Summary:
The method `getLoopPassPreservedAnalyses` should not mark MemorySSA as
preserved, because it's being called in a lot of passes that do not
preserve MemorySSA.
Instead, mark the MemorySSA analysis as preserved by each pass that does
preserve it.
These changes only affect the new pass mananger.
Reviewers: chandlerc
Subscribers: mehdi_amini, jlebar, Prazek, george.burgess.iv, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62536
llvm-svn: 363091
This was discussed as part of D62880. The basic thought is that computing BE taken count after widening should produce (on average) an equally good backedge taken count as the one before widening. Since there's only one test in the suite which is impacted by this change, and it's essentially equivelent codegen, that seems to be a reasonable assertion. This change was separated from r362971 so that if this turns out to be problematic, the triggering piece is obvious and easily revertable.
For the nestedIV example from elim-extend.ll, we end up with the following BE counts:
BEFORE: (-2 + (-1 * %innercount) + %limit)
AFTER: (-1 + (sext i32 (-1 + %limit) to i64) + (-1 * (sext i32 %innercount to i64))<nsw>)
Note that before is an i32 type, and the after is an i64. Truncating the i64 produces the i32.
llvm-svn: 362975
This change does the plumbing to wire an ExitingBB parameter through the LFTR implementation, and reorganizes the code to work in terms of a set of individual loop exits. Most of it is fairly obvious, but there's one key complexity which makes it worthy of consideration. The actual multi-exit LFTR patch is in D62625 for context.
Specifically, it turns out the existing code uses the backedge taken count from before a IV is widened. Oddly, we can end up with a different (more expensive, but semantically equivelent) BE count for the loop when requerying after widening. For the nestedIV example from elim-extend, we end up with the following BE counts:
BEFORE: (-2 + (-1 * %innercount) + %limit)
AFTER: (-1 + (sext i32 (-1 + %limit) to i64) + (-1 * (sext i32 %innercount to i64))<nsw>)
This is the only test in tree which seems sensitive to this difference. The actual result of using the wider BETC on this example is that we actually produce slightly better code. :)
In review, we decided to accept that test change. This patch is structured to preserve the old behavior, but a separate change will immediate follow with the behavior change. (I wanted it separate for problem attribution purposes.)
Differential Revision: https://reviews.llvm.org/D62880
llvm-svn: 362971
Summary: Move some code around, in preparation for later fixes
to the non-integral addrspace handling (D59661)
Patch By Jameson Nash <jameson@juliacomputing.com>
Reviewed By: reames, loladiro
Differential Revision: https://reviews.llvm.org/D59729
llvm-svn: 362853
This is a really silly bug that even a simple test w/an unconditional latch would have caught. I tried to guard against the case, but put it in the wrong if check. Oops.
llvm-svn: 362727
The AllConstant check needs to be moved out of the if/else if chain to
avoid a test regression. The "there is no SimplifyZExt" comment
puzzles me, since there is SimplifyCastInst. Additionally, the
Simplify* calls seem to not see the operand as constant, so this needs
to be tried if the simplify failed.
llvm-svn: 362653
This reverts commit 5b32f60ec3.
The fix is in commit 4f9e68148b.
This patch fixes the CorrelatedValuePropagation pass to keep
prof branch_weights metadata of SwitchInst consistent.
It makes use of SwitchInstProfUpdateWrapper.
New tests are added.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D62126
llvm-svn: 362583
Fix for https://bugs.llvm.org/show_bug.cgi?id=31181 and partial fix
for LFTR poison handling issues in general.
When LFTR moves a condition from pre-inc to post-inc, it may now
depend on value that is poison due to nowrap flags. To avoid this,
we clear any nowrap flag that SCEV cannot prove for the post-inc
addrec.
Additionally, LFTR may switch to a different IV that is dynamically
dead and as such may be arbitrarily poison. This patch will correct
nowrap flags in some but not all cases where this happens. This is
related to the adoption of IR nowrap flags for the pre-inc addrec.
