		macro_build (NULL, s, fmt, op[0],
 			     (int) offset_expr.X_add_number, breg);
@@ -12218,7 +12253,12 @@ macro (struct mips_cl_insn *ip, char *str)
 			   tempreg, breg, -1, offset_reloc[0],
 			   offset_reloc[1], offset_reloc[2]);
 	      if (offbits == 0)
-		macro_build (NULL, s, fmt, op[0], tempreg);
+		{
+		  if (ll_sc_paired)
+		    macro_build (NULL, s, fmt, op[0], op[1], tempreg);
+		  else
+		    macro_build (NULL, s, fmt, op[0], tempreg);
+		}
 	      else
 		macro_build (NULL, s, fmt, op[0], 0, tempreg);
 	    }
@@ -12261,7 +12301,10 @@ macro (struct mips_cl_insn *ip, char *str)
 	      if (offset_expr.X_add_number != 0)
 		macro_build (&offset_expr, ADDRESS_ADDI_INSN,
 			     "t,r,j", tempreg, tempreg, BFD_RELOC_LO16);
-	      macro_build (NULL, s, fmt, op[0], tempreg);
+	      if (ll_sc_paired)
+		macro_build (NULL, s, fmt, op[0], op[1], tempreg);
+	      else
+		macro_build (NULL, s, fmt, op[0], tempreg);
 	    }
 	  else if (offbits == 16)
 	    macro_build (&offset_expr, s, fmt, op[0], BFD_RELOC_LO16, tempreg);
@@ -12279,7 +12322,12 @@ macro (struct mips_cl_insn *ip, char *str)
 	    macro_build (NULL, ADDRESS_ADD_INSN, "d,v,t",
 			 tempreg, tempreg, breg);
 	  if (offbits == 0)
-	    macro_build (NULL, s, fmt, op[0], tempreg);
+	    {
+	      if (ll_sc_paired)
+		macro_build (NULL, s, fmt, op[0], op[1], tempreg);
+	      else
+		macro_build (NULL, s, fmt, op[0], tempreg);
+	    }
 	  else
 	    macro_build (NULL, s, fmt, op[0], 0, tempreg);
 	}

gas/testsuite/gas/mips/llpscp-32.d

@@ -0,0 +1,44 @@
+#objdump: -dr
+#name: Paired LL/SC for mips32r6
+#as: -32
+
+.*: +file format .*
+
+Disassembly of section \.text:
+
+00000000 <test>:
+   0:	7c821876 	llwp	v0,v1,a0
+   4:	7c821876 	llwp	v0,v1,a0
+   8:	24821234 	addiu	v0,a0,4660
+   c:	7c420076 	llwp	v0,zero,v0
+  10:	24430000 	addiu	v1,v0,0
+			10: R_MIPS_LO16	.data
+  14:	7c621876 	llwp	v0,v1,v1
+  18:	3c020123 	lui	v0,0x123
+  1c:	00431021 	addu	v0,v0,v1
+  20:	24424567 	addiu	v0,v0,17767
+  24:	7c421876 	llwp	v0,v1,v0
+  28:	3c010000 	lui	at,0x0
+			28: R_MIPS_HI16	.data
+  2c:	24210000 	addiu	at,at,0
+			2c: R_MIPS_LO16	.data
+  30:	00240821 	addu	at,at,a0
+  34:	7c200076 	llwp	zero,zero,at
+  38:	7c821866 	scwp	v0,v1,a0
+  3c:	7c821866 	scwp	v0,v1,a0
+  40:	24811234 	addiu	at,a0,4660
+  44:	7c220066 	scwp	v0,zero,at
+  48:	24410000 	addiu	at,v0,0
+			48: R_MIPS_LO16	.data
+  4c:	7c221866 	scwp	v0,v1,at
+  50:	3c010123 	lui	at,0x123
+  54:	00230821 	addu	at,at,v1
+  58:	24214567 	addiu	at,at,17767
+  5c:	7c221866 	scwp	v0,v1,at
+  60:	3c010000 	lui	at,0x0
+			60: R_MIPS_HI16	.data
+  64:	24210000 	addiu	at,at,0
+			64: R_MIPS_LO16	.data
+  68:	00240821 	addu	at,at,a0
+  6c:	7c200066 	scwp	zero,zero,at
+	...

