Now that we have atomics support properly detected by configure,

use it to implement Atomic.h.

This expunges the code previously imported from libatomic_ops.

llvm-svn: 72077

llvm/LICENSE.TXT

@@ -67,4 +67,3 @@ Autoconf            llvm/autoconf
                     llvm/projects/sample/autoconf
 CellSPU backend     llvm/lib/Target/CellSPU/README.txt
 Google Test         llvm/utils/unittest/googletest
-Atomics Library     llvm/include/llvm/System/Atomic.h

llvm/include/llvm/System/Atomic.h

@@ -9,197 +9,64 @@
 //
 // This file declares the llvm::sys atomic operations.
 //
-// Portions of this file use code from libatomic_ops, for which the following 
-// license applies:
-//
-// Copyright (c) 2003 by Hewlett-Packard Company.  All rights reserved.
-// 
-// Permission is hereby granted, free of charge, to any person obtaining a copy
-// of this software and associated documentation files (the "Software"), to deal
-// in the Software without restriction, including without limitation the rights
-// to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
-// copies of the Software, and to permit persons to whom the Software is
-// furnished to do so, subject to the following conditions:
-// 
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-// 
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
-// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
-// OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
-// SOFTWARE.
-//
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_SYSTEM_ATOMIC_H
 #define LLVM_SYSTEM_ATOMIC_H
 
-#include <stdint.h>
+#if defined(_MSC_VER)
-
-#if defined(_HPUX_SOURCE) && defined(__ia64)
-#include <machine/sys/inline.h>
-#elif defined(_MSC_VER)
 #include <windows.h>
-#endif // defined(_HPUX_SOURCE) && defined(__ia64)
+#endif
 
 
 namespace llvm {
   namespace sys {
     
-    inline void CompilerFence() {
+    inline void MemoryFence() {
-#if defined(__GNUC__) && !defined(__INTEL_COMPILER)
+#if !defined(ENABLE_THREADS) || ENABLE_THREADS == 0
+#  if defined(__GNUC__)
       __asm__ __volatile__("" : : : "memory");
-#elif defined(_MSC_VER)
+#  elif defined(_MSC_VER)
       __asm { };
-#elif defined(__INTEL_COMPILER)
+#  else
-      __memory_barrier(); /* Too strong? IA64-only? */
+#    error No memory fence implementation for your platform!
+#  endif
 #else
-    /* We conjecture that the following usually gives us the right 	*/
+#  if defined(__GNUC__)
-    /* semantics or an error.						*/
+      __sync_synchronize();
-      asm("");
+#  elif defined(_MSC_VER)
-#endif // defined(__GNUC__) && !defined(__INTEL_COMPILER)
+      MemoryBarrier();
+#  else
+#    error No memory fence implementation for your platform!
+#  endif
+#endif
 }
 
