MIPS/GAS: Unify GP-relative percent-ops

For a reason that is unclear commit d6f165938798 ("Support for MIPS16
HI16/LO16 relocations"),
<https://sourceware.org/ml/binutils/2005-02/msg00332.html>, which has
added support for the R_MIPS16_GPREL relocation, has spelled its
corresponding MIPS16 percent-op as `%gprel', rather than `%gp_rel' which
is how its regular MIPS counterpart is spelled.  To make assembly code
sharing easier between the regular MIPS and the MIPS16 ISA make both
percent-op spellings acceptable in both kinds of code now.

Parts of this change by Matthew Fortune.

	gas/
	* config/tc-mips.c (mips_percent_op): Add "%gprel".
	(mips16_percent_op): Add "%gp_rel".
	* testsuite/gas/mips/elf-rel8.s:: Add `%gprel' forms.
	* testsuite/gas/mips/elf-rel8-mips16.s: Add `%gp_rel' forms.
	* testsuite/gas/mips/elf-rel8.d: Adjust accordingly.
	* testsuite/gas/mips/elf-rel8-mips16.d: Likewise.

6 files changed, 38 insertions, 1 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 559e9e5..865142e 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,4 +1,14 @@
 2017-05-12  Maciej W. Rozycki  <macro@imgtec.com>
+	    Matthew Fortune  <matthew.fortune@imgtec.com>
+
+	* config/tc-mips.c (mips_percent_op): Add "%gprel".
+	(mips16_percent_op): Add "%gp_rel".
+	* testsuite/gas/mips/elf-rel8.s:: Add `%gprel' forms.
+	* testsuite/gas/mips/elf-rel8-mips16.s: Add `%gp_rel' forms.
+	* testsuite/gas/mips/elf-rel8.d: Adjust accordingly.
+	* testsuite/gas/mips/elf-rel8-mips16.d: Likewise.
+
+2017-05-12  Maciej W. Rozycki  <macro@imgtec.com>
 
 	* testsuite/gas/mips/mips16.d: Adjust BREAK disassembly.
 	* testsuite/gas/mips/mips16-64@mips16.d: Likewise.
diff --git a/gas/config/tc-mips.c b/gas/config/tc-mips.c
index 4ead209..e73b9c9 100644
--- a/gas/config/tc-mips.c
+++ b/gas/config/tc-mips.c
@@ -14094,6 +14094,7 @@ static const struct percent_op_match mips_percent_op[] =
   {"%got_lo", BFD_RELOC_MIPS_GOT_LO16},
   {"%got", BFD_RELOC_MIPS_GOT16},
   {"%gp_rel", BFD_RELOC_GPREL16},
+  {"%gprel", BFD_RELOC_GPREL16},
   {"%half", BFD_RELOC_16},
   {"%highest", BFD_RELOC_MIPS_HIGHEST},
   {"%higher", BFD_RELOC_MIPS_HIGHER},
@@ -14113,6 +14114,7 @@ static const struct percent_op_match mips_percent_op[] =
 static const struct percent_op_match mips16_percent_op[] =
 {
   {"%lo", BFD_RELOC_MIPS16_LO16},
+  {"%gp_rel", BFD_RELOC_MIPS16_GPREL},
   {"%gprel", BFD_RELOC_MIPS16_GPREL},
   {"%got", BFD_RELOC_MIPS16_GOT16},
   {"%call16", BFD_RELOC_MIPS16_CALL16},
diff --git a/gas/testsuite/gas/mips/elf-rel8-mips16.d b/gas/testsuite/gas/mips/elf-rel8-mips16.d
index 7c834fa..f1def80 100644
--- a/gas/testsuite/gas/mips/elf-rel8-mips16.d
+++ b/gas/testsuite/gas/mips/elf-rel8-mips16.d
@@ -34,5 +34,11 @@ Disassembly of section \.text:
 			32: R_MIPS16_GPREL	gvar
   36:	f000 4c00 	addiu	\$4,0
 			36: R_MIPS16_GPREL	gvar
-  3a:	6500      	nop
+  3a:	f000 9a80 	lw	\$4,0\(\$2\)
+			3a: R_MIPS16_GPREL	gvar
+  3e:	f000 da80 	sw	\$4,0\(\$2\)
+			3e: R_MIPS16_GPREL	gvar
+  42:	f000 4c00 	addiu	\$4,0
+			42: R_MIPS16_GPREL	gvar
+  46:	6500      	nop
 #pass
diff --git a/gas/testsuite/gas/mips/elf-rel8-mips16.s b/gas/testsuite/gas/mips/elf-rel8-mips16.s
index 0c9eefe..dfde21a 100644
--- a/gas/testsuite/gas/mips/elf-rel8-mips16.s
+++ b/gas/testsuite/gas/mips/elf-rel8-mips16.s
@@ -32,6 +32,13 @@ foo:
 	lw	$4,%gprel(gvar)($2)
 	sw	$4,%gprel(gvar)($2)
 	addiu	$4,%gprel(gvar)
+
+	# Check the alternative form.
+
+	lw	$4,%gp_rel(gvar)($2)
+	sw	$4,%gp_rel(gvar)($2)
+	addiu	$4,%gp_rel(gvar)
+
 	.align	6
 	.end	foo
 
diff --git a/gas/testsuite/gas/mips/elf-rel8.d b/gas/testsuite/gas/mips/elf-rel8.d
index 270533b..beacecf 100644
--- a/gas/testsuite/gas/mips/elf-rel8.d
+++ b/gas/testsuite/gas/mips/elf-rel8.d
@@ -54,4 +54,10 @@ Disassembly of section \.text:
 			5c: R_MIPS_GPREL16	gvar
   60:	27840000 	addiu	\$4,\$28,0
 			60: R_MIPS_GPREL16	gvar
+  64:	8f840000 	lw	\$4,0\(\$28\)
+			64: R_MIPS_GPREL16	gvar
+  68:	af840000 	sw	\$4,0\(\$28\)
+			68: R_MIPS_GPREL16	gvar
+  6c:	27840000 	addiu	\$4,\$28,0
+			6c: R_MIPS_GPREL16	gvar
 	\.\.\.
diff --git a/gas/testsuite/gas/mips/elf-rel8.s b/gas/testsuite/gas/mips/elf-rel8.s
index b3f5dab..4a84bee 100644
--- a/gas/testsuite/gas/mips/elf-rel8.s
+++ b/gas/testsuite/gas/mips/elf-rel8.s
@@ -46,6 +46,12 @@ foo:
 	sw	$4,%gp_rel(gvar)($28)
 	addiu	$4,$28,%gp_rel(gvar)
 
+	# Check the alternative form.
+
+	lw	$4,%gprel(gvar)($28)
+	sw	$4,%gprel(gvar)($28)
+	addiu	$4,$28,%gprel(gvar)
+
 	.space	64
 	.end	foo