[PowerPC64] pc-relative TLS relocations

This patch supports using pcrel instructions in TLS code sequences.  A
number of new relocations are needed, gas operand modifiers to
generate those relocations, and new TLS optimisation.  For
optimisation it turns out that the new pcrel GD and LD sequences can
be distinguished from the non-pcrel GD and LD sequences by there being
different relocations on the new sequence.  The final "add ra,rb,13"
on IE sequences similarly needs a new relocation, or as I chose, a
modification of R_PPC64_TLS.  On pcrel IE code, the R_PPC64_TLS points
one byte into the "add" instruction rather than being on the
instruction boundary.

GD:
 pla 3,z@got@tlsgd@pcrel	  # R_PPC64_GOT_TLSGD34
 bl __tls_get_addr@notoc(z@tlsgd) # R_PPC64_TLSGD and R_PPC64_REL24_NOTOC
  edited to IE
   pld 3,z@got@tprel@pcrel
   add 3,3,13
  edited to LE
   paddi 3,13,z@tprel
   nop

LD:
 pla 3,z@got@tlsld@pcrel	  # R_PPC64_GOT_TLSLD34
 bl __tls_get_addr@notoc(z@tlsld) # R_PPC64_TLSLD and R_PPC64_REL24_NOTOC
 ..
 paddi 9,3,z2@dtprel
 pld 10,z3@got@dtprel@pcrel
 add 10,10,3
  edited to LE
   paddi 3,13,0x1000
   nop

IE:
 pld 9,z@got@tprel@pcrel	  # R_PPC64_GOT_TPREL34
 add 3,9,z@tls@pcrel		  # R_PPC64_TLS at insn+1
 ldx 4,9,z@tls@pcrel
 lwax 5,9,z@tls@pcrel
 stdx 5,9,z@tls@pcrel
  edited to LE
  paddi 9,13,z@tprel
  nop
  ld 4,0(9)
  lwa 5,0(9)
  std 5,0(9)

LE:
 paddi 10,13,z@tprel

include/
	* elf/ppc64.h (R_PPC64_TPREL34, R_PPC64_DTPREL34),
	(R_PPC64_GOT_TLSGD34, R_PPC64_GOT_TLSLD34),
	(R_PPC64_GOT_TPREL34, R_PPC64_GOT_DTPREL34): Define.
	(IS_PPC64_TLS_RELOC): Include new tls relocs.
bfd/
	* reloc.c (BFD_RELOC_PPC64_TPREL34, BFD_RELOC_PPC64_DTPREL34),
	(BFD_RELOC_PPC64_GOT_TLSGD34, BFD_RELOC_PPC64_GOT_TLSLD34),
	(BFD_RELOC_PPC64_GOT_TPREL34, BFD_RELOC_PPC64_GOT_DTPREL34),
	(BFD_RELOC_PPC64_TLS_PCREL): New pcrel tls relocs.
	* elf64-ppc.c (ppc64_elf_howto_raw): Add howtos for pcrel tls relocs.
	(ppc64_elf_reloc_type_lookup): Translate pcrel tls relocs.
	(must_be_dyn_reloc, dec_dynrel_count): Add R_PPC64_TPREL64.
	(ppc64_elf_check_relocs): Support pcrel tls relocs.
	(ppc64_elf_tls_optimize, ppc64_elf_relocate_section): Likewise.
	* bfd-in2.h: Regenerate.
	* libbfd.h: Regenerate.
gas/
	* config/tc-ppc.c (ppc_elf_suffix): Map "tls@pcrel", "got@tlsgd@pcrel",
	"got@tlsld@pcrel", "got@tprel@pcrel", and "got@dtprel@pcrel".
	(fixup_size, md_assemble): Handle pcrel tls relocs.
	(ppc_force_relocation, ppc_fix_adjustable): Likewise.
	(md_apply_fix, tc_gen_reloc): Likewise.
ld/
	* testsuite/ld-powerpc/tlsgd.d,
	* testsuite/ld-powerpc/tlsgd.s,
	* testsuite/ld-powerpc/tlsie.d,
	* testsuite/ld-powerpc/tlsie.s,
	* testsuite/ld-powerpc/tlsld.d,
	* testsuite/ld-powerpc/tlsld.s: New tests.
	* testsuite/ld-powerpc/powerpc.exp: Run them.

