Add R_386_GOT32X support to gas and ld

This patch adds support for the R_386_GOT32X relocation proposed in

https://groups.google.com/forum/#!topic/ia32-abi/GbJJskkid4I

to gas and ld.  It updates gas to generate R_386_GOT32X relocation for
memory operand, foo@GOT[(%reg)].  We must encode "mov foo@GOT, %eax"
with the 0x8b opcode, instead of the 0xb8 opcode, so that it can be
transformed to "lea foo, %eax".  With the locally defined symbol, foo,
we convert

   mov foo@GOT[(%reg1)], %reg2
to
   lea foo[@GOTOFF(%reg1)], %reg2

and convert

   call/jmp *foo@GOT[(%reg)]
to

   nop call foo/jmp foo nop

When PIC is false, convert

   test %reg1, foo@GOT[(%reg2)]
to
   test $foo, %reg1

and convert

binop foo@GOT[(%reg1)], %reg2

to

binop $foo, %reg2

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

bfd/

	* elf32-i386.c: Include opcode/i386.h.
	(elf_howto_table): Add R_386_GOT32X.
	(R_386_ext2): Replace R_386_IRELATIVE with R_386_GOT32X.
	(elf_i386_reloc_type_lookup): Handle BFD_RELOC_386_GOT32X.
	(need_convert_mov_to_lea): Renamed to ...
	(need_convert_load): This.
	(elf_i386_check_relocs): Handle R_386_GOT32X.  Replace
	need_convert_mov_to_lea with need_convert_load.
	(elf_i386_gc_sweep_hook): Handle R_386_GOT32X.
	(elf_i386_size_dynamic_sections): Likewise.
	(elf_i386_relocate_section): Likewise.
	(elf_i386_convert_mov_to_lea): Renamed to ...
	(elf_i386_convert_load): This.  Replace need_convert_mov_to_lea
	with need_convert_load.  Support R_386_GOT32X transformations.
	* reloc.c (BFD_RELOC_386_GOT32X): New.
	* bfd-in2.h: Regenerated.
	* libbfd.h: Likewise.

gas/

	* config/tc-i386.c (tc_i386_fix_adjustable): Handle
	BFD_RELOC_386_GOT32X.
	(tc_gen_reloc): Likewise.
	(match_template): Force 0x8b encoding for "mov foo@GOT, %eax".
	(output_disp): Check for "call/jmp *mem", "mov mem, %reg",
	"test %reg, mem" and "binop mem, %reg" where binop is one of
	adc, add, and, cmp, or, sbb, sub, xor instructions.  Set
	fx_tcbit if the REX prefix is generated.  Set fx_tcbit2 if
	BFD_RELOC_386_GOT32X should be generated.
	(i386_validate_fix): Generate BFD_RELOC_386_GOT32X if fx_tcbit2
	is set.

gas/testsuite/

	* gas/i386/got.d: New file.
	* gas/i386/got.s: Likewise.
	* gas/i386/i386.exp: Run got.
	* gas/i386/localpic.d: Replace R_386_GOT32 with R_386_GOT32X.
	* gas/i386/mixed-mode-reloc32.d: Likewise.
	* gas/i386/reloc32.d: Likewise.

include/elf/

	* i386.h (R_386_GOT32X): New relocation.

ld/testsuite/

	* ld-i386/branch1.d: New file.
	* ld-i386/branch1.s: Likewise.
	* ld-i386/call1.d: Likewise.
	* ld-i386/call1.s: Likewise.
	* ld-i386/call2.d: Likewise.
	* ld-i386/call2.s: Likewise.
	* ld-i386/got1.dd: Likewise.
	* ld-i386/got1.out: Likewise.
	* ld-i386/got1a.S: Likewise.
	* ld-i386/got1b.c: Likewise.
	* ld-i386/got1c.c: Likewise.
	* ld-i386/got1d.S: Likewise.
	* ld-i386/jmp1.d: Likewise.
	* ld-i386/jmp1.s: Likewise.
	* ld-i386/jmp2.d: Likewise.
	* ld-i386/jmp2.s: Likewise.
	* ld-i386/load1.d: Likewise.
	* ld-i386/load1.s: Likewise.
	* ld-i386/load2.d: Likewise.
	* ld-i386/load2.s: Likewise.
	* ld-i386/load3.d: Likewise.
	* ld-i386/load3.s: Likewise.
	* ld-i386/load4.s: Likewise.
	* ld-i386/load4a.d: Likewise.
	* ld-i386/load4b.d: Likewise.
	* ld-i386/load5.s: Likewise.
	* ld-i386/load5a.d: Likewise.
	* ld-i386/load5b.d: Likewise.
	* ld-i386/load6.d: Likewise.
	* ld-i386/load6.s: Likewise.
	* ld-i386/i386.exp: Run branch1, call1, call2, jmp1, jmp2,
	load1, load2, load3, load4a, load4b, load5a, load5b and load6
	tests.  Run got1 test.

2 files changed, 6 insertions, 0 deletions

diff --git a/include/elf/ChangeLog b/include/elf/ChangeLog
index 5e4605d..8dc601c 100644
--- a/include/elf/ChangeLog
+++ b/include/elf/ChangeLog
@@ -1,3 +1,7 @@
+2015-10-22  H.J. Lu  <hongjiu.lu@intel.com>
+
+	* i386.h (R_386_GOT32X): New relocation.
+
 2015-10-07  Cupertino Miranda  <cmiranda@synopsys.com>
 
 	* arc-reloc.def: Macro file with definition of all relocation
diff --git a/include/elf/i386.h b/include/elf/i386.h
index 08c9455..dea65f4 100644
--- a/include/elf/i386.h
+++ b/include/elf/i386.h
@@ -66,6 +66,8 @@ START_RELOC_NUMBERS (elf_i386_reloc_type)
      RELOC_NUMBER (R_386_TLS_DESC_CALL,40)
      RELOC_NUMBER (R_386_TLS_DESC,     41)
      RELOC_NUMBER (R_386_IRELATIVE,    42) /* Adjust indirectly by program base */
+     /* Load from 32 bit GOT entry, relaxable.  */
+     RELOC_NUMBER (R_386_GOT32X,       43)
 
      /* Used by Intel.  */
      RELOC_NUMBER (R_386_USED_BY_INTEL_200, 200)