2007-08-06 Paul Brook <paul@codesourcery.com>
authorDaniel Jacobowitz <drow@false.org>
Mon, 6 Aug 2007 18:47:21 +0000 (18:47 +0000)
committerDaniel Jacobowitz <drow@false.org>
Mon, 6 Aug 2007 18:47:21 +0000 (18:47 +0000)
* elf32-arm.c (elf32_arm_link_hash_entry): Add
plt_maybe_thumb_refcount.
(elf32_arm_link_hash_newfunc): Set plt_maybe_thumb_refcount.
(elf32_arm_copy_indirect_symbol): Ditto.
(elf32_arm_adjust_dynamic_symbol): Ditto.
(bfd_elf32_arm_process_before_allocation): Handle R_ARM_THM_JUMP24.
(arm_add_to_rel): Ditto.
(elf32_arm_final_link_relocate): Merge R_ARM_THM_JUMP24 with
R_ARM_THM_CALL.  Handle R_ARM_THM_JUMP19 against a PLT stub.
(elf32_arm_gc_sweep_hook): Call check_use_blx.  Update plt counts
for R_ARM_THM_JUMP24 and R_ARM_THM_JUMP19.
(elf32_arm_check_relocs): Update plt counts for R_ARM_THM_JUMP24
and R_ARM_THM_JUMP19.
(allocate_dynrelocs): Use plt_maybe_thumb_refcount.
(elf32_arm_finish_dynamic_symbol): Ditto.
(elf32_arm_output_plt_map): Ditto.

bfd/ChangeLog
bfd/elf32-arm.c

index 50ce8c0aff763859164f69ac8226c7cae3d0cfb1..a410c9eaa650c895515c50fda40ad6880526afb6 100644 (file)
@@ -1,3 +1,22 @@
+2007-08-06  Paul Brook  <paul@codesourcery.com>
+
+       * elf32-arm.c (elf32_arm_link_hash_entry): Add
+       plt_maybe_thumb_refcount.
+       (elf32_arm_link_hash_newfunc): Set plt_maybe_thumb_refcount.
+       (elf32_arm_copy_indirect_symbol): Ditto.
+       (elf32_arm_adjust_dynamic_symbol): Ditto.
+       (bfd_elf32_arm_process_before_allocation): Handle R_ARM_THM_JUMP24.
+       (arm_add_to_rel): Ditto.
+       (elf32_arm_final_link_relocate): Merge R_ARM_THM_JUMP24 with
+       R_ARM_THM_CALL.  Handle R_ARM_THM_JUMP19 against a PLT stub.
+       (elf32_arm_gc_sweep_hook): Call check_use_blx.  Update plt counts
+       for R_ARM_THM_JUMP24 and R_ARM_THM_JUMP19.
+       (elf32_arm_check_relocs): Update plt counts for R_ARM_THM_JUMP24
+       and R_ARM_THM_JUMP19.  
+       (allocate_dynrelocs): Use plt_maybe_thumb_refcount.
+       (elf32_arm_finish_dynamic_symbol): Ditto.
+       (elf32_arm_output_plt_map): Ditto.
+
 2007-08-06  Daniel Jacobowitz  <dan@codesourcery.com>
 
        * elf.c (rewrite_elf_program_header): Handle sections not sorted
index ed877f7ce3fa4013083789b95ab5214872826a9a..ef066d3a79e6f5bd7176bc866522fcad18d2166a 100644 (file)
@@ -2129,6 +2129,10 @@ struct elf32_arm_link_hash_entry
        so that we can emit the Thumb trampoline only if needed.  */
     bfd_signed_vma plt_thumb_refcount;
 
+    /* Some references from Thumb code may be eliminated by BL->BLX
+       conversion, so record them separately.  */
+    bfd_signed_vma plt_maybe_thumb_refcount;
+
     /* Since PLT entries have variable size if the Thumb prologue is
        used, we need to record the index into .got.plt instead of
        recomputing it from the PLT offset.  */
@@ -2267,6 +2271,7 @@ elf32_arm_link_hash_newfunc (struct bfd_hash_entry * entry,
       ret->relocs_copied = NULL;
       ret->tls_type = GOT_UNKNOWN;
       ret->plt_thumb_refcount = 0;
+      ret->plt_maybe_thumb_refcount = 0;
       ret->plt_got_offset = -1;
       ret->export_glue = NULL;
     }
@@ -2422,6 +2427,8 @@ elf32_arm_copy_indirect_symbol (struct bfd_link_info *info,
       /* Copy over PLT info.  */
       edir->plt_thumb_refcount += eind->plt_thumb_refcount;
       eind->plt_thumb_refcount = 0;
+      edir->plt_maybe_thumb_refcount += eind->plt_maybe_thumb_refcount;
+      eind->plt_maybe_thumb_refcount = 0;
 
       if (dir->got.refcount <= 0)
        {
@@ -3162,7 +3169,8 @@ bfd_elf32_arm_process_before_allocation (bfd *abfd,
              && r_type != R_ARM_PLT32
              && r_type != R_ARM_CALL
              && r_type != R_ARM_JUMP24
-             && r_type != R_ARM_THM_CALL)
+             && r_type != R_ARM_THM_CALL
+             && r_type != R_ARM_THM_JUMP24)
            continue;
 
