Add R_X86_64_[REX_]GOTPCRELX support to gas and ld

This patch adds support for the R_X86_64_GOTPCRELX and
R_X86_64_REX_GOTPCRELX relocations proposed in

https://groups.google.com/forum/#!topic/x86-64-abi/n9AWHogmVY0

to gas and ld.  It updates gas to generate R_X86_64_GOTPCRELX,
R_X86_64_REX_GOTPCRELX if there is a REX prefix, relocation for memory
operand, foo@GOTPCREL(%rip).  With the locally defined symbol, foo, we
convert

  mov foo@GOTPCREL(%rip), %reg

to

   lea foo(%rip), %reg

and convert

   call/jmp *foo@GOTPCREL(%rip)
to

   nop call foo/jmp foo nop

When PIC is false, convert

   test %reg, foo@GOTPCREL(%rip)
to

test $foo, %reg

and convert

   binop foo@GOTPCREL(%rip), %reg

to

   binop $foo, %reg

where binop is one of adc, add, and, cmp, or, sbb, sub, xor instructions.

bfd/

	* elf64-x86-64.c: Include opcode/i386.h.
	(x86_64_elf_howto_table): Add R_X86_64_GOTPCRELX and
	R_X86_64_REX_GOTPCRELX.
	(R_X86_64_standard): Replace R_X86_64_PLT32_BND with
	R_X86_64_REX_GOTPCRELX.
	(x86_64_reloc_map): Add BFD_RELOC_X86_64_GOTPCRELX and
	BFD_RELOC_X86_64_REX_GOTPCRELX.
	(need_convert_mov_to_lea): Renamed to ...
	(need_convert_load): This.
	(elf_x86_64_check_relocs): Handle R_X86_64_GOTPCRELX and
	R_X86_64_REX_GOTPCRELX.  Replace need_convert_mov_to_lea with
	need_convert_load.
	(elf_x86_64_gc_sweep_hook): Handle R_X86_64_GOTPCRELX and
	R_X86_64_REX_GOTPCRELX.
	(elf_x86_64_size_dynamic_sections): Likewise.
	(elf_x86_64_relocate_section): Likewise.
	(elf_x86_64_convert_mov_to_lea): Renamed to ...
	(elf_x86_64_convert_load): This.  Replace need_convert_mov_to_lea
	with need_convert_load.  Support R_X86_64_GOTPCRELX and
	R_X86_64_REX_GOTPCRELX transformations.
	* reloc.c (BFD_RELOC_X86_64_GOTPCRELX): New.
	(BFD_RELOC_X86_64_REX_GOTPCRELX): Likewise.
	* bfd-in2.h: Regenerated.
	* libbfd.h: Likewise.

gas/

	* config/tc-i386.c (tc_i386_fix_adjustable): Handle
	BFD_RELOC_X86_64_GOTPCRELX and BFD_RELOC_X86_64_REX_GOTPCRELX.
	(tc_gen_reloc): Likewise.
	(i386_validate_fix): Generate BFD_RELOC_X86_64_GOTPCRELX or
	BFD_RELOC_X86_64_REX_GOTPCRELX if fx_tcbit2 is set.
	* config/tc-i386.h (TC_FORCE_RELOCATION_LOCAL): Also return
	true for BFD_RELOC_X86_64_GOTPCRELX and
	BFD_RELOC_X86_64_REX_GOTPCRELX.

gas/testsuite/

	* gas/i386/i386.exp: Run x86-64-gotpcrel.
	* gas/i386/x86-64-gotpcrel.d: New file.
	* gas/i386/x86-64-gotpcrel.s: Likewise.
	* gas/i386/ilp32/x86-64-gotpcrel.d: Likewise.
	* gas/i386/x86-64-localpic.d: Replace R_X86_64_GOTPCREL with
	R_X86_64_REX_GOTPCRELX.
	* gas/i386/ilp32/x86-64-localpic.d: Likewise.

include/elf/

	* x86-64.h (R_X86_64_GOTPCRELX): New.
	(R_X86_64_REX_GOTPCRELX): Likewise.

ld/testsuite/

	* ld-ifunc/ifunc-5r-local-x86-64.d: Replace R_X86_64_GOTPCREL
	with R_X86_64_REX_GOTPCRELX.
	* ld-x86-64/plt-main1.rd: Likewise.
	* ld-x86-64/plt-main3.rd: Likewise.
	* ld-x86-64/plt-main4.rd: Likewise.
	* ld-x86-64/gotpcrel1.dd: New file.
	* ld-x86-64/gotpcrel1.out: Likewise.
	* ld-x86-64/gotpcrel1a.S: Likewise.
	* ld-x86-64/gotpcrel1b.c: Likewise.
	* ld-x86-64/gotpcrel1c.c: Likewise.
	* ld-x86-64/gotpcrel1d.S: Likewise.
	* ld-x86-64/load1.s: Likewise.
	* ld-x86-64/load1a.d: Likewise.
	* ld-x86-64/load1b.d: Likewise.
	* ld-x86-64/load1c.d: Likewise.
	* ld-x86-64/load1d.d: Likewise.
	* ld-x86-64/x86-64.exp: Run load1a, load1b, load1c and load1d
	tests.  Run gotpcrel1 test.

