LoongArch: Add new relocation R_LARCH_CALL36

R_LARCH_CALL36 is used for medium code model function call pcaddu18i+jirl, and these two instructions must adjacent. The LoongArch ABI v2.20 at here: https://github.com/loongson/la-abi-specs.
2024-11-23 10:03:47 +08:00 · 2023-09-28 16:41:15 +08:00 · 2023-09-28 16:41:15 +08:00 · dc5f359ed6
commit dc5f359ed6
parent d51cd0f64c
11 changed files with 89 additions and 7 deletions
--- a/bfd/bfd-in2.h
+++ b/bfd/bfd-in2.h
@ -7460,6 +7460,7 @@ enum bfd_reloc_code_real
  BFD_RELOC_LARCH_ADD_ULEB128,
  BFD_RELOC_LARCH_SUB_ULEB128,
  BFD_RELOC_LARCH_64_PCREL,
+  BFD_RELOC_LARCH_CALL36,
  BFD_RELOC_UNUSED
 };
 typedef enum bfd_reloc_code_real bfd_reloc_code_real_type;
--- a/bfd/elfnn-loongarch.c
+++ b/bfd/elfnn-loongarch.c
@ -780,6 +780,7 @@ loongarch_elf_check_relocs (bfd *abfd, struct bfd_link_info *info,
 	case R_LARCH_B16:
 	case R_LARCH_B21:
 	case R_LARCH_B26:
+	case R_LARCH_CALL36:
 	  if (h != NULL)
 	    {
 	      h->needs_plt = 1;
@ -1884,20 +1885,24 @@ loongarch_check_offset (const Elf_Internal_Rela *rel,
    ret;					      \
   })

+/* Write immediate to instructions.  */
+
 static bfd_reloc_status_type
 loongarch_reloc_rewrite_imm_insn (const Elf_Internal_Rela *rel,
 				  const asection *input_section ATTRIBUTE_UNUSED,
 				  reloc_howto_type *howto, bfd *input_bfd,
 				  bfd_byte *contents, bfd_vma reloc_val)
 {
-  int bits = bfd_get_reloc_size (howto) * 8;
-  uint32_t insn = bfd_get (bits, input_bfd, contents + rel->r_offset);
-
+  /* Adjust the immediate based on alignment and
+     its position in the instruction.  */
  if (!loongarch_adjust_reloc_bitsfield (input_bfd, howto, &reloc_val))
    return bfd_reloc_overflow;

-  insn = (insn & (uint32_t)howto->src_mask)
-    | ((insn & (~(uint32_t)howto->dst_mask)) | reloc_val);
+  int bits = bfd_get_reloc_size (howto) * 8;
+  uint64_t insn = bfd_get (bits, input_bfd, contents + rel->r_offset);
+
+  /* Write immediate to instruction.  */
+  insn = (insn & ~howto->dst_mask) | (reloc_val & howto->dst_mask);

  bfd_put (bits, input_bfd, insn, contents + rel->r_offset);

@ -2120,6 +2125,7 @@ perform_relocation (const Elf_Internal_Rela *rel, asection *input_section,
    case R_LARCH_TLS_GD_PC_HI20:
    case R_LARCH_TLS_GD_HI20:
    case R_LARCH_PCREL20_S2:
+    case R_LARCH_CALL36:
      r = loongarch_check_offset (rel, input_section);
      if (r != bfd_reloc_ok)
 	break;
@ -3127,9 +3133,10 @@ loongarch_elf_relocate_section (bfd *output_bfd, struct bfd_link_info *info,
 	  break;

 	/* New reloc types.  */
+	case R_LARCH_B16:
 	case R_LARCH_B21:
 	case R_LARCH_B26:
-	case R_LARCH_B16:
+	case R_LARCH_CALL36:
 	  unresolved_reloc = false;
 	  if (is_undefweak)
 	    {
--- a/bfd/elfxx-loongarch.c
+++ b/bfd/elfxx-loongarch.c
@ -1547,6 +1547,24 @@ static loongarch_reloc_howto_type loongarch_howto_table[] =
 	 NULL,					/* adjust_reloc_bits */
 	 NULL),					/* larch_reloc_type_name */

+  /* Used for medium code model function call pcaddu18i+jirl,
+     these two instructions must adjacent.  */
+  LOONGARCH_HOWTO (R_LARCH_CALL36,		/* type (110).  */
+	 2,					/* rightshift.  */
+	 8,					/* size.  */
+	 36,					/* bitsize.  */
+	 true,					/* pc_relative.  */
+	 0,					/* bitpos.  */
+	 complain_overflow_signed,		/* complain_on_overflow.  */
+	 bfd_elf_generic_reloc,			/* special_function.  */
+	 "R_LARCH_CALL36",			/* name.  */
+	 false,					/* partial_inplace.  */
+	 0,					/* src_mask.  */
+	 0x03fffc0001ffffe0,			/* dst_mask.  */
+	 false,					/* pcrel_offset.  */
+	 BFD_RELOC_LARCH_CALL36,		/* bfd_reloc_code_real_type.  */
+	 reloc_sign_bits,			/* adjust_reloc_bits.  */
+	 "call36"),				/* larch_reloc_type_name.  */
 };

