diff options
Diffstat (limited to 'libatomic/config/arm')
| -rw-r--r-- | libatomic/config/arm/arm-config.h | 75 | ||||
| -rw-r--r-- | libatomic/config/arm/exch_n.c | 114 | ||||
| -rw-r--r-- | libatomic/config/arm/host-config.h | 4 |
3 files changed, 193 insertions, 0 deletions
diff --git a/libatomic/config/arm/arm-config.h b/libatomic/config/arm/arm-config.h new file mode 100644 index 00000000000..b94a372c1d8 --- /dev/null +++ b/libatomic/config/arm/arm-config.h @@ -0,0 +1,75 @@ +/* Copyright (C) 2012 Free Software Foundation, Inc. + Contributed by Richard Henderson <rth@redhat.com>. + + 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 + <http://www.gnu.org/licenses/>. */ + + +#if defined(__ARM_ARCH_2__) +# define __ARM_ARCH__ 2 +#endif + +#if defined(__ARM_ARCH_3__) +# define __ARM_ARCH__ 3 +#endif + +#if defined(__ARM_ARCH_3M__) || defined(__ARM_ARCH_4__) \ + || defined(__ARM_ARCH_4T__) +/* We use __ARM_ARCH__ set to 4 here, but in reality it's any processor with + long multiply instructions. That includes v3M. */ +# define __ARM_ARCH__ 4 +#endif + +#if defined(__ARM_ARCH_5__) || defined(__ARM_ARCH_5T__) \ + || defined(__ARM_ARCH_5E__) || defined(__ARM_ARCH_5TE__) \ + || defined(__ARM_ARCH_5TEJ__) +# define __ARM_ARCH__ 5 +#endif + +#if defined(__ARM_ARCH_6__) || defined(__ARM_ARCH_6J__) \ + || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6Z__) \ + || defined(__ARM_ARCH_6ZK__) || defined(__ARM_ARCH_6T2__) \ + || defined(__ARM_ARCH_6M__) +# define __ARM_ARCH__ 6 +#endif + +#if defined(__ARM_ARCH_7__) || defined(__ARM_ARCH_7A__) \ + || defined(__ARM_ARCH_7R__) || defined(__ARM_ARCH_7M__) \ + || defined(__ARM_ARCH_7EM__) +# define __ARM_ARCH__ 7 +#endif + +#ifndef __ARM_ARCH__ +#error Unable to determine architecture. +#endif + +#if __ARM_ARCH__ >= 7 || defined(__ARM_ARCH_6K__) || defined(__ARM_ARCH_6ZK__) +# define HAVE_STREX 1 +# define HAVE_STREXBHD 1 +#elif __ARM_ARCH__ == 6 +# define HAVE_STREX 1 +#endif + +#if __ARM_ARCH__ >= 7 +# define HAVE_DMB 1 +#elif __ARM_ARCH__ == 6 +# define HAVE_DMB_MCR 1 +#endif diff --git a/libatomic/config/arm/exch_n.c b/libatomic/config/arm/exch_n.c new file mode 100644 index 00000000000..ba6258b0f72 --- /dev/null +++ b/libatomic/config/arm/exch_n.c @@ -0,0 +1,114 @@ +/* Copyright (C) 2012 Free Software Foundation, Inc. + Contributed by Richard Henderson <rth@redhat.com>. + + 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 + <http://www.gnu.org/licenses/>. */ + +#include <libatomic_i.h> +#include <arm-config.h> + + +/* When using STREX to implement sub-word exchange, we can do much better + than the compiler by using the APSR.GE and APSR.C flags. */ + +#if !DONE && HAVE_STREX && !HAVE_STREXBH && N == 2 +UTYPE +SIZE(libat_exchange) (UTYPE *mptr, UTYPE newval, int smodel) +{ + UWORD t1, t2; + UTYPE oldval; + + __atomic_thread_fence (__ATOMIC_SEQ_CST); + + /* In the N=2 case, there are only two cases for MPTR: mptr % 4 == {0,2}. + Rather than computing a variable shift for this, we can store the one + bit of misalignment in the carry flag, and use conditional constant + shifts instead. This saves a register. */ +#ifdef __ARMEB__ +# define HI "cc" /* iff value is in high half */ +# define LO "cs" /* iff value is in low half */ +#else +# define HI "cs" +# define LO "cc" +#endif + + asm volatile ( + "lsrs %[t2],%[ptr],#2\n" /* carry = mptr & 2 */ + " bic %[ptr],%[ptr],#3\n" /* align mptr */ + " itt "HI"\n" + " lsl"HI" %[t1],%[t1],#16\n" /* shift mask into place */ + " lsl"HI" %[new],%[new],#16\n" /* shift newval into place */ + " uadd16 %[t1],%[t1],%[t1]\n" /* copy mask into APSR.GE */ + "0: ldrex %[t2],[%[ptr]]\n" + " ite "LO"\n" + " uxth"LO" %[old],%[t2]\n" /* return old value */ + " uxth"HI" %[old],%[t2], ror #16\n" + " sel %[t1],%[new],%[t2]\n" /* merge newval */ + " strex %[t2],%[t1],[%[ptr]]\n" + " tst %[t2],%[t2]\n" /* dont clobber carry */ + " bne 0b" + : [old] "=&r"(oldval), [t1] "=&r"(t1), [t2] "=&r"(t2), + [ptr] "+r"(mptr), [new] "+r"(newval) + : "1"(0xffff) + : "memory"); + + __atomic_thread_fence (__ATOMIC_SEQ_CST); + + return oldval; +} + +#define DONE 1 +#endif /* !HAVE_STREXBH && N == 2 */ + + +#if !DONE && HAVE_STREX && !HAVE_STREXBH && N == 1 +UTYPE +SIZE(libat_exchange) (UTYPE *mptr, UTYPE newval, int smodel) +{ + UWORD *wptr, woldval, wnewval, shift, mask, t1, t2; + + __atomic_thread_fence (__ATOMIC_SEQ_CST); + + wptr = (UWORD *)((uintptr_t)mptr & -WORDSIZE); + shift = (((uintptr_t)mptr % WORDSIZE) * CHAR_BIT) ^ INVERT_MASK_1; + mask = MASK_1 << shift; + wnewval = newval << shift; + + asm volatile ( + "uadd8 %[t1],%[t1],%[t1]\n" /* move mask to APSR.GE */ + "0: ldrex %[old],[%[wptr]]\n" + " sel %[t1],%[new],%[old]\n" /* merge newval */ + " strex %[t2],%[t1],[%[wptr]]\n" + " cmp %[t2],#0\n" + " bne 0b" + : [old] "=&r"(woldval), [t1] "=&r"(t1), [t2] "=&r"(t2) + : [new] "r"(wnewval), [wptr] "r"(wptr), "1"(mask) + : "memory"); + + __atomic_thread_fence (__ATOMIC_SEQ_CST); + + return woldval >> shift; +} + +#define DONE 1 +#endif /* !HAVE_STREXBH && N == 1 */ + +#include "../../exch_n.c" diff --git a/libatomic/config/arm/host-config.h b/libatomic/config/arm/host-config.h new file mode 100644 index 00000000000..bbf4a3f84c3 --- /dev/null +++ b/libatomic/config/arm/host-config.h @@ -0,0 +1,4 @@ +/* Avoiding the DMB (or kernel helper) can be a good thing. */ +#define WANT_SPECIALCASE_RELAXED + +#include_next <host-config.h> |