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.

5 files changed, 42 insertions, 6 deletions

diff --git a/bfd/bfd-in2.h b/bfd/bfd-in2.h
index 2807e69..53c40ec 100644
--- 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;
diff --git a/bfd/elfnn-loongarch.c b/bfd/elfnn-loongarch.c
index 024c5d4..aa88ee8 100644
--- 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)
 	    {
diff --git a/bfd/elfxx-loongarch.c b/bfd/elfxx-loongarch.c
index 7f298c0..d93b790 100644
--- 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;
diff --git a/bfd/libbfd.h b/bfd/libbfd.h
index cc43267..399b1f6 100644
--- 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
diff --git a/bfd/reloc.c b/bfd/reloc.c
index 93ebad8..4d3ac4c 100644
--- 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.