 #if !defined(ENABLE_THREADS) || ENABLE_THREADS == 0
-    inline void MemoryFence() {
+    typedef unsigned long cas_flag;
-      CompilerFence();
-    }
-
-    typedef uint32_t cas_flag;
     inline cas_flag CompareAndSwap(cas_flag* dest, cas_flag exc, cas_flag c) {
       cas_flag result = *dest;
       if (result == c)
         *dest = exc;
       return result;
     }
-
 #elif defined(__GNUC__)
-
-    inline void MemoryFence() {
-#  if defined(__i386__) || defined(__x86_64__)
-#    if defined(__SSE2__)
-      __asm__ __volatile__("mfence" : : : "memory");
-#    else
-      unsigned char dummy = 0;
-      volatile unsigned char* addr = &dummy;
-      unsigned char oldval;
-      __asm __ __volatile__("xchgb %0, %1" : "=r"(oldval),
-        "=m"(*addr), "0"(0xff), "m"(*addr) : "memory");
-#    endif // defined(__SSE2__)
-#  elif defined(__ia64__)
-      __asm__ __volatile__("mf" : : : "memory");
-# elif defined(__alpha__)
-      __asm__ __volatile__("mb" : : : "memory");
-# elif defined(__sparc__)
-      __asm__ __volatile__("membar	#StoreStore | #LoadStore | #LoadLoad | #StoreLoad");
-# elif defined(__powerpc__) || defined(__ppc__)
-      __asm__ __volatile__("sync" : : : "memory");
-# elif defined(__arm__)
-      __asm__ __volatile__ ("mcr	p15, 0, r0, c7, c10, 5	@ dmb");
-# endif
-    } // defined(__i386__) || defined(__x86_64__)
-    
     typedef unsigned long cas_flag;
     inline cas_flag CompareAndSwap(cas_flag* ptr,
                                    cas_flag new_value,
                                    cas_flag old_value) {
-      cas_flag prev;
+      return __sync_val_compare_and_swap(ptr, old_value, new_value);
-#  if defined(__i386__) || defined(__x86_64__)
-      __asm__ __volatile__("lock; cmpxchgl %1,%2"
-                           : "=a" (prev)
-                           : "q" (new_value), "m" (*ptr), "0" (old_value)
-                           : "memory");
-#  elif defined(__ia64__)
-      MemoryFence();
-#  if defined(_ILP32)
-      __asm__("zxt4 %1=%1": "=r"(prev) : "0"(prev));
-      __asm__ __volatile__("addp4 %1=0,%1;;\n"
-        "mov ar.ccv=%[old] ;; cmpxchg 4"
-        ".acq %0=[%1],%[new_val],ar.ccv"
-        : "=r"(prev) "1"(addr),
-        : "=r"(addr), [new_value]"r"(new_value), [old_value]"r"(old_value)
-        : "memory");
-#  else
-      __asm__ __volatile__(
-        "mov ar.ccv=%[old] ;; cmpxchg 8"
-        ".acq %0=[%1],%[new_val],ar.ccv"
-        : "=r"(prev)
-        : "r"(ptr), [new_value]"r"(new_value), 
-        [old_value]"r"(old_value)
-        : "memory");
-#  endif // defined(_ILP32)
-#  elif defined(__alpha__)
-      cas_flag was_equal;
-      __asm__ __volatile__(
-        "1:     ldq_l %0,%1\n"
-        "       cmpeq %0,%4,%2\n"
-        "	     mov %3,%0\n"
-        "       beq %2,2f\n"
-        "       stq_c %0,%1\n"
-        "       beq %0,1b\n"
-        "2:\n"
-        :"=&r" (prev), "=m" (*ptr), "=&r" (was_equal)
-        : "r" (new_value), "Ir" (old_value)
-        :"memory");
-#elif defined(__sparc__)
-#error No CAS implementation for SPARC yet.
-#elif defined(__powerpc__) || defined(__ppc__)
-      int result = 0;
-      __asm__ __volatile__(
-        "1:lwarx %0,0,%2\n"   /* load and reserve              */
-        "cmpw %0, %4\n"      /* if load is not equal to 	*/
-        "bne 2f\n"            /*   old, fail			*/
-        "stwcx. %3,0,%2\n"    /* else store conditional         */
-        "bne- 1b\n"           /* retry if lost reservation      */
-        "li %1,1\n"	     /* result = 1;			*/
-        "2:\n"
-        : "=&r"(prev), "=&r"(result)
-        : "r"(ptr), "r"(new_value), "r"(old_value), "1"(result)
-        : "memory", "cc");
-#elif defined(__arm__)
-      int result;
-      __asm__ __volatile__ (
-        "\n"
-        "0:\t"
-        "ldr     %1,[%2] \n\t"
-        "mov     %0,#0 \n\t"
-        "cmp     %1,%4 \n\t"
-        "bne     1f \n\t"
-        "swp     %0,%3,[%2] \n\t"
-        "cmp     %1,%0 \n\t"
-        "swpne   %1,%0,[%2] \n\t"
-        "bne     0b \n\t"
-        "mov     %0,#1 \n"
-        "1:\n\t"
-        ""
-        : "=&r"(result), "=&r"(prev) 
-        : "r" ptr), "r" (new_value), "r" (old_value) 
-        : "cc", "memory");
-#endif // defined(__i386__)
-      return prev;
     }
-
 #elif defined(_MSC_VER) && _M_IX86 > 400
-    inline void MemoryFence() {
+    typedef LONG cas_flag;
-      LONG dummy = 0;
-      InterlockedExchanged((LONG volatile *)&dummy, (LONG)0);
-    }
-    
-    typedef DWORD cas_flag;
     inline cas_flag CompareAndSwap(cas_flag* ptr,
                                    cas_flag new_value,
                                    cas_flag old_value) {
-      /* FIXME - This is nearly useless on win64.			*/
+      return InterlockedCompareExchange(addr, new_value, old_value);
-      /* Use InterlockedCompareExchange64 for win64?	*/
-      return InterlockedCompareExchange((DWORD volatile *)addr,
-                                        (DWORD)new_value, (DWORD) old_value)
     }
 #else
-#error No atomics implementation found for your platform.
+#  error No compare-and-swap implementation for your platform!
-#endif // !defined(ENABLE_THREADS) || ENABLE_THREADS == 0
+#endif
 
   }
 }