llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2024-11-09 10:05:41 +00:00

History

Dan Gohman 8a757aeac4 Revert r111199; it breaks -debug-pass=Structure output. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111500 91177308-0d34-0410-b5e6-96231b3b80d8		2010-08-19 01:29:07 +00:00
..
IPA	Revert r111199; it breaks -debug-pass=Structure output.	2010-08-19 01:29:07 +00:00
AliasAnalysis.cpp
AliasAnalysisCounter.cpp
AliasAnalysisEvaluator.cpp
AliasDebugger.cpp
AliasSetTracker.cpp
Analysis.cpp
BasicAliasAnalysis.cpp	refix PR1143 by making basicaa analyze zexts of indices aggresively,	2010-08-18 23:09:49 +00:00
CaptureTracking.cpp
CFGPrinter.cpp
CMakeLists.txt
ConstantFolding.cpp
DbgInfoPrinter.cpp
DebugInfo.cpp	Even if a variable has constant value all the time, it is still a variable in gdb's eyes.	2010-08-11 23:17:54 +00:00
DomPrinter.cpp
InlineCost.cpp
InstCount.cpp	Revert r111082. No warnings for this common pattern.	2010-08-15 10:27:23 +00:00
InstructionSimplify.cpp
Interval.cpp
IntervalPartition.cpp
IVUsers.cpp	Tweak IVUsers' concept of "interesting" to exclude add recurrences	2010-08-17 22:50:37 +00:00
LazyValueInfo.cpp	Use ConstantRange to propagate information through value definitions.	2010-08-18 21:11:37 +00:00
LibCallAliasAnalysis.cpp
LibCallSemantics.cpp
Lint.cpp	Revert r111058, the lint check for indirectbr successors that aren't	2010-08-16 14:39:19 +00:00
LiveValues.cpp
Loads.cpp
LoopDependenceAnalysis.cpp
LoopInfo.cpp
LoopPass.cpp	Revert r111199; it breaks -debug-pass=Structure output.	2010-08-19 01:29:07 +00:00
Makefile
MemoryBuiltins.cpp
MemoryDependenceAnalysis.cpp
ModuleDebugInfoPrinter.cpp
PHITransAddr.cpp
PointerTracking.cpp
PostDominators.cpp
ProfileEstimatorPass.cpp
ProfileInfo.cpp
ProfileInfoLoader.cpp
ProfileInfoLoaderPass.cpp
ProfileVerifierPass.cpp
README.txt
RegionInfo.cpp	RegionInfo: Do not assert if a BB is not part of the dominance tree.	2010-08-10 09:54:35 +00:00
RegionPrinter.cpp
ScalarEvolution.cpp	To create a copy of a SmallVector with an element removed from the	2010-08-16 16:57:24 +00:00
ScalarEvolutionAliasAnalysis.cpp
ScalarEvolutionExpander.cpp
ScalarEvolutionNormalization.cpp
SparsePropagation.cpp
Trace.cpp
TypeBasedAliasAnalysis.cpp
ValueTracking.cpp	move gep decomposition out of ValueTracking into BasicAA. The form of	2010-08-18 22:07:29 +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))

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