MIPS16/GAS: Fix absolute references with PC-relative synthetic instructions

Complement commit 88a7ef168927 ("MIPS16/GAS: Restore unsupported
relocation diagnostics") and also propagate constant expressions, either
already reduced from absolute symbol references or created from literals
in the first place, used as a PC-relative operand with the MIPS16 LA,
LW, DLA and LD synthetic instructions to relaxation, matching the way
forward absolute symbol references have been handled as from the commit
referred and letting relaxation produce any necessary relocations, if
possible, for the absolute value requested to be reproduced at the run
time.

Call `symbol_append' for any expression symbol created for the purpose
of MIPS16 relaxation as with constant expressions now propagated from
earlier on such symbols may make it through and have R_MIPS16_PC16_S1
relocations emitted against, and therefore need to appear in the symbol
table produced.

	gas/
	* config/tc-mips.c (append_insn): Call `symbol_append' for any
	expression symbol created for MIPS16 relaxation.
	(match_mips16_insn): Don't encode a constant value as an
	immediate with a PC-relative operand.

	* testsuite/gas/mips/mips16-pcrel-absolute-1.d: New test.
	* testsuite/gas/mips/mips16-branch-absolute-1.d: New test.
	* testsuite/gas/mips/mips16-branch-absolute-2.d: New test.
	* testsuite/gas/mips/mips16-branch-absolute-addend-1.d: New
	test.
	* testsuite/gas/mips/mips16-branch-absolute-n32-1.d: New test.
	* testsuite/gas/mips/mips16-branch-absolute-n32-2.d: New test.
	* testsuite/gas/mips/mips16-branch-absolute-addend-n32-1.d: New
	test.
	* testsuite/gas/mips/mips16-branch-absolute-n64-1.d: New test.
	* testsuite/gas/mips/mips16-branch-absolute-n64-2.d: New test.
	* testsuite/gas/mips/mips16-branch-absolute-addend-n64-1.d: New
	test.
	* testsuite/gas/mips/mips16-pcrel-absolute-1.l: New stderr
	output.
	* testsuite/gas/mips/mips16-pcrel-absolute-1.s: New test source.
	* testsuite/gas/mips/mips16-branch-absolute-1.s: New test
	source.
	* testsuite/gas/mips/mips16-branch-absolute-2.s: New test
	source.
	* testsuite/gas/mips/mips16-branch-absolute-addend-1.s: New test
	source.
	* testsuite/gas/mips/mips.exp: Run the new tests.

	ld/
	* testsuite/ld-mips-elf/mips16-branch-absolute-1.d: New test.
	* testsuite/ld-mips-elf/mips16-branch-absolute-2.d: New test.
	* testsuite/ld-mips-elf/mips16-branch-absolute-addend-1.d: New
	test.
	* testsuite/ld-mips-elf/mips16-branch-absolute-n32-1.d: New
	test.
	* testsuite/ld-mips-elf/mips16-branch-absolute-n32-2.d: New
	test.
	* testsuite/ld-mips-elf/mips16-branch-absolute-addend-n32-1.d:
	New test.
	* testsuite/ld-mips-elf/mips16-branch-absolute-n64-1.d: New
	test.
	* testsuite/ld-mips-elf/mips16-branch-absolute-n64-2.d: New
	test.
	* testsuite/ld-mips-elf/mips16-branch-absolute-addend-n64-1.d:
	New test.
	* testsuite/ld-mips-elf/mips-elf.exp: Run the new tests.

