Hal Finkel e30aa957e3 Implement X86TTI::getUnrollingPreferences ... This provides an initial implementation of getUnrollingPreferences for x86. getUnrollingPreferences is used by the generic (concatenation) unroller, which is distinct from the unrolling done by the loop vectorizer. Many modern x86 cores have some kind of uop cache and loop-stream detector (LSD) used to efficiently dispatch small loops, and taking full advantage of this requires unrolling small loops (small here means 10s of uops). These caches also have limits on the number of taken branches in the loop, and so we also cap the loop unrolling factor based on the maximum "depth" of the loop. This is currently calculated with a partial DFS traversal (partial because it will stop early if the path length grows too much). This is still an approximation, and one that is both conservative (because it does not account for branches eliminated via block placement) and optimistic (because it is only recording the maximum depth over minimum paths). Nevertheless, because the loops that fit in these uop caches are so small, it is not clear how much the details matter. The original set of patches posted for review produced the following test-suite performance results (from the TSVC benchmark) at that time: ControlLoops-dbl - 13% speedup ControlLoops-flt - 15% speedup Reductions-dbl - 7.5% speedup git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205348 91177308-0d34-0410-b5e6-96231b3b80d8		2014-04-01 18:50:34 +00:00
..
Analysis	Use TopTTI->getGEPCost from within getUserCost	2014-04-01 18:50:06 +00:00
AsmParser	Remove the linker_private and linker_private_weak linkages.	2014-03-13 23:18:37 +00:00
Bitcode	All new elements except the last one initialized to NULL. Ideally, once parsing is complete, all elements should be non-NULL.	2014-03-27 12:08:23 +00:00
CodeGen	Make isSetCCEquivalent respect the TargetBooleanContents	2014-04-01 18:13:26 +00:00
DebugInfo	DebugInfo: Support debug_loc under fission	2014-03-25 01:44:02 +00:00
ExecutionEngine	[Allocator] Lift the slab size and size threshold into template	2014-03-30 12:07:07 +00:00
IR	LTO type uniquing: store the Decl field of a DIImportedEntity as a DIRef.	2014-04-01 03:41:04 +00:00
IRReader	Replace OwningPtr<T> with std::unique_ptr<T>.	2014-03-06 05:51:42 +00:00
LineEditor	[CMake] Use LINK_LIBS instead of target_link_libraries().	2014-02-26 06:41:29 +00:00
Linker	[Layering] Sink Linker.h into a Linker subdirectory to make it	2014-03-06 03:42:23 +00:00
LTO	This patch fixes LTO's RecordStreamer so that it records symbols in the MCExpr	2014-03-31 16:59:13 +00:00
MC	DebugInfo: Avoid creating unnecessary/empty line tables and remove the special case of '0' in DwarfCompileUnit::initStmtList by just always using a label difference	2014-04-01 08:07:52 +00:00
Object	[yaml2obj] Add support for ELF e_flags.	2014-03-31 09:44:05 +00:00
Option	Avoid buffer copies when a Twine already is a StringRef.	2013-12-03 18:18:28 +00:00
ProfileData	InstrProf: Silence spurious warnings in GCC 4.8	2014-03-24 00:47:18 +00:00
Support	Support: generalise object type handling for Windows	2014-03-31 16:34:41 +00:00
TableGen	tblgen: Twinify PrintFatalError.	2014-03-29 17:17:15 +00:00
Target	Implement X86TTI::getUnrollingPreferences	2014-04-01 18:50:34 +00:00
Transforms	Add some additional fields to TTI::UnrollingPreferences	2014-04-01 18:50:30 +00:00
CMakeLists.txt	ProfileData: Introduce the InstrProfReader interface and a text reader	2014-03-21 17:24:48 +00:00
LLVMBuild.txt	ProfileData: Introduce the InstrProfReader interface and a text reader	2014-03-21 17:24:48 +00:00
Makefile	ProfileData: Introduce the InstrProfReader interface and a text reader	2014-03-21 17:24:48 +00:00