[Committed] S/390: Support basr in the TLS code optimization
Andreas Krebbel
krebbel@linux.vnet.ibm.com
Fri Feb 17 08:45:00 GMT 2012
Hi,
I recently made tls work on s390 without using -fpic:
http://gcc.gnu.org/ml/gcc-patches/2011-10/msg00583.html
This makes the ld tls code optimizer to encounter a different branch
instruction when invoking __tls_get_offset. Instead of a bas now a
basr can be used since the GOT pointer does not need to be added
anymore. I've committed the attached patch in order to cover basr as
well in the GD->LE and the LD->LE tls optimizations.
This fixes the run-gd and run-ld testcases in the GCC testsuite on
s390 ESA.
Committed to mainline.
Bye,
-Andreas-
2012-02-17 Andreas Krebbel <Andreas.Krebbel@de.ibm.com>
* elf32-s390.c (elf_s390_relocate_section): Support basr in the
GD->LE and LD->LE optimizations.
---
bfd/elf32-s390.c | 32 ++++++++++++++++++++++++++------
1 file changed, 26 insertions(+), 6 deletions(-)
Index: bfd/elf32-s390.c
===================================================================
--- bfd/elf32-s390.c.orig
+++ bfd/elf32-s390.c
@@ -2919,11 +2919,18 @@ elf_s390_relocate_section (output_bfd, i
insn = bfd_get_32 (input_bfd, contents + rel->r_offset);
if ((insn & 0xff000fff) != 0x4d000000 &&
- (insn & 0xffff0000) != 0xc0e50000)
+ (insn & 0xffff0000) != 0xc0e50000 &&
+ (insn & 0xff000000) != 0x0d000000)
invalid_tls_insn (input_bfd, input_section, rel);
if (!info->shared && (h == NULL || h->dynindx == -1))
{
- if ((insn & 0xff000000) == 0x4d000000)
+ if ((insn & 0xff000000) == 0x0d000000)
+ {
+ /* GD->LE transition.
+ basr rx, ry -> nopr r7 */
+ insn = 0x07070000 | (insn & 0xffff);
+ }
+ else if ((insn & 0xff000000) == 0x4d000000)
{
/* GD->LE transition.
bas %r14,0(%rx,%r13) -> bc 0,0 */
@@ -2932,7 +2939,7 @@ elf_s390_relocate_section (output_bfd, i
else
{
/* GD->LE transition.
- brasl %r14,_tls_get_addr@plt -> brcl 0,. */
+ brasl %r14,_tls_get_offset@plt -> brcl 0,. */
insn = 0xc0040000;
bfd_put_16 (output_bfd, 0x0000,
contents + rel->r_offset + 4);
@@ -2940,6 +2947,11 @@ elf_s390_relocate_section (output_bfd, i
}
else
{
+ /* If basr is used in the pic case to invoke
+ _tls_get_offset, something went wrong before. */
+ if ((insn & 0xff000000) == 0x0d000000)
+ invalid_tls_insn (input_bfd, input_section, rel);
+
if ((insn & 0xff000000) == 0x4d000000)
{
/* GD->IE transition.
@@ -2966,9 +2978,17 @@ elf_s390_relocate_section (output_bfd, i
insn = bfd_get_32 (input_bfd, contents + rel->r_offset);
if ((insn & 0xff000fff) != 0x4d000000 &&
- (insn & 0xffff0000) != 0xc0e50000)
+ (insn & 0xffff0000) != 0xc0e50000 &&
+ (insn & 0xff000000) != 0x0d000000)
invalid_tls_insn (input_bfd, input_section, rel);
- if ((insn & 0xff000000) == 0x4d000000)
+
+ if ((insn & 0xff000000) == 0x0d000000)
+ {
+ /* LD->LE transition.
+ basr rx, ry -> nopr r7 */
+ insn = 0x07070000 | (insn & 0xffff);
+ }
+ else if ((insn & 0xff000000) == 0x4d000000)
{
/* LD->LE transition.
bas %r14,0(%rx,%r13) -> bc 0,0 */
@@ -2977,7 +2997,7 @@ elf_s390_relocate_section (output_bfd, i
else
{
/* LD->LE transition.
- brasl %r14,__tls_get_addr@plt -> brcl 0,. */
+ brasl %r14,__tls_get_offset@plt -> brcl 0,. */
insn = 0xc0040000;
bfd_put_16 (output_bfd, 0x0000,
contents + rel->r_offset + 4);
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