          /* Get the section contents if we haven't done so already.  */
@@ -3216,10 +3224,12 @@ bfd_elf32_arm_process_before_allocation (bfd *abfd,
              break;
 
            case R_ARM_THM_CALL:
+           case R_ARM_THM_JUMP24:
              /* This one is a call from thumb code.  We look
                 up the target of the call.  If it is not a thumb
                  target, we insert glue.  */
-             if (ELF_ST_TYPE (h->type) != STT_ARM_TFUNC && !globals->use_blx
+             if (ELF_ST_TYPE (h->type) != STT_ARM_TFUNC
+                 && !(globals->use_blx && r_type == R_ARM_THM_CALL)
                  && h->root.type != bfd_link_hash_undefweak)
                record_thumb_to_arm_glue (link_info, h);
              break;
@@ -4996,6 +5006,7 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
 
     case R_ARM_THM_XPC22:
     case R_ARM_THM_CALL:
+    case R_ARM_THM_JUMP24:
       /* Thumb BL (branch long instruction).  */
       {
        bfd_vma relocation;
@@ -5059,7 +5070,7 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
                && (h == NULL || splt == NULL
                    || h->plt.offset == (bfd_vma) -1))
              {
-               if (globals->use_blx)
+               if (globals->use_blx && r_type == R_ARM_THM_CALL)
                  {
                    /* Convert BL to BLX.  */
                    lower_insn = (lower_insn & ~0x1000) | 0x0800;
@@ -5072,7 +5083,8 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
                else
                  return bfd_reloc_dangerous;
              }
-           else if (sym_flags == STT_ARM_TFUNC && globals->use_blx)
+           else if (sym_flags == STT_ARM_TFUNC && globals->use_blx
+                    && r_type == R_ARM_THM_CALL)
              {
                /* Make sure this is a BL.  */
                lower_insn |= 0x1800;
@@ -5085,7 +5097,7 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
            value = (splt->output_section->vma
                     + splt->output_offset
                     + h->plt.offset);
-           if (globals->use_blx)
+           if (globals->use_blx && r_type == R_ARM_THM_CALL)
              {
                /* If the Thumb BLX instruction is available, convert the
                   BL to a BLX instruction to call the ARM-mode PLT entry.  */
@@ -5125,7 +5137,7 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
        if (signed_check > reloc_signed_max || signed_check < reloc_signed_min)
          overflow = TRUE;
 
-       if ((lower_insn & 0x1800) == 0x0800)
+       if ((lower_insn & 0x5000) == 0x4000)
          /* For a BLX instruction, make sure that the relocation is rounded up
             to a word boundary.  This follows the semantics of the instruction
             which specifies that bit 1 of the target address will come from bit
@@ -5152,79 +5164,6 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
       }
       break;
 
