llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-05 12:31:33 +00:00

History

Reid Kleckner 8f32e5f0d6 Rename llvm.frameescape and llvm.framerecover to localescape and localrecover Summary: Initially, these intrinsics seemed like part of a family of "frame" related intrinsics, but now I think that's more confusing than helpful. Initially, the LangRef specified that this would create a new kind of allocation that would be allocated at a fixed offset from the frame pointer (EBP/RBP). We ended up dropping that design, and leaving the stack frame layout alone. These intrinsics are really about sharing local stack allocations, not frame pointers. I intend to go further and add an `llvm.localaddress()` intrinsic that returns whatever register (EBP, ESI, ESP, RBX) is being used to address locals, which should not be confused with the frame pointer. Naming suggestions at this point are welcome, I'm happy to re-run sed. Reviewers: majnemer, nicholas Subscribers: llvm-commits Differential Revision: http://reviews.llvm.org/D11011 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@241633 91177308-0d34-0410-b5e6-96231b3b80d8		2015-07-07 22:25:32 +00:00
..
IPA	Rename llvm.frameescape and llvm.framerecover to localescape and localrecover	2015-07-07 22:25:32 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
AssumptionCache.cpp	[PM] Actually add the new pass manager support for the assumption cache.	2015-01-22 21:53:09 +00:00
BasicAliasAnalysis.cpp
BlockFrequencyInfo.cpp
BlockFrequencyInfoImpl.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp
CFLAliasAnalysis.cpp
CGSCCPassManager.cpp
CMakeLists.txt	Move VectorUtils from Transforms to Analysis to correct layering violation	2015-06-26 18:02:52 +00:00
CodeMetrics.cpp
ConstantFolding.cpp
CostModel.cpp
Delinearization.cpp	Move delinearization from SCEVAddRecExpr to ScalarEvolution	2015-06-29 14:42:48 +00:00
DependenceAnalysis.cpp	Move delinearization from SCEVAddRecExpr to ScalarEvolution	2015-06-29 14:42:48 +00:00
DivergenceAnalysis.cpp
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IteratedDominanceFrontier.cpp
IVUsers.cpp
LazyCallGraph.cpp
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp
LLVMBuild.txt
Loads.cpp
LoopAccessAnalysis.cpp	Move VectorUtils from Transforms to Analysis to correct layering violation	2015-06-26 18:02:52 +00:00
LoopInfo.cpp
LoopPass.cpp
Makefile
MemDepPrinter.cpp
MemDerefPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp
MemoryLocation.cpp
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	Move delinearization from SCEVAddRecExpr to ScalarEvolution	2015-06-29 14:42:48 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp
ScopedNoAliasAA.cpp
SparsePropagation.cpp
StratifiedSets.h
TargetLibraryInfo.cpp
TargetTransformInfo.cpp	Add a routine to TargetTransformInfo that will allow targets to look	2015-07-02 01:11:47 +00:00
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	IR: Do not consider available_externally linkage to be linker-weak.	2015-07-05 20:52:35 +00:00
VectorUtils.cpp	Move VectorUtils from Transforms to Analysis to correct layering violation	2015-06-26 18:02:52 +00:00

README.txt

Analysis Opportunities:

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

In test/Transforms/LoopStrengthReduce/quadradic-exit-value.ll, the
ScalarEvolution expression for %r is this:

  {1,+,3,+,2}<loop>

Outside the loop, this could be evaluated simply as (%n * %n), however
ScalarEvolution currently evaluates it as

  (-2 + (2 * (trunc i65 (((zext i64 (-2 + %n) to i65) * (zext i64 (-1 + %n) to i65)) /u 2) to i64)) + (3 * %n))

In addition to being much more complicated, it involves i65 arithmetic,
which is very inefficient when expanded into code.

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

In formatValue in test/CodeGen/X86/lsr-delayed-fold.ll,

ScalarEvolution is forming this expression:

((trunc i64 (-1 * %arg5) to i32) + (trunc i64 %arg5 to i32) + (-1 * (trunc i64 undef to i32)))

This could be folded to

(-1 * (trunc i64 undef to i32))

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