18 files changed, 193 insertions, 1 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index d5849c0..24155f1 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,34 @@
+2017-05-02  Maciej W. Rozycki  <macro@imgtec.com>
+
+	* config/tc-mips.c (append_insn): Call `symbol_append' for any
+	expression symbol created for MIPS16 relaxation.
+	(match_mips16_insn): Don't encode a constant value as an
+	immediate with a PC-relative operand.
+
+	* testsuite/gas/mips/mips16-pcrel-absolute-1.d: New test.
+	* testsuite/gas/mips/mips16-branch-absolute-1.d: New test.
+	* testsuite/gas/mips/mips16-branch-absolute-2.d: New test.
+	* testsuite/gas/mips/mips16-branch-absolute-addend-1.d: New
+	test.
+	* testsuite/gas/mips/mips16-branch-absolute-n32-1.d: New test.
+	* testsuite/gas/mips/mips16-branch-absolute-n32-2.d: New test.
+	* testsuite/gas/mips/mips16-branch-absolute-addend-n32-1.d: New
+	test.
+	* testsuite/gas/mips/mips16-branch-absolute-n64-1.d: New test.
+	* testsuite/gas/mips/mips16-branch-absolute-n64-2.d: New test.
+	* testsuite/gas/mips/mips16-branch-absolute-addend-n64-1.d: New
+	test.
+	* testsuite/gas/mips/mips16-pcrel-absolute-1.l: New stderr
+	output.
+	* testsuite/gas/mips/mips16-pcrel-absolute-1.s: New test source.
+	* testsuite/gas/mips/mips16-branch-absolute-1.s: New test
+	source.
+	* testsuite/gas/mips/mips16-branch-absolute-2.s: New test
+	source.
+	* testsuite/gas/mips/mips16-branch-absolute-addend-1.s: New test
+	source.
+	* testsuite/gas/mips/mips.exp: Run the new tests.
+
 2017-04-27  Maciej W. Rozycki  <macro@imgtec.com>
 
 	* config/tc-mips.c (mips16_pcrel_val): New function, factored
diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index fbf67a1..8c387ba 100644
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -7419,6 +7419,7 @@ append_insn (struct mips_cl_insn *ip, expressionS *address_expr,
       else
 	{
 	  symbol = make_expr_symbol (address_expr);
+	  symbol_append (symbol, symbol_lastP, &symbol_rootP, &symbol_lastP);
 	  offset = 0;
 	}
       add_relaxed_insn (ip, 4, 0,
@@ -8087,6 +8088,7 @@ match_mips16_insn (struct mips_cl_insn *insn, const struct mips_opcode *opcode,
   const char *args;
   const struct mips_operand *operand;
   const struct mips_operand *ext_operand;
+  bfd_boolean pcrel = FALSE;
   int required_insn_length;
   struct mips_arg_info arg;
   int relax_char;
@@ -8148,6 +8150,7 @@ match_mips16_insn (struct mips_cl_insn *insn, const struct mips_opcode *opcode,
 	    }
 	  else if (relax_char
 		   && offset_expr.X_op == O_constant
+		   && !pcrel
 		   && calculate_reloc (*offset_reloc,
 				       offset_expr.X_add_number,
 				       &value))
@@ -8216,7 +8219,9 @@ match_mips16_insn (struct mips_cl_insn *insn, const struct mips_opcode *opcode,
       if (!operand)
 	abort ();
 
