[SimplifyCFG] Regenerate test checks (NFC)

The output for many of these slightly changed (mainly due to
switch indentation), so mass-regenerate them.

[SimplifyCFG] Convert tests to opaque pointers (NFC)

[NFC] Port all runlines for SimplifyCFG pass tests to -passes syntax

[SimplifyCFG][PhaseOrdering] Defer lowering switch into an integer range comparison and branch until after at least the IPSCCP

That transformation is lossy, as discussed in
https://github.com/llvm/l

[SimplifyCFG][PhaseOrdering] Defer lowering switch into an integer range comparison and branch until after at least the IPSCCP

That transformation is lossy, as discussed in
https://github.com/llvm/llvm-project/issues/53853
and https://github.com/rust-lang/rust/issues/85133#issuecomment-904185574

This is an alternative to D119839,
which would add a limited IPSCCP into SimplifyCFG.

Unlike lowering switch to lookup, we still want this transformation
to happen relatively early, but after giving a chance for the things
like CVP to do their thing. It seems like deferring it just until
the IPSCCP is enough for the tests at hand, but perhaps we need to
be more aggressive and disable it until CVP.

Fixes https://github.com/llvm/llvm-project/issues/53853
Refs. https://github.com/rust-lang/rust/issues/85133

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D119854

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[SimplifyCFG] Fix SimplifyBranchOnICmpChain to be undef/poison safe.

This patch fixes the problem of SimplifyBranchOnICmpChain that occurs
when extra values are Undef or poison.

Suppose the %mode i

[SimplifyCFG] Fix SimplifyBranchOnICmpChain to be undef/poison safe.

This patch fixes the problem of SimplifyBranchOnICmpChain that occurs
when extra values are Undef or poison.

Suppose the %mode is 51 and the %Cond is poison, and let's look at the
case below.
```
%A = icmp ne i32 %mode, 0
%B = icmp ne i32 %mode, 51
%C = select i1 %A, i1 %B, i1 false
%D = select i1 %C, i1 %Cond, i1 false
br i1 %D, label %T, label %F
=>
br i1 %Cond, label %switch.early.test, label %F
switch.early.test:
switch i32 %mode, label %T [
i32 51, label %F
i32 0, label %F
]
```
incorrectness: https://alive2.llvm.org/ce/z/BWScX

Code before transformation will not raise UB because %C and %D is false,
and it will not use %Cond. But after transformation, %Cond is being used
immediately, and it will raise UB.

This problem can be solved by adding freeze instruction.

correctness: https://alive2.llvm.org/ce/z/x9x4oY

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D104569

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[SimplifyCFG] Tail-merging all blocks with `ret` terminator

Based ontop of D104598, which is a NFCI-ish refactoring.
Here, a restriction, that only empty blocks can be merged, is lifted.

Reviewed B

[SimplifyCFG] Tail-merging all blocks with `ret` terminator

Based ontop of D104598, which is a NFCI-ish refactoring.
Here, a restriction, that only empty blocks can be merged, is lifted.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D104597

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[SimplifyCFG] Make test more robust (NFC)

These are supposed to test creation of a switch, so make sure
there is some actual code in the branches. Otherwise this could
be turned into a select instea

[SimplifyCFG] Make test more robust (NFC)

These are supposed to test creation of a switch, so make sure
there is some actual code in the branches. Otherwise this could
be turned into a select instead.

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Reland "[SimplifyCFG] Update FoldBranchToCommonDest to be poison-safe"

This relands commit 99108c791de0285ee726a10e8274772b18cee73c (D95026) which was
reverted by 8d5a981a135a0f0ae0a10c59b7c8093aae1

Reland "[SimplifyCFG] Update FoldBranchToCommonDest to be poison-safe"

This relands commit 99108c791de0285ee726a10e8274772b18cee73c (D95026) which was
reverted by 8d5a981a135a0f0ae0a10c59b7c8093aae1c28de because the underlying
problem (https://llvm.org/pr49495) is fixed.

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Revert "[SimplifyCFG] Update FoldBranchToCommonDest to be poison-safe"

This reverts commit 99108c791de0285ee726a10e8274772b18cee73c.
Clang is miscompiling LLVM with this change, a stage-2 build hits

Revert "[SimplifyCFG] Update FoldBranchToCommonDest to be poison-safe"

This reverts commit 99108c791de0285ee726a10e8274772b18cee73c.
Clang is miscompiling LLVM with this change, a stage-2 build hits
multiple failures.

As a repro, I built clang in a stage1 directory and used it this way:

cmake -G Ninja ../llvm \
-DCMAKE_CXX_COMPILER=`pwd`/../build-stage1/bin/clang++ \
-DCMAKE_C_COMPILER=`pwd`/../build-stage1/bin/clang \
-DLLVM_TARGETS_TO_BUILD="X86;NVPTX;AMDGPU" \
-DLLVM_ENABLE_PROJECTS=mlir \
-DLLVM_BUILD_EXAMPLES=ON \
-DCMAKE_BUILD_TYPE=Release \
-DLLVM_ENABLE_ASSERTIONS=On
ninja check-mlir

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[SimplifyCFG] Update FoldBranchToCommonDest to be poison-safe

This patch makes FoldBranchToCommonDest merge branch conditions into `select i1` rather than `and/or i1` when it is called by SimplifyCF

[SimplifyCFG] Update FoldBranchToCommonDest to be poison-safe

This patch makes FoldBranchToCommonDest merge branch conditions into `select i1` rather than `and/or i1` when it is called by SimplifyCFG.
It is known that merging conditions into and/or is poison-unsafe, and this is towards making things *more* correct by removing possible miscompilations.
Currently, InstCombine simply consumes these selects into and/or of i1 (which is also unsafe), so the visible effect would be very small. The unsafe select -> and/or transformation will be removed in the future.
There has been efforts for updating optimizations to support the select form as well, and they are linked to D93065.

