/*
    Copyright 2005-2014 Intel Corporation.  All Rights Reserved.

    This file is part of Threading Building Blocks. Threading Building Blocks is free software;
    you can redistribute it and/or modify it under the terms of the GNU General Public License
    version 2  as  published  by  the  Free Software Foundation.  Threading Building Blocks 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 Threading Building Blocks; if not, write to the
    Free Software Foundation, Inc.,  51 Franklin St,  Fifth Floor,  Boston,  MA 02110-1301 USA

    As a special exception,  you may use this file  as part of a free software library without
    restriction.  Specifically,  if other files instantiate templates  or use macros or inline
    functions from this file, or you compile this file and link it with other files to produce
    an executable,  this file does not by itself cause the resulting executable to be covered
    by the GNU General Public License. This exception does not however invalidate any other
    reasons why the executable file might be covered by the GNU General Public License.
*/

#if !defined(__TBB_machine_H) || defined(__TBB_machine_linux_ia32_H)
#error Do not #include this internal file directly; use public TBB headers instead.
#endif

#define __TBB_machine_linux_ia32_H

#include <stdint.h>
#include "gcc_ia32_common.h"

#define __TBB_WORDSIZE 4
#define __TBB_ENDIANNESS __TBB_ENDIAN_LITTLE

#define __TBB_compiler_fence() __asm__ __volatile__("": : :"memory")
#define __TBB_control_consistency_helper() __TBB_compiler_fence()
#define __TBB_acquire_consistency_helper() __TBB_compiler_fence()
#define __TBB_release_consistency_helper() __TBB_compiler_fence()
#define __TBB_full_memory_fence()          __asm__ __volatile__("mfence": : :"memory")

#if __TBB_ICC_ASM_VOLATILE_BROKEN
#define __TBB_VOLATILE
#else
#define __TBB_VOLATILE volatile
#endif

#define __TBB_MACHINE_DEFINE_ATOMICS(S,T,X,R)                                        \
static inline T __TBB_machine_cmpswp##S (volatile void *ptr, T value, T comparand )  \
{                                                                                    \
    T result;                                                                        \
                                                                                     \
    __asm__ __volatile__("lock\ncmpxchg" X " %2,%1"                                  \
                          : "=a"(result), "=m"(*(__TBB_VOLATILE T*)ptr)              \
                          : "q"(value), "0"(comparand), "m"(*(__TBB_VOLATILE T*)ptr) \
                          : "memory");                                               \
    return result;                                                                   \
}                                                                                    \
                                                                                     \
static inline T __TBB_machine_fetchadd##S(volatile void *ptr, T addend)              \
{                                                                                    \
    T result;                                                                        \
    __asm__ __volatile__("lock\nxadd" X " %0,%1"                                     \
                          : R (result), "=m"(*(__TBB_VOLATILE T*)ptr)                \
                          : "0"(addend), "m"(*(__TBB_VOLATILE T*)ptr)                \
                          : "memory");                                               \
    return result;                                                                   \
}                                                                                    \
                                                                                     \
static inline  T __TBB_machine_fetchstore##S(volatile void *ptr, T value)            \
{                                                                                    \
    T result;                                                                        \
    __asm__ __volatile__("lock\nxchg" X " %0,%1"                                     \
                          : R (result), "=m"(*(__TBB_VOLATILE T*)ptr)                \
                          : "0"(value), "m"(*(__TBB_VOLATILE T*)ptr)                 \
                          : "memory");                                               \
    return result;                                                                   \
}                                                                                    \
                                                                                     
__TBB_MACHINE_DEFINE_ATOMICS(1,int8_t,"","=q")
__TBB_MACHINE_DEFINE_ATOMICS(2,int16_t,"","=r")
__TBB_MACHINE_DEFINE_ATOMICS(4,int32_t,"l","=r")

#if __INTEL_COMPILER
#pragma warning( push )
// reference to EBX in a function requiring stack alignment
#pragma warning( disable: 998 )
#endif

#if __TBB_GCC_CAS8_BUILTIN_INLINING_BROKEN
#define  __TBB_IA32_CAS8_NOINLINE  __attribute__ ((noinline))
#else
#define  __TBB_IA32_CAS8_NOINLINE
#endif

static inline __TBB_IA32_CAS8_NOINLINE int64_t __TBB_machine_cmpswp8 (volatile void *ptr, int64_t value, int64_t comparand )  {
//TODO: remove the extra part of condition once __TBB_GCC_BUILTIN_ATOMICS_PRESENT is lowered to gcc version 4.1.2
#if (__TBB_GCC_BUILTIN_ATOMICS_PRESENT || (__TBB_GCC_VERSION >= 40102)) && !__TBB_GCC_64BIT_ATOMIC_BUILTINS_BROKEN
    return __sync_val_compare_and_swap( reinterpret_cast<volatile int64_t*>(ptr), comparand, value );
#else /* !__TBB_GCC_BUILTIN_ATOMICS_PRESENT */
    //TODO: look like ICC 13.0 has some issues with this code, investigate it more deeply
    int64_t result;
    union {
        int64_t i64;
        int32_t i32[2];
    };
    i64 = value;
#if __PIC__ 
    /* compiling position-independent code */
    // EBX register preserved for compliance with position-independent code rules on IA32
    int32_t tmp;
    __asm__ __volatile__ (
            "movl  %%ebx,%2\n\t"
            "movl  %5,%%ebx\n\t"
#if __GNUC__==3
            "lock\n\t cmpxchg8b %1\n\t"
#else
            "lock\n\t cmpxchg8b (%3)\n\t"
#endif
            "movl  %2,%%ebx"
             : "=A"(result)
             , "=m"(*(__TBB_VOLATILE int64_t *)ptr)
             , "=m"(tmp)
#if __GNUC__==3
             : "m"(*(__TBB_VOLATILE int64_t *)ptr)
#else
             : "SD"(ptr)
#endif
             , "0"(comparand)
             , "m"(i32[0]), "c"(i32[1])
             : "memory"
#if __INTEL_COMPILER
             ,"ebx"
#endif
    );
#else /* !__PIC__ */
    __asm__ __volatile__ (
            "lock\n\t cmpxchg8b %1\n\t"
             : "=A"(result), "=m"(*(__TBB_VOLATILE int64_t *)ptr)
             : "m"(*(__TBB_VOLATILE int64_t *)ptr)
             , "0"(comparand)
             , "b"(i32[0]), "c"(i32[1])
             : "memory"
    );
#endif /* __PIC__ */
    return result;
#endif /* !__TBB_GCC_BUILTIN_ATOMICS_PRESENT */
}

