MIPS: Fix the encoding of immediates with microMIPS JALX

The microMIPS JALX instruction shares the R_MICROMIPS_26_S1 relocation
with microMIPS J/JAL/JALS instructions, however unlike the latters its
encoded immediate argument is unusually shifted left by 2 rather than 1
in calculating the value used for the operation requested.

We already handle this exception in `mips_elf_calculate_relocation' in
LD, in a scenario where JALX is produced as a result of relaxing JAL for
the purpose of making a cross-mode jump.  We also get it right in the
disassembler in `decode_micromips_operand'.

What we don't correctly do however is processing microMIPS JALX produced
by GAS from an assembly source, where a non-zero constant argument or a
symbol reference with a non-zero in-place addend has been used.  In this
case the same calculation is made as for microMIPS J/JAL/JALS, causing
the wrong encoding to be produced by GAS on making an object file, and
then again by LD in the final link.  The latter in particular causes the
calculation, where the addend fits in the relocatable field, to produce
different final addresses for the same source code depending on whether
REL or RELA relocations are used.

Correct these issues by special-casing microMIPS JALX in the places that
have been previously missed.

	bfd/
	* elfxx-mips.c (mips_elf_read_rel_addend): Adjust the addend for
	microMIPS JALX.

	gas/
	* config/tc-mips.c (append_insn): Correct the encoding of a
	constant argument for microMIPS JALX.
	(tc_gen_reloc): Correct the encoding of an in-place addend for
	microMIPS JALX.
	* testsuite/gas/mips/jalx-addend.d: New test.
	* testsuite/gas/mips/jalx-addend-n32.d: New test.
	* testsuite/gas/mips/jalx-addend-n64.d: New test.
	* testsuite/gas/mips/jalx-imm.d: New test.
	* testsuite/gas/mips/jalx-imm-n32.d: New test.
	* testsuite/gas/mips/jalx-imm-n64.d: New test.
	* testsuite/gas/mips/jalx-addend.s: New test source.
	* testsuite/gas/mips/jalx-imm.s: New test source.
	* testsuite/gas/mips/mips.exp: Run the new tests.

	ld/
	* testsuite/ld-mips-elf/jalx-addend.d: New test.
	* testsuite/ld-mips-elf/jalx-addend-n32.d: New test.
	* testsuite/ld-mips-elf/jalx-addend-n64.d: New test.
	* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.

