[InstCombine] Infer nusw + nneg -> nuw for getelementptr (#111144)

If the gep is nusw (usually via inbounds) and the offset is
non-negative, we can infer nuw.

Proof: https://alive2.llvm.org/ce/z

[InstCombine] Infer nusw + nneg -> nuw for getelementptr (#111144)

If the gep is nusw (usually via inbounds) and the offset is
non-negative, we can infer nuw.

Proof: https://alive2.llvm.org/ce/z/ihztLy

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[InstCombine] Preserve all gep flags in another select of gep fold

[InstCombine] Canonicalize constant GEPs to i8 source element type (#68882)

This patch canonicalizes getelementptr instructions with constant
indices to use the `i8` source element type. This makes

[InstCombine] Canonicalize constant GEPs to i8 source element type (#68882)

This patch canonicalizes getelementptr instructions with constant
indices to use the `i8` source element type. This makes it easier for
optimizations to recognize that two GEPs are identical, because they
don't need to see past many different ways to express the same offset.

This is a first step towards
https://discourse.llvm.org/t/rfc-replacing-getelementptr-with-ptradd/68699.
This is limited to constant GEPs only for now, as they have a clear
canonical form, while we're not yet sure how exactly to deal with
variable indices.

The test llvm/test/Transforms/PhaseOrdering/switch_with_geps.ll gives
two representative examples of the kind of optimization improvement we
expect from this change. In the first test SimplifyCFG can now realize
that all switch branches are actually the same. In the second test it
can convert it into simple arithmetic. These are representative of
common optimization failures we see in Rust.

Fixes https://github.com/llvm/llvm-project/issues/69841.

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[InstCombine] Preserve inbounds when folding select of GEP

The select base, (gep base, offset) to gep base, select (0, offset)
fold used to drop inbounds, because the gep base, 0 this introduces
mig

[InstCombine] Preserve inbounds when folding select of GEP

The select base, (gep base, offset) to gep base, select (0, offset)
fold used to drop inbounds, because the gep base, 0 this introduces
might not be inbounds. After the semantics change in D154051, such
a GEP is always considered inbounds, in which allows us to preserve
the flag here.

As the PhaseOrdering test demonstrates, this can result in major
optimization improvements in some cases.

Differential Revision: https://reviews.llvm.org/D154055

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[InstCombine] Regenerate all test checks (NFC)

Due to an improvement to name preservation, a lot of InstCombine
tests now show spurious diffs when regenerated.

Rather than regenerating individual f

[InstCombine] Regenerate all test checks (NFC)

Due to an improvement to name preservation, a lot of InstCombine
tests now show spurious diffs when regenerated.

Rather than regenerating individual files when they get touched,
mass-regenerate all UTC-based InstCombine tests. I have then reset
a number of files showing suspicious diffs where the UTC output
has clearly been manually adjusted. I apologize if I missed
anything in the mass of changes.

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[InstCombine] Regenerate select-gep.ll test checks

Fixes superfluous diffs identified in D139253

[test][InstCombine] Update some test cases to use opaque pointers

These tests cases were converted using the script at
https://gist.github.com/nikic/98357b71fd67756b0f064c9517b62a34

Differential Re

[test][InstCombine] Update some test cases to use opaque pointers

These tests cases were converted using the script at
https://gist.github.com/nikic/98357b71fd67756b0f064c9517b62a34

Differential Revision: https://reviews.llvm.org/D135094

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[InstCombine] Canonicalize SPF to min/max intrinsics

Now that integer min/max intrinsics have good support in both
InstCombine and other passes, start canonicalizing SPF min/max
to intrinsic min/max

[InstCombine] Canonicalize SPF to min/max intrinsics

Now that integer min/max intrinsics have good support in both
InstCombine and other passes, start canonicalizing SPF min/max
to intrinsic min/max.

Once this sticks, we can stop matching SPF min/max in various
places, and can remove hacks we have for preventing infinite loops
and breaking of SPF canonicalization.

Differential Revision: https://reviews.llvm.org/D98152

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[test] Use -passes=instcombine instead of -instcombine in lots of tests. NFC

Another step moving away from the deprecated syntax of specifying
pass pipeline in opt.

Differential Revision: https://r

[test] Use -passes=instcombine instead of -instcombine in lots of tests. NFC

Another step moving away from the deprecated syntax of specifying
pass pipeline in opt.

