llvm/Analysis at 4d4bbaf997c16f9e79503bd640306d784efd090e - llvm

RPCS3/llvm

mirror of https://github.com/RPCS3/llvm.git synced 2025-01-25 20:14:26 +00:00

History

Andrew Trick 4d4bbaf997 Fix SCEVExpander: don't try to expand quadratic recurrences outside a loop.

Partial fix for PR17459: wrong code at -O3 on x86_64-linux-gnu
(affecting trunk and 3.3)

When SCEV expands a recurrence outside of a loop it attempts to scale
by the stride of the recurrence. Chained recurrences don't work that
way. We could compute binomial coefficients, but would hve to
guarantee that the chained AddRec's are in a perfectly reduced form.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193438 91177308-0d34-0410-b5e6-96231b3b80d8

2013-10-25 21:35:56 +00:00

IPA

Call destroy from ~BasicCallGraph.

2013-10-25 15:01:34 +00:00

AliasAnalysis.cpp

Reimplement isPotentiallyReachable to make nocapture deduction much stronger.

2013-07-27 01:24:00 +00:00

AliasAnalysisCounter.cpp

…

AliasAnalysisEvaluator.cpp

…

AliasDebugger.cpp

…

AliasSetTracker.cpp

In AliasSetTracker, do not change the alias set to "mod/ref" when adding

2013-09-12 20:15:50 +00:00

Analysis.cpp

Remove the very substantial, largely unmaintained legacy PGO

2013-10-02 15:42:23 +00:00

BasicAliasAnalysis.cpp

Use address-taken to disambiguate global variable and indirect memops.

2013-10-23 17:28:19 +00:00

BlockFrequencyInfo.cpp

…

BranchProbabilityInfo.cpp

Use SmallVectorImpl::iterator/const_iterator instead of SmallVector to avoid specifying the vector size.

2013-07-04 01:31:24 +00:00

CaptureTracking.cpp

CaptureTracking: Plug a loophole in the "too many uses" heuristic.

2013-10-03 13:24:02 +00:00

CFG.cpp

Add some constantness.

2013-08-20 23:04:15 +00:00

CFGPrinter.cpp

…

CMakeLists.txt

Remove the very substantial, largely unmaintained legacy PGO

2013-10-02 15:42:23 +00:00

CodeMetrics.cpp

…

ConstantFolding.cpp

Fix a constant folding address space place I missed.

2013-09-17 23:23:16 +00:00

CostModel.cpp

Move variable into assert to avoid unused variable warning.

2013-09-17 21:13:57 +00:00

DependenceAnalysis.cpp

Remove extraneous semicolon.

2013-08-06 16:40:40 +00:00

DominanceFrontier.cpp

…

DomPrinter.cpp

…

InstCount.cpp

…

InstructionSimplify.cpp

Teach MemoryBuiltins and InstructionSimplify that operator new never returns NULL.

2013-09-24 16:37:51 +00:00

Interval.cpp

…

IntervalPartition.cpp

…

IVUsers.cpp

…

LazyValueInfo.cpp

Use SmallVectorImpl::iterator/const_iterator instead of SmallVector to avoid specifying the vector size.

2013-07-04 01:31:24 +00:00

LibCallAliasAnalysis.cpp

…

LibCallSemantics.cpp

…

Lint.cpp

Fix lint assert on integer vector division

2013-08-26 23:29:33 +00:00

LLVMBuild.txt

…

Loads.cpp

…

LoopInfo.cpp

Add 'const' qualifiers to static const char* variables.

2013-07-16 01:17:10 +00:00

LoopPass.cpp

Comment: try to clarify loop iteration order.

2013-07-20 23:10:31 +00:00

Makefile

…

MemDepPrinter.cpp

…

MemoryBuiltins.cpp

fix PR17635: false positive with packed structures

2013-10-24 09:17:24 +00:00

MemoryDependenceAnalysis.cpp

…

ModuleDebugInfoPrinter.cpp

…

NoAliasAnalysis.cpp

…

PHITransAddr.cpp

…

PostDominators.cpp

…

PtrUseVisitor.cpp

…

README.txt

…

RegionInfo.cpp

Reorder headers according to lint.

2013-08-21 21:14:19 +00:00

RegionPass.cpp

…

RegionPrinter.cpp

…

ScalarEvolution.cpp

Clarify SCEV comments.

2013-10-22 05:09:40 +00:00

ScalarEvolutionAliasAnalysis.cpp

…

ScalarEvolutionExpander.cpp

Fix SCEVExpander: don't try to expand quadratic recurrences outside a loop.

2013-10-25 21:35:56 +00:00

ScalarEvolutionNormalization.cpp

Fix LSR: don't normalize quadratic recurrences.

2013-10-25 21:35:52 +00:00

SparsePropagation.cpp

…

TargetTransformInfo.cpp

Costmodel: Add support for horizontal vector reductions

2013-09-17 18:06:50 +00:00

Trace.cpp

…

TypeBasedAliasAnalysis.cpp

TBAA: fix PR17620.

2013-10-22 01:40:25 +00:00

ValueTracking.cpp

Remove x86_sse42_crc32_64_8 intrinsic. It has no functional difference from x86_sse42_crc32_32_8 and was not mapped to a clang builtin. I'm not even sure why this form of the instruction is even called out explicitly in the docs. Also add AutoUpgrade support to convert it into the other intrinsic with appropriate trunc and zext.

2013-10-15 05:20:47 +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))

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