gas/testsuite/gas/mips/llpscp-32.s

@@ -0,0 +1,23 @@
+	.text
+test:
+	llwp $2, $3, $4  /* No macro expansion needed */
+	llwp $2, $3, 0($4)
+	llwp $2, $0, 0x1234($4)
+	llwp $2, $3, %lo(sync_mem)($2)
+	llwp $2, $3, 0xffffffff01234567($3)
+	llwp $0, $0, sync_mem($4)
+
+	scwp $2, $3, $4  /* No macro expansion needed */
+	scwp $2, $3, 0($4)
+	scwp $2, $0, 0x1234($4)
+	scwp $2, $3, %lo(sync_mem)($2)
+	scwp $2, $3, 0xffffffff01234567($3)
+	scwp $0, $0, sync_mem($4)
+	.space 8
+
+	.data
+sync_mem:
+	.word
+	.word
+
+	.space 8

gas/testsuite/gas/mips/llpscp-64.d

@@ -0,0 +1,43 @@
+#objdump: -dr
+#name: Paired LL/SC for mips64r6
+
+.*: +file format .*
+
+Disassembly of section \.text:
+
+00000000 <test>:
+   0:	7c821877 	lldp	v0,v1,a0
+   4:	7c821877 	lldp	v0,v1,a0
+   8:	24821234 	addiu	v0,a0,4660
+   c:	7c420077 	lldp	v0,zero,v0
+  10:	24430000 	addiu	v1,v0,0
+			10: R_MIPS_LO16	.data
+  14:	7c621877 	lldp	v0,v1,v1
+  18:	3c020123 	lui	v0,0x123
+  1c:	00431021 	addu	v0,v0,v1
+  20:	24424567 	addiu	v0,v0,17767
+  24:	7c421877 	lldp	v0,v1,v0
+  28:	3c010000 	lui	at,0x0
+			28: R_MIPS_HI16	.data
+  2c:	24210000 	addiu	at,at,0
+			2c: R_MIPS_LO16	.data
+  30:	00240821 	addu	at,at,a0
+  34:	7c200077 	lldp	zero,zero,at
+  38:	7c821867 	scdp	v0,v1,a0
+  3c:	7c821867 	scdp	v0,v1,a0
+  40:	24811234 	addiu	at,a0,4660
+  44:	7c220067 	scdp	v0,zero,at
+  48:	24410000 	addiu	at,v0,0
+			48: R_MIPS_LO16	.data
+  4c:	7c221867 	scdp	v0,v1,at
+  50:	3c010123 	lui	at,0x123
+  54:	00230821 	addu	at,at,v1
+  58:	24214567 	addiu	at,at,17767
+  5c:	7c221867 	scdp	v0,v1,at
+  60:	3c010000 	lui	at,0x0
+			60: R_MIPS_HI16	.data
+  64:	24210000 	addiu	at,at,0
+			64: R_MIPS_LO16	.data
+  68:	00240821 	addu	at,at,a0
+  6c:	7c200067 	scdp	zero,zero,at
+	...

gas/testsuite/gas/mips/llpscp-64.s

@@ -0,0 +1,23 @@
+	.text
+test:
+	lldp $2, $3, $4  /* No macro expansion needed */
+	lldp $2, $3, 0($4)
+	lldp $2, $0, 0x1234($4)
+	lldp $2, $3, %lo(sync_mem)($2)
+	lldp $2, $3, 0xffffffff01234567($3)
+	lldp $0, $0, sync_mem($4)
+
+	scdp $2, $3, $4  /* No macro expansion needed */
+	scdp $2, $3, 0($4)
+	scdp $2, $0, 0x1234($4)
+	scdp $2, $3, %lo(sync_mem)($2)
+	scdp $2, $3, 0xffffffff01234567($3)
+	scdp $0, $0, sync_mem($4)
+
+	.space 8
+
+	.data
+sync_mem:
+	.word
+	.word
+	.space 8

gas/testsuite/gas/mips/mips.exp

@@ -2083,4 +2083,7 @@ if { [istarget mips*-*-vxworks*] } {
 
     run_dump_test_arches "ginv"	[mips_arch_list_matching mips32r6]
     run_dump_test_arches "ginv-err"	[mips_arch_list_matching mips32r6]
+
+    run_dump_test_arches "llpscp-32" [mips_arch_list_matching mips32r6]
+    run_dump_test_arch "llpscp-64" "" mips64r6
 }