(See some of the switch_to_different_iv tests, where flags are not
dropped or insufficiently dropped.)
Finally, there are likely similar issues with the handling of GEP
inbounds, but we don't have a test case for this yet.
Differential Revision: https://reviews.llvm.org/D60935
llvm-svn: 362292
At the moment, LoopPredication completely bails out if it sees a latch of the form:
%cmp = icmp ne %iv, %N
br i1 %cmp, label %loop, label %exit
OR
%cmp = icmp ne %iv.next, %NPlus1
br i1 %cmp, label %loop, label %exit
This is unfortunate since this is exactly the form that LFTR likes to produce. So, go ahead and recognize simple cases where we can.
For pre-increment loops, we leverage the fact that LFTR likes canonical counters (i.e. those starting at zero) and a (presumed) range fact on RHS to discharge the check trivially.
For post-increment forms, the key insight is in remembering that LFTR had to insert a (N+1) for the RHS. CVP can hopefully prove that add nsw/nuw (if there's appropriate range on N to start with). This leaves us both with the post-inc IV and the RHS involving an nsw/nuw add, and SCEV can discharge that with no problem.
This does still need to be extended to handle non-one steps, or other harder patterns of variable (but range restricted) starting values. That'll come later.
Differential Revision: https://reviews.llvm.org/D62748
llvm-svn: 362282
If we can determine that a saturating add/sub will not overflow based
on range analysis, convert it into a simple binary operation. This is
a sibling transform to the existing with.overflow handling.
Reapplying this with an additional check that the saturating intrinsic
has integer type, as LVI currently does not support vector types.
Differential Revision: https://reviews.llvm.org/D62703
llvm-svn: 362263
Noticed on D62703. LVI only handles plain integers, not vectors of
integers. This was previously not an issue, because vector support
for with.overflow is only a relatively recent addition.
llvm-svn: 362261
If we can determine that a saturating add/sub will not overflow
based on range analysis, convert it into a simple binary operation.
This is a sibling transform to the existing with.overflow handling.
Differential Revision: https://reviews.llvm.org/D62703
llvm-svn: 362242
Summary:
I'm adding ORE to memset/memcpy formation, with tests,
but mainly this is split off from D61144.
Reviewers: reames, anemet, thegameg, craig.topper
Reviewed By: thegameg
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62631
llvm-svn: 362092
This reverts commit 53f2f32865.
As reported on D62126, this causes assertion failures if the switch
has incorrect branch_weights metadata, which may happen as a result
of other transforms not handling it correctly yet.
llvm-svn: 361881
This patch fixes the CorrelatedValuePropagation pass to keep
prof branch_weights metadata of SwitchInst consistent.
It makes use of SwitchInstProfUpdateWrapper.
New tests are added.
Reviewed By: nikic
Differential Revision: https://reviews.llvm.org/D62126
llvm-svn: 361808
The code to preserve LCSSA PHIs currently only properly supports
reduction PHIs and PHIs for values defined outside the latches.
This patch improves the LCSSA PHI handling to cover PHIs for values
defined in the latches.
Fixes PR41725.
Reviewers: efriedma, mcrosier, davide, jdoerfert
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D61576
llvm-svn: 361743
The guaranteed no-wrap region is never empty, it always contains at
least zero, so these optimizations don't ever apply.
To make this more obviously true, replace the conversative return
in makeGNWR with an assertion.
llvm-svn: 361698
Just a minor refactoring to use the new helper method
DataLayout::typeSizeEqualsStoreSize(). This is done when
checking if getTypeSizeInBits is equal/non-equal to
getTypeStoreSizeInBits.
llvm-svn: 361613
This change relaxes the checks for hasOnlyUniformBranches such that our
region is uniform if:
1. All conditional branches that are direct children are uniform.
2. And either:
a. All sub-regions are uniform.
b. There is one or less conditional branches among the direct
children.
