[LoopUnroll] Use smallest exact trip count from any exit

This is a more general alternative/extension to D102635. Rather than
handling the special case of "header exit with non-exiting latch",
this

[LoopUnroll] Use smallest exact trip count from any exit

This is a more general alternative/extension to D102635. Rather than
handling the special case of "header exit with non-exiting latch",
this unrolls against the smallest exact trip count from any exit.
The latch exit is no longer treated as priviledged when it comes to
full unrolling.

The motivating case is in full-unroll-one-unpredictable-exit.ll.
Here the header exit is an IV-based exit, while the latch exit is
a data comparison. This kind of loop does not get rotated, because
the latch is already exiting, and loop rotation doesn't try to
distinguish IV-based/analyzable latches.

Differential Revision: https://reviews.llvm.org/D102982

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[LoopUnroll] Regenerate test checks (NFC)

[NewPM][LoopUnroll] Rename unroll* to loop-unroll*

The legacy pass is called "loop-unroll", but in the new PM it's called "unroll".
Also applied to unroll-and-jam and unroll-full.

Fixes various che

[NewPM][LoopUnroll] Rename unroll* to loop-unroll*

The legacy pass is called "loop-unroll", but in the new PM it's called "unroll".
Also applied to unroll-and-jam and unroll-full.

Fixes various check-llvm tests when NPM is turned on.

Reviewed By: Whitney, dmgreen

Differential Revision: https://reviews.llvm.org/D82590

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[LoopUnroll] Add support for loops with exiting headers and uncond latches.

This patch generalizes the UnrollLoop utility to support loops that exit
from the header instead of the latch. Usually, Lo

[LoopUnroll] Add support for loops with exiting headers and uncond latches.

This patch generalizes the UnrollLoop utility to support loops that exit
from the header instead of the latch. Usually, LoopRotate would take care
of must of those cases, but in some cases (e.g. -Oz), LoopRotate does
not kick in.

Codesize impact looks relatively neutral on ARM64 with -Oz + LTO.

Program master patch diff
External/S.../CFP2006/447.dealII/447.dealII 629060.00 627676.00 -0.2%
External/SPEC/CINT2000/176.gcc/176.gcc 1245916.00 1244932.00 -0.1%
MultiSourc...Prolangs-C/simulator/simulator 86100.00 86156.00 0.1%
MultiSourc...arks/Rodinia/backprop/backprop 66212.00 66252.00 0.1%
MultiSourc...chmarks/Prolangs-C++/life/life 67276.00 67312.00 0.1%
MultiSourc...s/Prolangs-C/compiler/compiler 69824.00 69788.00 -0.1%
MultiSourc...Prolangs-C/assembler/assembler 86672.00 86696.00 0.0%

Reviewers: efriedma, vsk, paquette

Reviewed By: paquette

Differential Revision: https://reviews.llvm.org/D61962

llvm-svn: 364398

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Revert "Temporarily Revert "Add basic loop fusion pass.""

The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552

[PM] Split LoopUnrollPass and make partial unroller a function pass

Summary:
This is largely NFC*, in preparation for utilizing ProfileSummaryInfo
and BranchFrequencyInfo analyses. In this patch I a

[PM] Split LoopUnrollPass and make partial unroller a function pass

Summary:
This is largely NFC*, in preparation for utilizing ProfileSummaryInfo
and BranchFrequencyInfo analyses. In this patch I am only doing the
splitting for the New PM, but I can do the same for the legacy PM as
a follow-on if this looks good.

*Not NFC since for partial unrolling we lose the updates done to the
loop traversal (adding new sibling and child loops) - according to
Chandler this is not very useful for partial unrolling, but it also
means that the debugging flag -unroll-revisit-child-loops no longer
works for partial unrolling.

Reviewers: chandlerc

Subscribers: mehdi_amini, mzolotukhin, eraman, llvm-commits

Differential Revision: https://reviews.llvm.org/D36157

llvm-svn: 309886

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[PM] Teach LoopUnroll to update the LPM infrastructure as it unrolls
loops.

We do this by reconstructing the newly added loops after the unroll
completes to avoid threading pass manager details thro

[PM] Teach LoopUnroll to update the LPM infrastructure as it unrolls
loops.

We do this by reconstructing the newly added loops after the unroll
completes to avoid threading pass manager details through all the mess
of the unrolling infrastructure.

I've enabled some extra assertions in the LPM to try and catch issues
here and enabled a bunch of unroller tests to try and make sure this is
sane.

Currently, I'm manually running loop-simplify when needed. That should
go away once it is folded into the LPM infrastructure.