gas/testsuite/gas/mips/r6-64-n32.d

@@ -61,4 +61,6 @@ Disassembly of section .text:
 0+00a4 <[^>]*> ec9a0000 	ldpc	a0,fff000a0 <[^>]*>
 0+00a8 <[^>]*> ec99ffff 	ldpc	a0,001000a0 <[^>]*>
 0+00ac <[^>]*> ec99ffff 	ldpc	a0,001000a0 <[^>]*>
+0+00b0 <[^>]*> 7cc52077 	lldp	a1,a0,a2
+0+00b4 <[^>]*> 7cc52067 	scdp	a1,a0,a2
 	\.\.\.

gas/testsuite/gas/mips/r6-64-n64.d

@@ -79,4 +79,6 @@ Disassembly of section .text:
 0+00a4 <[^>]*> ec9a0000 	ldpc	a0,f+ff000a0 <[^>]*>
 0+00a8 <[^>]*> ec99ffff 	ldpc	a0,0+01000a0 <[^>]*>
 0+00ac <[^>]*> ec99ffff 	ldpc	a0,0+01000a0 <[^>]*>
+0+00b0 <[^>]*> 7cc52077 	lldp	a1,a0,a2
+0+00b4 <[^>]*> 7cc52067 	scdp	a1,a0,a2
 	\.\.\.

gas/testsuite/gas/mips/r6-64.s

@@ -56,7 +56,9 @@
         ld     $4, (131071 << 3)($pc)
         .align 3
 1:
-        nop
+	lldp	$5, $4, $6
+	scdp	$5, $4, $6
+	nop
 	nop
 
 # Force at least 8 (non-delay-slot) zero bytes, to make 'objdump' print ...

gas/testsuite/gas/mips/r6-n32.d

@@ -499,4 +499,7 @@ Disassembly of section .text:
 0+05a0 <[^>]*> 41620024 	dvp	v0
 0+05a4 <[^>]*> 04170000 	sigrie	0x0
 0+05a8 <[^>]*> 0417ffff 	sigrie	0xffff
+0+05ac <[^>]*> 7cc52076 	llwp	a1,a0,a2
+0+05b0 <[^>]*> 7cc52066 	scwp	a1,a0,a2
+
 	\.\.\.

gas/testsuite/gas/mips/r6-n64.d

@@ -755,4 +755,6 @@ Disassembly of section .text:
 0+05a0 <[^>]*> 41620024 	dvp	v0
 0+05a4 <[^>]*> 04170000 	sigrie	0x0
 0+05a8 <[^>]*> 0417ffff 	sigrie	0xffff
+0+05ac <[^>]*> 7cc52076 	llwp	a1,a0,a2
+0+05b0 <[^>]*> 7cc52066 	scwp	a1,a0,a2
 	\.\.\.

gas/testsuite/gas/mips/r6.d

@@ -498,4 +498,6 @@ Disassembly of section .text:
 0+05a0 <[^>]*> 41620024 	dvp	v0
 0+05a4 <[^>]*> 04170000 	sigrie	0x0
 0+05a8 <[^>]*> 0417ffff 	sigrie	0xffff
+0+05ac <[^>]*> 7cc52076 	llwp	a1,a0,a2
+0+05b0 <[^>]*> 7cc52066 	scwp	a1,a0,a2
 	\.\.\.

gas/testsuite/gas/mips/r6.s

@@ -269,6 +269,9 @@ new:	maddf.s	$f0,$f1,$f2
 	sigrie	0
 	sigrie	0xffff
 
+	llwp	$5, $4, $6
+	scwp	$5, $4, $6
+
 # Force at least 8 (non-delay-slot) zero bytes, to make 'objdump' print ...
 	.align  2
 	.space  8

include/ChangeLog

@@ -1,3 +1,9 @@
+2019-04-26  Andrew Bennett  <andrew.bennett@imgtec.com>
+	    Faraz Shahbazker  <fshahbazker@wavecomp.com>
+
+	* opcode/mips.h (M_LLWP_AB, M_LLDP_AB): New enum values.
+	(M_SCWP_AB, M_SCDP_AB): Likewise.
+
 2019-04-25  Maciej W. Rozycki  <macro@linux-mips.org>
 
 	* opcode/mips.h: Update comment for MIPS32 CODE20 operand.

