From 15545563128f0240192c263522d4a36b7f86250f Mon Sep 17 00:00:00 2001 From: Tom de Vries Date: Mon, 7 Sep 2020 10:47:25 +0200 Subject: [PATCH] [libatomic] Add nvptx support Add nvptx support to libatomic. Given that atomic_test_and_set is not implemented for nvptx (PR96964), the compiler translates __atomic_test_and_set falling back onto the "Failing all else, assume a single threaded environment and simply perform the operation" case in expand_atomic_test_and_set, so it doesn't map onto an actual atomic operation. Still, that counts as supported for the configure test of libatomic, so we end up with HAVE_ATOMIC_TAS_1/2/4/8/16 == 1, and the corresponding __atomic_test_and_set_1/2/4/8/16 in libatomic all using that non-atomic implementation. Fix this by adding an atomic_test_and_set expansion for nvptx, that uses libatomics __atomic_test_and_set_1. This again makes the configure tests for HAVE_ATOMIC_TAS_1/2/4/8/16 fail, so instead we use this case in tas_n.c: ... /* If this type is smaller than word-sized, fall back to a word-sized compare-and-swap loop. */ bool SIZE(libat_test_and_set) (UTYPE *mptr, int smodel) ... which for __atomic_test_and_set_8 uses INVERT_MASK_8. Add INVERT_MASK_8 in libatomic_i.h, as well as MASK_8. Tested libatomic testsuite on nvptx. gcc/ChangeLog: PR target/96964 * config/nvptx/nvptx.md (define_expand "atomic_test_and_set"): New expansion. libatomic/ChangeLog: PR target/96898 * configure.tgt: Add nvptx. * libatomic_i.h (MASK_8, INVERT_MASK_8): New macro definition. * config/nvptx/host-config.h: New file. * config/nvptx/lock.c: New file. --- gcc/config/nvptx/nvptx.md | 16 ++++++++ libatomic/config/nvptx/host-config.h | 56 ++++++++++++++++++++++++++++ libatomic/config/nvptx/lock.c | 56 ++++++++++++++++++++++++++++ libatomic/configure.tgt | 3 ++ libatomic/libatomic_i.h | 2 + 5 files changed, 133 insertions(+) create mode 100644 libatomic/config/nvptx/host-config.h create mode 100644 libatomic/config/nvptx/lock.c diff --git a/gcc/config/nvptx/nvptx.md b/gcc/config/nvptx/nvptx.md index 4168190fa42..6178e6a0f77 100644 --- a/gcc/config/nvptx/nvptx.md +++ b/gcc/config/nvptx/nvptx.md @@ -1667,6 +1667,22 @@ "%.\\tatom%A1.b%T0.\\t%0, %1, %2;" [(set_attr "atomic" "true")]) +(define_expand "atomic_test_and_set" + [(match_operand:SI 0 "nvptx_register_operand") ;; bool success output + (match_operand:QI 1 "memory_operand") ;; memory + (match_operand:SI 2 "const_int_operand")] ;; model + "" +{ + rtx libfunc; + rtx addr; + libfunc = init_one_libfunc ("__atomic_test_and_set_1"); + addr = convert_memory_address (ptr_mode, XEXP (operands[1], 0)); + emit_library_call_value (libfunc, operands[0], LCT_NORMAL, SImode, + addr, ptr_mode, + operands[2], SImode); + DONE; +}) + (define_insn "nvptx_barsync" [(unspec_volatile [(match_operand:SI 0 "nvptx_nonmemory_operand" "Ri") (match_operand:SI 1 "const_int_operand")] diff --git a/libatomic/config/nvptx/host-config.h b/libatomic/config/nvptx/host-config.h new file mode 100644 index 00000000000..eb9de81f388 --- /dev/null +++ b/libatomic/config/nvptx/host-config.h @@ -0,0 +1,56 @@ +/* Copyright (C) 2020 Free Software