Differential Revision: https://reviews.llvm.org/D119081

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Don't fold (select C, (gep Ptr, Idx), Ptr) if C is vector but Idx is scalar

The folding rule (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C,
Idx, 0)) creates a malformed SELECT IR if C is a

Don't fold (select C, (gep Ptr, Idx), Ptr) if C is vector but Idx is scalar

The folding rule (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C,
Idx, 0)) creates a malformed SELECT IR if C is a vector while Idx is scalar.

SELECT VecC, ScalarIdx, 0

We could splat Idx to a vector but it defeats the purpose of
optimisation. Don't apply the folding rule in this case.

This fixes a regression from commit d561b6fbdbe6d1da05fd92003a4ac1e37bf4b8bc.

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Revert rG1c9bec727ab5c53fa060560dc8d346a911142170 : [InstCombine] Fold (gep (oneuse(gep Ptr, Idx0)), Idx1) -> (gep Ptr, (add Idx0, Idx1)) (PR51069)

Reverted (manually due to merge conflicts) while r

Revert rG1c9bec727ab5c53fa060560dc8d346a911142170 : [InstCombine] Fold (gep (oneuse(gep Ptr, Idx0)), Idx1) -> (gep Ptr, (add Idx0, Idx1)) (PR51069)

Reverted (manually due to merge conflicts) while regressions reported on PR51540 are investigated

As noticed on D106352, after we've folded "(select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0))" if the inner Ptr was also a (now one use) gep we could then merge the geps, using the sum of the indices instead.

I've limited this to basic 2-op geps - a more general case further down InstCombinerImpl.visitGetElementPtrInst doesn't have the one-use limitation but only creates the add if it can be created via SimplifyAddInst.

https://alive2.llvm.org/ce/z/f8pLfD (Thanks Roman!)

Differential Revision: https://reviews.llvm.org/D106450

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[InstCombine] Fold (gep (oneuse(gep Ptr, Idx0)), Idx1) -> (gep Ptr, (add Idx0, Idx1)) (PR51069)

As noticed on D106352, after we've folded "(select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx

[InstCombine] Fold (gep (oneuse(gep Ptr, Idx0)), Idx1) -> (gep Ptr, (add Idx0, Idx1)) (PR51069)

As noticed on D106352, after we've folded "(select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0))" if the inner Ptr was also a (now one use) gep we could then merge the geps, using the sum of the indices instead.

I've limited this to basic 2-op geps - a more general case further down InstCombinerImpl.visitGetElementPtrInst doesn't have the one-use limitation but only creates the add if it can be created via SimplifyAddInst.

https://alive2.llvm.org/ce/z/f8pLfD (Thanks Roman!)

Differential Revision: https://reviews.llvm.org/D106450

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[InstCombine] Add multiuse test for D106352

[InstCombine] Add select(cond,gep(gep(x,y),z),gep(x,y)) tests from PR51069

[InstCombine] Add 3-operand gep test with different ptr and same indices

[InstCombine] Strip inbounds from (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0)) fold

As discussed on rGd561b6fbdbe6, we can't guarantee that the new gep is inbounds

[InstCombine] Fold (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0)) (PR50183) (REAPPLIED)

As discussed on PR50183, we already fold to prefer 'select-of-idx' vs 'select-of-gep':

defi

[InstCombine] Fold (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0)) (PR50183) (REAPPLIED)

As discussed on PR50183, we already fold to prefer 'select-of-idx' vs 'select-of-gep':

define <4 x i32>* @select0a(<4 x i32>* %a0, i64 %a1, i1 %a2, i64 %a3) {
%gep0 = getelementptr inbounds <4 x i32>, <4 x i32>* %a0, i64 %a1
%gep1 = getelementptr inbounds <4 x i32>, <4 x i32>* %a0, i64 %a3
%sel = select i1 %a2, <4 x i32>* %gep0, <4 x i32>* %gep1
ret <4 x i32>* %sel
}
-->
define <4 x i32>* @select1a(<4 x i32>* %a0, i64 %a1, i1 %a2, i64 %a3) {
%sel = select i1 %a2, i64 %a1, i64 %a3
%gep = getelementptr inbounds <4 x i32>, <4 x i32>* %a0, i64 %sel
ret <4 x i32>* %gep
}