Differential Revision: https://reviews.llvm.org/D62198
llvm-svn: 361610
Summary:
The DeadStoreElimination pass now skips doing
PartialStoreMerging when stores overlap according to
OW_PartialEarlierWithFullLater and at least one of
the stores is having a store size that is different
from the size of the type being stored.
This solves problems seen in
https://bugs.llvm.org/show_bug.cgi?id=41949
for which we in the past could end up with
mis-compiles or assertions.
The content and location of the padding bits is not
formally described (or undefined) in the LangRef
at the moment. So the solution is chosen based on
that we cannot assume anything about the padding bits
when having a store that clobbers more memory than
indicated by the type of the value that is stored
(such as storing an i6 using an 8-bit store instruction).
Fixes: https://bugs.llvm.org/show_bug.cgi?id=41949
Reviewers: spatel, efriedma, fhahn
Reviewed By: efriedma
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62250
llvm-svn: 361605
Summary:
This PR extends the loop object with more utilities to get loop bounds, step, induction variable, and guard branch. There already exists passes which try to obtain the loop induction variable in their own pass, e.g. loop interchange. It would be useful to have a common area to get these information. Moreover, loop fusion (https://reviews.llvm.org/D55851) is planning to use getGuard() to extend the kind of loops it is able to fuse, e.g. rotated loop with non-constant upper bound, which would have a loop guard.
/// Example:
/// for (int i = lb; i < ub; i+=step)
/// <loop body>
/// --- pseudo LLVMIR ---
/// beforeloop:
/// guardcmp = (lb < ub)
/// if (guardcmp) goto preheader; else goto afterloop
/// preheader:
/// loop:
/// i1 = phi[{lb, preheader}, {i2, latch}]
/// <loop body>
/// i2 = i1 + step
/// latch:
/// cmp = (i2 < ub)
/// if (cmp) goto loop
/// exit:
/// afterloop:
///
/// getBounds
/// getInitialIVValue --> lb
/// getStepInst --> i2 = i1 + step
/// getStepValue --> step
/// getFinalIVValue --> ub
/// getCanonicalPredicate --> '<'
/// getDirection --> Increasing
/// getGuard --> if (guardcmp) goto loop; else goto afterloop
/// getInductionVariable --> i1
/// getAuxiliaryInductionVariable --> {i1}
/// isCanonical --> false
Committed on behalf of @Whitney (Whitney Tsang).
Reviewers: kbarton, hfinkel, dmgreen, Meinersbur, jdoerfert, syzaara, fhahn
Reviewed By: kbarton
Subscribers: tvvikram, bmahjour, etiotto, fhahn, jsji, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60565
llvm-svn: 361517
`fadd` and `fsub` have recently (r351850) been added as `atomicrmw`
operations. This diff adds lowering cases for them to the LowerAtomic
transform.
Patch by Josh Berdine!
llvm-svn: 361512
Summary:
Because the sort order was not strongly stable on the RHS, whether the
chain could merge would depend on the order of the blocks in the Phi.
EXPENSIVE_CHECKS would shuffle the blocks before sorting, resulting in
non-deterministic merging.
Reviewers: gchatelet
Subscribers: hiraditya, llvm-commits, RKSimon
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62193
llvm-svn: 361281
And handle for self-move. This is required so that llvm::sort can work
with EXPENSIVE_CHECKS, as it will do a random shuffle of the input
which can result in self-moves.
llvm-svn: 361257
With a fix for PR41917: The predecessor list was changing under our feet.
- for (BasicBlock *Pred : predecessors(EntryBlock_)) {
+ while (!pred_empty(EntryBlock_)) {
+ BasicBlock* const Pred = *pred_begin(EntryBlock_);
llvm-svn: 361009
Using dominance vs a set membership check is indistinguishable from a compile time perspective, and the two queries return equivelent results. Simplify code by using the existing function.
llvm-svn: 360976
Summary:
The return value of a TryToUnfoldSelect call was not checked, which led to an
incorrectly preserved loop info and some crash.