 reloc_howto_type *
@ -1726,6 +1744,12 @@ reloc_sign_bits (bfd *abfd, reloc_howto_type *howto, bfd_vma *fix_val)
      /* Perform insn bits field. 15:0<<10, 20:16>>16.  */
      val = ((val & 0xffff) << 10) | ((val >> 16) & 0x1f);
      break;
+    case R_LARCH_CALL36:
+      /* 0x8000: If low 16-bit immediate greater than 0x7fff,
+	 it become to a negative number due to sign-extended,
+	 so the high part need to add 0x8000.  */
+      val = (((val + 0x8000) >> 16) << 5) | (((val & 0xffff) << 10) << 32);
+      break;
    default:
      val <<= howto->bitpos;
      break;
--- a/bfd/libbfd.h
+++ b/bfd/libbfd.h
@ -3599,6 +3599,7 @@ static const char *const bfd_reloc_code_real_names[] = { "@@uninitialized@@",
  "BFD_RELOC_LARCH_ADD_ULEB128",
  "BFD_RELOC_LARCH_SUB_ULEB128",
  "BFD_RELOC_LARCH_64_PCREL",
+  "BFD_RELOC_LARCH_CALL36",
 "@@overflow: BFD_RELOC_UNUSED@@",
 };
 #endif
--- a/bfd/reloc.c
+++ b/bfd/reloc.c
@ -8292,6 +8292,9 @@ ENUMX
 ENUMX
  BFD_RELOC_LARCH_64_PCREL

+ENUMX
+  BFD_RELOC_LARCH_CALL36
+
 ENUMDOC
  LARCH relocations.

--- a/gas/config/tc-loongarch.c
+++ b/gas/config/tc-loongarch.c
@ -682,7 +682,7 @@ loongarch_args_parser_can_match_arg_helper (char esc_ch1, char esc_ch2,
 		      esc_ch1, esc_ch2, bit_field, arg);

 	  if (ip->reloc_info[0].type >= BFD_RELOC_LARCH_B16
-	      && ip->reloc_info[0].type < BFD_RELOC_LARCH_64_PCREL)
+	      && ip->reloc_info[0].type < BFD_RELOC_UNUSED)
 	    {
 	      /* As we compact stack-relocs, it is no need for pop operation.
 		 But break out until here in order to check the imm field.
@ -956,6 +956,10 @@ move_insn (struct loongarch_cl_insn *insn, fragS *frag, long where)
 static void
 append_fixed_insn (struct loongarch_cl_insn *insn)
 {
+  /* Ensure the jirl is emitted to the same frag as the pcaddu18i.  */
+  if (BFD_RELOC_LARCH_CALL36 == insn->reloc_info[0].type)
+    frag_grow (8);
+
  char *f = frag_more (insn->insn_length);
  move_insn (insn, frag_now, f - frag_now->fr_literal);
 }
--- a/gas/testsuite/gas/loongarch/medium-call.d
+++ b/gas/testsuite/gas/loongarch/medium-call.d
@ -0,0 +1,15 @@
+#as:
+#objdump: -dr
+
+.*:[    ]+file format .*
+
+
+Disassembly of section .text:
+
+.* <.text>:
+[ 	]+0:[ 	]+1e000001[ 	]+pcaddu18i[ 	]+\$ra, 0
+[ 	]+0: R_LARCH_CALL36[ 	]+a
+[ 	]+4:[ 	]+4c000021[ 	]+jirl[ 	]+\$ra, \$ra, 0
+[ 	]+8:[ 	]+1e00000c[ 	]+pcaddu18i[ 	]+\$t0, 0
+[ 	]+8: R_LARCH_CALL36[ 	]+a
+[ 	]+c:[ 	]+4c000180[ 	]+jr[ 	]+\$t0
--- a/gas/testsuite/gas/loongarch/medium-call.s
+++ b/gas/testsuite/gas/loongarch/medium-call.s
@ -0,0 +1,6 @@
+  # call .L1, r1(ra) temp register, r1(ra) return register.
+  pcaddu18i $r1, %call36(a)
+  jirl	    $r1, $r1, 0
+  # tail .L1, r12(t0) temp register, r0(zero) return register.
+  pcaddu18i $r12, %call36(a)
+  jirl	    $r0, $r12, 0
--- a/include/elf/loongarch.h
+++ b/include/elf/loongarch.h
@ -251,6 +251,8 @@ RELOC_NUMBER (R_LARCH_SUB_ULEB128, 108)

 RELOC_NUMBER (R_LARCH_64_PCREL, 109)

+RELOC_NUMBER (R_LARCH_CALL36, 110)
+
 END_RELOC_NUMBERS (R_LARCH_count)

 /* Processor specific flags for the ELF header e_flags field.  */
--- a/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
+++ b/ld/testsuite/ld-loongarch-elf/ld-loongarch-elf.exp
@ -55,4 +55,16 @@ if [istarget "loongarch64-*-*"] {
 	      "64_pcrel" \
 	  ] \
      ]
+
+  run_ld_link_tests \
+      [list \
+	  [list \
+	      "medium code model call" \
+	      "-e 0x0" "" \
+	      "" \
+	      {medium-call.s} \
+	      {} \
+	      "medium-call" \
+	  ] \
+      ]
 }
--- a/ld/testsuite/ld-loongarch-elf/medium-call.s
+++ b/ld/testsuite/ld-loongarch-elf/medium-call.s
@ -0,0 +1,7 @@
+.L1:
+  # call .L1, r1(ra) temp register, r1(ra) return register.
+  pcaddu18i $r1, %call36(.L1)
+  jirl	    $r1, $r1, 0
+  # tail .L1, r12(t0) temp register, r0(zero) return register.
+  pcaddu18i $r12, %call36(.L1)
+  jirl	    $r0, $r12, 0