[PM] Sink an LCSSA preservation assert from the LoopSimplify pass into
the library routine shared with the new PM and other code.

This assert checks that when LCSSA preservation is requested we star

[PM] Sink an LCSSA preservation assert from the LoopSimplify pass into
the library routine shared with the new PM and other code.

This assert checks that when LCSSA preservation is requested we start in
LCSSA form. Without this early assert, given *very* complex test cases
we can hit an assert or crash much later on when trying to preserve
LCSSA.

The new PM's loop simplify doesn't need to (and indeed can't) preserve
LCSSA as the new PM doesn't deal in transforms in the dependency graph.
But we asked the library to and shockingly, this didn't work very well!
Stop doing that. Now the assert will tell us immediately with existing
test cases. Before this, it took a pretty convoluted input to trigger
this.

However, sinking the assert also found a bug in LoopUnroll where we
asked simplifyLoop to preserve LCSSA *right before we reform it*. That's
kinda silly and unsurprising that it wasn't available. =D Stop doing
that too.

We also would assert that the unrolled loop was in LCSSA even if
preserving LCSSA was never requested! I don't have a test case or
anything here. I spotted it by inspection and it seems quite obvious. No
logic change anyways, that's just avoiding a spurrious assert.

llvm-svn: 292710

show more ...

Revert @llvm.assume with operator bundles (r289755-r289757)

This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

llvm-svn: 290086

Remove the AssumptionCache

After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is mo

Remove the AssumptionCache

After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

llvm-svn: 289756

show more ...

[LoopSimplify] Preserve LCSSA when removing edges from unreachable blocks.

This fixes PR30454.

llvm-svn: 287379

[simplifycfg][loop-simplify] Preserve loop metadata in 2 transformations.

insertUniqueBackedgeBlock in lib/Transforms/Utils/LoopSimplify.cpp now
propagates existing llvm.loop metadata to newly the a

[simplifycfg][loop-simplify] Preserve loop metadata in 2 transformations.

insertUniqueBackedgeBlock in lib/Transforms/Utils/LoopSimplify.cpp now
propagates existing llvm.loop metadata to newly the added backedge.

llvm::TryToSimplifyUncondBranchFromEmptyBlock in lib/Transforms/Utils/Local.cpp
now propagates existing llvm.loop metadata to the branch instructions in the
predecessor blocks of the empty block that is removed.

Differential Revision: https://reviews.llvm.org/D26495

llvm-svn: 287341

show more ...

[LCSSA] Implement linear algorithm for the isRecursivelyLCSSAForm

For each block check that it doesn't have any uses outside of it's innermost loop.

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

[LCSSA] Implement linear algorithm for the isRecursivelyLCSSAForm

For each block check that it doesn't have any uses outside of it's innermost loop.

Differential Revision: https://reviews.llvm.org/D25364

llvm-svn: 283877

show more ...

[LoopSimplify] When simplifying phis in loop-simplify, do it only if it preserves LCSSA form.

llvm-svn: 282541

[LoopSimplify] Rebuild LCSSA for the inner loop after separating nested loops.

Summary:
This hopefully fixes PR28825. The problem now was that a value from the
original loop was used in a subloop, w

[LoopSimplify] Rebuild LCSSA for the inner loop after separating nested loops.

Summary:
This hopefully fixes PR28825. The problem now was that a value from the
original loop was used in a subloop, which became a sibling after separation.
While a subloop doesn't need an lcssa phi node, a sibling does, and that's
where we broke LCSSA. The most natural way to fix this now is to simply call
formLCSSA on the original loop: it'll do what we've been doing before plus
it'll cover situations described above.

I think we don't need to run formLCSSARecursively here, and we have an assert
to verify this (I've tried testing it on LLVM testsuite + SPECs). I'd be happy
to be corrected here though.

I also changed a run line in the test from '-lcssa -loop-unroll' to
'-lcssa -loop-simplify -indvars', because it exercises LCSSA
preservation to the same extent, but also makes less unrelated
transformation on the CFG, which makes it easier to verify.

Reviewers: chandlerc, sanjoy, silvas

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D23288

llvm-svn: 278173

show more ...

Consistently use FunctionAnalysisManager

Besides a general consistently benefit, the extra layer of indirection
allows the mechanical part of https://reviews.llvm.org/D23256 that
requires touching e

Consistently use FunctionAnalysisManager

Besides a general consistently benefit, the extra layer of indirection
allows the mechanical part of https://reviews.llvm.org/D23256 that
requires touching every transformation and analysis to be factored out
cleanly.

Thanks to David for the suggestion.

llvm-svn: 278077

show more ...

Add some comments linking back to PR28400.

Thanks to Mehdi for the suggestion!

llvm-svn: 277984

[PM] More workaround for PR28400

llvm-svn: 277982

Revert "Revert "[LoopSimplify] Fix updating LCSSA after separating nested loops.""

