llvm-project/llvm/lib/CodeGen
Eugene Zelenko fb7f792f55 [CodeGen] Fix some Clang-tidy modernize-use-bool-literals and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 313941
2017-09-21 23:20:16 +00:00
..
AsmPrinter Fixed reverted commit rL312318 2017-09-21 10:04:02 +00:00
GlobalISel [GlobalISel] Only build expensive remarks if they're enabled. NFC. 2017-09-18 18:50:09 +00:00
MIRParser [MIParser] Ensure getHexUint doesn't produce APInts with a bitwidth of 0 2017-09-01 22:17:14 +00:00
SelectionDAG [CodeGen] Fix some Clang-tidy modernize-use-bool-literals and Include What You Use warnings; other minor fixes (NFC). 2017-09-21 23:20:16 +00:00
AggressiveAntiDepBreaker.cpp [AntiDepBreaker] Revert r299124 and add a test. 2017-05-30 22:26:52 +00:00
AggressiveAntiDepBreaker.h
AllocationOrder.cpp
AllocationOrder.h
Analysis.cpp Fix a bug for rL312641. 2017-09-08 16:44:52 +00:00
AntiDepBreaker.h Resubmit r301309: [DebugInfo][X86] Fix handling of DBG_VALUE's in post-RA scheduler. 2017-04-25 15:39:57 +00:00
AtomicExpandPass.cpp [Instruction] add moveAfter() convenience function; NFCI 2017-08-29 14:07:48 +00:00
BasicTargetTransformInfo.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
BranchFolding.cpp Insert IMPLICIT_DEFS for undef uses in tail merging 2017-09-06 20:45:24 +00:00
BranchFolding.h Insert IMPLICIT_DEFS for undef uses in tail merging 2017-09-06 20:45:24 +00:00
BranchRelaxation.cpp [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-09-13 21:15:20 +00:00
BuiltinGCs.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
CMakeLists.txt Update branch coalescing to be a PowerPC specific pass 2017-09-12 18:39:11 +00:00
CalcSpillWeights.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
CallingConvLower.cpp [CodeGen] Remove dead call-or-prologue enum from CCState 2017-02-02 21:58:22 +00:00
CodeGen.cpp Update branch coalescing to be a PowerPC specific pass 2017-09-12 18:39:11 +00:00
CodeGenPrepare.cpp Unmerge GEPs to reduce register pressure on IndirectBr edges. 2017-09-11 17:52:08 +00:00
CountingFunctionInserter.cpp Module::getOrInsertFunction is using C-style vararg instead of variadic templates. 2017-04-11 15:01:18 +00:00
CriticalAntiDepBreaker.cpp [AntiDepBreaker] Revert r299124 and add a test. 2017-05-30 22:26:52 +00:00
CriticalAntiDepBreaker.h
DFAPacketizer.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-06-07 23:53:32 +00:00
DeadMachineInstructionElim.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
DetectDeadLanes.cpp CodeGen: Rename DEBUG_TYPE to match passnames 2017-05-25 21:26:32 +00:00
DwarfEHPrepare.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
EarlyIfConversion.cpp CodeGen: Rename DEBUG_TYPE to match passnames 2017-05-25 21:26:32 +00:00
EdgeBundles.cpp
ExecutionDepsFix.cpp [ExecutionDepsFix] Don't recurse over the CFG 2017-04-05 17:42:56 +00:00
ExpandISelPseudos.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
ExpandPostRAPseudos.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
ExpandReductions.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
FEntryInserter.cpp [X86] Fix a crash in FEntryInserter Pass. 2017-08-01 15:39:12 +00:00
FaultMaps.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
FuncletLayout.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
GCMetadata.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-06-07 23:53:32 +00:00
GCMetadataPrinter.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-06-07 23:53:32 +00:00
GCRootLowering.cpp
GCStrategy.cpp [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-02-27 22:45:06 +00:00
GlobalMerge.cpp Add support for #pragma clang section 2017-06-05 10:09:13 +00:00
IfConversion.cpp [IfConversion] More simple, correct dead/kill liveness handling 2017-09-14 15:53:11 +00:00
ImplicitNullChecks.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-29 22:32:07 +00:00
InlineSpiller.cpp [RegAlloc] Keep a copy of live interval for the spilled vregs in HoistSpillHelper. 2017-09-13 21:41:30 +00:00
InterferenceCache.cpp
InterferenceCache.h
