Reverting [JumpThreading] Preservation of DT and LVI across the pass

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llvm-svn: 320641

[JumpThreading] Preservation of DT and LVI across the pass

Summary:
See D37528 for a previous (non-deferred) version of this
patch and its description.

Preserves dominance in a deferred manner usin

[JumpThreading] Preservation of DT and LVI across the pass

Summary:
See D37528 for a previous (non-deferred) version of this
patch and its description.

Preserves dominance in a deferred manner using a new class
DeferredDominance. This reduces the performance impact of
updating the DominatorTree at every edge insertion and
deletion. A user may call DDT->flush() within JumpThreading
for an up-to-date DT. This patch currently has one flush()
at the end of runImpl() to ensure DT is preserved across
the pass.

LVI is also preserved to help subsequent passes such as
CorrelatedValuePropagation. LVI is simpler to maintain and
is done immediately (not deferred). The code to perfom the
preversation was minimally altered and was simply marked
as preserved for the PassManager to be informed.

This extends the analysis available to JumpThreading for
future enhancements. One example is loop boundary threading.

Reviewers: dberlin, kuhar, sebpop

Reviewed By: kuhar, sebpop

Subscribers: hiraditya, llvm-commits

Differential Revision: https://reviews.llvm.org/D40146

llvm-svn: 320612

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loop-rotate: eliminate duplicate debug intrinsics after splicing.

Fixes part of PR35113.

This reapplies r317105 with an additional check for isa<Instruction>
as found by the bots.

llvm-svn: 317120

Revert r317105 to investigate bot breakage.

llvm-svn: 317110

loop-rotate: eliminate duplicate debug intrinsics after splicing.

Fixes part of PR35113.

llvm-svn: 317105

[Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).

llvm-svn: 316724

Rename WeakVH to WeakTrackingVH; NFC

This relands r301424.

llvm-svn: 301812

Reverts commit r301424, r301425 and r301426

Commits were:

"Use WeakVH instead of WeakTrackingVH in AliasSetTracker's UnkownInsts"
"Add a new WeakVH value handle; NFC"
"Rename WeakVH to WeakTracking

Reverts commit r301424, r301425 and r301426

Commits were:

"Use WeakVH instead of WeakTrackingVH in AliasSetTracker's UnkownInsts"
"Add a new WeakVH value handle; NFC"
"Rename WeakVH to WeakTrackingVH; NFC"

The changes assumed pointers are 8 byte aligned on all architectures.

llvm-svn: 301429

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Rename WeakVH to WeakTrackingVH; NFC

Summary:
I plan to use WeakVH to mean "nulls itself out on deletion, but does
not track RAUW" in a subsequent commit.

Reviewers: dblaikie, davide

Reviewed By:

Rename WeakVH to WeakTrackingVH; NFC

Summary:
I plan to use WeakVH to mean "nulls itself out on deletion, but does
not track RAUW" in a subsequent commit.

Reviewers: dblaikie, davide

Reviewed By: davide

Subscribers: arsenm, mehdi_amini, mcrosier, mzolotukhin, jfb, llvm-commits, nhaehnle

Differential Revision: https://reviews.llvm.org/D32266

llvm-svn: 301424

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[BasicBlockUtils] Check for nullptr before updating LoopInfo.

LoopInfo::getLoopFor returns nullptr if a BB is not in a loop and only
then can the loop be updated to contain the newly created BBs. Ad

[BasicBlockUtils] Check for nullptr before updating LoopInfo.

LoopInfo::getLoopFor returns nullptr if a BB is not in a loop and only
then can the loop be updated to contain the newly created BBs. Add the
missing nullptr check to SplitBlockAndInsertIfThen.

Within LLVM, the only user of this function that also passes a LoopInfo
to be updated is InnerLoopVectorizer::predicateInstructions().
As the method's name implies, the BB operataten on will always be within
a loop, but out-of-tree users may also use it differently (here: Polly).