-      if (operand->type != OP_PCREL)
+      if (operand->type == OP_PCREL)
+	pcrel = TRUE;
+      else
 	{
 	  ext_operand = decode_mips16_operand (c, TRUE);
 	  if (operand != ext_operand)
diff --git a/gas/testsuite/gas/mips/mips.exp b/gas/testsuite/gas/mips/mips.exp
index 30e2342..a46f7c2 100644
--- a/gas/testsuite/gas/mips/mips.exp
+++ b/gas/testsuite/gas/mips/mips.exp
@@ -1544,6 +1544,7 @@ if { [istarget mips*-*-vxworks*] } {
     run_dump_test "mips16-pcrel-addend-2"
     run_dump_test "mips16-pcrel-addend-3"
     run_dump_test "mips16-pcrel-absolute"
+    run_dump_test "mips16-pcrel-absolute-1"
     run_dump_test "mips16-branch-reloc-0"
     run_dump_test "mips16-branch-reloc-1"
     run_dump_test "mips16-branch-reloc-2"
@@ -1555,12 +1556,21 @@ if { [istarget mips*-*-vxworks*] } {
     run_dump_test "mips16-branch-addend-4"
     run_dump_test "mips16-branch-addend-5"
     run_dump_test "mips16-branch-absolute"
+    run_dump_test "mips16-branch-absolute-1"
+    run_dump_test "mips16-branch-absolute-2"
     run_dump_test "mips16-branch-absolute-addend"
+    run_dump_test "mips16-branch-absolute-addend-1"
     if $has_newabi {
 	run_dump_test "mips16-branch-absolute-n32"
+	run_dump_test "mips16-branch-absolute-n32-1"
+	run_dump_test "mips16-branch-absolute-n32-2"
 	run_dump_test "mips16-branch-absolute-addend-n32"
+	run_dump_test "mips16-branch-absolute-addend-n32-1"
 	run_dump_test "mips16-branch-absolute-n64"
+	run_dump_test "mips16-branch-absolute-n64-1"
+	run_dump_test "mips16-branch-absolute-n64-2"
 	run_dump_test "mips16-branch-absolute-addend-n64"
+	run_dump_test "mips16-branch-absolute-addend-n64-1"
     }
     run_dump_test "mips16-absolute-reloc-0"
     run_dump_test "mips16-absolute-reloc-1"
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-1.d b/gas/testsuite/gas/mips/mips16-branch-absolute-1.d
new file mode 100644
index 0000000..539bc90
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-1.d
@@ -0,0 +1,20 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS16 branch to absolute expression 1
+#as: -32
+
+.*: +file format .*mips.*
+
+Disassembly of section \.text:
+	\.\.\.
+[0-9a-f]+ <[^>]*> f7ff 101e 	b	00001000 <foo>
+[ 	]*[0-9a-f]+: R_MIPS16_PC16_S1	L0\001
+[0-9a-f]+ <[^>]*> f7ff 601e 	bteqz	00001004 <foo\+0x4>
+[ 	]*[0-9a-f]+: R_MIPS16_PC16_S1	L0\001
+[0-9a-f]+ <[^>]*> f7ff 611e 	btnez	00001008 <foo\+0x8>
+[ 	]*[0-9a-f]+: R_MIPS16_PC16_S1	L0\001
+[0-9a-f]+ <[^>]*> f7ff 221e 	beqz	v0,0000100c <foo\+0xc>
+[ 	]*[0-9a-f]+: R_MIPS16_PC16_S1	L0\001
+[0-9a-f]+ <[^>]*> f7ff 2a1e 	bnez	v0,00001010 <foo\+0x10>
+[ 	]*[0-9a-f]+: R_MIPS16_PC16_S1	L0\001
+[0-9a-f]+ <[^>]*> 6500      	nop
+	\.\.\.
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-1.s b/gas/testsuite/gas/mips/mips16-branch-absolute-1.s
new file mode 100644
index 0000000..dc7ee4d
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-1.s
@@ -0,0 +1,22 @@
+	.text
+
+	.space	0x1000
+
+	.set	bar, 0x1235
+
+	.globl	foo
+	.ent	foo
+	.set	mips16
+foo:
+	b	bar
+	bteqz	bar
+	btnez	bar
+	beqz	$2, bar
+	bnez	$2, bar
+	nop
+	.set	nomips16
+	.end	foo
+
+# Force some (non-delay-slot) zero bytes, to make 'objdump' print ...
+	.align	4, 0
+	.space	16
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-2.d b/gas/testsuite/gas/mips/mips16-branch-absolute-2.d
new file mode 100644
index 0000000..49a331f
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-2.d
@@ -0,0 +1,4 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS16 branch to absolute expression 2
+#as: -32
+#dump: mips16-branch-absolute-1.d
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-2.s b/gas/testsuite/gas/mips/mips16-branch-absolute-2.s
new file mode 100644
index 0000000..64aebb4
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-2.s
@@ -0,0 +1,20 @@
+	.text
+
+	.space	0x1000
+
+	.globl	foo
+	.ent	foo
+	.set	mips16
+foo:
+	b	0x1235
+	bteqz	0x1235
+	btnez	0x1235
+	beqz	$2, 0x1235
+	bnez	$2, 0x1235
+	nop
+	.set	nomips16
+	.end	foo
+
+# Force some (non-delay-slot) zero bytes, to make 'objdump' print ...
+	.align	4, 0
+	.space	16
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-addend-1.d b/gas/testsuite/gas/mips/mips16-branch-absolute-addend-1.d
new file mode 100644
index 0000000..66841c3
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-addend-1.d
@@ -0,0 +1,4 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS16 branch to absolute expression with addend 1
+#as: -32
+#dump: mips16-branch-absolute-1.d