#undef __TBB_IA32_CAS8_NOINLINE

#if __INTEL_COMPILER
#pragma warning( pop )
#endif // warning 998 is back

static inline void __TBB_machine_or( volatile void *ptr, uint32_t addend ) {
    __asm__ __volatile__("lock\norl %1,%0" : "=m"(*(__TBB_VOLATILE uint32_t *)ptr) : "r"(addend), "m"(*(__TBB_VOLATILE uint32_t *)ptr) : "memory");
}

static inline void __TBB_machine_and( volatile void *ptr, uint32_t addend ) {
    __asm__ __volatile__("lock\nandl %1,%0" : "=m"(*(__TBB_VOLATILE uint32_t *)ptr) : "r"(addend), "m"(*(__TBB_VOLATILE uint32_t *)ptr) : "memory");
}

//TODO: Check if it possible and profitable for IA-32 architecture on (Linux* and Windows*)
//to use of 64-bit load/store via floating point registers together with full fence
//for sequentially consistent load/store, instead of CAS.

#if __clang__
#define __TBB_fildq  "fildll"
#define __TBB_fistpq "fistpll"
#else
#define __TBB_fildq  "fildq"
#define __TBB_fistpq "fistpq"
#endif

static inline int64_t __TBB_machine_aligned_load8 (const volatile void *ptr) {
    __TBB_ASSERT(tbb::internal::is_aligned(ptr,8),"__TBB_machine_aligned_load8 should be used with 8 byte aligned locations only \n");
    int64_t result;
    __asm__ __volatile__ ( __TBB_fildq  " %1\n\t"
                           __TBB_fistpq " %0" :  "=m"(result) : "m"(*(const __TBB_VOLATILE uint64_t*)ptr) : "memory" );
    return result;
}

static inline void __TBB_machine_aligned_store8 (volatile void *ptr, int64_t value ) {
    __TBB_ASSERT(tbb::internal::is_aligned(ptr,8),"__TBB_machine_aligned_store8 should be used with 8 byte aligned locations only \n");
    // Aligned store
    __asm__ __volatile__ ( __TBB_fildq  " %1\n\t"
                           __TBB_fistpq " %0" :  "=m"(*(__TBB_VOLATILE int64_t*)ptr) : "m"(value) : "memory" );
}

static inline int64_t __TBB_machine_load8 (const volatile void *ptr) {
#if __TBB_FORCE_64BIT_ALIGNMENT_BROKEN
    if( tbb::internal::is_aligned(ptr,8)) {
#endif
        return __TBB_machine_aligned_load8(ptr);
#if __TBB_FORCE_64BIT_ALIGNMENT_BROKEN
    } else {
        // Unaligned load
        return __TBB_machine_cmpswp8(const_cast<void*>(ptr),0,0);
    }
#endif
}

//! Handles misaligned 8-byte store
/** Defined in tbb_misc.cpp */
extern "C" void __TBB_machine_store8_slow( volatile void *ptr, int64_t value );
extern "C" void __TBB_machine_store8_slow_perf_warning( volatile void *ptr );

static inline void __TBB_machine_store8(volatile void *ptr, int64_t value) {
#if __TBB_FORCE_64BIT_ALIGNMENT_BROKEN
    if( tbb::internal::is_aligned(ptr,8)) {
#endif
        __TBB_machine_aligned_store8(ptr,value);
#if __TBB_FORCE_64BIT_ALIGNMENT_BROKEN
    } else {
        // Unaligned store
#if TBB_USE_PERFORMANCE_WARNINGS
        __TBB_machine_store8_slow_perf_warning(ptr);
#endif /* TBB_USE_PERFORMANCE_WARNINGS */
        __TBB_machine_store8_slow(ptr,value);
    }
#endif
}
 
// Machine specific atomic operations
#define __TBB_AtomicOR(P,V) __TBB_machine_or(P,V)
#define __TBB_AtomicAND(P,V) __TBB_machine_and(P,V)

#define __TBB_USE_GENERIC_DWORD_FETCH_ADD                   1
#define __TBB_USE_GENERIC_DWORD_FETCH_STORE                 1
#define __TBB_USE_FETCHSTORE_AS_FULL_FENCED_STORE           1
#define __TBB_USE_GENERIC_HALF_FENCED_LOAD_STORE            1
#define __TBB_USE_GENERIC_RELAXED_LOAD_STORE                1
#define __TBB_USE_GENERIC_SEQUENTIAL_CONSISTENCY_LOAD_STORE 1