InterleavedAccessPass.cpp CodeGen: Rename DEBUG_TYPE to match passnames 2017-05-25 21:26:32 +00:00
IntrinsicLowering.cpp Module::getOrInsertFunction is using C-style vararg instead of variadic templates. 2017-04-11 15:01:18 +00:00
LLVMBuild.txt LLVMCodeGen: Add ProfileData into deps corresponding to r300277. 2017-04-14 00:36:06 +00:00
LLVMTargetMachine.cpp Delete Default and JITDefault code models 2017-08-03 02:16:21 +00:00
LatencyPriorityQueue.cpp
LazyMachineBlockFrequencyInfo.cpp [LazyMachineBFI] Reimplement with getAnalysisIfAvailable 2017-02-23 17:30:01 +00:00
LexicalScopes.cpp Fixing an issue with the initialization of LexicalScopes objects when mixing debug 2017-07-19 19:36:40 +00:00
LiveDebugValues.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-24 21:21:39 +00:00
LiveDebugVariables.cpp Re-land "[DebugInfo] Insert DW_OP_deref when spilling indirect DBG_VALUEs" 2017-09-20 18:19:08 +00:00
LiveDebugVariables.h [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-24 21:21:39 +00:00
LiveInterval.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-24 21:21:39 +00:00
LiveIntervalAnalysis.cpp LiveIntervalAnalysis: Fix alias regunit reserved definition 2017-09-01 18:36:26 +00:00
LiveIntervalUnion.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
LivePhysRegs.cpp [IfConversion] More simple, correct dead/kill liveness handling 2017-09-14 15:53:11 +00:00
LiveRangeCalc.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-24 21:21:39 +00:00
LiveRangeCalc.h [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-24 21:21:39 +00:00
LiveRangeEdit.cpp [LiveRangeEdit] Don't mess up with LiveInterval when a new vreg is created. 2017-02-02 20:44:36 +00:00
LiveRangeShrink.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-24 21:21:39 +00:00
LiveRangeUtils.h
LiveRegMatrix.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
LiveRegUnits.cpp Preserve existing regs when adding pristines to LivePhysRegs/LiveRegUnits 2017-09-08 16:29:50 +00:00
LiveStackAnalysis.cpp CodeGen: Rename DEBUG_TYPE to match passnames 2017-05-25 21:26:32 +00:00
LiveVariables.cpp [LiveVariables] Switch Kill/Defs sets to be DenseSet(s). 2017-05-11 19:37:43 +00:00
LocalStackSlotAllocation.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
LowLevelType.cpp [GlobalISel] Support vector-of-pointers in LLT 2017-04-19 07:23:57 +00:00
LowerEmuTLS.cpp CodeGen: Rename DEBUG_TYPE to match passnames 2017-05-25 21:26:32 +00:00
MIRPrinter.cpp [MIRPrinter] Print empty successor lists when they cannot be guessed 2017-09-19 23:34:12 +00:00
MIRPrintingPass.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
MachineBasicBlock.cpp Revert "r306529 - [X86] Correct dwarf unwind information in function epilogue" 2017-06-29 13:58:24 +00:00
MachineBlockFrequencyInfo.cpp Add options to dump block frequency/branch probability info in text. 2017-08-26 00:31:00 +00:00
MachineBlockPlacement.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-24 21:21:39 +00:00
MachineBranchProbabilityInfo.cpp
MachineCSE.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-24 21:21:39 +00:00
MachineCombiner.cpp Recommit [MachineCombiner] Update instruction depths incrementally for large BBs. 2017-09-20 11:54:37 +00:00
MachineCopyPropagation.cpp Revert "Re-enable "[MachineCopyPropagation] Extend pass to do COPY source forwarding"" 2017-09-04 15:47:00 +00:00
MachineDominanceFrontier.cpp [Dominators] Make IsPostDominator a template parameter 2017-07-14 18:26:09 +00:00
MachineDominators.cpp [Dominators] Make IsPostDominator a template parameter 2017-07-14 18:26:09 +00:00
MachineFrameInfo.cpp Add an ID field to StackObjects 2017-07-20 21:03:45 +00:00
MachineFunction.cpp Add AddresSpace to PseudoSourceValue. 2017-09-14 20:53:51 +00:00
MachineFunctionPass.cpp CodeGen: Refactor MIR parsing 2017-06-06 00:44:35 +00:00
MachineFunctionPrinterPass.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
MachineInstr.cpp [DebugInfo] Add missing DW_OP_deref when an NRVO pointer is spilled 2017-09-15 21:49:56 +00:00
MachineInstrBundle.cpp