2 files changed, 47 insertions, 5 deletions

diff --git a/gas/ChangeLog b/gas/ChangeLog
index 6e457d9..b445ba3 100644
--- a/gas/ChangeLog
+++ b/gas/ChangeLog
@@ -1,3 +1,11 @@
+2019-07-19  Alan Modra  <amodra@gmail.com>
+
+	* config/tc-ppc.c (ppc_elf_suffix): Map "tls@pcrel", "got@tlsgd@pcrel",
+	"got@tlsld@pcrel", "got@tprel@pcrel", and "got@dtprel@pcrel".
+	(fixup_size, md_assemble): Handle pcrel tls relocs.
+	(ppc_force_relocation, ppc_fix_adjustable): Likewise.
+	(md_apply_fix, tc_gen_reloc): Likewise.
+
 2019-07-17  Jose E. Marchesi  <jose.marchesi@oracle.com>
 
 	* config/tc-bpf.c: Make .lcomm to get a third argument with the
diff --git a/gas/config/tc-ppc.c b/gas/config/tc-ppc.c
index 5f8d120..7d6459a 100644
--- a/gas/config/tc-ppc.c
+++ b/gas/config/tc-ppc.c
@@ -2224,6 +2224,11 @@ ppc_elf_suffix (char **str_p, expressionS *exp_p)
     MAP64 ("pcrel",		BFD_RELOC_PPC64_PCREL34),
     MAP64 ("got@pcrel",		BFD_RELOC_PPC64_GOT_PCREL34),
     MAP64 ("plt@pcrel",		BFD_RELOC_PPC64_PLT_PCREL34),
+    MAP64 ("tls@pcrel",		BFD_RELOC_PPC64_TLS_PCREL),
+    MAP64 ("got@tlsgd@pcrel",	BFD_RELOC_PPC64_GOT_TLSGD34),
+    MAP64 ("got@tlsld@pcrel",	BFD_RELOC_PPC64_GOT_TLSLD34),
+    MAP64 ("got@tprel@pcrel",	BFD_RELOC_PPC64_GOT_TPREL34),
+    MAP64 ("got@dtprel@pcrel",	BFD_RELOC_PPC64_GOT_DTPREL34),
     MAP64 ("higher34",		BFD_RELOC_PPC64_ADDR16_HIGHER34),
     MAP64 ("highera34",		BFD_RELOC_PPC64_ADDR16_HIGHERA34),
     MAP64 ("highest34",		BFD_RELOC_PPC64_ADDR16_HIGHEST34),
@@ -3155,6 +3160,7 @@ fixup_size (bfd_reloc_code_real_type reloc, bfd_boolean *pc_relative)
     case BFD_RELOC_PPC_VLE_SDAREL_HI16D:
     case BFD_RELOC_PPC_VLE_SDAREL_LO16A:
     case BFD_RELOC_PPC_VLE_SDAREL_LO16D:
+    case BFD_RELOC_PPC64_TLS_PCREL:
     case BFD_RELOC_RVA:
       size = 4;
       break;
@@ -3196,6 +3202,8 @@ fixup_size (bfd_reloc_code_real_type reloc, bfd_boolean *pc_relative)
     case BFD_RELOC_PPC64_D34_LO:
     case BFD_RELOC_PPC64_D34_HI30:
     case BFD_RELOC_PPC64_D34_HA30:
+    case BFD_RELOC_PPC64_TPREL34:
+    case BFD_RELOC_PPC64_DTPREL34:
     case BFD_RELOC_PPC64_TOC:
       size = 8;
       break;
@@ -3203,6 +3211,10 @@ fixup_size (bfd_reloc_code_real_type reloc, bfd_boolean *pc_relative)
     case BFD_RELOC_64_PCREL:
     case BFD_RELOC_64_PLT_PCREL:
     case BFD_RELOC_PPC64_GOT_PCREL34:
+    case BFD_RELOC_PPC64_GOT_TLSGD34:
+    case BFD_RELOC_PPC64_GOT_TLSLD34:
+    case BFD_RELOC_PPC64_GOT_TPREL34:
+    case BFD_RELOC_PPC64_GOT_DTPREL34:
     case BFD_RELOC_PPC64_PCREL28:
     case BFD_RELOC_PPC64_PCREL34:
     case BFD_RELOC_PPC64_PLT_PCREL34:
@@ -3744,6 +3756,7 @@ md_assemble (char *str)
 		  break;
 
 		case BFD_RELOC_PPC_TLS:
+		case BFD_RELOC_PPC64_TLS_PCREL:
 		  if (!_bfd_elf_ppc_at_tls_transform (opcode->opcode, 0))
 		    as_bad (_("@tls may not be used with \"%s\" operands"),
 			    opcode->name);
@@ -3756,13 +3769,19 @@ md_assemble (char *str)
 		  break;
 
