llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-02-22 13:29:44 +00:00

History

Duncan Sands 593faa53fa My auto-simplifier noticed that ((X/Y)*Y)/Y occurs several times in SPEC

benchmarks, and that it can be simplified to X/Y.  (In general you can only
simplify (Z*Y)/Y to Z if the multiplication did not overflow; if Z has the
form "X/Y" then this is the case).  This patch implements that transform and
moves some Div logic out of instcombine and into InstructionSimplify.
Unfortunately instcombine gets in the way somewhat, since it likes to change
(X/Y)*Y into X-(X rem Y), so I had to teach instcombine about this too.
Finally, thanks to the NSW/NUW flags, sometimes we know directly that "Z*Y"
does not overflow, because the flag says so, so I added that logic too.  This
eliminates a bunch of divisions and subtractions in 447.dealII, and has good
effects on some other benchmarks too.  It seems to have quite an effect on
tramp3d-v4 but it's hard to say if it's good or bad because inlining decisions
changed, resulting in massive changes all over.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124487 91177308-0d34-0410-b5e6-96231b3b80d8

2011-01-28 16:51:11 +00:00

IPA

Use the new addEscapingValue callback to update GlobalsModRef when GVN adds PHIs of GEPs. For the moment,

2011-01-03 23:51:43 +00:00

AliasAnalysis.cpp

Stub out a new updating interface to AliasAnalysis, allowing stateful analyses to be informed when

2011-01-03 21:38:41 +00:00

AliasAnalysisCounter.cpp

Teach AliasAnalysisCounter about PartialAlias.

2010-12-10 19:53:05 +00:00

AliasAnalysisEvaluator.cpp

Teach AliasAnalysisEvaluator about PartialAlias.

2010-12-10 19:52:40 +00:00

AliasDebugger.cpp

Extend the AliasAnalysis::pointsToConstantMemory interface to allow it

2010-11-08 16:45:26 +00:00

AliasSetTracker.cpp

Update this code to handle PartialAlias as MayAlias.

2010-12-10 19:40:47 +00:00

Analysis.cpp

Move DominanceFrontier from VMCore to Analysis.

2011-01-18 06:06:27 +00:00

BasicAliasAnalysis.cpp

Give GetUnderlyingObject a TargetData, to keep it in sync

2011-01-24 18:53:32 +00:00

CaptureTracking.cpp

VAArg doesn't capture its operand.

2010-11-09 20:09:35 +00:00

CFGPrinter.cpp

Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which

2010-10-19 17:21:58 +00:00

CMakeLists.txt

Move DominanceFrontier from VMCore to Analysis.

2011-01-18 06:06:27 +00:00

ConstantFolding.cpp

Give GetUnderlyingObject a TargetData, to keep it in sync

2011-01-24 18:53:32 +00:00

DbgInfoPrinter.cpp

Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which

2010-10-19 17:21:58 +00:00

DebugInfo.cpp

Add support to create class type.

2010-12-08 20:18:20 +00:00

DIBuilder.cpp

Use type's file info while describing inheritance relationship.

2010-12-08 21:46:37 +00:00

DominanceFrontier.cpp

Move DominanceFrontier from VMCore to Analysis.

2011-01-18 06:06:27 +00:00

DomPrinter.cpp

split dom frontier handling stuff out to its own DominanceFrontier header,

2011-01-02 22:09:33 +00:00

InlineCost.cpp

Temporarily revert 124275 to see if it brings the dragonegg buildbot back.

2011-01-26 19:40:31 +00:00

InstCount.cpp

Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which

2010-10-19 17:21:58 +00:00

InstructionSimplify.cpp

My auto-simplifier noticed that ((X/Y)*Y)/Y occurs several times in SPEC

2011-01-28 16:51:11 +00:00

Interval.cpp

Change Pass::print to take a raw ostream instead of std::ostream,

2009-08-23 06:03:38 +00:00

IntervalPartition.cpp

Now with fewer extraneous semicolons!

2010-10-07 22:25:06 +00:00

IVUsers.cpp

split dom frontier handling stuff out to its own DominanceFrontier header,

2011-01-02 22:09:33 +00:00

LazyValueInfo.cpp

Teach LazyValueInfo that allocas aren't NULL. Over all of llvm-test, this saves

2011-01-15 09:16:12 +00:00

LibCallAliasAnalysis.cpp

Now with fewer extraneous semicolons!

