Optimise PowerPC64 r2 adjusting stubs

Sometimes these stubs don't need to change the low 16-bits of r2, so in
that case omit a useless addi r2,r2,0 insn.  Also, change the get_r2off
error return from 0 to -1 since 0 is a valid return for ELFv2 -R objects.

	* elf64-ppc.c (get_r2off): Return -1 on error.
	(ppc_build_one_stub): Adjust for get_r2off change.  Don't emit
	addi r2,r2,0 on r2off stubs when the low 16-bit delta is zero.
	(ppc_size_one_stub): Corresponding size changes for r2off stubs.
	Add condition in test for -R objects.
This commit is contained in:
Alan Modra 2015-08-31 17:55:14 +09:30
parent 6f20ed8a6b
commit a7c4979727
2 changed files with 28 additions and 12 deletions

View File

@ -1,3 +1,11 @@
2015-08-31 Alan Modra <amodra@gmail.com>
* elf64-ppc.c (get_r2off): Return -1 on error.
(ppc_build_one_stub): Adjust for get_r2off change. Don't emit
addi r2,r2,0 on r2off stubs when the low 16-bit delta is zero.
(ppc_size_one_stub): Corresponding size changes for r2off stubs.
Add condition in test for -R objects.
2015-08-31 Alan Modra <amodra@gmail.com>
* section.c (section_id): Make file scope.

View File

@ -10540,10 +10540,10 @@ get_r2off (struct bfd_link_info *info,
info->callbacks->einfo (_("%P: cannot find opd entry toc for `%T'\n"),
stub_entry->h->elf.root.root.string);
bfd_set_error (bfd_error_bad_value);
return 0;
return (bfd_vma) -1;
}
if (!bfd_get_section_contents (opd->owner, opd, buf, opd_off + 8, 8))
return 0;
return (bfd_vma) -1;
r2off = bfd_get_64 (opd->owner, buf);
r2off -= elf_gp (info->output_bfd);
}
@ -10599,23 +10599,28 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
{
bfd_vma r2off = get_r2off (info, stub_entry);
if (r2off == 0)
if (r2off == (bfd_vma) -1)
{
htab->stub_error = TRUE;
return FALSE;
}
bfd_put_32 (htab->params->stub_bfd, STD_R2_0R1 + STK_TOC (htab), loc);
loc += 4;
size = 12;
size = 8;
if (PPC_HA (r2off) != 0)
{
size = 16;
bfd_put_32 (htab->params->stub_bfd,
ADDIS_R2_R2 | PPC_HA (r2off), loc);
loc += 4;
size += 4;
}
if (PPC_LO (r2off) != 0)
{
bfd_put_32 (htab->params->stub_bfd,
ADDI_R2_R2 | PPC_LO (r2off), loc);
loc += 4;
size += 4;
}
bfd_put_32 (htab->params->stub_bfd, ADDI_R2_R2 | PPC_LO (r2off), loc);
loc += 4;
off -= size - 4;
}
bfd_put_32 (htab->params->stub_bfd, B_DOT | (off & 0x3fffffc), loc);
@ -10796,7 +10801,7 @@ ppc_build_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
{
bfd_vma r2off = get_r2off (info, stub_entry);
if (r2off == 0 && htab->opd_abi)
if (r2off == (bfd_vma) -1)
{
htab->stub_error = TRUE;
return FALSE;
@ -11062,14 +11067,16 @@ ppc_size_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
if (stub_entry->stub_type == ppc_stub_long_branch_r2off)
{
r2off = get_r2off (info, stub_entry);
if (r2off == 0 && htab->opd_abi)
if (r2off == (bfd_vma) -1)
{
htab->stub_error = TRUE;
return FALSE;
}
size = 12;
size = 8;
if (PPC_HA (r2off) != 0)
size = 16;
size += 4;
if (PPC_LO (r2off) != 0)
size += 4;
off -= size - 4;
}
@ -11079,7 +11086,8 @@ ppc_size_one_stub (struct bfd_hash_entry *gen_entry, void *in_arg)
Do the same for -R objects without function descriptors. */
if (off + (1 << 25) >= (bfd_vma) (1 << 26) - local_off
|| (stub_entry->stub_type == ppc_stub_long_branch_r2off
&& r2off == 0))
&& r2off == 0
&& htab->sec_info[stub_entry->target_section->id].toc_off == 0))
{
struct ppc_branch_hash_entry *br_entry;