MachineLICM.cpp [MachineLICM] Hoist TOC-based address instructions 2017-06-15 18:29:59 +00:00
MachineLoopInfo.cpp New OptimizationRemarkEmitter pass for MIR 2017-01-25 23:20:33 +00:00
MachineModuleInfo.cpp Retire the llvm.dbg.mir hack after r311594. 2017-08-23 22:02:36 +00:00
MachineModuleInfoImpls.cpp [WebAssembly] Use __stack_pointer global when writing wasm binary 2017-06-16 23:59:10 +00:00
MachineOptimizationRemarkEmitter.cpp [ORE] Add diagnostics hotness threshold 2017-06-30 23:14:53 +00:00
MachineOutliner.cpp [MachineOutliner] Recommit r312194, missed optimization remarks 2017-08-31 21:02:45 +00:00
MachinePassRegistry.cpp
MachinePipeliner.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-09-11 23:00:48 +00:00
MachinePostDominators.cpp [Dominators] Make IsPostDominator a template parameter 2017-07-14 18:26:09 +00:00
MachineRegionInfo.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
MachineRegisterInfo.cpp LiveIntervalAnalysis: Fix alias regunit reserved definition 2017-09-01 18:36:26 +00:00
MachineSSAUpdater.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-09-11 23:00:48 +00:00
MachineScheduler.cpp Allow target to decide when to cluster loads/stores in misched 2017-09-13 22:20:47 +00:00
MachineSink.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-29 22:32:07 +00:00
MachineTraceMetrics.cpp Recommit [MachineCombiner] Update instruction depths incrementally for large BBs. 2017-09-20 11:54:37 +00:00
MachineVerifier.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-09-11 23:00:48 +00:00
MacroFusion.cpp [CodeGen] Rename DEBUG_TYPE to match passnames 2017-07-11 22:08:28 +00:00
OptimizePHIs.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-09-11 23:00:48 +00:00
PHIElimination.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-09-11 23:00:48 +00:00
PHIEliminationUtils.cpp
PHIEliminationUtils.h
ParallelCG.cpp
PatchableFunction.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
PeepholeOptimizer.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-09-11 23:00:48 +00:00
PostRAHazardRecognizer.cpp fix typos in comments and error messges; NFC 2017-07-13 06:48:39 +00:00
PostRASchedulerList.cpp ScheduleDAGInstrs: Fix fixupKills() 2017-05-27 02:50:50 +00:00
PreISelIntrinsicLowering.cpp [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-09-13 21:15:20 +00:00
ProcessImplicitDefs.cpp CodeGen: Rename DEBUG_TYPE to match passnames 2017-05-25 21:26:32 +00:00
PrologEpilogInserter.cpp Retire the llvm.dbg.mir hack after r311594. 2017-08-23 22:02:36 +00:00
PseudoSourceValue.cpp Add AddresSpace to PseudoSourceValue. 2017-09-14 20:53:51 +00:00
README.txt
RegAllocBase.cpp [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-09-13 21:15:20 +00:00
RegAllocBase.h [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-09-13 21:15:20 +00:00
RegAllocBasic.cpp Recommit "[RegAlloc] Make sure live-ranges reflect the state of the IR when 2017-09-15 07:47:38 +00:00
RegAllocFast.cpp [DebugInfo] Add missing DW_OP_deref when an NRVO pointer is spilled 2017-09-15 21:49:56 +00:00
RegAllocGreedy.cpp Recommit "[RegAlloc] Make sure live-ranges reflect the state of the IR when 2017-09-15 07:47:38 +00:00
RegAllocPBQP.cpp Remove unneeded use of #undef DEBUG_TYPE. NFC 2017-07-12 20:49:21 +00:00
RegUsageInfoCollector.cpp IPRA: Don't crash on null getCallPreservedMask 2017-08-05 07:50:18 +00:00
RegUsageInfoPropagate.cpp IPRA: Don't assume called function is first call operand 2017-08-24 07:55:15 +00:00
RegisterClassInfo.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
RegisterCoalescer.cpp Fix typo 2017-09-11 15:23:22 +00:00
RegisterCoalescer.h
RegisterPressure.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
RegisterScavenging.cpp [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-09-13 21:15:20 +00:00
RegisterUsageInfo.cpp Fix typos 2017-06-19 21:54:25 +00:00
RenameIndependentSubregs.cpp RenameIndependentSubregs: Fix infinite loop 2017-06-27 18:28:10 +00:00
ResetMachineFunctionPass.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