The original crash was reported on https://reviews.llvm.org/D59514.
Reviewers: davidxl, amehsan
Reviewed By: davidxl
Subscribers: fhahn, brzycki, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61920
llvm-svn: 360780
Instead of patching the original blocks, we now generate new blocks and
delete the old blocks. This results in simpler code with a less twisted
control flow (see the change in `entry-block-shuffled.ll`).
This will make https://reviews.llvm.org/D60318 simpler by making it more
obvious where control flow created and deleted.
Reviewers: gchatelet
Subscribers: hiraditya, llvm-commits, spatel
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61736
llvm-svn: 360771
When an outer loop gets deleted by a different pass, before LICM visits
it, we cannot clean up its sub-loops in AliasSetMap, because at the
point we receive the deleteAnalysisLoop callback for the outer loop, the loop
object is already invalid and we cannot access its sub-loops any longer.
Reviewers: asbirlea, sanjoy, chandlerc
Reviewed By: asbirlea
Differential Revision: https://reviews.llvm.org/D61904
llvm-svn: 360704
The original change introduced a depth limit of 7 which caused a 22% regression
in the Swift MapReduceLazyCollection & Ackermann benchmarks. This new threshold
still ensures that the original test case doesn't hang.
rdar://50359639
llvm-svn: 360444
Summary:
- Constant expressions may not be added in strict postorder as the
forward instruction scan order. Thus, for a constant express (CE0), if
its operand (CE1) is used in an previous instruction, they are not in
postorder. However, different from
`cloneInstructionWithNewAddressSpace`,
`cloneConstantExprWithNewAddressSpace` doesn't bookkeep uninferred
instructions for later resolving. That results in failure of inferring
constant address.
- This patch adds the support to infer constant expression operand
recursively, since there won't be loop, if that operand is another
constant expression.
Reviewers: arsenm
Subscribers: jholewinski, jvesely, wdng, nhaehnle, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61760
llvm-svn: 360431
Summary:
Preserve MemorySSA in LoopSimplify, in the old pass manager, if the analysis is available.
Do not preserve it in the new pass manager.
Update tests.
Subscribers: nemanjai, jlebar, javed.absar, Prazek, kbarton, zzheng, jsji, llvm-commits, george.burgess.iv, chandlerc
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60833
llvm-svn: 360270
Reassociation's NegateValue moved instructions to the beginning of
blocks (after PHIs) without checking for exception handling pads.
It's possible for reassociation to move something into an exception
handling block so we need to make sure we don't move things too early
in the block. This change advances the insertion point past any
exception handling pads.
If the block we want to move into contains a catchswitch, we cannot
move into it. In that case just create a new neg as if we had not
found an existing neg to move.
Differential Revision: https://reviews.llvm.org/D61089
llvm-svn: 360262
If we fold a branch/switch to an unconditional branch to another dead block we
replace the branch with unreachable, to avoid attempting to fold the
unconditional branch.
Reviewers: davide, efriedma, mssimpso, jdoerfert
Reviewed By: jdoerfert
Differential Revision: https://reviews.llvm.org/D61300
llvm-svn: 360232
Summary:
It is a common thing to loop over every `PHINode` in some `BasicBlock`
and change old `BasicBlock` incoming block to a new `BasicBlock` incoming block.
`replaceSuccessorsPhiUsesWith()` already had code to do that,
it just wasn't a function.
So outline it into a new function, and use it.
Reviewers: chandlerc, craig.topper, spatel, danielcdh
Reviewed By: craig.topper
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61013
llvm-svn: 359996
Summary:
There is `PHINode::getBasicBlockIndex()`, `PHINode::setIncomingBlock()`
and `PHINode::getNumOperands()`, but no function to replace every
specified `BasicBlock*` predecessor with some other specified `BasicBlock*`.
Clearly, there are a lot of places that could use that functionality.
