sim: Remove FastAlloc

While FastAlloc provides a small performance increase (~1.5%) over regular malloc it isn't thread safe.
After removing FastAlloc and using tcmalloc I've seen a performance increase of 12% over libc malloc
when running twolf for ARM.

3 files changed, 0 insertions, 263 deletions

diff --git a/src/base/SConscript b/src/base/SConscript
index 7c3b0786b..8790942cd 100644
--- a/src/base/SConscript
+++ b/src/base/SConscript
@@ -40,7 +40,6 @@ Source('callback.cc')
 Source('circlebuf.cc')
 Source('cprintf.cc')
 Source('debug.cc')
-Source('fast_alloc.cc')
 if env['USE_FENV']:
     Source('fenv.c')
 Source('hostinfo.cc')
diff --git a/src/base/fast_alloc.cc b/src/base/fast_alloc.cc
deleted file mode 100644
index d370b93e8..000000000
--- a/src/base/fast_alloc.cc
+++ /dev/null
@@ -1,72 +0,0 @@
-/*
- * Copyright (c) 2000-2005 The Regents of The University of Michigan
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met: redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer;
- * redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution;
- * neither the name of the copyright holders nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * Authors: Steve Reinhardt
- */
-
-/*
- * This code was originally written by Steve Reinhardt as part of
- * the Wisconsin Wind Tunnel simulator.  Relicensed as part of M5
- * by permission.
- */
-
-#include <cassert>
-
-#include "base/fast_alloc.hh"
-
-#if USE_FAST_ALLOC
-
-void *FastAlloc::freeLists[Num_Buckets];
-
-#if FAST_ALLOC_STATS
-unsigned FastAlloc::newCount[Num_Buckets];
-unsigned FastAlloc::deleteCount[Num_Buckets];
-unsigned FastAlloc::allocCount[Num_Buckets];
-#endif
-
-void *
-FastAlloc::moreStructs(int bucket)
-{
-    assert(bucket > 0 && bucket < Num_Buckets);
-
-    int sz = bucket * Alloc_Quantum;
-    const int nstructs = Num_Structs_Per_New;   // how many to allocate?
-    char *p = ::new char[nstructs * sz];
-
-#if FAST_ALLOC_STATS
-    ++allocCount[bucket];
-#endif
-
-    freeLists[bucket] = p;
-    for (int i = 0; i < (nstructs-2); ++i, p += sz)
-        *(void **)p = p + sz;
-    *(void **)p = 0;
-
-    return (p + sz);
-}
-
-#endif // USE_FAST_ALLOC
diff --git a/src/base/fast_alloc.hh b/src/base/fast_alloc.hh
deleted file mode 100644
index d6dc593d4..000000000
--- a/src/base/fast_alloc.hh
+++ /dev/null
@@ -1,190 +0,0 @@
-/*
- * Copyright (c) 2000-2001, 2003-2005 The Regents of The University of Michigan
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions are
- * met: redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer;
- * redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution;
- * neither the name of the copyright holders nor the names of its
- * contributors may be used to endorse or promote products derived from
- * this software without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
- * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
- * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
- * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
- * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
- * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
- * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
- * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
- * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
- * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
- * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
- *
- * Authors: Steve Reinhardt
- */
-
-/*
- * This code was originally written by Steve Reinhardt as part of
- * the Wisconsin Wind Tunnel simulator.  Relicensed as part of M5
- * by permission.
- */
-
-#ifndef __BASE_FAST_ALLOC_HH__
-#define __BASE_FAST_ALLOC_HH__
-
-#include <cstddef>
-
-// Fast structure allocator.  Designed for small objects that are
-// frequently allocated and deallocated.  This code is derived from the
-// 'alloc_struct' package used in WWT and Blizzard.  C++ provides a