Differential Revision: https://reviews.llvm.org/D28848

llvm-svn: 293011

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[LoopUnroll] Include hotness of region in opt remark

LoopUnroll is a loop pass, so the analysis of OptimizationRemarkEmitter
is added to the common function analysis passes that loop passes
depend o

[LoopUnroll] Include hotness of region in opt remark

LoopUnroll is a loop pass, so the analysis of OptimizationRemarkEmitter
is added to the common function analysis passes that loop passes
depend on.

The BFI and indirectly BPI used in this pass is computed lazily so no
overhead should be observed unless -pass-remarks-with-hotness is used.

This is how the patch affects the O3 pipeline:

Dominator Tree Construction
Natural Loop Information
Canonicalize natural loops
Loop-Closed SSA Form Pass
Basic Alias Analysis (stateless AA impl)
Function Alias Analysis Results
Scalar Evolution Analysis
+ Lazy Branch Probability Analysis
+ Lazy Block Frequency Analysis
+ Optimization Remark Emitter
Loop Pass Manager
Rotate Loops
Loop Invariant Code Motion
Unswitch loops
Simplify the CFG
Dominator Tree Construction
Basic Alias Analysis (stateless AA impl)
Function Alias Analysis Results
Combine redundant instructions
Natural Loop Information
Canonicalize natural loops
Loop-Closed SSA Form Pass
Scalar Evolution Analysis
+ Lazy Branch Probability Analysis
+ Lazy Block Frequency Analysis
+ Optimization Remark Emitter
Loop Pass Manager
Induction Variable Simplification
Recognize loop idioms
Delete dead loops
Unroll loops
...

llvm-svn: 277203

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[PM] Port LoopUnroll.

We just set PreserveLCSSA to always true since we don't have an
analogous method `mustPreserveAnalysisID(LCSSA)`.

Also port LoopInfo verifier pass to test LoopUnrollPass.

llv

[PM] Port LoopUnroll.

We just set PreserveLCSSA to always true since we don't have an
analogous method `mustPreserveAnalysisID(LCSSA)`.

Also port LoopInfo verifier pass to test LoopUnrollPass.

llvm-svn: 276063

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LoopInfo: Simplify ownership of Loop objects

It's strange that LoopInfo mostly owns the Loop objects, but that it
defers deleting them to the loop pass manager. Instead, change the
oddly named "upda

LoopInfo: Simplify ownership of Loop objects

It's strange that LoopInfo mostly owns the Loop objects, but that it
defers deleting them to the loop pass manager. Instead, change the
oddly named "updateUnloop" to "markAsRemoved" and have it queue the
Loop object for deletion. We can't delete the Loop immediately when we
remove it, since we need its pointer identity still, so we'll mark the
object as "invalid" so that clients can see what's going on.

llvm-svn: 257191

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Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.

This update was done with the following bash script:

find test/Transforms -name "*.ll" | \
while read N

Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.

This update was done with the following bash script:

find test/Transforms -name "*.ll" | \
while read NAME; do
echo "$NAME"
if ! grep -q "^; *RUN: *llc" $NAME; then
TEMP=`mktemp -t temp`
cp $NAME $TEMP
sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
while read FUNC; do
sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP
done
mv $TEMP $NAME
fi
done

llvm-svn: 186268

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Prevent loop-unroll from making assumptions about undefined behavior.

Fixes rdar:14036816, PR16130.

There is an opportunity to compute precise trip counts for 'or'
expressions and multi-exit loops.

Prevent loop-unroll from making assumptions about undefined behavior.

Fixes rdar:14036816, PR16130.

There is an opportunity to compute precise trip counts for 'or'
expressions and multi-exit loops.
rdar:14038809: Optimize trip count computation for multi-exit loops.

To do this we need to record the fact that ExitLimit assumes NSW. When
it does not we can safely assume that the loop trip count is the
minimum ExitLimt across all subexpressions and loop exits.

llvm-svn: 183060

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Fix a corner case in updating LoopInfo after fully unrolling an outer loop.

The loop tree's inclusive block lists are painful and expensive to
update. (I have no idea why they're inclusive). The des

Fix a corner case in updating LoopInfo after fully unrolling an outer loop.

The loop tree's inclusive block lists are painful and expensive to
update. (I have no idea why they're inclusive). The design was
supposed to handle this case but the implementation missed it and my
unit tests weren't thorough enough.

Fixes PR11335: loop unroll update.

llvm-svn: 144970

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-unroll-scev flag removal

llvm-svn: 139010

A slew of unit tests for the recent LoopInfo::updateUnloop feature
checked in at r137276 and r137341.

llvm-svn: 137385