Reviewers: chandlerc, craig.topper, spatel, danielcdh
Reviewed By: craig.topper
Subscribers: llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61011
llvm-svn: 359995
This enables the pass to be used in the absence of
TargetTransformInfo. When the argument isn't passed, the factory
defaults to UninitializedAddressSpace and the flat address space is
obtained from the TargetTransformInfo as before this change. Existing
users won't have to change.
Patch by Kevin Petit.
Differential Revision: https://reviews.llvm.org/D60602
llvm-svn: 359290
Do not wrap the contents of printFusionCandidates in the LLVM_DEBUG macro. This
fixes an unused variable warning generated when compiling without asserts but
with -DENABLE_LLVM_DUMP.
Differential Revision: https://reviews.llvm.org/D61035
llvm-svn: 359161
Summary:
Both the input Value pointer and the returned Value
pointers in GetUnderlyingObjects are now declared as
const.
It turned out that all current (in-tree) uses of
GetUnderlyingObjects were trivial to update, being
satisfied with have those Value pointers declared
as const. Actually, in the past several of the users
had to use const_cast, just because of ValueTracking
not providing a version of GetUnderlyingObjects with
"const" Value pointers. With this patch we get rid
of those const casts.
Reviewers: hfinkel, materi, jkorous
Reviewed By: jkorous
Subscribers: dexonsmith, jkorous, jholewinski, sdardis, eraman, hiraditya, jrtc27, atanasyan, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D61038
llvm-svn: 359072
In some circumstances we can end up with setup costs that are very complex to
compute, even though the scevs are not very complex to create. This can also
lead to setupcosts that are calculated to be exactly -1, which LSR treats as an
invalid cost. This patch puts a limit on the recursion depth for setup cost to
prevent them taking too long.
Thanks to @reames for the report and test case.
Differential Revision: https://reviews.llvm.org/D60944
llvm-svn: 358958
This reverts commit 7bf4d7c07f2fac862ef34c82ad0fef6513452445.
After thinking about this more, this isn't right, the range is not exact
in the same sense as makeExactICmpRegion(). This needs a separate
function.
llvm-svn: 358876
Following D60632 makeGuaranteedNoWrapRegion() always returns an
exact nowrap region. Rename the function accordingly. This is in
line with the naming of makeExactICmpRegion().
llvm-svn: 358875
Summary:
Teach CorrelatedValuePropagation to also handle sub instructions in addition to add. Relatively simple since makeGuaranteedNoWrapRegion already understood sub instructions. Only subtle change is which range is passed as "Other" to that function, since sub isn't commutative.
Note that CorrelatedValuePropagation::processAddSub is still hidden behind a default-off flag as IndVarSimplify hasn't yet been fixed to strip the added nsw/nuw flags and causes a miscompile. (PR31181)
Reviewers: sanjoy, apilipenko, nikic
Reviewed By: nikic
Subscribers: hiraditya, jfb, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60036
llvm-svn: 358816
This is a follow-up to r291037+r291258, which used null debug locations
to prevent jumpy line tables.
Using line 0 locations achieves the same effect, but works better for
crash attribution because it preserves the right inline scope.
Differential Revision: https://reviews.llvm.org/D60913
llvm-svn: 358791
Summary:
Make the flags in LICM + MemorySSA tuning options in the old and new
pass managers.
Subscribers: mehdi_amini, jlebar, Prazek, george.burgess.iv, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60490
llvm-svn: 358772
The bug is that I didn't check whether the operand of the invariant_loads were themselves invariant. I don't know how this got missed in the patch and review. I even had an unreduced test case locally, and I remember handling this case, but I must have lost it in one of the rebases. Oops.
llvm-svn: 358688
The purpose of this patch is to eliminate a pass ordering dependence between LoopPredication and LICM. To understand the purpose, consider the following snippet of code inside some loop 'L' with IV 'i'
A = _a.length;
guard (i < A)
a = _a[i]
B = _b.length;
guard (i < B);
b = _b[i];
...