9 files changed, 206 insertions, 0 deletions

diff --git a/gas/testsuite/gas/mips/jalx-addend-n32.d b/gas/testsuite/gas/mips/jalx-addend-n32.d
new file mode 100644
index 0000000..1abb246
--- /dev/null
+++ b/gas/testsuite/gas/mips/jalx-addend-n32.d
@@ -0,0 +1,29 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS JAL/JALX addend encoding (n32)
+#as: -n32 -march=from-abi
+#source: jalx-addend.s
+
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+	\.\.\.
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> f400 0000 	jal	00000000 <foo-0x1000>
+[ 	]*[0-9a-f]+: R_MICROMIPS_26_S1	foo-0x3fffffe
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> f000 0000 	jalx	00000000 <foo-0x1000>
+[ 	]*[0-9a-f]+: R_MICROMIPS_26_S1	bar-0x7fffffc
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> 001f 0f3c 	jr	ra
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> 0000 0000 	nop
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 74000000 	jalx	00000000 <foo-0x1000>
+[ 	]*[0-9a-f]+: R_MIPS_26	foo-0x7fffffc
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 0c000000 	jal	00000000 <foo-0x1000>
+[ 	]*[0-9a-f]+: R_MIPS_26	bar-0x7fffffc
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 03e00009 	jalr	zero,ra
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+	\.\.\.
diff --git a/gas/testsuite/gas/mips/jalx-addend-n64.d b/gas/testsuite/gas/mips/jalx-addend-n64.d
new file mode 100644
index 0000000..469261f
--- /dev/null
+++ b/gas/testsuite/gas/mips/jalx-addend-n64.d
@@ -0,0 +1,37 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS JAL/JALX addend encoding (n64)
+#as: -64 -march=from-abi
+#source: jalx-addend.s
+
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+	\.\.\.
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> f400 0000 	jal	0000000000000000 <foo-0x1000>
+[ 	]*[0-9a-f]+: R_MICROMIPS_26_S1	foo-0x3fffffe
+[ 	]*[0-9a-f]+: R_MIPS_NONE	\*ABS\*-0x3fffffe
+[ 	]*[0-9a-f]+: R_MIPS_NONE	\*ABS\*-0x3fffffe
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> f000 0000 	jalx	0000000000000000 <foo-0x1000>
+[ 	]*[0-9a-f]+: R_MICROMIPS_26_S1	bar-0x7fffffc
+[ 	]*[0-9a-f]+: R_MIPS_NONE	\*ABS\*-0x7fffffc
+[ 	]*[0-9a-f]+: R_MIPS_NONE	\*ABS\*-0x7fffffc
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> 001f 0f3c 	jr	ra
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> 0000 0000 	nop
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 74000000 	jalx	0000000000000000 <foo-0x1000>
+[ 	]*[0-9a-f]+: R_MIPS_26	foo-0x7fffffc
+[ 	]*[0-9a-f]+: R_MIPS_NONE	\*ABS\*-0x7fffffc
+[ 	]*[0-9a-f]+: R_MIPS_NONE	\*ABS\*-0x7fffffc
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 0c000000 	jal	0000000000000000 <foo-0x1000>
+[ 	]*[0-9a-f]+: R_MIPS_26	bar-0x7fffffc
+[ 	]*[0-9a-f]+: R_MIPS_NONE	\*ABS\*-0x7fffffc
+[ 	]*[0-9a-f]+: R_MIPS_NONE	\*ABS\*-0x7fffffc
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 03e00009 	jalr	zero,ra
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+	\.\.\.
diff --git a/gas/testsuite/gas/mips/jalx-addend.d b/gas/testsuite/gas/mips/jalx-addend.d
new file mode 100644
index 0000000..442bc69
--- /dev/null
+++ b/gas/testsuite/gas/mips/jalx-addend.d
@@ -0,0 +1,28 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS JAL/JALX addend encoding
+#as: -32
+
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+	\.\.\.
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> f600 0001 	jal	04000002 <bar\+0x3ffefe2>
+[ 	]*[0-9a-f]+: R_MICROMIPS_26_S1	foo
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> f200 0001 	jalx	08000004 <bar\+0x7ffefe4>
+[ 	]*[0-9a-f]+: R_MICROMIPS_26_S1	bar
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> 001f 0f3c 	jr	ra
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> 0000 0000 	nop
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 76000001 	jalx	08000004 <bar\+0x7ffefe4>
+[ 	]*[0-9a-f]+: R_MIPS_26	foo
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 0e000001 	jal	08000004 <bar\+0x7ffefe4>
+[ 	]*[0-9a-f]+: R_MIPS_26	bar
