Chris@102: /*
Chris@102:  * Distributed under the Boost Software License, Version 1.0.
Chris@102:  * (See accompanying file LICENSE_1_0.txt or copy at
Chris@102:  * http://www.boost.org/LICENSE_1_0.txt)
Chris@102:  *
Chris@102:  * Copyright (c) 2009 Helge Bahmann
Chris@102:  * Copyright (c) 2013 Tim Blechmann
Chris@102:  * Copyright (c) 2014 Andrey Semashev
Chris@102:  */
Chris@102: /*!
Chris@102:  * \file   atomic/detail/ops_gcc_alpha.hpp
Chris@102:  *
Chris@102:  * This header contains implementation of the \c operations template.
Chris@102:  */
Chris@102: 
Chris@102: #ifndef BOOST_ATOMIC_DETAIL_OPS_GCC_ALPHA_HPP_INCLUDED_
Chris@102: #define BOOST_ATOMIC_DETAIL_OPS_GCC_ALPHA_HPP_INCLUDED_
Chris@102: 
Chris@102: #include <boost/memory_order.hpp>
Chris@102: #include <boost/atomic/detail/config.hpp>
Chris@102: #include <boost/atomic/detail/storage_type.hpp>
Chris@102: #include <boost/atomic/detail/operations_fwd.hpp>
Chris@102: #include <boost/atomic/capabilities.hpp>
Chris@102: 
Chris@102: #ifdef BOOST_HAS_PRAGMA_ONCE
Chris@102: #pragma once
Chris@102: #endif
Chris@102: 
Chris@102: namespace boost {
Chris@102: namespace atomics {
Chris@102: namespace detail {
Chris@102: 
Chris@102: /*
Chris@102:   Refer to http://h71000.www7.hp.com/doc/82final/5601/5601pro_004.html
Chris@102:   (HP OpenVMS systems documentation) and the Alpha Architecture Reference Manual.
Chris@102:  */
Chris@102: 
Chris@102: /*
Chris@102:     NB: The most natural thing would be to write the increment/decrement
Chris@102:     operators along the following lines:
Chris@102: 
Chris@102:     __asm__ __volatile__
Chris@102:     (
Chris@102:         "1: ldl_l %0,%1 \n"
Chris@102:         "addl %0,1,%0 \n"
Chris@102:         "stl_c %0,%1 \n"
Chris@102:         "beq %0,1b\n"
Chris@102:         : "=&b" (tmp)
Chris@102:         : "m" (value)
Chris@102:         : "cc"
Chris@102:     );
Chris@102: 
Chris@102:     However according to the comments on the HP website and matching
Chris@102:     comments in the Linux kernel sources this defies branch prediction,
Chris@102:     as the cpu assumes that backward branches are always taken; so
Chris@102:     instead copy the trick from the Linux kernel, introduce a forward
Chris@102:     branch and back again.
Chris@102: 
Chris@102:     I have, however, had a hard time measuring the difference between
Chris@102:     the two versions in microbenchmarks -- I am leaving it in nevertheless
Chris@102:     as it apparently does not hurt either.
Chris@102: */
Chris@102: 
Chris@102: struct gcc_alpha_operations_base
Chris@102: {
Chris@102:     static BOOST_FORCEINLINE void fence_before(memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         if ((order & memory_order_release) != 0)
Chris@102:             __asm__ __volatile__ ("mb" ::: "memory");
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE void fence_after(memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         if ((order & (memory_order_consume | memory_order_acquire)) != 0)
Chris@102:             __asm__ __volatile__ ("mb" ::: "memory");
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE void fence_after_store(memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         if (order == memory_order_seq_cst)
Chris@102:             __asm__ __volatile__ ("mb" ::: "memory");
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: 
Chris@102: template< bool Signed >
Chris@102: struct operations< 4u, Signed > :
Chris@102:     public gcc_alpha_operations_base
Chris@102: {
Chris@102:     typedef typename make_storage_type< 4u, Signed >::type storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE void store(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         fence_before(order);
Chris@102:         storage = v;
Chris@102:         fence_after_store(order);
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type load(storage_type const volatile& storage, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type v = storage;
Chris@102:         fence_after(order);
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, tmp;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "mov %3, %1\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (tmp)        // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool compare_exchange_weak(
Chris@102:         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order success_order, memory_order failure_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         fence_before(success_order);
Chris@102:         int success;
Chris@102:         storage_type current;
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %2, %4\n"                // current = *(&storage)
Chris@102:             "cmpeq %2, %0, %3\n"            // success = current == expected
Chris@102:             "mov %2, %0\n"                  // expected = current
Chris@102:             "beq %3, 2f\n"                  // if (success == 0) goto end
Chris@102:             "stl_c %1, %4\n"                // storage = desired; desired = store succeeded
Chris@102:             "mov %1, %3\n"                  // success = desired
Chris@102:             "2:\n"
Chris@102:             : "+&r" (expected),  // %0
Chris@102:               "+&r" (desired),   // %1
Chris@102:               "=&r" (current),   // %2
Chris@102:               "=&r" (success)    // %3
Chris@102:             : "m" (storage)      // %4
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         if (success)
Chris@102:             fence_after(success_order);
Chris@102:         else
Chris@102:             fence_after(failure_order);
Chris@102:         return !!success;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool compare_exchange_strong(
Chris@102:         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order success_order, memory_order failure_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         int success;
