llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-12-14 11:32:34 +00:00

History

Tom Roeder 5d0f7af3dc Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute. It includes a pass that rewrites all indirect calls to jumptable functions to pass through these tables. This also adds backend support for generating the jump-instruction tables on ARM and X86. Note that since the jumptable attribute creates a second function pointer for a function, any function marked with jumptable must also be marked with unnamed_addr. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@210280 91177308-0d34-0410-b5e6-96231b3b80d8		2014-06-05 19:29:43 +00:00
..
IPA	Check the alwaysinline attribute on the call as well as on the caller.	2014-05-19 18:25:54 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp	Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute.	2014-06-05 19:29:43 +00:00
BasicAliasAnalysis.cpp
BlockFrequencyInfo.cpp
BlockFrequencyInfoImpl.cpp
BranchProbabilityInfo.cpp
CaptureTracking.cpp
CFG.cpp
CFGPrinter.cpp	Clean up language and grammar.	2014-05-20 17:11:11 +00:00
CGSCCPassManager.cpp
CMakeLists.txt	Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute.	2014-06-05 19:29:43 +00:00
CodeMetrics.cpp
ConstantFolding.cpp	Add a Constant version of stripPointerCasts.	2014-06-04 19:01:48 +00:00
CostModel.cpp
Delinearization.cpp	remove BasePointer before delinearizing	2014-05-27 22:41:51 +00:00
DependenceAnalysis.cpp	remove BasePointer before delinearizing	2014-05-27 22:41:51 +00:00
DominanceFrontier.cpp
DomPrinter.cpp
InstCount.cpp
InstructionSimplify.cpp	InstSimplify: Improve handling of ashr/lshr	2014-05-16 17:14:03 +00:00
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp
JumpInstrTableInfo.cpp	Add a new attribute called 'jumptable' that creates jump-instruction tables for functions marked with this attribute.	2014-06-05 19:29:43 +00:00
LazyCallGraph.cpp	Fix typos	2014-05-15 01:52:21 +00:00
LazyValueInfo.cpp
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp	Rename ComputeMaskedBits to computeKnownBits. "Masked" has been	2014-05-14 21:14:37 +00:00
LLVMBuild.txt
Loads.cpp
LoopInfo.cpp
LoopPass.cpp	Add C API for thread yielding callback.	2014-05-16 02:33:15 +00:00
Makefile
MemDepPrinter.cpp
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp
ModuleDebugInfoPrinter.cpp
NoAliasAnalysis.cpp
PHITransAddr.cpp
PostDominators.cpp
PtrUseVisitor.cpp
README.txt
RegionInfo.cpp
RegionPass.cpp
RegionPrinter.cpp
ScalarEvolution.cpp	implement missing SCEVDivision case	2014-05-29 19:44:09 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp	test check-in: added missing parenthesis in comment	2014-05-28 19:03:33 +00:00
SparsePropagation.cpp
TargetTransformInfo.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	Teach isKnownNonNull that a nonnull return is not null. Add a test for this case as well as the case of a nonnull attribute (already handled but not tested).	2014-05-20 05:13:21 +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))

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