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llvm-project/llvm/test/Transforms
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Nick Lewycky 762f8a8549 Add optimization for 'icmp slt (or A, B), A' and some related idioms based on knowledge of the sign bit for A and B. 
No matter what value you OR in to A, the result of (or A, B) is going to be UGE A. When A and B are positive, it's SGE too. If A is negative, OR'ing a value into it can't make it positive, but can increase its value closer to -1, therefore (or A, B) is SGE A. Working through all possible combinations produces this truth table:

```
A is
+, -, +/-
F  F   F   +    B is
T  F   ?   -
?  F   ?   +/-
```

The related optimizations are flipping the 'slt' for 'sge' which always NOTs the result (if the result is known), and swapping the LHS and RHS while swapping the comparison predicate.

There are more idioms left to implement (aren't there always!) but I've stopped here because any more would risk becoming unreasonable for reviewers.

llvm-svn: 266939
 		2016-04-21 00:53:14 +00:00
..
ADCE [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
AddDiscriminators [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
AlignmentFromAssumptions Revert "Change memcpy/memset/memmove to have dest and source alignments." 2015-11-19 05:56:52 +00:00
ArgumentPromotion [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
AtomicExpand ARM: use a pseudo-instruction for cmpxchg at -O0. 2016-04-18 21:48:55 +00:00
BBVectorize Have a single way for creating unique value names. 2015-11-22 00:16:24 +00:00
BDCE
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BranchFolding Move branch folding test to a better location. 2015-12-03 19:41:25 +00:00
CodeExtractor
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CodeGenPrepare [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
ConstProp IR: Make ConstantDataArray::getFP actually return a ConstantDataArray 2015-12-09 21:21:07 +00:00
ConstantHoisting ARM: don't try to hoist constant RHS out of a division. 2016-04-15 18:17:18 +00:00
ConstantMerge [opaque pointer type] Add textual IR support for explicit type parameter for global aliases 2015-09-11 03:22:04 +00:00
CorrelatedValuePropagation [CVP] Convert an SDiv to a UDiv if both operands are known to be nonnegative 2016-03-14 03:24:28 +00:00
CrossDSOCFI [cfi] Cross-DSO CFI diagnostic mode (LLVM part). 2016-01-25 23:35:03 +00:00
DeadArgElim [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
DeadStoreElimination [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
EarlyCSE Fix several accidental DOS line endings in source files 2016-01-03 17:22:03 +00:00
EliminateAvailableExternally
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Float2Int [Float2Int] Don't operate on vector instructions 2015-12-09 21:08:18 +00:00
ForcedFunctionAttrs [attrs] Split off the forced attributes utility into its own pass that 2015-12-27 08:13:45 +00:00
FunctionAttrs Don't IPO over functions that can be de-refined 2016-04-08 00:48:30 +00:00
FunctionImport [ThinLTO] Prevent importing of "llvm.used" values 2016-04-20 14:39:45 +00:00
GCOVProfiling [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
GVN [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
GlobalDCE [opaque pointer type] Add textual IR support for explicit type parameter for global aliases 2015-09-11 03:22:04 +00:00
GlobalOpt [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
IPConstantProp Don't IPO over functions that can be de-refined 2016-04-08 00:48:30 +00:00
IRCE [SCEV] Try to reuse existing value during SCEV expansion 2016-02-04 01:27:38 +00:00
IndVarSimplify [LLVM] Remove unwanted --check-prefix=CHECK from unit tests. NFC. 2016-04-19 23:51:52 +00:00
InferFunctionAttrs [NVPTX] Infer __nvvm_reflect as nounwind, readnone 2016-03-31 21:29:57 +00:00
Inline Revert "Replace the use of MaxFunctionCount module flag" 2016-04-18 15:31:11 +00:00
InstCombine [InstCombine][X86] Added extra tests introduced for D17490 2016-04-19 12:59:52 +00:00
InstMerge fixed typo - CHECK-LABEL 2016-03-29 06:49:38 +00:00
InstSimplify Add optimization for 'icmp slt (or A, B), A' and some related idioms based on knowledge of the sign bit for A and B. 2016-04-21 00:53:14 +00:00
Internalize [opaque pointer type] Add textual IR support for explicit type parameter for global aliases 2015-09-11 03:22:04 +00:00
JumpThreading [ValueTracking] Improve isImpliedCondition for conditions with matching operands. 2016-04-19 17:19:14 +00:00
LCSSA [WinEH] Update LCSSA to handle catchswitch with handlers inside and outside a loop 2015-12-18 18:12:35 +00:00
LICM [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
LoadCombine
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LoopDataPrefetch [LoopDataPrefetch] Centralize the tuning cl::opts under the pass 2016-03-29 23:45:52 +00:00