-    case R_ARM_THM_JUMP24:
-      /* Thumb32 unconditional branch instruction.  */
-      {
-       bfd_vma relocation;
-       bfd_boolean overflow = FALSE;
-       bfd_vma upper_insn = bfd_get_16 (input_bfd, hit_data);
-       bfd_vma lower_insn = bfd_get_16 (input_bfd, hit_data + 2);
-       bfd_signed_vma reloc_signed_max = ((1 << (howto->bitsize - 1)) - 1) >> howto->rightshift;
-       bfd_signed_vma reloc_signed_min = ~ reloc_signed_max;
-       bfd_vma check;
-       bfd_signed_vma signed_check;
-
-       /* Need to refetch the addend, reconstruct the top three bits, and glue the
-          two pieces together.  */
-       if (globals->use_rel)
-         {
-           bfd_vma S  = (upper_insn & 0x0400) >> 10;
-           bfd_vma hi = (upper_insn & 0x03ff);
-           bfd_vma I1 = (lower_insn & 0x2000) >> 13;
-           bfd_vma I2 = (lower_insn & 0x0800) >> 11;
-           bfd_vma lo = (lower_insn & 0x07ff);
-
-           I1 = !(I1 ^ S);
-           I2 = !(I2 ^ S);
-           S  = !S;
-
-           signed_addend = (S << 24) | (I1 << 23) | (I2 << 22) | (hi << 12) | (lo << 1);
-           signed_addend -= (1 << 24); /* Sign extend.  */
-         }
-
-       /* ??? Should handle interworking?  GCC might someday try to
-          use this for tail calls.  */
-
-       relocation = value + signed_addend;
-       relocation -= (input_section->output_section->vma
-                      + input_section->output_offset
-                      + rel->r_offset);
-
-       check = relocation >> howto->rightshift;
-
-       /* If this is a signed value, the rightshift just dropped
-          leading 1 bits (assuming twos complement).  */
-       if ((bfd_signed_vma) relocation >= 0)
-         signed_check = check;
-       else
-         signed_check = check | ~((bfd_vma) -1 >> howto->rightshift);
-
-       /* Assumes two's complement.  */
-       if (signed_check > reloc_signed_max || signed_check < reloc_signed_min)
-         overflow = TRUE;
-
-       /* Put RELOCATION back into the insn.  */
-       {
-         bfd_vma S  = (relocation & 0x01000000) >> 24;
-         bfd_vma I1 = (relocation & 0x00800000) >> 23;
-         bfd_vma I2 = (relocation & 0x00400000) >> 22;
-         bfd_vma hi = (relocation & 0x003ff000) >> 12;
-         bfd_vma lo = (relocation & 0x00000ffe) >>  1;
-
-         I1 = !(I1 ^ S);
-         I2 = !(I2 ^ S);
-
-         upper_insn = (upper_insn & (bfd_vma) 0xf800) | (S << 10) | hi;
-         lower_insn = (lower_insn & (bfd_vma) 0xd000) | (I1 << 13) | (I2 << 11) | lo;
-       }
-
-       /* Put the relocated value back in the object file:  */
-       bfd_put_16 (input_bfd, upper_insn, hit_data);
-       bfd_put_16 (input_bfd, lower_insn, hit_data + 2);
-
-       return (overflow ? bfd_reloc_overflow : bfd_reloc_ok);
-      }
-
     case R_ARM_THM_JUMP19:
       /* Thumb32 conditional branch instruction.  */
       {
@@ -5255,6 +5194,17 @@ elf32_arm_final_link_relocate (reloc_howto_type *           howto,
            signed_addend = addend;
          }
 
+       /* Handle calls via the PLT.  */
+       if (h != NULL && splt != NULL && h->plt.offset != (bfd_vma) -1)
+         {
+           value = (splt->output_section->vma
+                    + splt->output_offset
+                    + h->plt.offset);
+           /* Target the Thumb stub before the ARM PLT entry.  */
+           value -= PLT_THUMB_STUB_SIZE;
+           *unresolved_reloc_p = FALSE;
+         }
+
        /* ??? Should handle interworking?  GCC might someday try to
           use this for tail calls.  */
 
@@ -6266,7 +6216,8 @@ arm_add_to_rel (bfd *              abfd,
 {
   bfd_signed_vma addend;
 
-  if (howto->type == R_ARM_THM_CALL)
+  if (howto->type == R_ARM_THM_CALL
+      || howto->type == R_ARM_THM_JUMP24)
     {
       int upper_insn, lower_insn;
       int upper, lower;
@@ -7400,6 +7351,8 @@ elf32_arm_gc_sweep_hook (bfd *                     abfd,
   sym_hashes = elf_sym_hashes (abfd);
   local_got_refcounts = elf_local_got_refcounts (abfd);
 
+  check_use_blx(globals);
+
   relend = relocs + sec->reloc_count;
   for (rel = relocs; rel < relend; rel++)
     {
@@ -7450,6 +7403,8 @@ elf32_arm_gc_sweep_hook (bfd *                     abfd,
        case R_ARM_JUMP24:
        case R_ARM_PREL31:
        case R_ARM_THM_CALL:
+       case R_ARM_THM_JUMP24:
+       case R_ARM_THM_JUMP19:
        case R_ARM_MOVW_ABS_NC:
        case R_ARM_MOVT_ABS:
        case R_ARM_MOVW_PREL_NC:
@@ -7471,7 +7426,11 @@ elf32_arm_gc_sweep_hook (bfd *                     abfd,
              if (h->plt.refcount > 0)
                {
                  h->plt.refcount -= 1;
-                 if (ELF32_R_TYPE (rel->r_info) == R_ARM_THM_CALL)
+                 if (r_type == R_ARM_THM_CALL)
+                   eh->plt_maybe_thumb_refcount--;
+
+                 if (r_type == R_ARM_THM_JUMP24
+                     || r_type == R_ARM_THM_JUMP19)
                    eh->plt_thumb_refcount--;
                }
 
@@ -7673,6 +7632,8 @@ elf32_arm_check_relocs (bfd *abfd, struct bfd_link_info *info,
          case R_ARM_JUMP24:
          case R_ARM_PREL31:
          case R_ARM_THM_CALL:
+         case R_ARM_THM_JUMP24:
+         case R_ARM_THM_JUMP19:
          case R_ARM_MOVW_ABS_NC:
          case R_ARM_MOVT_ABS:
          case R_ARM_MOVW_PREL_NC:
@@ -7708,7 +7669,15 @@ elf32_arm_check_relocs (bfd *abfd, struct bfd_link_info *info,
                   it, even if it's an ABS32 relocation.  */
                h->plt.refcount += 1;
 