The safe transformation is fired when it is called by SimplifyCFG only. This is done by setting the new `PoisonSafe` argument as true.
Another place that calls FoldBranchToCommonDest is LoopSimplify. `PoisonSafe` flag is set to false in this case because enabling it has a nontrivial impact in performance because SCEV is more conservative with select form and InductiveRangeCheckElimination isn't aware of select form of and/or i1.

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D95026

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[SimplifyCFG] Reapply update_test_checks.py (NFC)

[SimplifyCFG] Teach tryToSimplifyUncondBranchWithICmpInIt() to preserve DomTree

Reland [DataLayout] Fix occurrences that size and range of pointers are assumed to be the same.

GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still pla

Reland [DataLayout] Fix occurrences that size and range of pointers are assumed to be the same.

GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in which getIndexSizeInBits was used interchangeably with getPointerSizeInBits. This notably caused issues
with Instcombine's visitPtrToInt; but the unit tests was incorrect, so this remained undiscovered.

This fixes the buildbot failures.

Differential Revision: https://reviews.llvm.org/D68328

Patch by Joseph Faulls!

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Temporarily Revert "[DataLayout] Fix occurrences that size and range of pointers are assumed to be the same."

This reverts commit 5f6208778ff92567c57d7c1e2e740c284d7e69a5.

This caused failures in T

Temporarily Revert "[DataLayout] Fix occurrences that size and range of pointers are assumed to be the same."

This reverts commit 5f6208778ff92567c57d7c1e2e740c284d7e69a5.

This caused failures in Transforms/PhaseOrdering/scev-custom-dl.ll
const: Assertion `getBitWidth() == CR.getBitWidth() && "ConstantRange types don't agree!"' failed.

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[DataLayout] Fix occurrences that size and range of pointers are assumed to be the same.

GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in

[DataLayout] Fix occurrences that size and range of pointers are assumed to be the same.

GEP index size can be specified in the DataLayout, introduced in D42123. However, there were still places
in which getIndexSizeInBits was used interchangeably with getPointerSizeInBits. This notably caused issues
with Instcombine's visitPtrToInt; but the unit tests was incorrect, so this remained undiscovered.

Differential Revision: https://reviews.llvm.org/D68328

Patch by Joseph Faulls!

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[SimplifyCFG] NFC, update Switch tests as a baseline.

Also add baseline tests to show effect of later patches.

There were a couple of regressions here that were never caught,
but my patch set that

[SimplifyCFG] NFC, update Switch tests as a baseline.

Also add baseline tests to show effect of later patches.

There were a couple of regressions here that were never caught,
but my patch set that this is a preparation to will fix them.

This is the third attempt to land this patch.

Differential Revision: https://reviews.llvm.org/D61150

llvm-svn: 363319

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[SimplifyCFG] reverting preliminary Switch patches again

This reverts 363226 and 363227, both NFC intended

I swear I fixed the test case that is failing, and ran
the tests, but I will look into it

[SimplifyCFG] reverting preliminary Switch patches again

This reverts 363226 and 363227, both NFC intended

I swear I fixed the test case that is failing, and ran
the tests, but I will look into it again.

llvm-svn: 363229

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[SimplifyCFG] NFC, update Switch tests to better examine successive patches

Also add baseline tests to show effect of later patches.

There were a couple of regressions here that were never caught,

[SimplifyCFG] NFC, update Switch tests to better examine successive patches

Also add baseline tests to show effect of later patches.

There were a couple of regressions here that were never caught,
but my patch set that this is a preparation to will fix them.

Differential Revision: https://reviews.llvm.org/D61150

llvm-svn: 363226

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[SimplifyCFG] revert the last commit.

I ran ALL the test suite locally, so I will look into this...

llvm-svn: 363223

[SimplifyCFG] NFC, update Switch tests to HEAD so I can

see if my changes change anything

Also add baseline tests to show effect of later patches.

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

[SimplifyCFG] NFC, update Switch tests to HEAD so I can

see if my changes change anything

Also add baseline tests to show effect of later patches.

Differential Revision: https://reviews.llvm.org/D61150

llvm-svn: 363222

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[SimplifyCFG] back out all SwitchInst commits

They caused the sanitizer builds to fail.

My suspicion is the change the countLeadingZeros().

llvm-svn: 361736

[SimplifyCFG] NFC, update Switch tests to HEAD so I can see if my changes change anything

Also add baseline tests to show effect of later patches.

llvm-svn: 361725

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

The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552

Adding a width of the GEP index to the Data Layout.

Making a width of GEP Index, which is used for address calculation, to be one of the pointer properties in the Data Layout.
p[address space]:size:

Adding a width of the GEP index to the Data Layout.

Making a width of GEP Index, which is used for address calculation, to be one of the pointer properties in the Data Layout.
p[address space]:size:memory_size:alignment:pref_alignment:index_size_in_bits.
The index size parameter is optional, if not specified, it is equal to the pointer size.

Till now, the InstCombiner normalized GEPs and extended the Index operand to the pointer width.
It works fine if you can convert pointer to integer for address calculation and all registered targets do this.
But some ISAs have very restricted instruction set for the pointer calculation. During discussions were desided to retrieve information for GEP index from the Data Layout.
http://lists.llvm.org/pipermail/llvm-dev/2018-January/120416.html

I added an interface to the Data Layout and I changed the InstCombiner and some other passes to take the Index width into account.
This change does not affect any in-tree target. I added tests to cover data layouts with explicitly specified index size.

Differential Revision: https://reviews.llvm.org/D42123

llvm-svn: 325102

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