LoopDeletion
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LoopDistribute Allow LLE/LD and the loop versioning infrastructure to use SCEV predicates 2015-11-09 13:26:09 +00:00
LoopIdiom [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
LoopInterchange
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LoopLoadElim [LLE] Check for mismatching types between the store and the load earlier 2016-03-24 17:59:26 +00:00
LoopReroll [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
LoopRotate [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
LoopSimplify [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
LoopSimplifyCFG Add LoopSimplifyCFG pass 2016-01-29 22:35:36 +00:00
LoopStrengthReduce Don't delete empty preheaders in CodeGenPrepare if it would create a critical edge 2016-04-05 14:06:20 +00:00
LoopUnroll [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
LoopUnswitch [SimlifyCFG] Prevent passes from destroying canonical loop structure, especially for nested loops 2016-03-29 04:08:57 +00:00
LoopVectorize [ARM] AArch32 v8 NEON is still not IEEE-754 compliant 2016-04-18 12:06:47 +00:00
LoopVersioning [LVers] Change CHECK_LABEL to CHECK-LABEL (underscore->dash) 2016-03-28 21:04:13 +00:00
LoopVersioningLICM Corrected tests for Loop Versioning LICM, by adding “REQUIRES: asserts”. 2016-02-06 12:34:41 +00:00
LowerAtomic
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LowerBitSets [cfi] Support explicit sections for functions in cfi-icall. 2016-04-15 22:55:38 +00:00
LowerExpectIntrinsic [PM] Port StripDeadPrototypes to the new pass manager 2015-10-30 23:28:12 +00:00
LowerGuardIntrinsic Introduce a @llvm.experimental.guard intrinsic 2016-03-31 00:18:46 +00:00
LowerInvoke
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LowerSwitch Have a single way for creating unique value names. 2015-11-22 00:16:24 +00:00
Mem2Reg [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
MemCpyOpt Imporove load to store => memcpy 2016-03-14 22:52:27 +00:00
MergeFunc MergeFunctions: test alloca better 2016-04-12 00:03:26 +00:00
MetaRenamer Revert "Change memcpy/memset/memmove to have dest and source alignments." 2015-11-19 05:56:52 +00:00
NameAnonFunctions Add a pass to name anonymous/nameless function 2016-04-12 21:35:28 +00:00
NaryReassociate [NaryReassociate] allow candidate to have a different type 2015-12-18 21:36:30 +00:00
ObjCARC [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
PGOProfile [test/PGOProfile] Make tests independent of the raw profile version (NFC) 2016-04-20 22:24:01 +00:00
PartiallyInlineLibCalls
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PhaseOrdering
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PlaceSafepoints [PlaceSafepoints] Clamp NoStatepoints to true 2016-01-28 21:51:14 +00:00
PruneEH [PruneEH] Don't try to insert a terminator after another terminator 2016-01-23 06:00:44 +00:00
Reassociate Reassociate: Reprocess RedoInsts after each inst 2016-01-26 18:42:36 +00:00
Reg2Mem
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RewriteStatepointsForGC [RS4GC] Better codegen for deoptimize calls 2016-04-05 23:18:35 +00:00
SCCP Don't IPO over functions that can be de-refined 2016-04-08 00:48:30 +00:00
SLPVectorizer [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
SROA [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
SafeStack [AArch64] [ARM] Make a target-independent llvm.thread.pointer intrinsic. 2016-04-19 20:51:05 +00:00
SampleProfile [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
ScalarRepl [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
Scalarizer [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
SeparateConstOffsetFromGEP [ValueTracking] Remove dead code from an old experiment 2016-03-03 19:44:06 +00:00
SimplifyCFG [LLVM] Remove unwanted --check-prefix=CHECK from unit tests. NFC. 2016-04-19 23:51:52 +00:00
Sink [IR] Reformulate LLVM's EH funclet IR 2015-12-12 05:38:55 +00:00
SpeculativeExecution Move divergent-target test into CodeGen/NVPTX because it requires an NVPTX target. 2016-04-15 01:20:52 +00:00
StraightLineStrengthReduce
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StripDeadPrototypes [PM] Port StripDeadPrototypes to the new pass manager 2015-10-30 23:28:12 +00:00
StripSymbols [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
StructurizeCFG AMDGPU: Remove leftover ShaderType attributes in tests 2016-04-13 00:39:48 +00:00
TailCallElim Push isDereferenceableAndAlignedPointer down into isSafeToLoadUnconditionally 2016-01-17 12:35:29 +00:00
Util [PR27284] Reverse the ownership between DICompileUnit and DISubprogram. 2016-04-15 15:57:41 +00:00
WholeProgramDevirt WholeProgramDevirt: introduce. 2016-02-09 22:50:34 +00:00