On Fri, Jun 24, 2016 at 5:59 PM, H.J. Lu <hongjiu...@intel.com> wrote: > There are extensions to x86-64 psABI: > > https://groups.google.com/forum/#!topic/x86-64-abi/de5_KnLHxtI > > and i386 psABI: > > https://groups.google.com/forum/#!topic/ia32-abi/awsRSvJOJfs > > to call tls_get_addr via GOT. X86 assembler and linker in binutils 2.27 > implemented > > call *__tls_get_addr@GOTPCREL(%rip) > > in 64-bit and > > call *___tls_get_addr@GOT(%reg) > > in 32-bit to access global and local thread loal variables in shared > library. We check if 32-bit x86 assembler and linker work with > > call *___tls_get_addr@GOT(%reg) > > as 32-bit and 64-bit assembler and linker are enabled togther. > > In 32-bit, since any integer register except EAX, which is used to pass > parameter to ___tls_get_addr, and ESP, can be used as GOT base, a new > register class, TLS_REGS, along with a new constraint, Yb, are added. > They are used to improve register allocation for 32-bit dynamic TLS > patterns. > > Tested on i686 and x86-64. OK for trunk? > > Thanks. > > H.J. > --- > gcc/ > > * configure.ac (calling ___tls_get_addr via GOT): New > assembler/linker check. > (HAVE_AS_IX86_TLS_GET_ADDR_GOT): New. Defined to 1 if 32-bit > assembler and linker supports calling ___tls_get_addr via GOT. > Otherise, defined to 0. > * config.in: Regenerated. > * configure: Likewise. > * config/i386/constraints.md (Yb): New constraint. > * config/i386/i386.h (reg_class): Add TLS_REGS. > (REG_CLASS_NAMES): Add TLS_REGS. > (REG_CLASS_CONTENTS): Likewise. > * config/i386/i386.md (*tls_global_dynamic_32_gnu): Replace > the b constraint with the Yb constraint. Call ___tls_get_addr > via GOT for GNU TLS with -fno-plt if HAVE_AS_IX86_TLS_GET_ADDR_GOT > is 1. > (*tls_local_dynamic_base_32_gnu): Likewise. > (*tls_global_dynamic_64_<mode>): Call _tls_get_addr via GOT for > GNU TLS with -fno-plt if HAVE_AS_IX86_TLS_GET_ADDR_GOT is 1. > (*tls_local_dynamic_base_64_<mode>): Likewise. > > gcc/testsuite/ > > * gcc.target/i386/noplt-gd-1.c: New test. > * gcc.target/i386/noplt-gd-2.c: Likewise. > * gcc.target/i386/noplt-gd-3.c: Likewise. > * gcc.target/i386/noplt-ld-1.c: Likewise. > * gcc.target/i386/noplt-ld-2.c: Likewise. > * gcc.target/i386/noplt-ld-3.c: Likewise. > * lib/target-supports.exp > (check_effective_target_tls_get_addr_via_got): New.
OK for mainline, but please name new register class TLS_GOTBASE_REGS. Thanks, Uros.