+               /* It's too early to use htab->use_blx here, so we have to
+                  record possible blx references separately from
+                  relocs that definitely need a thumb stub.  */
+
                if (r_type == R_ARM_THM_CALL)
+                 eh->plt_maybe_thumb_refcount += 1;
+
+               if (r_type == R_ARM_THM_JUMP24
+                   || r_type == R_ARM_THM_JUMP19)
                  eh->plt_thumb_refcount += 1;
              }
 
@@ -8059,6 +8028,7 @@ elf32_arm_adjust_dynamic_symbol (struct bfd_link_info * info,
             linkage table, and we can just do a PC24 reloc instead.  */
          h->plt.offset = (bfd_vma) -1;
          eh->plt_thumb_refcount = 0;
+         eh->plt_maybe_thumb_refcount = 0;
          h->needs_plt = 0;
        }
 
@@ -8073,6 +8043,7 @@ elf32_arm_adjust_dynamic_symbol (struct bfd_link_info * info,
         the link may change h->type.  So fix it now.  */
       h->plt.offset = (bfd_vma) -1;
       eh->plt_thumb_refcount = 0;
+      eh->plt_maybe_thumb_refcount = 0;
     }
 
   /* If this is a weak symbol, and there is a real definition, the
@@ -8150,6 +8121,7 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
   struct elf32_arm_link_hash_table *htab;
   struct elf32_arm_link_hash_entry *eh;
   struct elf32_arm_relocs_copied *p;
+  bfd_signed_vma thumb_refs;
 
   eh = (struct elf32_arm_link_hash_entry *) h;
 
@@ -8191,7 +8163,11 @@ allocate_dynrelocs (struct elf_link_hash_entry *h, void * inf)
 
          /* If we will insert a Thumb trampoline before this PLT, leave room
             for it.  */
-         if (!htab->use_blx && eh->plt_thumb_refcount > 0)
+         thumb_refs = eh->plt_thumb_refcount;
+         if (!htab->use_blx)
+           thumb_refs += eh->plt_maybe_thumb_refcount;
+
+         if (thumb_refs > 0)
            {
              h->plt.offset += PLT_THUMB_STUB_SIZE;
              s->size += PLT_THUMB_STUB_SIZE;
@@ -8900,6 +8876,7 @@ elf32_arm_finish_dynamic_symbol (bfd * output_bfd, struct bfd_link_info * info,
            }
          else
            {
+             bfd_signed_vma thumb_refs;
              /* Calculate the displacement between the PLT slot and the
                 entry in the GOT.  The eight-byte offset accounts for the
                 value produced by adding to pc in the first instruction
@@ -8908,7 +8885,11 @@ elf32_arm_finish_dynamic_symbol (bfd * output_bfd, struct bfd_link_info * info,
 
              BFD_ASSERT ((got_displacement & 0xf0000000) == 0);
 
-             if (!htab->use_blx && eh->plt_thumb_refcount > 0)
+             thumb_refs = eh->plt_thumb_refcount;
+             if (!htab->use_blx)
+               thumb_refs += eh->plt_maybe_thumb_refcount;
+
+             if (thumb_refs > 0)
                {
                  put_thumb_insn (htab, output_bfd,
                                  elf32_arm_plt_thumb_stub[0], ptr - 4);
@@ -9638,10 +9619,13 @@ elf32_arm_output_plt_map (struct elf_link_hash_entry *h, void *inf)
     }
   else
     {
-      bfd_boolean thumb_stub;
+      bfd_signed_vma thumb_refs;
+
+      thumb_refs = eh->plt_thumb_refcount;
+      if (!htab->use_blx)
+       thumb_refs += eh->plt_maybe_thumb_refcount;
 
-      thumb_stub = eh->plt_thumb_refcount > 0 && !htab->use_blx;
-      if (thumb_stub)
+      if (thumb_refs > 0)
        {
          if (!elf32_arm_ouput_plt_map_sym (osi, ARM_MAP_THUMB, addr - 4))
            return FALSE;
@@ -9655,7 +9639,7 @@ elf32_arm_output_plt_map (struct elf_link_hash_entry *h, void *inf)
       /* A three-word PLT with no Thumb thunk contains only Arm code, 
         so only need to output a mapping symbol for the first PLT entry and
         entries with thumb thunks.  */
-      if (thumb_stub || addr == 20)
+      if (thumb_refs > 0 || addr == 20)
        {
          if (!elf32_arm_ouput_plt_map_sym (osi, ARM_MAP_ARM, addr))
            return FALSE;
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