[Lldb-commits] [lldb] r105834 - in /lldb/trunk: include/lldb/Symbol/Symtab.h source/Symbol/Symtab.cpp
Owen Anderson
resistor at mac.com
Fri Jun 11 14:40:17 PDT 2010
OK, so I did some measurement on this issue, using optimized (-Os) builds of LLDB, without debug symbols, targeting x86-64.
When using qsort_r, Symtab.o is 43KB.
When using std::sort, Symtab.o is 46KB.
A 7% increase in file size on a single file.
The qsort_r version of LLDB.framework is 32,840,512 bytes.
The std::sort version of LLDB.framework is 32,840,937 bytes.
A 0.001% increase in file size of the overall library. :-)
Interestingly, it appears that those extra symbols get coalesced with ones already present (presumably in the LLVM libraries), so it doesn't actually add much at all to the resulting library.
--Owen
On Jun 11, 2010, at 2:03 PM, Jason Molenda wrote:
> Please back this change out Owen, until you've addressed the point Greg made here -
> http://lists.cs.uiuc.edu/pipermail/lldb-dev/2010-June/000039.html
>
> J
>
> On Jun 11, 2010, at 1:52 PM, Owen Anderson wrote:
>
>> Author: resistor
>> Date: Fri Jun 11 15:52:57 2010
>> New Revision: 105834
>>
>> URL: http://llvm.org/viewvc/llvm-project?rev=105834&view=rev
>> Log:
>> Replace qsort_r with std::sort. This gets rid of a lot of portability
>> ickiness, and is cleaner to boot.
>>
>> I'm fairly confident that I converted the comparator over properly,
>> and what testing I could figure out how to run seemed to pass, but it
>> would be great if someone in the know could check behind me.
>>
>> Modified:
>> lldb/trunk/include/lldb/Symbol/Symtab.h
>> lldb/trunk/source/Symbol/Symtab.cpp
>>
>> Modified: lldb/trunk/include/lldb/Symbol/Symtab.h
>> URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/include/lldb/Symbol/Symtab.h?rev=105834&r1=105833&r2=105834&view=diff
>> ==============================================================================
>> --- lldb/trunk/include/lldb/Symbol/Symtab.h (original)
>> +++ lldb/trunk/include/lldb/Symbol/Symtab.h Fri Jun 11 15:52:57 2010
>> @@ -59,8 +59,6 @@
>> typedef collection::iterator iterator;
>> typedef collection::const_iterator const_iterator;
>>
>> - static int CompareSymbolValueByIndex (void *thunk, const void *a, const void *b);
>> - static int CompareSymbolValueByIndexLinux (const void *a, const void *b, void *thunk);
>> void InitNameIndexes ();
>> void InitAddressIndexes ();
>>
>>
>> Modified: lldb/trunk/source/Symbol/Symtab.cpp
>> URL: http://llvm.org/viewvc/llvm-project/lldb/trunk/source/Symbol/Symtab.cpp?rev=105834&r1=105833&r2=105834&view=diff
>> ==============================================================================
>> --- lldb/trunk/source/Symbol/Symtab.cpp (original)
>> +++ lldb/trunk/source/Symbol/Symtab.cpp Fri Jun 11 15:52:57 2010
>> @@ -214,46 +214,36 @@
>> const Symbol *symbols;
>> };
>>
>> -int
>> -Symtab::CompareSymbolValueByIndex (void *thunk, const void *a, const void *b)
>> -{
>> - const Symbol *symbols = (const Symbol *)thunk;
>> - uint32_t index_a = *((uint32_t *) a);
>> - uint32_t index_b = *((uint32_t *) b);
>> -
>> - addr_t value_a;
>> - addr_t value_b;
>> - if (symbols[index_a].GetValue().GetSection() == symbols[index_b].GetValue().GetSection())
>> - {
>> - value_a = symbols[index_a].GetValue ().GetOffset();
>> - value_b = symbols[index_b].GetValue ().GetOffset();
>> - }
>> - else
>> - {
>> - value_a = symbols[index_a].GetValue ().GetFileAddress();
>> - value_b = symbols[index_b].GetValue ().GetFileAddress();
>> - }
>> -
>> - if (value_a == value_b)
>> - {
>> - // The if the values are equal, use the original symbol user ID
>> - lldb::user_id_t uid_a = symbols[index_a].GetID();
>> - lldb::user_id_t uid_b = symbols[index_b].GetID();
>> - if (uid_a < uid_b)
>> - return -1;
>> - if (uid_a > uid_b)
>> - return 1;
>> - return 0;
>> - }
>> - else if (value_a < value_b)
>> - return -1;
>> -
>> - return 1;
>> -}
>> +namespace {
>> + struct SymbolIndexComparator {
>> + const std::vector<Symbol>& symbols;
>> + SymbolIndexComparator(const std::vector<Symbol>& s) : symbols(s) { }
>> + bool operator()(uint32_t index_a, uint32_t index_b) {
>> + addr_t value_a;
>> + addr_t value_b;
>> + if (symbols[index_a].GetValue().GetSection() == symbols[index_b].GetValue().GetSection()) {
>> + value_a = symbols[index_a].GetValue ().GetOffset();
>> + value_b = symbols[index_b].GetValue ().GetOffset();
>> + } else {
>> + value_a = symbols[index_a].GetValue ().GetFileAddress();
>> + value_b = symbols[index_b].GetValue ().GetFileAddress();
>> + }
>>
>> -int Symtab::CompareSymbolValueByIndexLinux(const void* a, const void* b, void* thunk)
>> -{
>> - return CompareSymbolValueByIndex(thunk, a, b);
>> + if (value_a == value_b) {
>> + // The if the values are equal, use the original symbol user ID
>> + lldb::user_id_t uid_a = symbols[index_a].GetID();
>> + lldb::user_id_t uid_b = symbols[index_b].GetID();
>> + if (uid_a < uid_b)
>> + return true;
>> + if (uid_a > uid_b)
>> + return false;
>> + return false;
>> + } else if (value_a < value_b)
>> + return true;
>> +
>> + return false;
>> + }
>> + };
>> }
>>
>> void
>> @@ -263,13 +253,8 @@
>> if (indexes.size() <= 1)
>> return;
>>
>> - // Sort the indexes in place using qsort
>> - // FIXME: (WRONGDEFINE) Need a better define for this!
>> -#ifdef __APPLE__
>> - ::qsort_r (&indexes[0], indexes.size(), sizeof(uint32_t), (void *)&m_symbols[0], Symtab::CompareSymbolValueByIndex);
>> -#else
>> - ::qsort_r (&indexes[0], indexes.size(), sizeof(uint32_t), CompareSymbolValueByIndexLinux, (void *)&m_symbols[0]);
>> -#endif
>> + // Sort the indexes in place using std::sort
>> + std::sort(indexes.begin(), indexes.end(), SymbolIndexComparator(m_symbols));
>>
>> // Remove any duplicates if requested
>> if (remove_duplicates)
>>
>>
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