include/opcode/mips.h

@@ -1628,7 +1628,9 @@ enum
   M_LI_SS,
   M_LL_AB,
   M_LLD_AB,
+  M_LLDP_AB,
   M_LLE_AB,
+  M_LLWP_AB,
   M_LQ_AB,
   M_LW_AB,
   M_LWE_AB,
@@ -1679,7 +1681,9 @@ enum
   M_SAAD_AB,
   M_SC_AB,
   M_SCD_AB,
+  M_SCDP_AB,
   M_SCE_AB,
+  M_SCWP_AB,
   M_SD_AB,
   M_SDC1_AB,
   M_SDC2_AB,

opcodes/ChangeLog

@@ -1,3 +1,8 @@
+2019-04-26  Andrew Bennett  <andrew.bennett@imgtec.com>
+	    Faraz Shahbazker  <fshahbazker@wavecomp.com>
+
+	* mips-opc.c (mips_builtin_opcodes): Add llwp, lldp, scwp, scdp.
+
 2019-04-24  John Darrington  <john@darrington.wattle.id.au>
 
         * s12z-opc.h: Add extern "C" bracketing to help

opcodes/mips-opc.c

@@ -1300,6 +1300,10 @@ const struct mips_opcode mips_builtin_opcodes[] =
 {"lld",			"t,+j(b)",	0x7c000037, 0xfc00007f, WR_1|RD_3|LM,		0,		I69,		0,	0 },
 {"lld",			"t,o(b)",	0xd0000000, 0xfc000000, WR_1|RD_3|LM,		0,		I3,		0,	EE|I69 },
 {"lld",			"t,A(b)",	0,    (int) M_LLD_AB,	INSN_MACRO,		0,		I3,		0,	EE },
+{"lldp",		"t,d,s",	0x7c000077, 0xfc0007ff, WR_1|WR_2|RD_3|LM,	0,		I69,		0,	0 },
+{"lldp",		"t,d,A(b)",	0,    (int) M_LLDP_AB,	INSN_MACRO,		0,		I69,		0,	0 },
+{"llwp",		"t,d,s",	0x7c000076, 0xfc0007ff, WR_1|WR_2|RD_3|LM,	0,		I37,		0,	0 },
+{"llwp",		"t,d,A(b)",	0,    (int) M_LLWP_AB,	INSN_MACRO,		0,		I37,		0,	0 },
 {"lq",			"t,o(b)",	0x78000000, 0xfc000000, WR_1|RD_3|LM,		0,		MMI,		0,	0 },
 {"lq",			"t,A(b)",	0,    (int) M_LQ_AB,	INSN_MACRO,		0,		MMI,		0,	0 },
 {"lqc2",		"+7,o(b)",	0xd8000000, 0xfc000000,	RD_3|WR_C2|LM,		0,		EE,		0,	0 },
@@ -1831,6 +1835,10 @@ const struct mips_opcode mips_builtin_opcodes[] =
 {"scd",			"t,+j(b)",	0x7c000027, 0xfc00007f, MOD_1|RD_3|SM,		0,		I69,		0,	0 },
 {"scd",			"t,o(b)",	0xf0000000, 0xfc000000, MOD_1|RD_3|SM,		0,		I3,		0,	EE|I69 },
 {"scd",			"t,A(b)",	0,    (int) M_SCD_AB,	INSN_MACRO,		0,		I3,		0,	EE },
+{"scdp",		"t,d,s",	0x7c000067, 0xfc0007ff, MOD_1|RD_2|RD_3|SM,	0,		I69,		0,	0 },
+{"scdp",		"t,d,A(b)",	0,    (int) M_SCDP_AB,	INSN_MACRO,		0,		I69,		0,	0 },
+{"scwp",		"t,d,s",	0x7c000066, 0xfc0007ff, MOD_1|RD_2|RD_3|SM,	0,		I37,		0,	0 },
+{"scwp",		"t,d,A(b)",	0,    (int) M_SCWP_AB,	INSN_MACRO,		0,		I37,		0,	0 },
 /* The macro has to be first to handle o32 correctly.  */
 {"sd",			"t,A(b)",	0,    (int) M_SD_AB,	INSN_MACRO,		0,		I1,		0,	0 },
 {"sd",			"t,o(b)",	0xfc000000, 0xfc000000,	RD_1|RD_3|SM,		0,		I3,		0,	0 },