Extend sinking logic to duplicate scalar steps recipe if it enables
sinking, that is if all users in a destination block require all lanes.

This should be the last step before removing legacy sinkScalarOperands.

PR: https://github.com/llvm/llvm-project/pull/136021

Considering that "or disjoint" is the canonical for certain add
operations, then I think we want to support such "add like" operations
when doing ADD+GEP->GEP+GEP rewrites to make things more consistent.

Problem was found when improving ValueTracking, which turned an ADD into
OR, and then suddenly optimizations got worse due to these rewrites no
longer triggering.

Follow-up to dfca6c0d3bf9d1a056 to extend isUnrolled handle any unrolled
VPlan, which means there's a single UF, but it will be > 1 if unrolling
took place.

Update and generalize materializeBroadcasts to also introduce explicit
broadcasts for VPValues defined in the Plans Entry block.

This fixes a crash when trying to insert the broadcasts generated by
VPTransformState::get after the generating instruction, which isn't
possible after invoke instructions.

Fixes https://github.com/llvm/llvm-project/issues/128838.

Add a new VPInstruction::Broadcast opcode and use it to materialize
explicit broadcasts of live-ins. The initial patch only materlizes the
broadcasts if the vector preheader dominates all uses that need it.
Later patches will pick the best valid insert point, thus retiring
implicit hoisting of broadcasts from VPTransformsState::get().

PR: https://github.com/llvm/llvm-project/pull/124644

Update getOrCreateVPValueForSCEVExpr to only skip expansion of
SCEVUnknown if the underlying value isn't an instruction. Instructions
may be defined in a loop and using them without expansion may break
LCSSA form. SCEVExpander will take care of preserving LCSSA if needed.

We could also try to pass LoopInfo, but there are some users of the
function where it won't be available and main benefit from skipping
expansion is slightly more concise VPlans.

Note that SCEVExpander is now used to expand SCEVUnknown with floats.
Adjust the check in expandCodeFor to only check the types and casts if
the type of the value is different to the requested type. Otherwise we
crash when trying to expand a float and requesting a float type.

Fixes https://github.com/llvm/llvm-project/issues/121518.

PR: https://github.com/llvm/llvm-project/pull/125235

This reverts commit f09b16e2671cbcdf7cb7dc7ed705db092a9deda1.

The crash when building llvm-test-suite with stage2 should have been
fixed by 1091fad31a83d5ab87eb6fa11fe3bdb3f0d152ea.

This reverts commit 0678e2058364ec10b94560d27ec7138dfa003287.
This reverts commit 1091fad31a83d5ab87eb6fa11fe3bdb3f0d152ea.

Causes crashes in llvm-test-suite when using stage 2 clang.

Updated ILV.createInductionResumeValues (now createInductionResumeVPValue)
to directly update the VPIRInstructions wrapping the original phis with the 
created resume values.

This is the first step towards modeling them completely in VPlan.
Subsequent patches will move creation of the resume values completely
into VPlan.

Depends on https://github.com/llvm/llvm-project/pull/109975.

PR: https://github.com/llvm/llvm-project/pull/110577

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