MIPS16/opcodes: Annotate instruction aliases

Complement commit 986e18a5a9fd ("Add a second 'pinfo' member to
mips_opcode to extend number of available bits"),
<https://sourceware.org/ml/binutils/2005-01/msg00261.html>, and annotate
MIPS16 NOP, LA, DLA and the synthetic forms of LD and LW instructions as
aliases.  These correspond to MOVE, and the PC-relative ADDIU, DADDIU,
LD and LW hardware instructions respectively.

	binutils/
	* testsuite/binutils-all/mips/mips16-alias.d: New test.
	* testsuite/binutils-all/mips/mips16-noalias.d: New test.
	* testsuite/binutils-all/mips/mips16-alias.s: New test source.
	* testsuite/binutils-all/mips/mips.exp: Run the new tests.

	opcodes/
	* mips16-opc.c (AL): New macro.
	(mips16_opcodes): Mark "nop", "la", "dla", and synthetic forms
	of "ld" and "lw" as aliases.

4 files changed, 53 insertions, 0 deletions

diff --git a/binutils/testsuite/binutils-all/mips/mips.exp b/binutils/testsuite/binutils-all/mips/mips.exp
index 255d4f7..672515c 100644
--- a/binutils/testsuite/binutils-all/mips/mips.exp
+++ b/binutils/testsuite/binutils-all/mips/mips.exp
@@ -30,4 +30,6 @@ if [is_elf_format] {
     run_dump_test "mips16-pcrel"
     run_dump_test "mips16-extend-noinsn"
     run_dump_test "mips16-extend-insn"
+    run_dump_test "mips16-alias"
+    run_dump_test "mips16-noalias"
 }
diff --git a/binutils/testsuite/binutils-all/mips/mips16-alias.d b/binutils/testsuite/binutils-all/mips/mips16-alias.d
new file mode 100644
index 0000000..875615b
--- /dev/null
+++ b/binutils/testsuite/binutils-all/mips/mips16-alias.d
@@ -0,0 +1,15 @@
+#PROG: objcopy
+#objdump: -d --prefix-addresses --show-raw-insn
+#name: MIPS16 instruction alias disassembly
+#as: -32 -mips3
+
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+[0-9a-f]+ <[^>]*> 6500      	nop
+[0-9a-f]+ <[^>]*> 0a08      	la	v0,00000020 <bar>
+[0-9a-f]+ <[^>]*> b207      	lw	v0,00000020 <bar>
+[0-9a-f]+ <[^>]*> fe47      	dla	v0,00000020 <bar>
+[0-9a-f]+ <[^>]*> fc43      	ld	v0,00000020 <bar>
+	\.\.\.
+	\.\.\.
diff --git a/binutils/testsuite/binutils-all/mips/mips16-alias.s b/binutils/testsuite/binutils-all/mips/mips16-alias.s
new file mode 100644
index 0000000..bda4f9e
--- /dev/null
+++ b/binutils/testsuite/binutils-all/mips/mips16-alias.s
@@ -0,0 +1,20 @@
+	.text
+	.set	mips16
+	.ent	foo
+foo:
+	nop
+	la	$2, bar
+	lw	$2, bar
+	dla	$2, bar
+	ld	$2, bar
+	.set	nomips16
+	.end	foo
+
+# Force some (non-delay-slot) zero bytes, to make 'objdump' print ...
+	.align	4, 0
+	.space	16
+
+	.type	bar, @object
+bar:
+	.long	0
+	.size	bar, . - bar
diff --git a/binutils/testsuite/binutils-all/mips/mips16-noalias.d b/binutils/testsuite/binutils-all/mips/mips16-noalias.d
new file mode 100644
index 0000000..76f61bd
--- /dev/null
+++ b/binutils/testsuite/binutils-all/mips/mips16-noalias.d
@@ -0,0 +1,16 @@
+#PROG: objcopy
+#objdump: -M no-aliases -d --prefix-addresses --show-raw-insn
+#name: MIPS16 canonical alias disassembly
+#as: -32 -mips3
+#source: mips16-alias.s
+
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+[0-9a-f]+ <[^>]*> 6500      	move	zero,s0
+[0-9a-f]+ <[^>]*> 0a08      	addiu	v0,\$pc,32
+[0-9a-f]+ <[^>]*> b207      	lw	v0,28\(\$pc\)
+[0-9a-f]+ <[^>]*> fe47      	daddiu	v0,\$pc,28
+[0-9a-f]+ <[^>]*> fc43      	ld	v0,24\(\$pc\)
+	\.\.\.
+	\.\.\.