SafeStack.cpp [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-09-13 21:15:20 +00:00
SafeStackColoring.cpp [safestack] Disable stack coloring by default. 2017-05-19 20:58:48 +00:00
SafeStackColoring.h
SafeStackLayout.cpp
SafeStackLayout.h
ScalarizeMaskedMemIntrin.cpp Sink some IntrinsicInst.h and Intrinsics.h out of llvm/include 2017-09-07 23:27:44 +00:00
ScheduleDAG.cpp [CodeGen] Add dependency printer 2017-07-12 15:30:59 +00:00
ScheduleDAGInstrs.cpp Fix typo. 2017-08-03 22:41:12 +00:00
ScheduleDAGPrinter.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
ScoreboardHazardRecognizer.cpp [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-02-22 22:32:51 +00:00
ShadowStackGCLowering.cpp [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-09-13 21:15:20 +00:00
ShrinkWrap.cpp CodeGen: Rename DEBUG_TYPE to match passnames 2017-05-25 21:26:32 +00:00
SjLjEHPrepare.cpp [SjLj] Replace recursive block marking algorithm with iterative algorithm 2017-07-12 23:05:15 +00:00
SlotIndexes.cpp CodeGen: Rename DEBUG_TYPE to match passnames 2017-05-25 21:26:32 +00:00
SpillPlacement.cpp [CodeGen] Fix some Clang-tidy modernize-use-bool-literals and Include What You Use warnings; other minor fixes (NFC). 2017-09-21 23:20:16 +00:00
SpillPlacement.h [CodeGen] Fix some Clang-tidy modernize-use-bool-literals and Include What You Use warnings; other minor fixes (NFC). 2017-09-21 23:20:16 +00:00
Spiller.h [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-29 22:32:07 +00:00
SplitKit.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-29 22:32:07 +00:00
SplitKit.h [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-08-29 22:32:07 +00:00
StackColoring.cpp [StackColoring] Update AliasAnalysis information in stack coloring pass (part 2) 2017-08-02 18:16:32 +00:00
StackMapLivenessAnalysis.cpp LivePhysReg: Use reference instead of pointer in init(); NFC 2016-12-08 00:15:51 +00:00
StackMaps.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
StackProtector.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-06-07 23:53:32 +00:00
StackSlotColoring.cpp [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-09-13 21:15:20 +00:00
TailDuplication.cpp Add test case for r311511 2017-08-23 03:17:59 +00:00
TailDuplicator.cpp Add test case for r311511 2017-08-23 03:17:59 +00:00
TargetFrameLoweringImpl.cpp [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC). 2017-06-06 22:22:41 +00:00
TargetInstrInfo.cpp TargetInstrInfo: Change duplicate() to work on bundles. 2017-08-22 23:56:30 +00:00
TargetLoweringBase.cpp [CodeGen] Fix some Clang-tidy modernize-use-bool-literals and Include What You Use warnings; other minor fixes (NFC). 2017-09-21 23:20:16 +00:00
TargetLoweringObjectFileImpl.cpp [WebAssembly] MC: Create wasm data segments based on MCSections 2017-09-15 20:54:59 +00:00
TargetOptionsImpl.cpp Sort the remaining #include lines in include/... and lib/.... 2017-06-06 11:49:48 +00:00
TargetPassConfig.cpp Update branch coalescing to be a PowerPC specific pass 2017-09-12 18:39:11 +00:00
TargetRegisterInfo.cpp TableGen support for parameterized register class information 2017-09-14 16:56:21 +00:00
TargetSchedule.cpp This patch returns proper value to indicate the case when instruction throughput can't be calculated. 2017-07-26 18:55:14 +00:00
TargetSubtargetInfo.cpp Support itineraries in TargetSubtargetInfo::getSchedInfoStr - Now if the given instr does not have sched model then we try to calculate the latecy/throughput with help of itineraries. 2017-08-01 09:15:43 +00:00
TwoAddressInstructionPass.cpp Remove redundant copy in recurrences 2017-06-29 23:11:24 +00:00
UnreachableBlockElim.cpp [UnreachableBlockElim] Check return value of constrainRegClass(). 2017-05-10 06:33:43 +00:00
VirtRegMap.cpp [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC). 2017-09-13 21:15:20 +00:00
WinEHPrepare.cpp Guard print() functions only used by dump() functions. 2017-07-31 10:07:49 +00:00
XRayInstrumentation.cpp [XRay][CodeGen][PowerPC] Fix tail exit codegen for XRay in PPC 2017-09-08 01:47:56 +00:00