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 03e00009 	jalr	zero,ra
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+	\.\.\.
diff --git a/gas/testsuite/gas/mips/jalx-addend.s b/gas/testsuite/gas/mips/jalx-addend.s
new file mode 100644
index 0000000..b9b0db3
--- /dev/null
+++ b/gas/testsuite/gas/mips/jalx-addend.s
@@ -0,0 +1,35 @@
+	.text
+	.set	noreorder
+	.space	0x1000
+
+	.align	4
+	.set	micromips
+	.globl	foo
+	.ent	foo
+foo:
+	nor	$0, $0
+	jal	foo - 0x3fffffe
+	 nor	$0, $0
+	jalx	bar - 0x7fffffc
+	 nor	$0, $0
+	jalr	$0, $ra
+	 nor	$0, $0
+	.end	foo
+
+	.align	4
+	.set	nomicromips
+	.globl	bar
+	.ent	bar
+bar:
+	nor	$0, $0
+	jalx	foo - 0x7fffffc
+	 nor	$0, $0
+	jal	bar - 0x7fffffc
+	 nor	$0, $0
+	jalr	$0, $ra
+	 nor	$0, $0
+	.end	bar
+
+# Force some (non-delay-slot) zero bytes, to make 'objdump' print ...
+	.align	4, 0
+	.space	16
diff --git a/gas/testsuite/gas/mips/jalx-imm-n32.d b/gas/testsuite/gas/mips/jalx-imm-n32.d
new file mode 100644
index 0000000..188bb49
--- /dev/null
+++ b/gas/testsuite/gas/mips/jalx-imm-n32.d
@@ -0,0 +1,5 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS JAL/JALX immediate operand encoding (n32)
+#as: -n32 -march=from-abi
+#source: jalx-imm.s
+#dump: jalx-imm.d
diff --git a/gas/testsuite/gas/mips/jalx-imm-n64.d b/gas/testsuite/gas/mips/jalx-imm-n64.d
new file mode 100644
index 0000000..7b0c23e
--- /dev/null
+++ b/gas/testsuite/gas/mips/jalx-imm-n64.d
@@ -0,0 +1,5 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS JAL/JALX immediate operand encoding (n64)
+#as: -64 -march=from-abi
+#source: jalx-imm.s
+#dump: jalx-imm.d
diff --git a/gas/testsuite/gas/mips/jalx-imm.d b/gas/testsuite/gas/mips/jalx-imm.d
new file mode 100644
index 0000000..aa487ff
--- /dev/null
+++ b/gas/testsuite/gas/mips/jalx-imm.d
@@ -0,0 +1,24 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS JAL/JALX immediate operand encoding
+#as: -32
+
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+	\.\.\.
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> f600 0001 	jal	0+4000002 <bar\+0x3ffefe2>
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> f200 0001 	jalx	0+8000004 <bar\+0x7ffefe4>
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> 001f 0f3c 	jr	ra
+[0-9a-f]+ <[^>]*> 0000 02d0 	not	zero,zero
+[0-9a-f]+ <[^>]*> 0000 0000 	nop
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 76000001 	jalx	0+8000004 <bar\+0x7ffefe4>
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 0e000001 	jal	0+8000004 <bar\+0x7ffefe4>
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+[0-9a-f]+ <[^>]*> 03e00009 	jalr	zero,ra
+[0-9a-f]+ <[^>]*> 00000027 	nor	zero,zero,zero
+	\.\.\.
diff --git a/gas/testsuite/gas/mips/jalx-imm.s b/gas/testsuite/gas/mips/jalx-imm.s
new file mode 100644
index 0000000..eef8717
--- /dev/null
+++ b/gas/testsuite/gas/mips/jalx-imm.s
@@ -0,0 +1,35 @@
+	.text
+	.set	noreorder
+	.space	0x1000
+
+	.align	4
+	.set	micromips
+	.globl	foo
+	.ent	foo
+foo:
+	nor	$0, $0
+	jal	0x4000002
+	 nor	$0, $0
+	jalx	0x8000004
+	 nor	$0, $0
+	jalr	$0, $ra
+	 nor	$0, $0
+	.end	foo
+
+	.align	4
+	.set	nomicromips
+	.globl	bar
+	.ent	bar
+bar:
+	nor	$0, $0
+	jalx	0x8000004
+	 nor	$0, $0
+	jal	0x8000004
+	 nor	$0, $0
+	jalr	$0, $ra
+	 nor	$0, $0
+	.end	bar
+
+# Force some (non-delay-slot) zero bytes, to make 'objdump' print ...
+	.align	4, 0
+	.space	16
diff --git a/gas/testsuite/gas/mips/mips.exp b/gas/testsuite/gas/mips/mips.exp
index 88d15c8..1b1ac02 100644
--- a/gas/testsuite/gas/mips/mips.exp
+++ b/gas/testsuite/gas/mips/mips.exp
@@ -794,6 +794,14 @@ if { [istarget mips*-*-vxworks*] } {
     run_dump_test "mips16-jalx"
     run_dump_test "mips-jalx"
     run_dump_test "mips-jalx-2"
+    run_dump_test "jalx-imm"
+    run_dump_test "jalx-addend"
+    if $has_newabi {
+	run_dump_test "jalx-imm-n32"
+	run_dump_test "jalx-addend-n32"
+	run_dump_test "jalx-imm-n64"
+	run_dump_test "jalx-addend-n64"
+    }
     # Check MIPS16 HI16/LO16 relocations
     run_dump_test "mips16-hilo"
     if $has_newabi {