Foundation, Inc. + + This file is part of the GNU Atomic Library (libatomic). + + Libatomic 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 of the License, or + (at your option) any later version. + + Libatomic 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 + . */ + +/* Copied from libatomic/config/posix/host-config.h. */ + +/* Included after all more target-specific host-config.h. */ + + +#ifndef protect_start_end +# ifdef HAVE_ATTRIBUTE_VISIBILITY +# pragma GCC visibility push(hidden) +# endif + +void libat_lock_1 (void *ptr); +void libat_unlock_1 (void *ptr); + +static inline UWORD +protect_start (void *ptr) +{ + libat_lock_1 (ptr); + return 0; +} + +static inline void +protect_end (void *ptr, UWORD dummy UNUSED) +{ + libat_unlock_1 (ptr); +} + +# define protect_start_end 1 +# ifdef HAVE_ATTRIBUTE_VISIBILITY +# pragma GCC visibility pop +# endif +#endif /* protect_start_end */ + +#include_next diff --git a/libatomic/config/nvptx/lock.c b/libatomic/config/nvptx/lock.c new file mode 100644 index 00000000000..dea85a3e5bd --- /dev/null +++ b/libatomic/config/nvptx/lock.c @@ -0,0 +1,56 @@ +/* Copyright (C) 2020 Free Software Foundation, Inc. + + This file is part of the GNU Atomic Library (libatomic). + + Libatomic 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 of the License, or + (at your option) any later version. + + Libatomic 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 + . */ + +/* Functions libat_lock_n/libat_unlock_n based on GOMP_atomic_start/end in + libgomp/atomic.c. */ + +#include "libatomic_i.h" + +static int atomic_lock; + +void +libat_lock_n (void *ptr __attribute__((unused)), + size_t n __attribute__((unused))) +{ + while (__sync_lock_test_and_set (&atomic_lock, 1)) + ; /* Spin. */ +} + +void +libat_unlock_n (void *ptr __attribute__((unused)), + size_t n __attribute__((unused))) +{ + __sync_lock_release (&atomic_lock); +} + +void +libat_lock_1 (void *ptr) +{ + libat_lock_n (ptr, 1); +} + +void +libat_unlock_1 (void *ptr) +{ + libat_unlock_n (ptr, 1); +} diff --git a/libatomic/configure.tgt b/libatomic/configure.tgt index efb3b1efb68..7834e0a6528 100644 --- a/libatomic/configure.tgt +++ b/libatomic/configure.tgt @@ -174,6 +174,9 @@ case "${target}" in UNSUPPORTED=1 ;; + nvptx*-*-*) + ;; + *) # Who are you? UNSUPPORTED=1 diff --git a/libatomic/libatomic_i.h b/libatomic/libatomic_i.h index 081b154e9d7..37de9921024 100644 --- a/libatomic/libatomic_i.h +++ b/libatomic/libatomic_i.h @@ -109,9 +109,11 @@ typedef unsigned UWORD __attribute__((mode(word))); #define MASK_1 ((UWORD)0xff) #define MASK_2 ((UWORD)0xffff) #define MASK_4 ((UWORD)0xffffffff) +#define MASK_8 ((UWORD)0xffffffffffffffff) #define INVERT_MASK_1 ((UWORD)WORDS_BIGENDIAN << ((WORDSIZE - 1) * CHAR_BIT)) #define INVERT_MASK_2 ((UWORD)WORDS_BIGENDIAN << ((WORDSIZE - 2) * CHAR_BIT)) #define INVERT_MASK_4 ((UWORD)WORDS_BIGENDIAN << ((WORDSIZE - 4) * CHAR_BIT)) +#define INVERT_MASK_8 ((UWORD)WORDS_BIGENDIAN << ((WORDSIZE - 8) * CHAR_BIT)) /* Most of the files in this library are compiled multiple times with N defined to be a power of 2 between 1 and 16. The SIZE macro is -- 2.30.2