All other uses of LoopInfo::getLoopFor in the file properly check its
return value for nullptr.

llvm-svn: 297016

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[BasicBlockUtils] Use getFirstNonPHIOrDbg to set debugloc for instructions created in SplitBlockPredecessors

Summary:
When setting debugloc for instructions created in SplitBlockPredecessors, curren

[BasicBlockUtils] Use getFirstNonPHIOrDbg to set debugloc for instructions created in SplitBlockPredecessors

Summary:
When setting debugloc for instructions created in SplitBlockPredecessors, current implementation copies debugloc from the first-non-phi instruction of the original basic block. However, if the first-non-phi instruction is a call for @llvm.dbg.value, the debugloc of the instruction may point the location outside of the block itself. For the example code of

```
1 typedef struct _node_t {
2 struct _node_t *next;
3 } node_t;
4
5 extern node_t *root;
6
7 int foo() {
8 node_t *node, *tmp;
9 int ret = 0;
10
11 node = tmp = root->next;
12 while (node != root) {
13 while (node) {
14 tmp = node;
15 node = node->next;
16 ret++;
17 }
18 }
19
20 return ret;
21 }
```

, below is the basicblock corresponding to line 12 after Reassociate expressions pass:

```
while.cond: ; preds = %while.cond2, %entry
%node.0 = phi %struct._node_t* [ %1, %entry ], [ null, %while.cond2 ]
%ret.0 = phi i32 [ 0, %entry ], [ %ret.1, %while.cond2 ]
tail call void @llvm.dbg.value(metadata i32 %ret.0, i64 0, metadata !19, metadata !20), !dbg !21
tail call void @llvm.dbg.value(metadata %struct._node_t* %node.0, i64 0, metadata !11, metadata !20), !dbg !31
%cmp = icmp eq %struct._node_t* %node.0, %0, !dbg !33
br i1 %cmp, label %while.end5, label %while.cond2, !dbg !35
```

As you can see, the first-non-phi instruction is a call for @llvm.dbg.value, and the debugloc is

```
!21 = !DILocation(line: 9, column: 7, scope: !6)
```

, which is a definition of 'ret' variable and outside of the scope of the basicblock itself. However, current implementation picks up this debugloc for the instructions created in SplitBlockPredecessors. This patch addresses this problem by picking up debugloc from the first-non-phi-non-dbg instruction.

Reviewers: dblaikie, samsonov, eugenis

Reviewed By: eugenis

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29867

llvm-svn: 295106

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Apply clang-tidy's modernize-loop-convert to most of lib/Transforms.

Only minor manual fixes. No functionality change intended.

llvm-svn: 273808

improve documentation comments; NFC

llvm-svn: 267292

[LV] Preserve LoopInfo when store predication is used

This was a latent bug that got exposed by the change to add LoopSimplify
as a dependence to LoopLoadElimination. Since LoopInfo was corrupted
a

[LV] Preserve LoopInfo when store predication is used

This was a latent bug that got exposed by the change to add LoopSimplify
as a dependence to LoopLoadElimination. Since LoopInfo was corrupted
after LV, LoopSimplify mis-compiled nbench in the test-suite (more
details in the PR).

The problem was that when we create the blocks for predicated stores we
didn't add those to any loops.

The original testcase for store predication provides coverage for this
assuming we verify LI on the way out of LV.

Fixes PR26952.

llvm-svn: 263565

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[PM] Port memdep to the new pass manager.

This is a fairly straightforward port to the new pass manager with one
exception. It removes a very questionable use of releaseMemory() in
the old pass to i

[PM] Port memdep to the new pass manager.

This is a fairly straightforward port to the new pass manager with one
exception. It removes a very questionable use of releaseMemory() in
the old pass to invalidate its caches between runs on a function.
I don't think this is really guaranteed to be safe. I've just used the
more direct port to the new PM to address this by nuking the results
object each time the pass runs. While this could cause some minor malloc
traffic increase, I don't expect the compile time performance hit to be
noticable, and it makes the correctness and other aspects of the pass
much easier to reason about. In some cases, it may make things faster by
making the sets and maps smaller with better locality. Indeed, the
measurements collected by Bruno (thanks!!!) show mostly compile time
improvements.

There is sadly very limited testing at this point as there are only two
tests of memdep, and both rely on GVN. I'll be porting GVN next and that
will exercise this heavily though.

Differential Revision: http://reviews.llvm.org/D17962

llvm-svn: 263082

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[SplitLandingPadPredecessors] Create a PHINode for the original landingpad only if it has some uses

Summary: This patch adds a check in SplitLandingPadPredecessors to see if the original landingpad

[SplitLandingPadPredecessors] Create a PHINode for the original landingpad only if it has some uses

Summary: This patch adds a check in SplitLandingPadPredecessors to see if the original landingpad instruction has any uses. If not, we don't need to create a PHINode for it in the joint block since it's gonna be a dead code anyway. The motivation for this patch is that we found a bug that SplitLandingPadPredecessors created a PHINode of token type landingpad, which failed the verifier since PHINode can not be token type. However, the created PHINode will never be used in our code pattern. This patch will workaround this bug, and we might add supports in SplitLandingPadPredecessors to handle token type landingpad with uses in the future.

