[ARC] Fix/improve small data support.

The R_ARC_SDA32 is wrongly described as a ME relocation, fix it.  Offset the
__SDATA_BEGIN__ to take advantage of the signed 9-bit field of the
load/store instructions.

include/
2016-07-08  Claudiu Zissulescu  <claziss@synopsys.com>

	* elf/arc-reloc.def (ARC_SDA32): Don't use ME transformation.

ld/
2016-07-08  Claudiu Zissulescu  <claziss@synopsys.com>

	* emulparams/arcelf.sh (SDATA_START_SYMBOLS): Add offset.
	* testsuite/ld-arc/sda-relocs.dd: New file.
	* testsuite/ld-arc/sda-relocs.ld: Likewise.
	* testsuite/ld-arc/sda-relocs.rd: Likewise.
	* testsuite/ld-arc/sda-relocs.s: Likewise.
	* testsuite/ld-arc/arc.exp: Add SDA tests.

5 files changed, 98 insertions, 0 deletions

diff --git a/ld/testsuite/ld-arc/arc.exp b/ld/testsuite/ld-arc/arc.exp
index 0cf6228..f8838cc 100644
--- a/ld/testsuite/ld-arc/arc.exp
+++ b/ld/testsuite/ld-arc/arc.exp
@@ -28,3 +28,11 @@ foreach arc_test $arc_test_list {
     run_dump_test [file rootname $arc_test]
 }
 
+set arccommon_tests {
+    { "SDA relocs"
+        "-q -T sda-relocs.ld" "" "-mcpu=archs" {sda-relocs.s}
+        {{objdump -fdw sda-relocs.dd} {readelf --relocs sda-relocs.rd}}
+        "sda-relocs.so" }
+}
+
+run_ld_link_tests $arccommon_tests
diff --git a/ld/testsuite/ld-arc/sda-relocs.dd b/ld/testsuite/ld-arc/sda-relocs.dd
new file mode 100644
index 0000000..c4a3ff6
--- /dev/null
+++ b/ld/testsuite/ld-arc/sda-relocs.dd
@@ -0,0 +1,23 @@
+
+.*:     file format .*
+architecture: ARCv2, flags 0x00000113:
+HAS_RELOC, EXEC_P, HAS_SYMS, D_PAGED
+start address 0x00010000
+
+
+Disassembly of section .text:
+
+[0-9a-f]+ <__SDATA_BEGIN__>:
+   [0-9a-f]+:	c8[0-9a-f]+                	ld_s	r0,\[gp,[0-9]+\]
+   [0-9a-f]+:	cc[0-9a-f]+                	ld(h|w)_s	r0,\[gp,[0-9]+\]
+   [0-9a-f]+:	ca[0-9a-f]+                	ldb_s	r0,\[gp,[0-9]+\]
+   [0-9a-f]+:	12[0-9a-f]+ 3600           	ld.as	r0,\[gp,[0-9]+\]
+   [0-9a-f]+:	1a[0-9a-f]+ 3018           	st.as	r0,\[gp,[0-9]+\]
+   [0-9a-f]+:	12[0-9a-f]+ 3000           	ld	r0,\[gp,[0-9]+\]
+   [0-9a-f]+:	12[0-9a-f]+ 3080           	ldb	r0,\[gp,[0-9]+\]
+   [0-9a-f]+:	12[0-9a-f]+ 3100           	ld(h|w)	r0,\[gp,[0-9]+\]
+   [0-9a-f]+:	1a[0-9a-f]+ 301c           	sth.as	r0,\[gp,[0-9]+\]
+   [0-9a-f]+:	50[0-9a-f]+                	ld_s	r1,\[gp,[0-9]+\]
+   [0-9a-f]+:	50[0-9a-f]+                	st_s	r0,\[gp,[0-9]+\]
+   [0-9a-f]+:	2200 3f82 0000 002c 	add	r2,gp,0x[0-9a-f]+
+   [0-9a-f]+:	78e0                	nop_s
diff --git a/ld/testsuite/ld-arc/sda-relocs.ld b/ld/testsuite/ld-arc/sda-relocs.ld
new file mode 100644
index 0000000..80dbbb5
--- /dev/null
+++ b/ld/testsuite/ld-arc/sda-relocs.ld
@@ -0,0 +1,20 @@
+/* Default linker script, for normal executables */
+OUTPUT_FORMAT("elf32-littlearc", "elf32-bigarc",
+              "elf32-littlearc")
+
+OUTPUT_ARCH(arc)
+ENTRY(__start)
+
+SECTIONS
+{
+  /* Read-only sections, merged into text segment: */
+  PROVIDE (__start = 0x10000);
+  . = 0x10000 + SIZEOF_HEADERS;
+
+  .text           : {__SDATA_BEGIN__ = .; *(.text .stub .text.*)} =0
+  .sdata           : {*(.sdata .sdata.*)}
+  .sbss            : {*(.sbss .sbss.*)}
+
+  /DISCARD/ : { *(.__arc_profile_*) }
+  /DISCARD/ : { *(.note.GNU-stack) }
+}
diff --git a/ld/testsuite/ld-arc/sda-relocs.rd b/ld/testsuite/ld-arc/sda-relocs.rd
new file mode 100644
index 0000000..6a52eac
--- /dev/null
+++ b/ld/testsuite/ld-arc/sda-relocs.rd
@@ -0,0 +1,15 @@
+
+Relocation section '\.rela\.text' .*:
+ Offset +Info +Type +Sym.Value +Sym. Name \+ Addend
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA16_LD2   [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA16_LD1   [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA16_LD    [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA_LDST2   [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA_LDST2   [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA_LDST    [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA_LDST    [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA_LDST    [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA_LDST1   [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA16_ST2   [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA16_ST2   [0-9a-f]+   a \+ 0
+[0-9a-f]+  [0-9a-f]+ R_ARC_SDA32_ME    [0-9a-f]+   a \+ 0
diff --git a/ld/testsuite/ld-arc/sda-relocs.s b/ld/testsuite/ld-arc/sda-relocs.s
new file mode 100644
index 0000000..40ff37d
--- /dev/null
+++ b/ld/testsuite/ld-arc/sda-relocs.s
@@ -0,0 +1,32 @@
+	.section	.text
+	.align	4
+;;; all the ops should have the same offset.
+	ld_s	r0,[gp,@a@sda]
+	;; BFD_RELOC_ARC_SDA16_LD2
+	ldh_s	r0,[gp,@a@sda]
+	;; BFD_RELOC_ARC_SDA16_LD1
+	ldb_s	r0,[gp,@a@sda]
+	;; BFD_RELOC_ARC_SDA16_LD
+	ld.as	r0,[gp,@a@sda]
+	st.as	r0,[gp,@a@sda]
+	;; BFD_RELOC_ARC_SDA_LDST2
+	ld	r0,[gp,@a@sda]
+	ldb	r0,[gp,@a@sda]
+	ldh	r0,[gp,@a@sda]
+	;; 	ldd	r0,[gp,@a@sda]
+	;; BFD_RELOC_ARC_SDA_LDST
+	sth.as	r0,[gp,@a@sda]
+	;; BFD_RELOC_ARC_SDA_LDST1
+	ld_s	r1,[gp,@a@sda]
+	st_s	r0,[gp,@a@sda]
+	;; BFD_ARC_SDA16_ST2
+	add	r2, gp, @a@sda
+	;; BFD_ARC_SDA32_ME
+
+	.global	a
+	.section	.sbss,"aw",@nobits
+	.align 4
+	.type	a, @object
+	.size	a, 4
+a:
+	.zero	4