Jingyue Wu 2918efd551 Add straight-line strength reduction to LLVM ... Summary: Straight-line strength reduction (SLSR) is implemented in GCC but not yet in LLVM. It has proven to effectively simplify statements derived from an unrolled loop, and can potentially benefit many other cases too. For example, LLVM unrolls #pragma unroll foo (int i = 0; i < 3; ++i) { sum += foo((b + i) * s); } into sum += foo(b * s); sum += foo((b + 1) * s); sum += foo((b + 2) * s); However, no optimizations yet reduce the internal redundancy of the three expressions: b * s (b + 1) * s (b + 2) * s With SLSR, LLVM can optimize these three expressions into: t1 = b * s t2 = t1 + s t3 = t2 + s This commit is only an initial step towards implementing a series of such optimizations. I will implement more (see TODO in the file commentary) in the near future. This optimization is enabled for the NVPTX backend for now. However, I am more than happy to push it to the standard optimization pipeline after more thorough performance tests. Test Plan: test/StraightLineStrengthReduce/slsr.ll Reviewers: eliben, HaoLiu, meheff, hfinkel, jholewinski, atrick Reviewed By: jholewinski, atrick Subscribers: karthikthecool, jholewinski, llvm-commits Differential Revision: http://reviews.llvm.org/D7310 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228016 91177308-0d34-0410-b5e6-96231b3b80d8		2015-02-03 19:37:06 +00:00
..
InstPrinter
MCTargetDesc
TargetInfo
cl_common_defines.h
CMakeLists.txt
LLVMBuild.txt
Makefile
ManagedStringPool.h
NVPTX.h	[PM] Remove a bunch of stale TTI creation method declarations. I nuked	2015-02-01 00:22:15 +00:00
NVPTX.td
NVPTXAllocaHoisting.cpp
NVPTXAllocaHoisting.h
NVPTXAsmPrinter.cpp	Remove usernames from TODOs, NFC	2015-02-03 17:57:38 +00:00
NVPTXAsmPrinter.h	[NVPTX] Emit .pragma "nounroll" for loops marked with nounroll	2015-02-01 02:27:45 +00:00
NVPTXAssignValidGlobalNames.cpp	[C++11] Add 'override' keywords and remove 'virtual'. Additionally add 'final' and leave 'virtual' on some methods that are marked virtual without overriding anything and have no obvious overrides themselves. NVPTX edition	2014-04-29 07:57:44 +00:00
NVPTXFavorNonGenericAddrSpaces.cpp
NVPTXFrameLowering.cpp
NVPTXFrameLowering.h	Canonicalize header guards into a common format.	2014-08-13 16:26:38 +00:00
NVPTXGenericToNVVM.cpp
NVPTXImageOptimizer.cpp
NVPTXInstrFormats.td
NVPTXInstrInfo.cpp
NVPTXInstrInfo.h
NVPTXInstrInfo.td	Migrate NVPTXISelDAGToDAG's getSubtarget to a runOnMachineFunction	2015-01-30 01:40:59 +00:00
NVPTXIntrinsics.td
NVPTXISelDAGToDAG.cpp	Remove unused argument.	2015-01-30 01:41:01 +00:00
NVPTXISelDAGToDAG.h	Migrate NVPTXISelDAGToDAG's getSubtarget to a runOnMachineFunction	2015-01-30 01:40:59 +00:00
NVPTXISelLowering.cpp	Migrate NVPTXISelLowering to take the subtarget that it's dependent	2015-01-30 01:50:07 +00:00
NVPTXISelLowering.h	Migrate NVPTXISelLowering to take the subtarget that it's dependent	2015-01-30 01:50:07 +00:00
NVPTXLowerAggrCopies.cpp
NVPTXLowerAggrCopies.h
NVPTXLowerStructArgs.cpp
NVPTXMachineFunctionInfo.h
NVPTXMCExpr.cpp
NVPTXMCExpr.h
NVPTXPrologEpilogPass.cpp	Migrate a bare getSubtarget call to query the MachineFunction	2015-01-30 01:50:09 +00:00
NVPTXRegisterInfo.cpp
NVPTXRegisterInfo.h
NVPTXRegisterInfo.td
NVPTXReplaceImageHandles.cpp
NVPTXSection.h
NVPTXSubtarget.cpp	Migrate NVPTXISelLowering to take the subtarget that it's dependent	2015-01-30 01:50:07 +00:00
NVPTXSubtarget.h
NVPTXTargetMachine.cpp	Add straight-line strength reduction to LLVM	2015-02-03 19:37:06 +00:00
NVPTXTargetMachine.h	[multiversion] Switch all of the targets over to use the	2015-02-01 13:20:00 +00:00
NVPTXTargetObjectFile.h
NVPTXTargetTransformInfo.cpp	[PM] Switch the TargetMachine interface from accepting a pass manager	2015-01-31 11:17:59 +00:00
NVPTXTargetTransformInfo.h	[multiversion] Switch the TTI queries from TargetMachine to Subtarget	2015-02-01 14:22:17 +00:00
NVPTXutil.cpp
NVPTXutil.h
NVPTXUtilities.cpp
NVPTXUtilities.h
NVPTXVector.td
NVVMReflect.cpp