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-addend-1.s b/gas/testsuite/gas/mips/mips16-branch-absolute-addend-1.s
new file mode 100644
index 0000000..e75d7e1
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-addend-1.s
@@ -0,0 +1,22 @@
+	.text
+
+	.space	0x1000
+
+	.set	bar, 0x12345679
+
+	.globl	foo
+	.ent	foo
+	.set	mips16
+foo:
+	b	bar + 0x1234
+	bteqz	bar + 0x1234
+	btnez	bar + 0x1234
+	beqz	$2, bar + 0x1234
+	bnez	$2, bar + 0x1234
+	nop
+	.set	nomips16
+	.end	foo
+
+# Force some (non-delay-slot) zero bytes, to make 'objdump' print ...
+	.align	4, 0
+	.space	16
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-addend-n32-1.d b/gas/testsuite/gas/mips/mips16-branch-absolute-addend-n32-1.d
new file mode 100644
index 0000000..bf565a3
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-addend-n32-1.d
@@ -0,0 +1,5 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS16 branch to absolute expression with addend 1 (n32)
+#as: -n32 -march=from-abi
+#source: mips16-branch-absolute-addend-1.s
+#dump: mips16-branch-absolute-addend-n32.d
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-addend-n64-1.d b/gas/testsuite/gas/mips/mips16-branch-absolute-addend-n64-1.d
new file mode 100644
index 0000000..c953821
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-addend-n64-1.d
@@ -0,0 +1,5 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS16 branch to absolute expression with addend 1 (n64)
+#as: -64 -march=from-abi
+#source: mips16-branch-absolute-addend-1.s
+#dump: mips16-branch-absolute-addend-n64.d
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-n32-1.d b/gas/testsuite/gas/mips/mips16-branch-absolute-n32-1.d
new file mode 100644
index 0000000..543696d
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-n32-1.d
@@ -0,0 +1,5 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS16 branch to absolute expression 1 (n32)
+#as: -n32 -march=from-abi
+#source: mips16-branch-absolute-1.s
+#dump: mips16-branch-absolute-n32.d
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-n32-2.d b/gas/testsuite/gas/mips/mips16-branch-absolute-n32-2.d
new file mode 100644
index 0000000..5d80db8
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-n32-2.d
@@ -0,0 +1,5 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS16 branch to absolute expression 2 (n32)
+#as: -n32 -march=from-abi
+#source: mips16-branch-absolute-2.s
+#dump: mips16-branch-absolute-n32.d
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-n64-1.d b/gas/testsuite/gas/mips/mips16-branch-absolute-n64-1.d
new file mode 100644
index 0000000..0ea0c2d
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-n64-1.d
@@ -0,0 +1,5 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS16 branch to absolute expression 1 (n64)
+#as: -64 -march=from-abi
+#source: mips16-branch-absolute-1.s
+#dump: mips16-branch-absolute-n64.d
diff --git a/gas/testsuite/gas/mips/mips16-branch-absolute-n64-2.d b/gas/testsuite/gas/mips/mips16-branch-absolute-n64-2.d
new file mode 100644
index 0000000..7d338f3
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-branch-absolute-n64-2.d
@@ -0,0 +1,5 @@
+#objdump: -dr --prefix-addresses --show-raw-insn
+#name: MIPS16 branch to absolute expression 2 (n64)
+#as: -64 -march=from-abi
+#source: mips16-branch-absolute-2.s
+#dump: mips16-branch-absolute-n64.d
diff --git a/gas/testsuite/gas/mips/mips16-pcrel-absolute-1.d b/gas/testsuite/gas/mips/mips16-pcrel-absolute-1.d
new file mode 100644
index 0000000..d9f6fb7
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-pcrel-absolute-1.d
@@ -0,0 +1,3 @@
+#name: MIPS16 PC-relative reference to absolute expression 1
+#as: -32
+#error-output: mips16-pcrel-absolute-1.l
diff --git a/gas/testsuite/gas/mips/mips16-pcrel-absolute-1.l b/gas/testsuite/gas/mips/mips16-pcrel-absolute-1.l
new file mode 100644
index 0000000..60054fa
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-pcrel-absolute-1.l
@@ -0,0 +1,3 @@
+.*: Assembler messages:
+.*:10: Error: unsupported relocation
+.*:11: Error: unsupported relocation
diff --git a/gas/testsuite/gas/mips/mips16-pcrel-absolute-1.s b/gas/testsuite/gas/mips/mips16-pcrel-absolute-1.s
new file mode 100644
index 0000000..833a967
--- /dev/null
+++ b/gas/testsuite/gas/mips/mips16-pcrel-absolute-1.s
@@ -0,0 +1,18 @@
+	.text
+
+	.space	0x1000
+
+	.set	bar, 0x1234
+
+	.ent	foo
+	.set	mips16
+foo:
+	la	$2, bar
+	lw	$2, bar
+	nop
+	.set	nomips16
+	.end	foo
+
+# Force some (non-delay-slot) zero bytes, to make 'objdump' print ...
+	.align	4, 0
+	.space	16