diff options
Diffstat (limited to 'libgcc')
| -rw-r--r-- | libgcc/ChangeLog | 7 | ||||
| -rw-r--r-- | libgcc/config.host | 4 | ||||
| -rw-r--r-- | libgcc/config/aarch64/lse-init.c | 45 | ||||
| -rw-r--r-- | libgcc/config/aarch64/lse.S | 235 | ||||
| -rw-r--r-- | libgcc/config/aarch64/t-lse | 44 |
5 files changed, 335 insertions, 0 deletions
diff --git a/libgcc/ChangeLog b/libgcc/ChangeLog index d61374d..37fadd4 100644 --- a/libgcc/ChangeLog +++ b/libgcc/ChangeLog @@ -1,3 +1,10 @@ +2019-09-19 Richard Henderson <richard.henderson@linaro.org> + + * config/aarch64/lse-init.c: New file. + * config/aarch64/lse.S: New file. + * config/aarch64/t-lse: New file. + * config.host: Add t-lse to all aarch64 tuples. + 2019-09-10 Christophe Lyon <christophe.lyon@st.com> Mickaël Guêné <mickael.guene@st.com> diff --git a/libgcc/config.host b/libgcc/config.host index 728e543e..122113f 100644 --- a/libgcc/config.host +++ b/libgcc/config.host @@ -350,12 +350,14 @@ aarch64*-*-elf | aarch64*-*-rtems*) extra_parts="$extra_parts crtbegin.o crtend.o crti.o crtn.o" extra_parts="$extra_parts crtfastmath.o" tmake_file="${tmake_file} ${cpu_type}/t-aarch64" + tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc" tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm" md_unwind_header=aarch64/aarch64-unwind.h ;; aarch64*-*-freebsd*) extra_parts="$extra_parts crtfastmath.o" tmake_file="${tmake_file} ${cpu_type}/t-aarch64" + tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc" tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm" md_unwind_header=aarch64/freebsd-unwind.h ;; @@ -367,12 +369,14 @@ aarch64*-*-netbsd*) ;; aarch64*-*-fuchsia*) tmake_file="${tmake_file} ${cpu_type}/t-aarch64" + tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc" tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp" ;; aarch64*-*-linux*) extra_parts="$extra_parts crtfastmath.o" md_unwind_header=aarch64/linux-unwind.h tmake_file="${tmake_file} ${cpu_type}/t-aarch64" + tmake_file="${tmake_file} ${cpu_type}/t-lse t-slibgcc-libgcc" tmake_file="${tmake_file} ${cpu_type}/t-softfp t-softfp t-crtfm" ;; alpha*-*-linux*) diff --git a/libgcc/config/aarch64/lse-init.c b/libgcc/config/aarch64/lse-init.c new file mode 100644 index 0000000..33d2914 --- /dev/null +++ b/libgcc/config/aarch64/lse-init.c @@ -0,0 +1,45 @@ +/* Out-of-line LSE atomics for AArch64 architecture, Init. + Copyright (C) 2019 Free Software Foundation, Inc. + Contributed by Linaro Ltd. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +Under Section 7 of GPL version 3, you are granted additional +permissions described in the GCC Runtime Library Exception, version +3.1, as published by the Free Software Foundation. + +You should have received a copy of the GNU General Public License and +a copy of the GCC Runtime Library Exception along with this program; +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +<http://www.gnu.org/licenses/>. */ + +/* Define the symbol gating the LSE implementations. */ +_Bool __aarch64_have_lse_atomics + __attribute__((visibility("hidden"), nocommon)); + +/* Disable initialization of __aarch64_have_lse_atomics during bootstrap. */ +#ifndef inhibit_libc +# include <sys/auxv.h> + +/* Disable initialization if the system headers are too old. */ +# if defined(AT_HWCAP) && defined(HWCAP_ATOMICS) + +static void __attribute__((constructor)) +init_have_lse_atomics (void) +{ + unsigned long hwcap = getauxval (AT_HWCAP); + __aarch64_have_lse_atomics = (hwcap & HWCAP_ATOMICS) != 0; +} + +# endif /* HWCAP */ +#endif /* inhibit_libc */ diff --git a/libgcc/config/aarch64/lse.S b/libgcc/config/aarch64/lse.S new file mode 100644 index 0000000..a5f6673 --- /dev/null +++ b/libgcc/config/aarch64/lse.S @@ -0,0 +1,235 @@ +/* Out-of-line