This reverts commit r277901. Reaaply the commit as it looks like it has
nothing to do with the bots failures.

llvm

Revert "Revert "[LoopSimplify] Fix updating LCSSA after separating nested loops.""

This reverts commit r277901. Reaaply the commit as it looks like it has
nothing to do with the bots failures.

llvm-svn: 277946

show more ...

Revert "[LoopSimplify] Fix updating LCSSA after separating nested loops."

This reverts commit r277877.
Try to appease clang-x64-ninja-win7 buildbot.

llvm-svn: 277901

[LoopSimplify] Fix updating LCSSA after separating nested loops.

This fixes PR28825. The problem was that we only checked if a value from
a created inner loop is used in the outer loop, and fixed LC

[LoopSimplify] Fix updating LCSSA after separating nested loops.

This fixes PR28825. The problem was that we only checked if a value from
a created inner loop is used in the outer loop, and fixed LCSSA for
them. But we missed to fixup LCSSA for values used in exits of the outer
loop.

llvm-svn: 277877

show more ...

Revert "Revert r275883 and r275891. They seem to cause PR28608."

This reverts commit r276064, and thus reapplies r275891 and r275883 with
a fix for PR28608.

llvm-svn: 276077

Revert r275883 and r275891. They seem to cause PR28608.

Revert "[LoopSimplify] Update LCSSA after separating nested loops."

This reverts commit r275891.

Revert "[LCSSA] Post-process PHI-nodes crea

Revert r275883 and r275891. They seem to cause PR28608.

Revert "[LoopSimplify] Update LCSSA after separating nested loops."

This reverts commit r275891.

Revert "[LCSSA] Post-process PHI-nodes created by SSAUpdate when constructing LCSSA form."

This reverts commit r275883.

llvm-svn: 276064

show more ...

[LoopSimplify] Update LCSSA after separating nested loops.

Summary:
Usually LCSSA survives this transformation, but in some cases (see
attached test) it doesn't: values from the original loop after

[LoopSimplify] Update LCSSA after separating nested loops.

Summary:
Usually LCSSA survives this transformation, but in some cases (see
attached test) it doesn't: values from the original loop after
separating might be used from the outer loop. Before the transformation
it was the same loop, so LCSSA phis were not required.

This fixes PR28272.

Reviewers: sanjoy, hfinkel, chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21665

llvm-svn: 275891

show more ...

[LoopSimplify] Remove a comment which is unlikely to age well.

Chandler pointed out in his review but I forgot to remove before
committing, my bad.

llvm-svn: 274963

[PM] Port LoopSimplify to the new pass manager.

While here move simplifyLoop() function to the new header, as
suggested by Chandler in the review.

Differential Revision: http://reviews.llvm.org/D2

[PM] Port LoopSimplify to the new pass manager.

While here move simplifyLoop() function to the new header, as
suggested by Chandler in the review.

Differential Revision: http://reviews.llvm.org/D21404

llvm-svn: 274959

show more ...

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

Only minor manual fixes. No functionality change intended.

llvm-svn: 273808

Revert "[SimplifyCFG] Stop inserting calls to llvm.trap for UB"

This reverts commit r273778, it seems to break UBSan :/

llvm-svn: 273779

[SimplifyCFG] Stop inserting calls to llvm.trap for UB

SimplifyCFG had logic to insert calls to llvm.trap for two very
particular IR patterns: stores and invokes of undef/null.

While InstCombine ca

[SimplifyCFG] Stop inserting calls to llvm.trap for UB

SimplifyCFG had logic to insert calls to llvm.trap for two very
particular IR patterns: stores and invokes of undef/null.

While InstCombine canonicalizes certain undefined behavior IR patterns
to stores of undef, phase ordering means that this cannot be relied upon
in general.

There are much better tools than llvm.trap: UBSan and ASan.

N.B. I could be argued into reverting this change if a clear argument as
to why it is important that we synthesize llvm.trap for stores, I'd be
hard pressed to see why it'd be useful for invokes...

llvm-svn: 273778

show more ...

[LoopSimplify] Analyses do not need to be member variables.

In preparation for porting this pass to the new PM.

llvm-svn: 272818

[LoopSimplify] Preserve LCSSA when merging exit blocks.

Summary:
This fixes PR26682. Also add LCSSA as a preserved pass to LoopSimplify,
that looks correct to me and allows to write a test for the i

[LoopSimplify] Preserve LCSSA when merging exit blocks.

Summary:
This fixes PR26682. Also add LCSSA as a preserved pass to LoopSimplify,
that looks correct to me and allows to write a test for the issue.

Reviewers: chandlerc, bogner, sanjoy

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D21112

llvm-svn: 272224

show more ...

[PM] LoopSimplify. Remove unneeded pass dependencies. NFCI.

llvm-svn: 272140