2010-10-07 22:25:06 +00:00

LibCallSemantics.cpp

Thread const correctness through a bunch of AliasAnalysis interfaces and

2010-08-03 21:48:53 +00:00

Lint.cpp

Give GetUnderlyingObject a TargetData, to keep it in sync

2011-01-24 18:53:32 +00:00

LiveValues.cpp

split dom frontier handling stuff out to its own DominanceFrontier header,

2011-01-02 22:09:33 +00:00

Loads.cpp

Move Value::getUnderlyingObject to be a standalone

2010-12-15 20:02:24 +00:00

LoopDependenceAnalysis.cpp

split dom frontier handling stuff out to its own DominanceFrontier header,

2011-01-02 22:09:33 +00:00

LoopInfo.cpp

Fix typo pointed out by Trevor Harmon.

2010-11-13 12:16:27 +00:00

LoopPass.cpp

zap dead code.

2010-09-04 18:12:00 +00:00

Makefile

make -fno-rtti the default unless a directory builds with REQUIRES_RTTI.

2010-01-24 20:43:08 +00:00

MemDepPrinter.cpp

Add helper functions for computing the Location of load, store,

2010-11-11 21:50:19 +00:00

MemoryBuiltins.cpp

minor enhancement to llvm::isFreeCall API: return CallInst; no functional change

2010-06-23 21:51:12 +00:00

MemoryDependenceAnalysis.cpp

Give GetUnderlyingObject a TargetData, to keep it in sync

2011-01-24 18:53:32 +00:00

ModuleDebugInfoPrinter.cpp

Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which

2010-10-19 17:21:58 +00:00

NoAliasAnalysis.cpp

Use the new addEscapingValue callback to update GlobalsModRef when GVN adds PHIs of GEPs. For the moment,

2011-01-03 23:51:43 +00:00

PHITransAddr.cpp

split dom frontier handling stuff out to its own DominanceFrontier header,

2011-01-02 22:09:33 +00:00

PostDominators.cpp

split dom frontier handling stuff out to its own DominanceFrontier header,

2011-01-02 22:09:33 +00:00

ProfileEstimatorPass.cpp

fix PR8928 by clearing a stale map, patch by Jakub Staszak!

2011-01-24 18:36:51 +00:00

ProfileInfo.cpp

Null initialize a few variables flagged by

2011-01-23 17:05:06 +00:00

ProfileInfoLoader.cpp

Reapplied r81355 with the problems fixed.

2009-09-16 11:35:50 +00:00

ProfileInfoLoaderPass.cpp

Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which

2010-10-19 17:21:58 +00:00

ProfileVerifierPass.cpp

Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which

2010-10-19 17:21:58 +00:00

README.txt

When checking whether the special handling for an addrec increment which

2010-04-26 21:46:36 +00:00

RegionInfo.cpp

Add single entry / single exit accessors.

2011-01-13 23:18:04 +00:00

RegionPass.cpp

Remove useless dynamic_cast<>().

2010-12-12 21:58:28 +00:00

RegionPrinter.cpp

Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which

2010-10-19 17:21:58 +00:00

ScalarEvolution.cpp

Fix memory corruption. If one of the SCEV creation functions calls another but

2011-01-26 08:40:22 +00:00

ScalarEvolutionAliasAnalysis.cpp

Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which

2010-10-19 17:21:58 +00:00

ScalarEvolutionExpander.cpp

Introduce memoization for ScalarEvolution dominates and properlyDominates

2010-11-18 00:34:22 +00:00

ScalarEvolutionNormalization.cpp

Disable the asserts that check that normalization is perfectly

2010-09-03 22:12:56 +00:00

SparsePropagation.cpp

Convert debug messages to use dbgs(). Generally this means

2009-12-23 22:28:01 +00:00

Trace.cpp

Convert debug messages to use dbgs(). Generally this means

2009-12-23 22:35:10 +00:00

TypeBasedAliasAnalysis.cpp

Update a comment.

2010-12-16 02:55:10 +00:00

ValueTracking.cpp

APInt has a method for determining whether a number is a power of 2

2011-01-26 08:44:16 +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))

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