Chris@102:         storage_type current, tmp;
Chris@102:         fence_before(success_order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "mov %5, %1\n"                  // tmp = desired
Chris@102:             "ldl_l %2, %4\n"                // current = *(&storage)
Chris@102:             "cmpeq %2, %0, %3\n"            // success = current == expected
Chris@102:             "mov %2, %0\n"                  // expected = current
Chris@102:             "beq %3, 2f\n"                  // if (success == 0) goto end
Chris@102:             "stl_c %1, %4\n"                // storage = tmp; tmp = store succeeded
Chris@102:             "beq %1, 3f\n"                  // if (tmp == 0) goto retry
Chris@102:             "mov %1, %3\n"                  // success = tmp
Chris@102:             "2:\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "3: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "+&r" (expected),  // %0
Chris@102:               "=&r" (tmp),       // %1
Chris@102:               "=&r" (current),   // %2
Chris@102:               "=&r" (success)    // %3
Chris@102:             : "m" (storage),     // %4
Chris@102:               "r" (desired)      // %5
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         if (success)
Chris@102:             fence_after(success_order);
Chris@102:         else
Chris@102:             fence_after(failure_order);
Chris@102:         return !!success;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "addl %0, %3, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "subl %0, %3, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "and %0, %3, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "bis %0, %3, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "xor %0, %3, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool test_and_set(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         return !!exchange(storage, (storage_type)1, order);
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE void clear(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         store(storage, 0, order);
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool is_lock_free(storage_type const volatile&) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         return true;
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: 
Chris@102: template< >
Chris@102: struct operations< 1u, false > :
Chris@102:     public operations< 4u, false >
Chris@102: {
Chris@102:     typedef operations< 4u, false > base_type;
Chris@102:     typedef base_type::storage_type storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "addl %0, %3, %1\n"
Chris@102:             "zapnot %1, #1, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "subl %0, %3, %1\n"
Chris@102:             "zapnot %1, #1, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: template< >
Chris@102: struct operations< 1u, true > :
Chris@102:     public operations< 4u, true >
Chris@102: {
Chris@102:     typedef operations< 4u, true > base_type;
Chris@102:     typedef base_type::storage_type storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "addl %0, %3, %1\n"
Chris@102:             "sextb %1, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "subl %0, %3, %1\n"
Chris@102:             "sextb %1, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: 
Chris@102: template< >
Chris@102: struct operations< 2u, false > :
Chris@102:     public operations< 4u, false >
Chris@102: {
Chris@102:     typedef operations< 4u, false > base_type;
Chris@102:     typedef base_type::storage_type storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "addl %0, %3, %1\n"
Chris@102:             "zapnot %1, #3, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "subl %0, %3, %1\n"
Chris@102:             "zapnot %1, #3, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: template< >
Chris@102: struct operations< 2u, true > :
Chris@102:     public operations< 4u, true >
Chris@102: {
Chris@102:     typedef operations< 4u, true > base_type;
Chris@102:     typedef base_type::storage_type storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "addl %0, %3, %1\n"
Chris@102:             "sextw %1, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldl_l %0, %2\n"
Chris@102:             "subl %0, %3, %1\n"
Chris@102:             "sextw %1, %1\n"
Chris@102:             "stl_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: 
Chris@102: template< bool Signed >
Chris@102: struct operations< 8u, Signed > :
Chris@102:     public gcc_alpha_operations_base
Chris@102: {
Chris@102:     typedef typename make_storage_type< 8u, Signed >::type storage_type;
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE void store(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         fence_before(order);
Chris@102:         storage = v;
Chris@102:         fence_after_store(order);
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type load(storage_type const volatile& storage, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type v = storage;
Chris@102:         fence_after(order);
Chris@102:         return v;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type exchange(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, tmp;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "mov %3, %1\n"
Chris@102:             "ldq_l %0, %2\n"
Chris@102:             "stq_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (tmp)        // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool compare_exchange_weak(
Chris@102:         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order success_order, memory_order failure_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         fence_before(success_order);
Chris@102:         int success;
Chris@102:         storage_type current;
