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Diffstat (limited to 'src/systemc/dt/fx/scfx_mant.cc')
-rw-r--r-- | src/systemc/dt/fx/scfx_mant.cc | 117 |
1 files changed, 117 insertions, 0 deletions
diff --git a/src/systemc/dt/fx/scfx_mant.cc b/src/systemc/dt/fx/scfx_mant.cc new file mode 100644 index 000000000..41f3aedcb --- /dev/null +++ b/src/systemc/dt/fx/scfx_mant.cc @@ -0,0 +1,117 @@ +/***************************************************************************** + + Licensed to Accellera Systems Initiative Inc. (Accellera) under one or + more contributor license agreements. See the NOTICE file distributed + with this work for additional information regarding copyright ownership. + Accellera licenses this file to you under the Apache License, Version 2.0 + (the "License"); you may not use this file except in compliance with the + License. You may obtain a copy of the License at + + http://www.apache.org/licenses/LICENSE-2.0 + + Unless required by applicable law or agreed to in writing, software + distributed under the License is distributed on an "AS IS" BASIS, + WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or + implied. See the License for the specific language governing + permissions and limitations under the License. + + *****************************************************************************/ + +/***************************************************************************** + + scfx_mant.cpp - + + Original Author: Robert Graulich, Synopsys, Inc. + Martin Janssen, Synopsys, Inc. + + *****************************************************************************/ + +/***************************************************************************** + + MODIFICATION LOG - modifiers, enter your name, affiliation, date and + changes you are making here. + + Name, Affiliation, Date: + Description of Modification: + + *****************************************************************************/ + + +// $Log: scfx_mant.cpp,v $ +// Revision 1.1.1.1 2006/12/15 20:20:04 acg +// SystemC 2.3 +// +// Revision 1.3 2006/01/13 18:53:58 acg +// Andy Goodrich: added $Log command so that CVS comments are reproduced in +// the source. +// + +#include "systemc/ext/dt/fx/scfx_mant.hh" + +namespace sc_dt +{ + +// ---------------------------------------------------------------------------- +// word memory management +// ---------------------------------------------------------------------------- + +class word_list // Entry in free_words bucket. +{ + public: + word_list *m_next_p; +}; + +static inline unsigned +next_pow2_index(std::size_t size) +{ + unsigned index = scfx_find_msb(size); + // If this was a power of 2 we are one bucket too low. + if (~(UINT64_ONE << index) & size) + index++; + // If this is a 64-bit machine and we are using 32-bit words go down + // one slot size, as all the slots are 2x in size. + if (index != 0 && (sizeof(word_list) != sizeof(word))) { + index -= 1; + } + return index; +} + +static word_list *free_words[32] = { 0 }; + +word * +scfx_mant::alloc_word(std::size_t size) +{ + const int ALLOC_SIZE = 128; + + unsigned slot_index = next_pow2_index(size); + unsigned alloc_size = (UINT64_ONE << slot_index); + + word_list*& slot = free_words[slot_index]; + + if (!slot) { + slot = new word_list[ALLOC_SIZE * alloc_size]; + unsigned i; + for (i = 0; i < alloc_size * (ALLOC_SIZE - 1) ; i += alloc_size) { + slot[i].m_next_p = &slot[i + alloc_size]; + } + slot[i].m_next_p = 0; + } + + word *result = (word *)slot; + free_words[slot_index] = slot[0].m_next_p; + return result; +} + +void +scfx_mant::free_word(word *array, std::size_t size) +{ + if (array && size) { + int slot_index = next_pow2_index(size); + word_list *wl_p = (word_list *)array; + + wl_p->m_next_p = free_words[slot_index]; + free_words[slot_index] = wl_p; + } +} + +} // namespace sc_dt |