Add macro expansions for ADD, SUB, DADD and DSUB for MIPS r6

Release 6 of the MIPS architecture does not have an ADDI instruction.
ADD/SUB instructions with immediate operands can be expanded to load
and immediate value and then perform the operation.

gas/
	* config/tc-mips.c (macro) <M_ADD_I, M_SUB_I, M_DADD_I, M_DSUB_I>:
	Add expansions for MIPS r6.
	* testsuite/gas/mips/add.s: Enable tests for R6.
	* testsuite/gas/mips/daddi.s: Annotate to test DADD for R6.
	* testsuite/gas/mips/mipsr6@add.d: Likewise.
	* gas/testsuite/gas/mips/mipsr6@dadd.d: New test.
	* gas/testsuite/gas/mips/mips.exp: Run the new test.

opcodes/
        * mips-opc.c (mips_opcodes): Enable ADD, SUB, DADD and DSUB
	macros for R6.

7 files changed, 62 insertions, 10 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 5307d23..c524fec 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,13 @@
+2019-05-10  Faraz Shahbazker  <fshahbazker@wavecomp.com>
+
+	* config/tc-mips.c (macro) <M_ADD_I, M_SUB_I, M_DADD_I, M_DSUB_I>:
+	Add expansions for MIPS r6.
+	* testsuite/gas/mips/add.s: Enable tests for R6.
+	* testsuite/gas/mips/daddi.s: Annotate to test DADD for R6.
+	* testsuite/gas/mips/mipsr6@add.d: Likewise.
+	* gas/testsuite/gas/mips/mipsr6@dadd.d: New test.
+	* gas/testsuite/gas/mips/mips.exp: Run the new test.
+
 2019-05-09  Matthew Malcomson  <matthew.malcomson@arm.com>
 
 	* testsuite/gas/aarch64/sve2.d: Remove file format restriction.
diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index 6a945e3..05527d80 100644
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -10350,7 +10350,10 @@ macro (struct mips_cl_insn *ip, char *str)
     case M_ADD_I:
       s = "addi";
       s2 = "add";
-      goto do_addi;
+      if (ISA_IS_R6 (mips_opts.isa))
+	goto do_addi_i;
+      else
+	goto do_addi;
     case M_ADDU_I:
       s = "addiu";
       s2 = "addu";
@@ -10359,10 +10362,11 @@ macro (struct mips_cl_insn *ip, char *str)
       dbl = 1;
       s = "daddi";
       s2 = "dadd";
-      if (!mips_opts.micromips)
+      if (!mips_opts.micromips && !ISA_IS_R6 (mips_opts.isa))
 	goto do_addi;
       if (imm_expr.X_add_number >= -0x200
-	  && imm_expr.X_add_number < 0x200)
+	  && imm_expr.X_add_number < 0x200
+	  && !ISA_IS_R6 (mips_opts.isa))
 	{
 	  macro_build (NULL, s, "t,r,.", op[0], op[1],
 		       (int) imm_expr.X_add_number);
@@ -13716,7 +13720,10 @@ macro (struct mips_cl_insn *ip, char *str)
     case M_SUB_I:
       s = "addi";
       s2 = "sub";
-      goto do_subi;
+      if (ISA_IS_R6 (mips_opts.isa))
+	goto do_subi_i;
+      else
+	goto do_subi;
     case M_SUBU_I:
       s = "addiu";
       s2 = "subu";
@@ -13725,10 +13732,11 @@ macro (struct mips_cl_insn *ip, char *str)
       dbl = 1;
       s = "daddi";
       s2 = "dsub";
-      if (!mips_opts.micromips)
+      if (!mips_opts.micromips && !ISA_IS_R6 (mips_opts.isa))
 	goto do_subi;
       if (imm_expr.X_add_number > -0x200
-	  && imm_expr.X_add_number <= 0x200)
+	  && imm_expr.X_add_number <= 0x200
+	  && !ISA_IS_R6 (mips_opts.isa))
 	{
 	  macro_build (NULL, s, "t,r,.", op[0], op[1],
 		       (int) -imm_expr.X_add_number);
diff --git a/gas/testsuite/gas/mips/add.s b/gas/testsuite/gas/mips/add.s
index 5702d92..d1c70ed 100644
--- a/gas/testsuite/gas/mips/add.s
+++ b/gas/testsuite/gas/mips/add.s
@@ -1,14 +1,12 @@
 # Source file used to test the add macro.
 	
 foo:
-	.ifndef r6
 	add	$4,$4,0
 	add	$4,$4,1
 	add	$4,$4,0x8000
 	add	$4,$4,-0x8000
 	add	$4,$4,0x10000
 	add	$4,$4,0x1a5a5
-	.endif
 