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldq_l %2, %4\n"                // current = *(&storage)
Chris@102:             "cmpeq %2, %0, %3\n"            // success = current == expected
Chris@102:             "mov %2, %0\n"                  // expected = current
Chris@102:             "beq %3, 2f\n"                  // if (success == 0) goto end
Chris@102:             "stq_c %1, %4\n"                // storage = desired; desired = store succeeded
Chris@102:             "mov %1, %3\n"                  // success = desired
Chris@102:             "2:\n"
Chris@102:             : "+&r" (expected),  // %0
Chris@102:               "+&r" (desired),   // %1
Chris@102:               "=&r" (current),   // %2
Chris@102:               "=&r" (success)    // %3
Chris@102:             : "m" (storage)      // %4
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         if (success)
Chris@102:             fence_after(success_order);
Chris@102:         else
Chris@102:             fence_after(failure_order);
Chris@102:         return !!success;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool compare_exchange_strong(
Chris@102:         storage_type volatile& storage, storage_type& expected, storage_type desired, memory_order success_order, memory_order failure_order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         int success;
Chris@102:         storage_type current, tmp;
Chris@102:         fence_before(success_order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "mov %5, %1\n"                  // tmp = desired
Chris@102:             "ldq_l %2, %4\n"                // current = *(&storage)
Chris@102:             "cmpeq %2, %0, %3\n"            // success = current == expected
Chris@102:             "mov %2, %0\n"                  // expected = current
Chris@102:             "beq %3, 2f\n"                  // if (success == 0) goto end
Chris@102:             "stq_c %1, %4\n"                // storage = tmp; tmp = store succeeded
Chris@102:             "beq %1, 3f\n"                  // if (tmp == 0) goto retry
Chris@102:             "mov %1, %3\n"                  // success = tmp
Chris@102:             "2:\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "3: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "+&r" (expected),  // %0
Chris@102:               "=&r" (tmp),       // %1
Chris@102:               "=&r" (current),   // %2
Chris@102:               "=&r" (success)    // %3
Chris@102:             : "m" (storage),     // %4
Chris@102:               "r" (desired)      // %5
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         if (success)
Chris@102:             fence_after(success_order);
Chris@102:         else
Chris@102:             fence_after(failure_order);
Chris@102:         return !!success;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_add(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldq_l %0, %2\n"
Chris@102:             "addq %0, %3, %1\n"
Chris@102:             "stq_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_sub(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldq_l %0, %2\n"
Chris@102:             "subq %0, %3, %1\n"
Chris@102:             "stq_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_and(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldq_l %0, %2\n"
Chris@102:             "and %0, %3, %1\n"
Chris@102:             "stq_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_or(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldq_l %0, %2\n"
Chris@102:             "bis %0, %3, %1\n"
Chris@102:             "stq_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE storage_type fetch_xor(storage_type volatile& storage, storage_type v, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         storage_type original, modified;
Chris@102:         fence_before(order);
Chris@102:         __asm__ __volatile__
Chris@102:         (
Chris@102:             "1:\n"
Chris@102:             "ldq_l %0, %2\n"
Chris@102:             "xor %0, %3, %1\n"
Chris@102:             "stq_c %1, %2\n"
Chris@102:             "beq %1, 2f\n"
Chris@102: 
Chris@102:             ".subsection 2\n"
Chris@102:             "2: br 1b\n"
Chris@102:             ".previous\n"
Chris@102: 
Chris@102:             : "=&r" (original),  // %0
Chris@102:               "=&r" (modified)   // %1
Chris@102:             : "m" (storage),     // %2
Chris@102:               "r" (v)            // %3
Chris@102:             : BOOST_ATOMIC_DETAIL_ASM_CLOBBER_CC
Chris@102:         );
Chris@102:         fence_after(order);
Chris@102:         return original;
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool test_and_set(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         return !!exchange(storage, (storage_type)1, order);
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE void clear(storage_type volatile& storage, memory_order order) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         store(storage, 0, order);
Chris@102:     }
Chris@102: 
Chris@102:     static BOOST_FORCEINLINE bool is_lock_free(storage_type const volatile&) BOOST_NOEXCEPT
Chris@102:     {
Chris@102:         return true;
Chris@102:     }
Chris@102: };
Chris@102: 
Chris@102: 
Chris@102: BOOST_FORCEINLINE void thread_fence(memory_order order) BOOST_NOEXCEPT
Chris@102: {
Chris@102:     if (order != memory_order_relaxed)
Chris@102:         __asm__ __volatile__ ("mb" ::: "memory");
Chris@102: }
Chris@102: 
Chris@102: BOOST_FORCEINLINE void signal_fence(memory_order order) BOOST_NOEXCEPT
Chris@102: {
Chris@102:     if (order != memory_order_relaxed)
Chris@102:         __asm__ __volatile__ ("" ::: "memory");
Chris@102: }
Chris@102: 
Chris@102: } // namespace detail
Chris@102: } // namespace atomics
Chris@102: } // namespace boost
Chris@102: 
Chris@102: #endif // BOOST_ATOMIC_DETAIL_OPS_GCC_ALPHA_HPP_INCLUDED_