2 files changed, 15 insertions, 6 deletions

diff --git a/gas/config/tc-i386.c b/gas/config/tc-i386.c
index dd1a41b..d74e870 100644
--- a/gas/config/tc-i386.c
+++ b/gas/config/tc-i386.c
@@ -2942,6 +2942,8 @@ tc_i386_fix_adjustable (fixS *fixP ATTRIBUTE_UNUSED)
       || fixP->fx_r_type == BFD_RELOC_X86_64_PLT32
       || fixP->fx_r_type == BFD_RELOC_X86_64_GOT32
       || fixP->fx_r_type == BFD_RELOC_X86_64_GOTPCREL
+      || fixP->fx_r_type == BFD_RELOC_X86_64_GOTPCRELX
+      || fixP->fx_r_type == BFD_RELOC_X86_64_REX_GOTPCRELX
       || fixP->fx_r_type == BFD_RELOC_X86_64_TLSGD
       || fixP->fx_r_type == BFD_RELOC_X86_64_TLSLD
       || fixP->fx_r_type == BFD_RELOC_X86_64_DTPOFF32
@@ -10363,7 +10365,9 @@ i386_validate_fix (fixS *fixp)
 		abort ();
 #if defined (OBJ_ELF) || defined (OBJ_MAYBE_ELF)
 	      if (fixp->fx_tcbit2)
-		fixp->fx_r_type = BFD_RELOC_X86_64_GOTPCREL;
+		fixp->fx_r_type = (fixp->fx_tcbit
+				   ? BFD_RELOC_X86_64_REX_GOTPCRELX
+				   : BFD_RELOC_X86_64_GOTPCRELX);
 	      else
 #endif
 		fixp->fx_r_type = BFD_RELOC_X86_64_GOTPCREL;
@@ -10419,6 +10423,8 @@ tc_gen_reloc (asection *section ATTRIBUTE_UNUSED, fixS *fixp)
     case BFD_RELOC_X86_64_PLT32:
     case BFD_RELOC_X86_64_GOT32:
     case BFD_RELOC_X86_64_GOTPCREL:
+    case BFD_RELOC_X86_64_GOTPCRELX:
+    case BFD_RELOC_X86_64_REX_GOTPCRELX:
     case BFD_RELOC_386_PLT32:
     case BFD_RELOC_386_GOT32:
     case BFD_RELOC_386_GOT32X:
@@ -10573,6 +10579,8 @@ tc_gen_reloc (asection *section ATTRIBUTE_UNUSED, fixS *fixp)
 	  case BFD_RELOC_X86_64_PLT32:
 	  case BFD_RELOC_X86_64_GOT32:
 	  case BFD_RELOC_X86_64_GOTPCREL:
+	  case BFD_RELOC_X86_64_GOTPCRELX:
+	  case BFD_RELOC_X86_64_REX_GOTPCRELX:
 	  case BFD_RELOC_X86_64_TLSGD:
 	  case BFD_RELOC_X86_64_TLSLD:
 	  case BFD_RELOC_X86_64_GOTTPOFF:
diff --git a/gas/config/tc-i386.h b/gas/config/tc-i386.h
index 40483a1..2c43044 100644
--- a/gas/config/tc-i386.h
+++ b/gas/config/tc-i386.h
@@ -170,11 +170,12 @@ extern int tc_i386_fix_adjustable (struct fix *);
    the .o file.  GOTOFF and GOT32 do not need to be checked here because
    they are not pcrel.  .*/
 
-#define TC_FORCE_RELOCATION_LOCAL(FIX)			\
-  (!(FIX)->fx_pcrel					\
-   || (FIX)->fx_r_type == BFD_RELOC_386_PLT32		\
-   || (FIX)->fx_r_type == BFD_RELOC_386_GOTPC		\
-   || (FIX)->fx_r_type == BFD_RELOC_X86_64_GOTPCREL	\
+#define TC_FORCE_RELOCATION_LOCAL(FIX)				\
+  (!(FIX)->fx_pcrel						\
+   || (FIX)->fx_r_type == BFD_RELOC_386_PLT32			\
+   || (FIX)->fx_r_type == BFD_RELOC_386_GOTPC			\
+   || (FIX)->fx_r_type == BFD_RELOC_X86_64_GOTPCRELX		\
+   || (FIX)->fx_r_type == BFD_RELOC_X86_64_REX_GOTPCRELX	\
    || TC_FORCE_RELOCATION (FIX))
 
 extern int i386_parse_name (char *, expressionS *, char *);