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Nick Desaulniers 639b29b1b5 [INLINER] allow inlining of blockaddresses if sole uses are callbrs 
Summary:
It was supposed that Ref LazyCallGraph::Edge's were being inserted by
inlining, but that doesn't seem to be the case.  Instead, it seems that
there was no test for a blockaddress Constant in an instruction that
referenced the function that contained the instruction. Ex:

```
define void @f() {
  %1 = alloca i8*, align 8
2:
  store i8* blockaddress(@f, %2), i8** %1, align 8
  ret void
}
```

When iterating blockaddresses, do not add the function they refer to
back to the worklist if the blockaddress is referring to the contained
function (as opposed to an external function).

Because blockaddress has sligtly different semantics than GNU C's
address of labels, there are 3 cases that can occur with blockaddress,
where only 1 can happen in GNU C due to C's scoping rules:
* blockaddress is within the function it refers to (possible in GNU C).
* blockaddress is within a different function than the one it refers to
(not possible in GNU C).
* blockaddress is used in to declare a global (not possible in GNU C).

The second case is tested in:

```
$ ./llvm/build/unittests/Analysis/AnalysisTests \
  --gtest_filter=LazyCallGraphTest.HandleBlockAddress
```

This patch adjusts the iteration of blockaddresses in
LazyCallGraph::visitReferences to not revisit the blockaddresses
function in the first case.

The Linux kernel contains code that's not semantically valid at -O0;
specifically code passed to asm goto. It requires that asm goto be
inline-able. This patch conservatively does not attempt to handle the
more general case of inlining blockaddresses that have non-callbr users
(pr/39560).

https://bugs.llvm.org/show_bug.cgi?id=39560
https://bugs.llvm.org/show_bug.cgi?id=40722
https://github.com/ClangBuiltLinux/linux/issues/6
https://reviews.llvm.org/rL212077

Reviewers: jyknight, eli.friedman, chandlerc

Reviewed By: chandlerc

Subscribers: george.burgess.iv, nathanchance, mgorny, craig.topper, mengxu.gatech, void, mehdi_amini, E5ten, chandlerc, efriedma, eraman, hiraditya, haicheng, pirama, llvm-commits, srhines

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58260

llvm-svn: 361173
 		2019-05-20 16:48:09 +00:00
..
AliasAnalysisTest.cpp [AliasAnalysis] Second prototype to cache BasicAA / anyAA state. 2019-03-22 17:22:19 +00:00
AliasSetTrackerTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
BasicAliasAnalysisTest.cpp [AliasAnalysis] Second prototype to cache BasicAA / anyAA state. 2019-03-22 17:22:19 +00:00
BlockFrequencyInfoTest.cpp Replace llvm::isPodLike<...> by llvm::is_trivially_copyable<...> 2019-01-20 21:19:56 +00:00
BranchProbabilityInfoTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
CFGTest.cpp An unreachable block may have a route to a reachable block, don't fast-path return that it can't. 2019-04-04 23:09:40 +00:00
CGSCCPassManagerTest.cpp [NewPM] Fix a nasty bug with analysis invalidation in the new PM. 2019-03-28 00:51:36 +00:00
CMakeLists.txt Save the induction binary operator in IVDescriptors for non FP induction variables. 2019-05-14 13:26:36 +00:00
CallGraphTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
CaptureTrackingTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
DivergenceAnalysisTest.cpp [opaque pointer types] Add a FunctionCallee wrapper type, and use it. 2019-02-01 02:28:03 +00:00
DomTreeUpdaterTest.cpp [DTU] Refine the interface and logic of applyUpdates 2019-02-22 13:48:38 +00:00
GlobalsModRefTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
IVDescriptorsTest.cpp Save the induction binary operator in IVDescriptors for non FP induction variables. 2019-05-14 13:26:36 +00:00
LazyCallGraphTest.cpp [INLINER] allow inlining of blockaddresses if sole uses are callbrs 2019-05-20 16:48:09 +00:00
LoopInfoTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
MemoryBuiltinsTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
MemorySSATest.cpp [MemorySSA] Make insertDef insert corresponding phi nodes. 2019-02-27 22:20:22 +00:00
OrderedBasicBlockTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
OrderedInstructionsTest.cpp [opaque pointer types] Pass value type to LoadInst creation. 2019-02-01 20:44:24 +00:00
PhiValuesTest.cpp [opaque pointer types] Pass value type to LoadInst creation. 2019-02-01 20:44:24 +00:00
ProfileSummaryInfoTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
ScalarEvolutionTest.cpp [opaque pointer types] Pass value type to GetElementPtr creation. 2019-02-01 20:44:47 +00:00
SparsePropagation.cpp [opaque pointer types] Pass value type to LoadInst creation. 2019-02-01 20:44:24 +00:00
TBAATest.cpp [opaque pointer types] Add a FunctionCallee wrapper type, and use it. 2019-02-01 02:28:03 +00:00
TargetLibraryInfoTest.cpp Fix TargetLibraryInfoTest.ValidProto after rL357552 2019-04-03 02:30:35 +00:00
UnrollAnalyzerTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
ValueLatticeTest.cpp Update the file headers across all of the LLVM projects in the monorepo 2019-01-19 08:50:56 +00:00
ValueTrackingTest.cpp [ValueTracking] Known bits support for unsigned saturating add/sub 2019-03-01 20:07:04 +00:00