[committed] MIPS/GAS: Unify GP-relative percent-ops

[Maciej W. Rozycki]

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.
---
binutils-mips16-matthewf-gprel.diff
Index: binutils/gas/config/tc-mips.c
===================================================================
--- binutils.orig/gas/config/tc-mips.c	2017-05-12 00:12:16.440212444 +0100
+++ binutils/gas/config/tc-mips.c	2017-05-12 02:01:55.271447015 +0100
@@ -14094,6 +14094,7 @@ static const struct percent_op_match mip
   {"%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 mip
 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},
Index: binutils/gas/testsuite/gas/mips/elf-rel8-mips16.d
===================================================================
--- binutils.orig/gas/testsuite/gas/mips/elf-rel8-mips16.d	2017-05-12 00:12:16.451626351 +0100
+++ binutils/gas/testsuite/gas/mips/elf-rel8-mips16.d	2017-05-12 01:24:29.372183202 +0100
@@ -34,5 +34,11 @@
 			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
Index: binutils/gas/testsuite/gas/mips/elf-rel8-mips16.s
===================================================================
--- binutils.orig/gas/testsuite/gas/mips/elf-rel8-mips16.s	2017-05-12 00:12:16.494331325 +0100
+++ binutils/gas/testsuite/gas/mips/elf-rel8-mips16.s	2017-05-12 01:24:29.397970410 +0100
@@ -32,6 +32,13 @@
 	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
 
Index: binutils/gas/testsuite/gas/mips/elf-rel8.d
===================================================================
--- binutils.orig/gas/testsuite/gas/mips/elf-rel8.d	2017-05-12 00:12:16.507519877 +0100
+++ binutils/gas/testsuite/gas/mips/elf-rel8.d	2017-05-12 01:24:29.476514484 +0100
@@ -54,4 +54,10 @@
 			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
 	\.\.\.
Index: binutils/gas/testsuite/gas/mips/elf-rel8.s
===================================================================
--- binutils.orig/gas/testsuite/gas/mips/elf-rel8.s	2017-05-12 00:12:16.521783066 +0100
+++ binutils/gas/testsuite/gas/mips/elf-rel8.s	2017-05-12 01:24:29.554556813 +0100
@@ -46,6 +46,12 @@
 	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