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author | hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4> | 2016-06-24 17:32:52 +0000 |
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committer | hjl <hjl@138bc75d-0d04-0410-961f-82ee72b054a4> | 2016-06-24 17:32:52 +0000 |
commit | c7f16cfa30360489a9d42e244cb800c7da0396d9 (patch) | |
tree | aee674d43127c835322300b182f3d315b08bbe59 /gcc/config/i386/constraints.md | |
parent | e50240d32aad02bb9c5d8109dbf68d84dba1f1f9 (diff) | |
download | gcc-c7f16cfa30360489a9d42e244cb800c7da0396d9.tar.gz |
Call tls_get_addr via GOT for GNU TLS if possible
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_GOTBASE_REGS, along with a new constraint, Yb, are
added. They are used to improve register allocation for 32-bit dynamic
TLS patterns.
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_GOTBASE_REGS.
(REG_CLASS_NAMES): Likewise.
(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.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@237765 138bc75d-0d04-0410-961f-82ee72b054a4
Diffstat (limited to 'gcc/config/i386/constraints.md')
-rw-r--r-- | gcc/config/i386/constraints.md | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/gcc/config/i386/constraints.md b/gcc/config/i386/constraints.md index a2466a965fb..d61033679ac 100644 --- a/gcc/config/i386/constraints.md +++ b/gcc/config/i386/constraints.md @@ -104,6 +104,10 @@ ;; m MMX inter-unit moves to MMX register enabled ;; n MMX inter-unit moves from MMX register enabled ;; a Integer register when zero extensions with AND are disabled +;; b Any register that can be used as the GOT base when calling +;; ___tls_get_addr: that is, any general register except EAX +;; and ESP, for -fno-plt if linker supports it. Otherwise, +;; EBX. ;; p Integer register when TARGET_PARTIAL_REG_STALL is disabled ;; f x87 register when 80387 floating point arithmetic is enabled ;; r SSE regs not requiring REX prefix when prefixes avoidance is enabled @@ -137,6 +141,13 @@ ? NO_REGS : GENERAL_REGS" "@internal Any integer register when zero extensions with AND are disabled.") +(define_register_constraint "Yb" + "(!flag_plt && HAVE_AS_IX86_TLS_GET_ADDR_GOT) ? TLS_GOTBASE_REGS : BREG" + "@internal Any register that can be used as the GOT base when calling + ___tls_get_addr: that is, any general register except @code{a} and + @code{sp} registers, for -fno-plt if linker supports it. Otherwise, + @code{b} register.") + (define_register_constraint "Yf" "(ix86_fpmath & FPMATH_387) ? FLOAT_REGS : NO_REGS" "@internal Any x87 register when 80387 FP arithmetic is enabled.") |