-// much nicer framework for the same optimization.  The package is
-// implemented as a class, FastAlloc.  Allocation and deletion are
-// performed using FastAlloc's new and delete operators.  Any object
-// that derives from the FastAlloc class will transparently use this
-// allocation package.
-
-// The static allocate() and deallocate() methods can also be called
-// directly if desired.
-
-// In order for derived classes to call delete with the correct
-// structure size even when they are deallocated via a base-type
-// pointer, they must have a virtual destructor.  It is sufficient for
-// FastAlloc to declare a virtual destructor (as it does); it is not
-// required for derived classes to declare their own destructor.  The
-// compiler will automatically generate a virtual destructor for each
-// derived class.  However, it is more efficient if each derived class
-// defines an inline destructor, so that the compiler can statically
-// collapse the destructor call chain back up the inheritance
-// hierarchy.
-
-#include "config/fast_alloc_stats.hh"
-#include "config/force_fast_alloc.hh"
-#include "config/no_fast_alloc.hh"
-
-// By default, we want to enable FastAlloc in any build other than
-// m5.debug.  (FastAlloc's reuse policies can mask allocation bugs, so
-// we typically want it disabled when debugging.)  Set
-// FORCE_FAST_ALLOC to enable even when debugging, and set
-// NO_FAST_ALLOC to disable even in non-debug builds.
-#define USE_FAST_ALLOC \
-    (FORCE_FAST_ALLOC || (!defined(DEBUG) && !NO_FAST_ALLOC))
-
-#if !USE_FAST_ALLOC
-
-class FastAlloc
-{
-};
-
-#else
-
-class FastAlloc
-{
-  public:
-    static void *allocate(size_t);
-    static void deallocate(void *, size_t);
-
-    void *operator new(size_t);
-    void operator delete(void *, size_t);
-
-    virtual ~FastAlloc() {}
-
-  private:
-
-    // Max_Alloc_Size is the largest object that can be allocated with
-    // this class.  There's no fundamental limit, but this limits the
-    // size of the freeLists array.  Let's not make this really huge
-    // like in Blizzard.
-    static const size_t Max_Alloc_Size = 512;
-
-    // Alloc_Quantum is the difference in size between adjacent
-    // buckets in the free list array.
-    static const int Log2_Alloc_Quantum = 3;
-    static const int Alloc_Quantum = (1 << Log2_Alloc_Quantum);
-
-    // Num_Buckets = bucketFor(Max_Alloc_Size) + 1
-    static const int Num_Buckets =
-        ((Max_Alloc_Size + Alloc_Quantum - 1) >> Log2_Alloc_Quantum) + 1;
-
-    // when we call new() for more structures, how many should we get?
-    static const int Num_Structs_Per_New = 20;
-
-    static int bucketFor(size_t);
-    static void *moreStructs(int bucket);
-
-    static void *freeLists[Num_Buckets];
-
-#if FAST_ALLOC_STATS
-    static unsigned newCount[Num_Buckets];
-    static unsigned deleteCount[Num_Buckets];
-    static unsigned allocCount[Num_Buckets];
-#endif
-};
-
-inline int
-FastAlloc::bucketFor(size_t sz)
-{
-    return (sz + Alloc_Quantum - 1) >> Log2_Alloc_Quantum;
-}
-
-inline void *
-FastAlloc::allocate(size_t sz)
-{
-    int b;
-    void *p;
-
-    if (sz > Max_Alloc_Size)
-        return (void *)::new char[sz];
-
-    b = bucketFor(sz);
-    p = freeLists[b];
-
-    if (p)
-        freeLists[b] = *(void **)p;
-    else
-        p = moreStructs(b);
-
-#if FAST_ALLOC_STATS
-    ++newCount[b];
-#endif
-
-    return p;
-}
-
-inline void
-FastAlloc::deallocate(void *p, size_t sz)
-{
-    int b;
-
-    if (sz > Max_Alloc_Size) {
-        ::delete [] (char *)p;
-        return;
-    }
-
-    b = bucketFor(sz);
-    *(void **)p = freeLists[b];
-    freeLists[b] = p;
-#if FAST_ALLOC_STATS
-    ++deleteCount[b];
-#endif
-}
-
-inline void *
-FastAlloc::operator new(size_t sz)
-{
-    return allocate(sz);
-}
-
-inline void
-FastAlloc::operator delete(void *p, size_t sz)
-{
-    deallocate(p, sz);
-}
-
-#endif // USE_FAST_ALLOC
-
-#endif // __BASE_FAST_ALLOC_HH__