 		  /* We'll only use the 32 (or 64) bit form of these relocations
-		     in constants.  Instructions get the 16 bit form.  */
+		     in constants.  Instructions get the 16 or 34 bit form.  */
 		case BFD_RELOC_PPC_DTPREL:
-		  reloc = BFD_RELOC_PPC_DTPREL16;
+		  if (operand->bitm == 0x3ffffffffULL)
+		    reloc = BFD_RELOC_PPC64_DTPREL34;
+		  else
+		    reloc = BFD_RELOC_PPC_DTPREL16;
 		  break;
 
 		case BFD_RELOC_PPC_TPREL:
-		  reloc = BFD_RELOC_PPC_TPREL16;
+		  if (operand->bitm == 0x3ffffffffULL)
+		    reloc = BFD_RELOC_PPC64_TPREL34;
+		  else
+		    reloc = BFD_RELOC_PPC_TPREL16;
 		  break;
 
 		case BFD_RELOC_PPC64_PCREL34:
@@ -3774,6 +3793,10 @@ md_assemble (char *str)
 		  /* Fall through.  */
 		case BFD_RELOC_PPC64_GOT_PCREL34:
 		case BFD_RELOC_PPC64_PLT_PCREL34:
+		case BFD_RELOC_PPC64_GOT_TLSGD34:
+		case BFD_RELOC_PPC64_GOT_TLSLD34:
+		case BFD_RELOC_PPC64_GOT_TPREL34:
+		case BFD_RELOC_PPC64_GOT_DTPREL34:
 		  if (operand->bitm != 0x3ffffffffULL
 		      || (operand->flags & PPC_OPERAND_NEGATIVE) != 0)
 		    as_warn (_("%s unsupported on this instruction"), "@pcrel");
@@ -7003,7 +7026,7 @@ ppc_force_relocation (fixS *fix)
     }
 
   if (fix->fx_r_type >= BFD_RELOC_PPC_TLS
-      && fix->fx_r_type <= BFD_RELOC_PPC64_DTPREL16_HIGHESTA)
+      && fix->fx_r_type <= BFD_RELOC_PPC64_TLS_PCREL)
     return 1;
 
   return generic_force_reloc (fix);
@@ -7071,7 +7094,7 @@ ppc_fix_adjustable (fixS *fix)
 	  && fix->fx_r_type != BFD_RELOC_VTABLE_INHERIT
 	  && fix->fx_r_type != BFD_RELOC_VTABLE_ENTRY
 	  && !(fix->fx_r_type >= BFD_RELOC_PPC_TLS
-	       && fix->fx_r_type <= BFD_RELOC_PPC64_DTPREL16_HIGHESTA));
+	       && fix->fx_r_type <= BFD_RELOC_PPC64_TLS_PCREL));
 }
 #endif
 
@@ -7503,6 +7526,12 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
 	case BFD_RELOC_PPC64_DTPREL16_HIGHERA:
 	case BFD_RELOC_PPC64_DTPREL16_HIGHEST:
 	case BFD_RELOC_PPC64_DTPREL16_HIGHESTA:
+	case BFD_RELOC_PPC64_TPREL34:
+	case BFD_RELOC_PPC64_DTPREL34:
+	case BFD_RELOC_PPC64_GOT_TLSGD34:
+	case BFD_RELOC_PPC64_GOT_TLSLD34:
+	case BFD_RELOC_PPC64_GOT_TPREL34:
+	case BFD_RELOC_PPC64_GOT_DTPREL34:
 	  gas_assert (fixP->fx_addsy != NULL);
 	  S_SET_THREAD_LOCAL (fixP->fx_addsy);
 	  fieldval = 0;
@@ -7573,6 +7602,7 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
 	case BFD_RELOC_PPC_TLS:
 	case BFD_RELOC_PPC_TLSGD:
 	case BFD_RELOC_PPC_TLSLD:
+	case BFD_RELOC_PPC64_TLS_PCREL:
 	  fieldval = 0;
 	  break;
 #endif
@@ -7826,6 +7856,7 @@ md_apply_fix (fixS *fixP, valueT *valP, segT seg)
 	case BFD_RELOC_PPC64_TPREL16_HIGHERA:
 	case BFD_RELOC_PPC64_TPREL16_HIGHEST:
 	case BFD_RELOC_PPC64_TPREL16_HIGHESTA:
+	case BFD_RELOC_PPC64_TLS_PCREL:
 	  fixP->fx_done = 0;
 	  break;
 #endif
@@ -7918,6 +7949,9 @@ tc_gen_reloc (asection *seg ATTRIBUTE_UNUSED, fixS *fixp)
   reloc->sym_ptr_ptr = XNEW (asymbol *);
   *reloc->sym_ptr_ptr = symbol_get_bfdsym (fixp->fx_addsy);
   reloc->address = fixp->fx_frag->fr_address + fixp->fx_where;
+  /* BFD_RELOC_PPC64_TLS_PCREL generates R_PPC64_TLS with an odd r_offset.  */
+  if (fixp->fx_r_type == BFD_RELOC_PPC64_TLS_PCREL)
+    reloc->address++;
   reloc->howto = bfd_reloc_type_lookup (stdoutput, fixp->fx_r_type);
   if (reloc->howto == (reloc_howto_type *) NULL)
     {