* elf64-alpha.c (elf64_alpha_relax_with_lituse): Nop out gpdisp

        following a call to a near function.

diff --git a/bfd/ChangeLog b/bfd/ChangeLog
index c17ff62cc69de3cd02061aac7c420efd29221c6d..78f3649759f71688644b56324b32486623429baf 100644 (file)
--- a/bfd/ChangeLog
+++ b/bfd/ChangeLog
@@ -1,3 +1,8 @@
+2001-09-09  Richard Henderson  <rth@redhat.com>
+
+       * elf64-alpha.c (elf64_alpha_relax_with_lituse): Nop out gpdisp
+       following a call to a near function.
+
 2001-09-08  Richard Henderson  <rth@redhat.com>
 
        * elf64-alpha.c (elf64_alpha_relocate_section): Soft fail

diff --git a/bfd/elf64-alpha.c b/bfd/elf64-alpha.c
index 9e22023f5d884af83091f448fea6c0e2d7575d00..df0650bec4110f6c3960e84b8d37a91ad98724f1 100644 (file)
--- a/bfd/elf64-alpha.c
+++ b/bfd/elf64-alpha.c
@@ -1149,14 +1149,36 @@ elf64_alpha_relax_with_lituse (info, symval, irel, irelend)
            else
              all_optimized = false;
 
-           /* ??? If target gp == current gp we can eliminate the gp reload.
-              This does depend on every place a gp could be reloaded will
-              be, which currently happens for all code produced by gcc, but
-              not necessarily by hand-coded assembly, or if sibling calls
-              are enabled in gcc.
-
-              Perhaps conditionalize this on a flag being set in the target
-              object file's header, and have gcc set it?  */
+           /* Even if the target is not in range for a direct branch,
+              if we share a GP, we can eliminate the gp reload.  */
+           if (optdest)
+             {
+               Elf_Internal_Rela *gpdisp
+                 = (elf64_alpha_find_reloc_at_ofs
+                    (irel, irelend, urel->r_offset + 4, R_ALPHA_GPDISP));
+               if (gpdisp)
+                 {
+                   bfd_byte *p_ldah = info->contents + gpdisp->r_offset; 
+                   bfd_byte *p_lda = p_ldah + gpdisp->r_addend;
+                   unsigned int ldah = bfd_get_32 (info->abfd, p_ldah);
+                   unsigned int lda = bfd_get_32 (info->abfd, p_lda);
+
+                   /* Verify that the instruction is "ldah $29,0($26)".
+                      Consider a function that ends in a noreturn call,
+                      and that the next function begins with an ldgp,
+                      and that by accident there is no padding between.
+                      In that case the insn would use $27 as the base.  */
+                   if (ldah == 0x27ba0000 && lda == 0x23bd0000)
+                     {
+                       bfd_put_32 (info->abfd, INSN_UNOP, p_ldah);
+                       bfd_put_32 (info->abfd, INSN_UNOP, p_lda);
+
+                       gpdisp->r_info = ELF64_R_INFO (0, R_ALPHA_NONE);
+                       info->changed_contents = true;
+                       info->changed_relocs = true;
+                     }
+                 }
+             }
          }
          break;
        }