The syntax we ended up with for -m32 -fPIC calls to __tls_get_addr is
rather weird.
bl __tls_get_addr+0x8000(gd0@tlsgd)@plt
This came about by accident, probably due to requiring the arg reloc
before the call reloc.
Of course the @plt really belongs with __tls_get_addr since it affects
the call rather than the call arg, and it isn't a great deal of
trouble to ensure the relocs are emitted in the correct order. This
patch supports a newer syntax, like so:
bl __tls_get_addr+0x8000@plt(gd0@tlsgd)
gas/
* config/tc-ppc.c (parse_tls_arg): New function, extracted..
(md_assembler): ..from here. Call it after parsing other
suffix modifiers too.
ld/
* testsuite/ld-powerpc/tls32.s: Test new @plt syntax.
In the TLS GD/LD to LE optimization, ld replaces a sequence like
addi 3,2,x@got@tlsgd R_PPC64_GOT_TLSGD16 x
bl __tls_get_addr(x@tlsgd) R_PPC64_TLSGD x
R_PPC64_REL24 __tls_get_addr
nop
with
addis 3,13,x@tprel@ha R_PPC64_TPREL16_HA x
addi 3,3,x@tprel@l R_PPC64_TPREL16_LO x
nop
When the tprel offset is small, this can be further optimized to
nop
addi 3,13,x@tprel
nop
bfd/
* elf64-ppc.c (struct ppc_link_hash_table): Add do_tls_opt.
(ppc64_elf_tls_optimize): Set it.
(ppc64_elf_relocate_section): Nop addis on TPREL16_HA, and convert
insn on TPREL16_LO and TPREL16_LO_DS relocs to use r13 when
addis would add zero.
* elf32-ppc.c (struct ppc_elf_link_hash_table): Add do_tls_opt.
(ppc_elf_tls_optimize): Set it.
(ppc_elf_relocate_section): Nop addis on TPREL16_HA, and convert
insn on TPREL16_LO relocs to use r2 when addis would add zero.
gold/
* powerpc.cc (Target_powerpc::Relocate::relocate): Nop addis on
TPREL16_HA, and convert insn on TPREL16_LO and TPREL16_LO_DS
relocs to use r2/r13 when addis would add zero.
ld/
* testsuite/ld-powerpc/tls.s: Add calls with tls markers.
* testsuite/ld-powerpc/tls32.s: Likewise.
* testsuite/ld-powerpc/powerpc.exp: Run tls marker tests.
* testsuite/ld-powerpc/tls.d: Adjust for TPREL16_HA/LO optimization.
* testsuite/ld-powerpc/tlsexe.d: Likewise.
* testsuite/ld-powerpc/tlsexetoc.d: Likewise.
* testsuite/ld-powerpc/tlsld.d: Likewise.
* testsuite/ld-powerpc/tlsmark.d: Likewise.
* testsuite/ld-powerpc/tlsopt4.d: Likewise.
* testsuite/ld-powerpc/tlstoc.d: Likewise.
* elf32-ppc.c (ppc_elf_relocate_section): Copy addend from
first relocation to the second when relaxing TLS GD to LE;
zero it out when relaxing to IE.
ld/testsuite/ChangeLog:
* ld-powerpc/tls32.s: Verify that +32768 @plt addend is
discarded.