Z = _z.length;
guard (i < Z)
z = _z[i]
accum += a + b + ... + z;
Today, we need LICM to hoist the length loads, LoopPredication to make the guards loop invariant, and TrivialUnswitch to eliminate the loop invariant guard to establish must execute for the next length load. Today, if we can't prove speculation safety, we'd have to iterate these three passes 26 times to reduce this example down to the minimal form.
Using the fact that the array lengths are known to be invariant, we can short circuit this iteration. By forming the loop invariant form of all the guards at once, we remove the need for LoopPredication from the iterative cycle. At the moment, we'd still have to iterate LICM and TrivialUnswitch; we'll leave that part for later.
As a secondary benefit, this allows LoopPred to expose peeling oppurtunities in a much more obvious manner. See the udiv test changes as an example. If the udiv was not hoistable (i.e. we couldn't prove speculation safety) this would be an example where peeling becomes obviously profitable whereas it wasn't before.
A couple of subtleties in the implementation:
- SCEV's isSafeToExpand guarantees speculation safety (i.e. let's us expand at a new point). It is not a precondition for expansion if we know the SCEV corresponds to a Value which dominates the requested expansion point.
- SCEV's isLoopInvariant returns true for expressions which compute the same value across all iterations executed, regardless of where the original Value is located. (i.e. it can be in the loop) This implies we have a speculation burden to prove before expanding them outside loops.
- invariant_loads and AA->pointsToConstantMemory are two cases that SCEV currently does not handle, but meets the SCEV definition of invariance. I plan to sink this part into SCEV once this has baked for a bit.
Differential Revision: https://reviews.llvm.org/D60093
llvm-svn: 358684
Reverse the checking of the domiance order so that when a self compare happens,
it returns false. This makes compare function have strict weak ordering.
llvm-svn: 358636
This patch adds a basic loop fusion pass. It will fuse loops that conform to the
following 4 conditions:
1. Adjacent (no code between them)
2. Control flow equivalent (if one loop executes, the other loop executes)
3. Identical bounds (both loops iterate the same number of iterations)
4. No negative distance dependencies between the loop bodies.
The pass does not make any changes to the IR to create opportunities for fusion.
Instead, it checks if the necessary conditions are met and if so it fuses two
loops together.
The pass has not been added to the pass pipeline yet, and thus is not enabled by
default. It can be run stand alone using the -loop-fusion option.
Differential Revision: https://reviews.llvm.org/D55851
llvm-svn: 358607
Summary:
In the following cases, unrolling can be beneficial, even when
optimizing for code size:
1) very low trip counts
2) potential to constant fold most instructions after fully unrolling.
We can unroll in those cases, by setting the unrolling threshold to the
loop size. This might highlight some cost modeling issues and fixing
them will have a positive impact in general.
Reviewers: vsk, efriedma, dmgreen, paquette
Reviewed By: paquette
Differential Revision: https://reviews.llvm.org/D60265
llvm-svn: 358586
As it's causing some bot failures (and per request from kbarton).
This reverts commit r358543/ab70da07286e618016e78247e4a24fcb84077fda.
llvm-svn: 358546
This patch adds a basic loop fusion pass. It will fuse loops that conform to the
following 4 conditions:
1. Adjacent (no code between them)
2. Control flow equivalent (if one loop executes, the other loop executes)
3. Identical bounds (both loops iterate the same number of iterations)
4. No negative distance dependencies between the loop bodies.
The pass does not make any changes to the IR to create opportunities for fusion.
Instead, it checks if the necessary conditions are met and if so it fuses two
loops together.
The pass has not been added to the pass pipeline yet, and thus is not enabled by
default. It can be run stand alone using the -loop-fusion option.