This patch adds basic handling for the 'fallthrough' cases where the gep idx == 0 has been folded away to the base address:

define <4 x i32>* @select0(<4 x i32>* %a0, i64 %a1, i1 %a2) {
%gep = getelementptr inbounds <4 x i32>, <4 x i32>* %a0, i64 %a1
%sel = select i1 %a2, <4 x i32>* %a0, <4 x i32>* %gep
ret <4 x i32>* %sel
}
-->
define <4 x i32>* @select1(<4 x i32>* %a0, i64 %a1, i1 %a2) {
%sel = select i1 %a2, i64 0, i64 %a1
%gep = getelementptr inbounds <4 x i32>, <4 x i32>* %a0, i64 %sel
ret <4 x i32>* %gep
}

Reapplied with a fix for the bpf "-bpf-disable-avoid-speculation" tests

Differential Revision: https://reviews.llvm.org/D105901

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Revert rGb803294cf78714303db2d3647291a2308347ef23 : "[InstCombine] Fold (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0)) (PR50183)"

Missed some BPF test changes that need addressing

[InstCombine] Fold (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0)) (PR50183)

As discussed on PR50183, we already fold to prefer 'select-of-idx' vs 'select-of-gep':

define <4 x i32>

[InstCombine] Fold (select C, (gep Ptr, Idx), Ptr) -> (gep Ptr, (select C, Idx, 0)) (PR50183)

As discussed on PR50183, we already fold to prefer 'select-of-idx' vs 'select-of-gep':

define <4 x i32>* @select0a(<4 x i32>* %a0, i64 %a1, i1 %a2, i64 %a3) {
%gep0 = getelementptr inbounds <4 x i32>, <4 x i32>* %a0, i64 %a1
%gep1 = getelementptr inbounds <4 x i32>, <4 x i32>* %a0, i64 %a3
%sel = select i1 %a2, <4 x i32>* %gep0, <4 x i32>* %gep1
ret <4 x i32>* %sel
}
-->
define <4 x i32>* @select1a(<4 x i32>* %a0, i64 %a1, i1 %a2, i64 %a3) {
%sel = select i1 %a2, i64 %a1, i64 %a3
%gep = getelementptr inbounds <4 x i32>, <4 x i32>* %a0, i64 %sel
ret <4 x i32>* %gep
}

This patch adds basic handling for the 'fallthrough' cases where the gep idx == 0 has been folded away to the base address:

define <4 x i32>* @select0(<4 x i32>* %a0, i64 %a1, i1 %a2) {
%gep = getelementptr inbounds <4 x i32>, <4 x i32>* %a0, i64 %a1
%sel = select i1 %a2, <4 x i32>* %a0, <4 x i32>* %gep
ret <4 x i32>* %sel
}
-->
define <4 x i32>* @select1(<4 x i32>* %a0, i64 %a1, i1 %a2) {
%sel = select i1 %a2, i64 0, i64 %a1
%gep = getelementptr inbounds <4 x i32>, <4 x i32>* %a0, i64 %sel
ret <4 x i32>* %gep
}

Differential Revision: https://reviews.llvm.org/D105901

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[InstCombine] Add basic (select C, (gep Ptr, Idx), Ptr) tests from PR50183

[InstCombine] Regenerate select-gep.ll tests

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

The reversion apparently deleted the test/Transforms directory.

Will be re-reverting again.

llvm-svn: 358552

[InstCombine] Do not fold scalar ops over select with vector condition.

If OtherOpT or OtherOpF have scalar types and the condition is a vector,
we would create an invalid select.

Reviewers: spatel

[InstCombine] Do not fold scalar ops over select with vector condition.

If OtherOpT or OtherOpF have scalar types and the condition is a vector,
we would create an invalid select.

Reviewers: spatel, john.brawn, mssimpso, craig.topper

Reviewed By: spatel

Differential Revision: https://reviews.llvm.org/D51781

llvm-svn: 341666

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[InstCombine] Make foldSelectOpOp able to handle two-operand getelementptr

Three (or more) operand getelementptrs could plausibly also be handled, but
handling only two-operand fits in easily with t

[InstCombine] Make foldSelectOpOp able to handle two-operand getelementptr

Three (or more) operand getelementptrs could plausibly also be handled, but
handling only two-operand fits in easily with the existing BinaryOperator
handling.

Differential Revision: https://reviews.llvm.org/D39958

llvm-svn: 322930

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[InstCombine] add baseline tests for D39958; NFC

llvm-svn: 322733