 # addu is handled the same way add is; just confirm that it isn't
 # totally broken.
diff --git a/gas/testsuite/gas/mips/daddi.s b/gas/testsuite/gas/mips/daddi.s
index b06dbee..b942a9f 100644
--- a/gas/testsuite/gas/mips/daddi.s
+++ b/gas/testsuite/gas/mips/daddi.s
@@ -5,7 +5,7 @@
 
 	.text
 text_label:
-
+	.ifndef r6
 	daddi	$3, $2, 511
 	daddi	$5, $4, -512
 
@@ -17,6 +17,7 @@ text_label:
 	daddi	$9, $8, -513
 	daddi	$11, $10, 32767
 	daddi	$13, $12, -32768
+	.endif
 
 	# 16 bits accepted for standard MIPS code.
 	.ifndef	micromips
diff --git a/gas/testsuite/gas/mips/mips.exp b/gas/testsuite/gas/mips/mips.exp
index 3e66fcf..4db6683 100644
--- a/gas/testsuite/gas/mips/mips.exp
+++ b/gas/testsuite/gas/mips/mips.exp
@@ -1502,6 +1502,7 @@ if { [istarget mips*-*-vxworks*] } {
 					[mips_arch_list_matching mips32] ] ]
     run_dump_test_arches "daddi"	[mips_arch_list_matching mips3 \
 						!mips32r6]
+    run_dump_test_arches "dadd" 	[mips_arch_list_matching mips64r6]
     run_dump_test_arches "pref" [lsort -dictionary -unique [concat \
 					[mips_arch_list_matching mips4] \
 					[mips_arch_list_matching mips32] ] ]
diff --git a/gas/testsuite/gas/mips/mipsr6@add.d b/gas/testsuite/gas/mips/mipsr6@add.d
index 65a5214..fe32999 100644
--- a/gas/testsuite/gas/mips/mipsr6@add.d
+++ b/gas/testsuite/gas/mips/mipsr6@add.d
@@ -8,5 +8,18 @@
 .*: +file format .*mips.*
 
 Disassembly of section .text:
-0+0000 <[^>]*> addiu	a0,a0,1
+[0-9a-f]+ <[^>]*> li	at,0
+[0-9a-f]+ <[^>]*> add	a0,a0,at
+[0-9a-f]+ <[^>]*> li	at,1
+[0-9a-f]+ <[^>]*> add	a0,a0,at
+[0-9a-f]+ <[^>]*> li	at,0x8000
+[0-9a-f]+ <[^>]*> add	a0,a0,at
+[0-9a-f]+ <[^>]*> li	at,-32768
+[0-9a-f]+ <[^>]*> add	a0,a0,at
+[0-9a-f]+ <[^>]*> lui	at,0x1
+[0-9a-f]+ <[^>]*> add	a0,a0,at
+[0-9a-f]+ <[^>]*> lui	at,0x1
+[0-9a-f]+ <[^>]*> ori	at,at,0xa5a5
+[0-9a-f]+ <[^>]*> add	a0,a0,at
+[0-9a-f]+ <[^>]*> addiu	a0,a0,1
 	\.\.\.
diff --git a/gas/testsuite/gas/mips/mipsr6@dadd.d b/gas/testsuite/gas/mips/mipsr6@dadd.d
new file mode 100644
index 0000000..0701f26
--- /dev/null
+++ b/gas/testsuite/gas/mips/mipsr6@dadd.d
@@ -0,0 +1,21 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS DADD immediate expansion for R6
+#as: -32
+#source: daddi.s
+
+# Check MIPS DADD macro expansion with an immediate operand.
+
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+[0-9a-f]+ <[^>]*> 34018000 	li	at,0x8000
+[0-9a-f]+ <[^>]*> 01c1782c 	dadd	t7,t6,at
+[0-9a-f]+ <[^>]*> 3c01ffff 	lui	at,0xffff
+[0-9a-f]+ <[^>]*> 34217fff 	ori	at,at,0x7fff
+[0-9a-f]+ <[^>]*> 0201882c 	dadd	s1,s0,at
+[0-9a-f]+ <[^>]*> 34018200 	li	at,0x8200
+[0-9a-f]+ <[^>]*> 0241982c 	dadd	s3,s2,at
+[0-9a-f]+ <[^>]*> 3c01ffff 	lui	at,0xffff
+[0-9a-f]+ <[^>]*> 34217dff 	ori	at,at,0x7dff
+[0-9a-f]+ <[^>]*> 0281a82c 	dadd	s5,s4,at
+	\.\.\.