Phabricator: https://reviews.llvm.org/D55851
llvm-svn: 358543
This is 1 of the problems discussed in the post-commit thread for:
rL355741 / http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20190311/635516.html
and filed as:
https://bugs.llvm.org/show_bug.cgi?id=41101
Instcombine tries to canonicalize some of these cases (and there's room for improvement
there independently of this patch), but it can't always do that because of extra uses.
So we need to recognize these commuted operand patterns here in EarlyCSE. This is similar
to how we detect commuted compares and commuted min/max/abs.
Differential Revision: https://reviews.llvm.org/D60723
llvm-svn: 358523
If a umul.with.overflow or smul.with.overflow operation cannot
overflow, simplify it to a simple mul nuw / mul nsw. After the
refactoring in D60668 this is just a matter of removing an
explicit check against multiplications.
Differential Revision: https://reviews.llvm.org/D60791
llvm-svn: 358521
This adds a WithOverflowInst class with a few helper methods to get
the underlying binop, signedness and nowrap type and makes use of it
where sensible. There will be two more uses in D60650/D60656.
The refactorings are all NFC, though I left some TODOs where things
could be improved. In particular we have two places where add/sub are
handled but mul isn't.
Differential Revision: https://reviews.llvm.org/D60668
llvm-svn: 358512
If LSR split critical edge during rewriting phi operands and
phi node has other pending fixup operands, we need to
update those pending fixups. Otherwise formulae will not be
implemented completely and some instructions will not be eliminated.
llvm.org/PR41445
Differential Revision: https://reviews.llvm.org/D60645
Patch by: Denis Bakhvalov <denis.bakhvalov@intel.com>
llvm-svn: 358457
This is a preparatory patch for D60093. This patch itself is NFC, but while preparing this I noticed and committed a small hoisting change in rL358419.
The basic structure of the new scheme is that we pass around the guard ("the using instruction"), and select an optimal insert point by examining operands at each construction point. This seems conceptually a bit cleaner to start with as it isolates the knowledge about insertion safety at the actual insertion point.
Note that the non-hoisting path is not actually used at the moment. That's not exercised until D60093 is rebased on this one.
Differential Revision: https://reviews.llvm.org/D60718
llvm-svn: 358434
Summary:
Enable some of the existing size optimizations for cold code under PGO.
A ~5% code size saving in big internal app under PGO.
The way it gets BFI/PSI is discussed in the RFC thread
http://lists.llvm.org/pipermail/llvm-dev/2019-March/130894.html
Note it doesn't currently touch loop passes.
Reviewers: davidxl, eraman
Reviewed By: eraman
Subscribers: mgorny, javed.absar, smeenai, mehdi_amini, eraman, zzheng, steven_wu, dexonsmith, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59514
llvm-svn: 358422
If we have multiple range checks which can be predicated, hoist the and of the results outside the loop. This minorly cleans up the resulting IR, but the main motivation is as a building block for D60093.
llvm-svn: 358419
Summary:
Create a method to forget everything in SCEV.
Add a cl::opt and PassManagerBuilder option to use this in LoopUnroll.
Motivation: Certain Halide applications spend a very long time compiling in forgetLoop, and prefer to forget everything and rebuild SCEV from scratch.
Sample difference in compile time reduction: 21.04 to 14.78 using current ToT release build.
Testcase showcasing this cannot be opensourced and is fairly large.
The option disabled by default, but it may be desirable to enable by
default. Evidence in favor (two difference runs on different days/ToT state):
File Before (s) After (s)
clang-9.bc 7267.91 6639.14
llvm-as.bc 194.12 194.12
llvm-dis.bc 62.50 62.50
opt.bc 1855.85 1857.53
File Before (s) After (s)
clang-9.bc 8588.70 7812.83
llvm-as.bc 196.20 194.78
llvm-dis.bc 61.55 61.97
opt.bc 1739.78 1886.26
Reviewers: sanjoy
Subscribers: mehdi_amini, jlebar, zzheng, javed.absar, dmgreen, jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60144
llvm-svn: 358304
Alina Sbirlea