[80] | 1 | /* |
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| 2 | * Copyright (C) 1997 Todd Veldhuizen <tveldhui@oonumerics.org> |
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| 3 | * All rights reserved. Please see <blitz/blitz.h> for terms and |
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| 4 | * conditions of use. |
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| 5 | * |
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| 6 | */ |
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| 7 | |
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| 8 | #ifndef BZ_MEMBLOCK_CC |
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| 9 | #define BZ_MEMBLOCK_CC |
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| 10 | |
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| 11 | #include <blitz/numtrait.h> |
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| 12 | |
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| 13 | BZ_NAMESPACE(blitz) |
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| 14 | |
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| 15 | // Null memory block for each (template) instantiation of MemoryBlockReference |
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| 16 | template<typename P_type> |
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| 17 | NullMemoryBlock<P_type> MemoryBlockReference<P_type>::nullBlock_; |
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| 18 | |
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| 19 | template<typename P_type> |
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| 20 | void MemoryBlock<P_type>::deallocate() |
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| 21 | { |
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| 22 | #ifndef BZ_ALIGN_BLOCKS_ON_CACHELINE_BOUNDARY |
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| 23 | delete [] dataBlockAddress_; |
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| 24 | #else |
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| 25 | if (!NumericTypeTraits<T_type>::hasTrivialCtor) { |
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| 26 | for (int i=0; i < length_; ++i) |
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| 27 | data_[i].~T_type(); |
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| 28 | delete [] reinterpret_cast<char*>(dataBlockAddress_); |
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| 29 | } |
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| 30 | else { |
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| 31 | delete [] dataBlockAddress_; |
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| 32 | } |
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| 33 | #endif |
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| 34 | } |
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| 35 | |
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| 36 | template<typename P_type> |
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| 37 | inline void MemoryBlock<P_type>::allocate(size_t length) |
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| 38 | { |
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| 39 | TAU_TYPE_STRING(p1, "MemoryBlock<T>::allocate() [T=" |
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| 40 | + CT(P_type) + "]"); |
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| 41 | TAU_PROFILE(p1, "void ()", TAU_BLITZ); |
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| 42 | |
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| 43 | #ifndef BZ_ALIGN_BLOCKS_ON_CACHELINE_BOUNDARY |
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| 44 | dataBlockAddress_ = new T_type[length]; |
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| 45 | data_ = dataBlockAddress_; |
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| 46 | #else |
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| 47 | size_t numBytes = length * sizeof(T_type); |
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| 48 | |
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| 49 | if (numBytes < 1024) |
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| 50 | { |
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| 51 | dataBlockAddress_ = new T_type[length]; |
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| 52 | data_ = dataBlockAddress_; |
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| 53 | } |
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| 54 | else |
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| 55 | { |
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| 56 | // We're allocating a large array. For performance reasons, |
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| 57 | // it's advantageous to force the array to start on a |
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| 58 | // cache line boundary. We do this by allocating a little |
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| 59 | // more memory than necessary, then shifting the pointer |
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| 60 | // to the next cache line boundary. |
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| 61 | |
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| 62 | // Patches by Petter Urkedal to support types with nontrivial |
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| 63 | // constructors. |
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| 64 | |
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| 65 | const int cacheBlockSize = 128; // Will work for 32, 16 also |
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| 66 | |
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| 67 | dataBlockAddress_ = reinterpret_cast<T_type*> |
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| 68 | (new char[numBytes + cacheBlockSize - 1]); |
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| 69 | |
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| 70 | // Shift to the next cache line boundary |
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| 71 | |
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| 72 | ptrdiff_t offset = ptrdiff_t(dataBlockAddress_) % cacheBlockSize; |
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| 73 | ptrdiff_t shift = (offset == 0) ? 0 : (cacheBlockSize - offset); |
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| 74 | data_ = reinterpret_cast<T_type*> |
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| 75 | (reinterpret_cast<char*>(dataBlockAddress_) + shift); |
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| 76 | |
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| 77 | // Use placement new to construct types with nontrival ctors |
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| 78 | if (!NumericTypeTraits<T_type>::hasTrivialCtor) { |
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| 79 | for (int i=0; i < length; ++i) |
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| 80 | new(&data_[i]) T_type; |
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| 81 | } |
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| 82 | } |
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| 83 | #endif |
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| 84 | } |
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| 85 | |
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| 86 | |
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| 87 | BZ_NAMESPACE_END |
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| 88 | |
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| 89 | #endif // BZ_MEMBLOCK_CC |
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