Reviewers: reames

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D15835

llvm-svn: 256972

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TransformUtils: Remove implicit ilist iterator conversions, NFC

Continuing the work from last week to remove implicit ilist iterator
conversions. First related commit was probably r249767, with som

TransformUtils: Remove implicit ilist iterator conversions, NFC

Continuing the work from last week to remove implicit ilist iterator
conversions. First related commit was probably r249767, with some more
motivation in r249925. This edition gets LLVMTransformUtils compiling
without the implicit conversions.

No functional change intended.

llvm-svn: 250142

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Convert a bunch of loops to foreach. NFC.

After r244074, we now have a successors() method to iterate over
all the successors of a TerminatorInst. This commit changes a bunch
of eligible loops to

Convert a bunch of loops to foreach. NFC.

After r244074, we now have a successors() method to iterate over
all the successors of a TerminatorInst. This commit changes a bunch
of eligible loops to use it.

llvm-svn: 244260

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New EH representation for MSVC compatibility

This introduces new instructions neccessary to implement MSVC-compatible
exception handling support. Most of the middle-end and none of the
back-end hav

New EH representation for MSVC compatibility

This introduces new instructions neccessary to implement MSVC-compatible
exception handling support. Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.

Differential Revision: http://reviews.llvm.org/D11097

llvm-svn: 243766

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[PM/AA] Remove all of the dead AliasAnalysis pointers being threaded
through APIs that are no longer necessary now that the update API has
been removed.

This will make changes to the AA interfaces s

[PM/AA] Remove all of the dead AliasAnalysis pointers being threaded
through APIs that are no longer necessary now that the update API has
been removed.

This will make changes to the AA interfaces significantly less
disruptive (I hope). Either way, it seems like a really nice cleanup.

llvm-svn: 242882

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[PM/AA] Remove the last of the legacy update API from AliasAnalysis as
part of simplifying its interface and usage in preparation for porting
to work with the new pass manager.

Note that this will l

[PM/AA] Remove the last of the legacy update API from AliasAnalysis as
part of simplifying its interface and usage in preparation for porting
to work with the new pass manager.

Note that this will likely expose that we have dead arguments, members,
and maybe even pass requirements for AA. I'll be cleaning those up in
seperate patches. This just zaps the actual update API.

Differential Revision: http://reviews.llvm.org/D11325

llvm-svn: 242881

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[PM/AA] Completely remove the AliasAnalysis::copyValue interface.

No in-tree alias analysis used this facility, and it was not called in
any particularly rigorous way, so it seems unlikely to be cor

[PM/AA] Completely remove the AliasAnalysis::copyValue interface.

No in-tree alias analysis used this facility, and it was not called in
any particularly rigorous way, so it seems unlikely to be correct.

Note that one of the only stateful AA implementations in-tree,
GlobalsModRef is completely broken currently (and any AA passes like it
are equally broken) because Module AA passes are not effectively
invalidated when a function pass that fails to update the AA stack runs.

Ultimately, it doesn't seem like we know how we want to build stateful
AA, and until then trying to support and maintain correctness for an
untested API is essentially impossible. To that end, I'm planning to rip
out all of the update API. It can return if and when we need it and know
how to build it on top of the new pass manager and as part of *tested*
stateful AA implementations in the tree.

Differential Revision: http://reviews.llvm.org/D10889

llvm-svn: 241975

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Revert the new EH instructions

This reverts commits r241888-r241891, I didn't mean to commit them.

llvm-svn: 241893

New EH representation for MSVC compatibility

Summary:
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support. Most of the middle-end and none of the
bac

New EH representation for MSVC compatibility

Summary:
This introduces new instructions neccessary to implement MSVC-compatible
exception handling support. Most of the middle-end and none of the
back-end haven't been audited or updated to take them into account.

Reviewers: rnk, JosephTremoulet, reames, nlewycky, rjmccall

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D11041

llvm-svn: 241888

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Let llvm::ReplaceInstWithInst copy debug location from old to new instruction.

Currently some users of this function do this explicitly, and all the
rest forget to do this.

ThreadSanitizer was one

Let llvm::ReplaceInstWithInst copy debug location from old to new instruction.

Currently some users of this function do this explicitly, and all the
rest forget to do this.

ThreadSanitizer was one of such users, and had missing debug
locations for calls into TSan runtime handling atomic operations,
eventually leading to poorly symbolized stack traces and malfunctioning
suppressions.

This is another change relevant to PR23837.

llvm-svn: 240460

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