LSE atomics for AArch64 architecture. + Copyright (C) 2019 Free Software Foundation, Inc. + Contributed by Linaro Ltd. + +This file is part of GCC. + +GCC is free software; you can redistribute it and/or modify it under +the terms of the GNU General Public License as published by the Free +Software Foundation; either version 3, or (at your option) any later +version. + +GCC is distributed in the hope that it will be useful, but WITHOUT ANY +WARRANTY; without even the implied warranty of MERCHANTABILITY or +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License +for more details. + +Under Section 7 of GPL version 3, you are granted additional +permissions described in the GCC Runtime Library Exception, version +3.1, as published by the Free Software Foundation. + +You should have received a copy of the GNU General Public License and +a copy of the GCC Runtime Library Exception along with this program; +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see +<http://www.gnu.org/licenses/>. */ + +/* + * The problem that we are trying to solve is operating system deployment + * of ARMv8.1-Atomics, also known as Large System Exensions (LSE). + * + * There are a number of potential solutions for this problem which have + * been proposed and rejected for various reasons. To recap: + * + * (1) Multiple builds. The dynamic linker will examine /lib64/atomics/ + * if HWCAP_ATOMICS is set, allowing entire libraries to be overwritten. + * However, not all Linux distributions are happy with multiple builds, + * and anyway it has no effect on main applications. + * + * (2) IFUNC. We could put these functions into libgcc_s.so, and have + * a single copy of each function for all DSOs. However, ARM is concerned + * that the branch-to-indirect-branch that is implied by using a PLT, + * as required by IFUNC, is too much overhead for smaller cpus. + * + * (3) Statically predicted direct branches. This is the approach that + * is taken here. These functions are linked into every DSO that uses them. + * All of the symbols are hidden, so that the functions are called via a + * direct branch. The choice of LSE vs non-LSE is done via one byte load + * followed by a well-predicted direct branch. The functions are compiled + * separately to minimize code size. + */ + +/* Tell the assembler to accept LSE instructions. */ + .arch armv8-a+lse + +/* Declare the symbol gating the LSE implementations. */ + .hidden __aarch64_have_lse_atomics + +/* Turn size and memory model defines into mnemonic fragments. */ +#if SIZE == 1 +# define S b +# define UXT uxtb +#elif SIZE == 2 +# define S h +# define UXT uxth +#elif SIZE == 4 || SIZE == 8 || SIZE == 16 +# define S +# define UXT mov +#else +# error +#endif + +#if MODEL == 1 +# define SUFF _relax +# define A +# define L +#elif MODEL == 2 +# define SUFF _acq +# define A a +# define L +#elif MODEL == 3 +# define SUFF _rel +# define A +# define L l +#elif MODEL == 4 +# define SUFF _acq_rel +# define A a +# define L l +#else +# error +#endif + +/* Concatenate symbols. */ +#define glue2_(A, B) A ## B +#define glue2(A, B) glue2_(A, B) +#define glue3_(A, B, C) A ## B ## C +#define glue3(A, B, C) glue3_(A, B, C) +#define glue4_(A, B, C, D) A ## B ## C ## D +#define glue4(A, B, C, D) glue4_(A, B, C, D) + +/* Select the size of a register, given a regno. */ +#define x(N) glue2(x, N) +#define w(N) glue2(w, N) +#if SIZE < 8 +# define s(N) w(N) +#else +# define s(N) x(N) +#endif + +#define NAME(BASE) glue4(__aarch64_, BASE, SIZE, SUFF) +#define LDXR glue4(ld, A, xr, S) +#define STXR glue4(st, L, xr, S) + +/* Temporary registers used. Other than these, only the return value + register (x0) and the flags are modified. */ +#define tmp0 16 +#define tmp1 17 +#define