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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.
37 lines
951 B
Makefile
37 lines
951 B
Makefile
ifeq ($(subdir),string)
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CFLAGS-memcmp.c += -Wno-uninitialized
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endif
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ifeq ($(subdir),elf)
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# extra shared linker files to link into dl-allobjs.so and libc
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sysdep-dl-routines += dl-machine
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sysdep_routines += dl-machine
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# extra shared linker files to link only into dl-allobjs.so
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sysdep-rtld-routines += dl-machine
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# Don't optimize GD tls sequence to LE.
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LDFLAGS-tst-tlsopt-powerpc += -Wl,--no-tls-optimize
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tests += tst-tlsopt-powerpc
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endif
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ifeq ($(subdir),setjmp)
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ifeq (yes,$(build-shared))
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sysdep_routines += novmx-longjmp novmx-sigjmp
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endif
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endif
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ifeq ($(subdir),csu)
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# get offset to rtld_global._dl_hwcap and rtld_global._dl_hwcap2
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gen-as-const-headers += rtld-global-offsets.sym
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# get offset to __locale_struct.__ctype_tolower
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gen-as-const-headers += locale-defines.sym
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endif
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ifeq ($(subdir),misc)
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sysdep_headers += sys/platform/ppc.h
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tests += test-gettimebase
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endif
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ifneq (,$(filter %le,$(config-machine)))
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abilist-pattern = %-le.abilist
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endif
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