README.txt

//===---------------------------------------------------------------------===//

Common register allocation / spilling problem:

        mul lr, r4, lr
        str lr, [sp, #+52]
        ldr lr, [r1, #+32]
        sxth r3, r3
        ldr r4, [sp, #+52]
        mla r4, r3, lr, r4

can be:

        mul lr, r4, lr
        mov r4, lr
        str lr, [sp, #+52]
        ldr lr, [r1, #+32]
        sxth r3, r3
        mla r4, r3, lr, r4

and then "merge" mul and mov:

        mul r4, r4, lr
        str r4, [sp, #+52]
        ldr lr, [r1, #+32]
        sxth r3, r3
        mla r4, r3, lr, r4

It also increase the likelihood the store may become dead.

//===---------------------------------------------------------------------===//

bb27 ...
        ...
        %reg1037 = ADDri %reg1039, 1
        %reg1038 = ADDrs %reg1032, %reg1039, %NOREG, 10
    Successors according to CFG: 0x8b03bf0 (#5)

bb76 (0x8b03bf0, LLVM BB @0x8b032d0, ID#5):
    Predecessors according to CFG: 0x8b0c5f0 (#3) 0x8b0a7c0 (#4)
        %reg1039 = PHI %reg1070, mbb<bb76.outer,0x8b0c5f0>, %reg1037, mbb<bb27,0x8b0a7c0>

Note ADDri is not a two-address instruction. However, its result %reg1037 is an
operand of the PHI node in bb76 and its operand %reg1039 is the result of the
PHI node. We should treat it as a two-address code and make sure the ADDri is
scheduled after any node that reads %reg1039.

