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This patch is glibc support for a PowerPC TLS optimization, inspired by Alexandre Oliva's TLS optimization for other processors, http://www.lsd.ic.unicamp.br/~oliva/writeups/TLS/RFC-TLSDESC-x86.txt In essence, this optimization uses a zero module id in the tls_index GOT entry to indicate that a TLS variable is allocated space in the static TLS area. A special plt call linker stub for __tls_get_addr checks for such a tls_index and if found, returns the offset immediately. The linker communicates the fact that the special __tls_get_addr stub is used by setting a bit in the dynamic tag DT_PPC64_OPT/DT_PPC_OPT. glibc communicates to the linker that this optimization is available by the presence of __tls_get_addr_opt. tst-tlsmod2.so is built with -Wl,--no-tls-get-addr-optimize for tst-tls-dlinfo, which otherwise would fail since it tests that no static tls is allocated. The ld option --no-tls-get-addr-optimize has been available since binutils-2.20 so doesn't need a configure test. * NEWS: Advertise TLS optimization. * elf/elf.h (R_PPC_TLSGD, R_PPC_TLSLD, DT_PPC_OPT, PPC_OPT_TLS): Define. (DT_PPC_NUM): Increment. * elf/dynamic-link.h (HAVE_STATIC_TLS): Define. (CHECK_STATIC_TLS): Use here. * sysdeps/powerpc/powerpc32/dl-machine.h (elf_machine_rela): Optimize TLS descriptors. * sysdeps/powerpc/powerpc64/dl-machine.h (elf_machine_rela): Likewise. * sysdeps/powerpc/dl-tls.c: New file. * sysdeps/powerpc/Versions: Add __tls_get_addr_opt. * sysdeps/powerpc/tst-tlsopt-powerpc.c: New tls test. * sysdeps/unix/sysv/linux/powerpc/Makefile: Add new test. Build tst-tlsmod2.so with --no-tls-get-addr-optimize. * sysdeps/unix/sysv/linux/powerpc/powerpc32/ld.abilist: Update. * sysdeps/unix/sysv/linux/powerpc/powerpc64/ld.abilist: Likewise. * sysdeps/unix/sysv/linux/powerpc/powerpc64/ld-le.abilist: Likewise.
38 lines
1.0 KiB
Makefile
38 lines
1.0 KiB
Makefile
abi-variants := 32 64-v1 64-v2
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abi-32-options := -U__powerpc64__
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abi-32-condition := __WORDSIZE == 32
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abi-64-v1-options := -D__powerpc64__ -U_CALL_ELF -D_CALL_ELF=1
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abi-64-v1-condition := __WORDSIZE == 64 && _CALL_ELF != 2
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abi-64-v2-options := -D__powerpc64__ -U_CALL_ELF -D_CALL_ELF=2
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abi-64-v2-condition := __WORDSIZE == 64 && _CALL_ELF == 2
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ifeq ($(subdir),rt)
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librt-routines += rt-sysdep
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endif
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ifeq ($(subdir),stdlib)
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gen-as-const-headers += ucontext_i.sym
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endif
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ifeq ($(subdir),elf)
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sysdep_routines += dl-vdso
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ifeq ($(build-shared),yes)
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# This is needed for DSO loading from static binaries.
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sysdep-dl-routines += dl-static
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endif
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# Otherwise tst-tls-dlinfo fails due to tst-tlsmod2.so using static tls.
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LDFLAGS-tst-tlsmod2.so += -Wl,--no-tls-get-addr-optimize
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endif
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ifeq ($(subdir),misc)
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sysdep_headers += bits/ppc.h
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sysdep_routines += get_timebase_freq
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tests += test-gettimebasefreq
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endif
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ifeq ($(subdir),nptl)
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libpthread-routines += sysdep
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libpthread-sysdep_routines += elision-lock elision-unlock elision-timed \
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elision-trylock
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endif
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