llvm-6502

mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-01-23 17:32:49 +00:00

History

Duncan Sands c087e20331 Turn X-(X-Y) into Y. According to my auto-simplifier this is the most common

simplification present in fully optimized code (I think instcombine fails to
transform some of these when "X-Y" has more than one use).  Fires here and
there all over the test-suite, for example it eliminates 8 subtractions in
the final IR for 445.gobmk, 2 subs in 447.dealII, 2 in paq8p etc.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123442 91177308-0d34-0410-b5e6-96231b3b80d8

2011-01-14 15:26:10 +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

…

AliasAnalysisEvaluator.cpp

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AliasDebugger.cpp

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AliasSetTracker.cpp

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Analysis.cpp

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BasicAliasAnalysis.cpp

fix rdar://8813415 - a miscompilation of 164.gzip that loop-idiom

2011-01-03 21:03:33 +00:00

CaptureTracking.cpp

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CFGPrinter.cpp

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CMakeLists.txt

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ConstantFolding.cpp

Teach constant folding to perform conversions from constant floating

2011-01-11 01:07:24 +00:00

DbgInfoPrinter.cpp

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DebugInfo.cpp

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DIBuilder.cpp

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DomPrinter.cpp

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

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

InlineCost.cpp

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InstCount.cpp

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InstructionSimplify.cpp

Turn X-(X-Y) into Y. According to my auto-simplifier this is the most common

2011-01-14 15:26:10 +00:00

Interval.cpp

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IntervalPartition.cpp

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IVUsers.cpp

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

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

LazyValueInfo.cpp

Reorder, rename, and document some members to make this easier to follow.

2011-01-05 23:26:22 +00:00

LibCallAliasAnalysis.cpp

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LibCallSemantics.cpp

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Lint.cpp

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LiveValues.cpp

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

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

Loads.cpp

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LoopDependenceAnalysis.cpp

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

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

LoopInfo.cpp

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LoopPass.cpp

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Makefile

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MemDepPrinter.cpp

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MemoryBuiltins.cpp

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MemoryDependenceAnalysis.cpp

Revert r123207: "Turn on memdep's verifyRemoved() in an attempt to smoke out the cause of our gcc bootstrap miscompare."

2011-01-11 04:05:39 +00:00

ModuleDebugInfoPrinter.cpp

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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

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ProfileInfo.cpp

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ProfileInfoLoader.cpp

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ProfileInfoLoaderPass.cpp

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ProfileVerifierPass.cpp

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README.txt

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RegionInfo.cpp

Add single entry / single exit accessors.

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

RegionPass.cpp

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RegionPrinter.cpp

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ScalarEvolution.cpp

some comment improvements.

2011-01-11 17:11:59 +00:00

ScalarEvolutionAliasAnalysis.cpp

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ScalarEvolutionExpander.cpp

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ScalarEvolutionNormalization.cpp

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SparsePropagation.cpp

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Trace.cpp

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TypeBasedAliasAnalysis.cpp

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ValueTracking.cpp

fix an off-by-one bug that caused a crash analyzing

2011-01-04 18:19:15 +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))

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