//===---------------------------------------------------------------------===//

Use local info (i.e. register scavenger) to assign it a free register to allow
reuse:
        ldr r3, [sp, #+4]
        add r3, r3, #3
        ldr r2, [sp, #+8]
        add r2, r2, #2
        ldr r1, [sp, #+4]  <==
        add r1, r1, #1
        ldr r0, [sp, #+4]
        add r0, r0, #2

//===---------------------------------------------------------------------===//

LLVM aggressively lift CSE out of loop. Sometimes this can be negative side-
effects:

R1 = X + 4
R2 = X + 7
R3 = X + 15

loop:
load [i + R1]
...
load [i + R2]
...
load [i + R3]

Suppose there is high register pressure, R1, R2, R3, can be spilled. We need
to implement proper re-materialization to handle this:

R1 = X + 4
R2 = X + 7
R3 = X + 15

loop:
R1 = X + 4  @ re-materialized
load [i + R1]
...
R2 = X + 7 @ re-materialized
load [i + R2]
...
R3 = X + 15 @ re-materialized
load [i + R3]

Furthermore, with re-association, we can enable sharing:

R1 = X + 4
R2 = X + 7
R3 = X + 15

loop:
T = i + X
load [T + 4]
...
load [T + 7]
...
load [T + 15]
//===---------------------------------------------------------------------===//

It's not always a good idea to choose rematerialization over spilling. If all
the load / store instructions would be folded then spilling is cheaper because
it won't require new live intervals / registers. See 2003-05-31-LongShifts for
an example.

//===---------------------------------------------------------------------===//

With a copying garbage collector, derived pointers must not be retained across
collector safe points; the collector could move the objects and invalidate the
derived pointer. This is bad enough in the first place, but safe points can
crop up unpredictably. Consider:

        %array = load { i32, [0 x %obj] }** %array_addr
        %nth_el = getelementptr { i32, [0 x %obj] }* %array, i32 0, i32 %n
        %old = load %obj** %nth_el
        %z = div i64 %x, %y
        store %obj* %new, %obj** %nth_el

If the i64 division is lowered to a libcall, then a safe point will (must)
appear for the call site. If a collection occurs, %array and %nth_el no longer
point into the correct object.

The fix for this is to copy address calculations so that dependent pointers
are never live across safe point boundaries. But the loads cannot be copied
like this if there was an intervening store, so may be hard to get right.

Only a concurrent mutator can trigger a collection at the libcall safe point.
So single-threaded programs do not have this requirement, even with a copying
collector. Still, LLVM optimizations would probably undo a front-end's careful
work.

//===---------------------------------------------------------------------===//

The ocaml frametable structure supports liveness information. It would be good
to support it.

//===---------------------------------------------------------------------===//

The FIXME in ComputeCommonTailLength in BranchFolding.cpp needs to be
revisited. The check is there to work around a misuse of directives in inline
assembly.

//===---------------------------------------------------------------------===//

It would be good to detect collector/target compatibility instead of silently
doing the wrong thing.

//===---------------------------------------------------------------------===//

It would be really nice to be able to write patterns in .td files for copies,
which would eliminate a bunch of explicit predicates on them (e.g. no side 
effects).  Once this is in place, it would be even better to have tblgen 
synthesize the various copy insertion/inspection methods in TargetInstrInfo.

//===---------------------------------------------------------------------===//

Stack coloring improvements:

1. Do proper LiveStackAnalysis on all stack objects including those which are
   not spill slots.
2. Reorder objects to fill in gaps between objects.
   e.g. 4, 1, <gap>, 4, 1, 1, 1, <gap>, 4 => 4, 1, 1, 1, 1, 4, 4

//===---------------------------------------------------------------------===//

The scheduler should be able to sort nearby instructions by their address. For
example, in an expanded memset sequence it's not uncommon to see code like this:

  movl $0, 4(%rdi)
  movl $0, 8(%rdi)
  movl $0, 12(%rdi)
  movl $0, 0(%rdi)

Each of the stores is independent, and the scheduler is currently making an
arbitrary decision about the order.

//===---------------------------------------------------------------------===//

Another opportunitiy in this code is that the $0 could be moved to a register:

  movl $0, 4(%rdi)
  movl $0, 8(%rdi)
  movl $0, 12(%rdi)
  movl $0, 0(%rdi)

This would save substantial code size, especially for longer sequences like
this. It would be easy to have a rule telling isel to avoid matching MOV32mi
if the immediate has more than some fixed number of uses. It's more involved
to teach the register allocator how to do late folding to recover from
excessive register pressure.