tmp2 15 + +/* Start and end a function. */ +.macro STARTFN name + .text + .balign 16 + .globl \name + .hidden \name + .type \name, %function + .cfi_startproc +\name: +.endm + +.macro ENDFN name + .cfi_endproc + .size \name, . - \name +.endm + +/* Branch to LABEL if LSE is disabled. */ +.macro JUMP_IF_NOT_LSE label + adrp x(tmp0), __aarch64_have_lse_atomics + ldrb w(tmp0), [x(tmp0), :lo12:__aarch64_have_lse_atomics] + cbz w(tmp0), \label +.endm + +#ifdef L_cas + +STARTFN NAME(cas) + JUMP_IF_NOT_LSE 8f + +#if SIZE < 16 +#define CAS glue4(cas, A, L, S) + + CAS s(0), s(1), [x2] + ret + +8: UXT s(tmp0), s(0) +0: LDXR s(0), [x2] + cmp s(0), s(tmp0) + bne 1f + STXR w(tmp1), s(1), [x2] + cbnz w(tmp1), 0b +1: ret + +#else +#define LDXP glue3(ld, A, xp) +#define STXP glue3(st, L, xp) +#define CASP glue3(casp, A, L) + + CASP x0, x1, x2, x3, [x4] + ret + +8: mov x(tmp0), x0 + mov x(tmp1), x1 +0: LDXP x0, x1, [x4] + cmp x0, x(tmp0) + ccmp x1, x(tmp1), #0, eq + bne 1f + STXP w(tmp2), x(tmp0), x(tmp1), [x4] + cbnz w(tmp2), 0b +1: ret + +#endif + +ENDFN NAME(cas) +#endif + +#ifdef L_swp +#define SWP glue4(swp, A, L, S) + +STARTFN NAME(swp) + JUMP_IF_NOT_LSE 8f + + SWP s(0), s(0), [x1] + ret + +8: mov s(tmp0), s(0) +0: LDXR s(0), [x1] + STXR w(tmp1), s(tmp0), [x1] + cbnz w(tmp1), 0b + ret + +ENDFN NAME(swp) +#endif + +#if defined(L_ldadd) || defined(L_ldclr) \ + || defined(L_ldeor) || defined(L_ldset) + +#ifdef L_ldadd +#define LDNM ldadd +#define OP add +#elif defined(L_ldclr) +#define LDNM ldclr +#define OP bic +#elif defined(L_ldeor) +#define LDNM ldeor +#define OP eor +#elif defined(L_ldset) +#define LDNM ldset +#define OP orr +#else +#error +#endif +#define LDOP glue4(LDNM, A, L, S) + +STARTFN NAME(LDNM) + JUMP_IF_NOT_LSE 8f + + LDOP s(0), s(0), [x1] + ret + +8: mov s(tmp0), s(0) +0: LDXR s(0), [x1] + OP s(tmp1), s(0), s(tmp0) + STXR w(tmp1), s(tmp1), [x1] + cbnz w(tmp1), 0b + ret + +ENDFN NAME(LDNM) +#endif diff --git a/libgcc/config/aarch64/t-lse b/libgcc/config/aarch64/t-lse new file mode 100644 index 0000000..fe3868d --- /dev/null +++ b/libgcc/config/aarch64/t-lse @@ -0,0 +1,44 @@ +# Out-of-line LSE atomics for AArch64 architecture. +# Copyright (C) 2019 Free Software Foundation, Inc. +# Contributed by Linaro Ltd. +# +# This file is part of GCC. +# +# GCC is free software; you can redistribute it and/or modify it +# under the terms of the GNU General Public License as published by +# the Free Software Foundation; either version 3, or (at your option) +# any later version. +# +# GCC is distributed in the hope that it will be useful, but +# WITHOUT ANY WARRANTY; without even the implied warranty of +# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU +# General Public License for more details. +# +# You should have received a copy of the GNU General Public License +# along with GCC; see the file COPYING3. If not see +# <http://www.gnu.org/licenses/>. + +# Compare-and-swap has 5 sizes and 4 memory models. +S0 := $(foreach s, 1 2 4 8 16, $(addsuffix _$(s), cas)) +O0 := $(foreach m, 1 2 3 4, $(addsuffix _$(m)$(objext), $(S0))) + +# Swap, Load-and-operate have 4 sizes and 4 memory models +S1 := $(foreach s, 1 2 4 8, $(addsuffix _$(s), swp ldadd ldclr ldeor ldset)) +O1 := $(foreach m, 1 2 3 4, $(addsuffix _$(m)$(objext), $(S1))) + +LSE_OBJS := $(O0) $(O1) + +libgcc-objects += $(LSE_OBJS) lse-init$(objext) + +empty = +space = $(empty) $(empty) +PAT_SPLIT = $(subst _,$(space),$(*F)) +PAT_BASE = $(word 1,$(PAT_SPLIT)) +PAT_N = $(word 2,$(PAT_SPLIT)) +PAT_M = $(word 3,$(PAT_SPLIT)) + +lse-init$(objext): $(srcdir)/config/aarch64/lse-init.c + $(gcc_compile) -c $< + +$(LSE_OBJS): $(srcdir)/config/aarch64/lse.S + $(gcc_compile) -DL_$(PAT_BASE) -DSIZE=$(PAT_N) -DMODEL=$(PAT_M) -c $< |