llvm-svn: 354673

This patch adds LazyValueInfo to LowerSwitch to compute the range of the
value being switched over and reduce the size of the tree LowerSwitch
builds to lower a switch.

Reviewed By: arsenm

Differential Revision: https://reviews.llvm.org/D58096

llvm-svn: 354670

Summary:
This patch separates two semantics of `applyUpdates`:
1. User provides an accurate CFG diff and the dominator tree is updated according to the difference of `the number of edge insertions` and `the number of edge deletions` to infer the status of an edge before and after the update.
2. User provides a sequence of hints. Updates mentioned in this sequence might never happened and even duplicated.

Logic changes:

Previously, removing invalid updates is considered a side-effect of deduplication and is not guaranteed to be reliable. To handle the second semantic, `applyUpdates` does validity checking before deduplication, which can cause updates that have already been applied to be submitted again. Then, different calls to `applyUpdates` might cause unintended consequences, for example,
```
DTU(Lazy) and Edge A->B exists.
1. DTU.applyUpdates({{Delete, A, B}, {Insert, A, B}}) // User expects these 2 updates result in a no-op, but {Insert, A, B} is queued
2. Remove A->B
3. DTU.applyUpdates({{Delete, A, B}}) // DTU cancels this update with {Insert, A, B} mentioned above together (Unintended)
```
But by restricting the precondition that updates of an edge need to be strictly ordered as how CFG changes were made, we can infer the initial status of this edge to resolve this issue.

Interface changes:
The second semantic of `applyUpdates`  is separated to `applyUpdatesPermissive`.
These changes enable DTU(Lazy) to use the first semantic if needed, which is quite useful in `transforms/utils`.

Reviewers: kuhar, brzycki, dmgreen, grosser

Reviewed By: brzycki

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58170

llvm-svn: 354669

The correct edge being deleted is not to the unswitched exit block, but to the
original block before it was split. That's the key in the map, not the
value.
The insert is correct. The new edge is to the .split block.

The splitting turns OriginalBB into:
OriginalBB -> OriginalBB.split.
Assuming the orignal CFG edge: ParentBB->OriginalBB, we must now delete
ParentBB->OriginalBB, not ParentBB->OriginalBB.split.

llvm-svn: 354656

Summary: This patch converts all existing `insertEdge*/deleteEdge*` to `applyUpdates` and marks `insertEdge*/deleteEdge*` as deprecated.

Reviewers: kuhar, brzycki

Reviewed By: kuhar, brzycki

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58443

llvm-svn: 354652

MemorySSA is now updated when forming dedicated exit blocks.
Resolves PR40037.

llvm-svn: 354623

Summary:
MemorySSA is not properly updated in LoopSimplifyCFG after recent changes. Use SplitBlock utility to resolve that and clear all updates once handleDeadExits is finished.
All updates that follow are removal of edges which are safe to handle via the removeEdge() API.
Also, deleting dead blocks is done correctly as is, i.e. delete from MemorySSA before updating the CFG and DT.

Reviewers: mkazantsev, rtereshin

Subscribers: sanjoy, jlebar, Prazek, george.burgess.iv, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58524

llvm-svn: 354613

Summary: Cleanup nop assignments.

Reviewers: george.burgess.iv, davide

Subscribers: sanjoy, jlebar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58308

llvm-svn: 354612

llvm-svn: 354580

Check the operands of a select are pointers, to determine if it is an address
expression or not.

https://reviews.llvm.org/D58226

llvm-svn: 354576

When we create fictive switch in preheader, we should take
care about MSSA and delete edge between old preheader and
header.

llvm-svn: 354547

is false.

Right now for inliner and partial inliner, we always pass the address of a
valid ORE object to getInlineCost even if RemarkEnabled is false because of
no -Rpass is specified. Since ComputeFullInlineCost will be set to true if
ORE is non-null in getInlineCost, this introduces the problem that in
getInlineCost we cannot return early even if we already know the cost is
definitely higher than the threshold. It is a general problem for compile
time.

This patch fixes that by pass nullptr as the ORE argument if RemarkEnabled is
false.

Differential Revision: https://reviews.llvm.org/D58399

llvm-svn: 354542

Noticed these while doing a final sweep of the code to make sure I hadn't missed anything in my last couple of patches.  The (minor) missed optimization was noticed because of the stylistic fix to avoid an overly specific cast.

llvm-svn: 354412

Same case as for memset and memcpy, but this time for clobbering stores and loads.  We still can't allow coercion to or from non-integrals, regardless of the transform.

Now that I'm done the whole little sequence, it seems apparent that we'd entirely missed reasoning about clobbers in the original GVN support for non-integral pointers.

My appologies, I thought we'd upstreamed all of this, but it turns out we were still carrying a downstream hack which hid all of these issues.  My chanks to Cherry Zhang for helping debug.

llvm-svn: 354407

Problem is very similiar to the one fixed for memsets in r354399, we try to coerce a value to non-integral type, and then crash while try to do so.  Since we shouldn't be doing such coercions to start with, easy fix.  From inspection, I see two other cases which look to be similiar and will follow up with most test cases and fixes if confirmed.

llvm-svn: 354403

GVN generally doesn't forward structs or array types, but it *will* forward vector types to non-vectors and vice versa.  As demonstrated in tests, we need to inhibit the same set of transforms for vector of non-integral pointers as for non-integral pointers themselves.

llvm-svn: 354401

If we encountered a location where we tried to forward the value of a memset to a load of a non-integral pointer, we crashed.  Such a forward is not legal in general, but we can forward null pointers.  Test for both cases are included.

llvm-svn: 354399

We want to use the sum in the icmp to allow matching with
m_UAddWithOverflow and eliminate the 'not'. This is discussed
in D51929 and is another step towards solving PR14613:
https://bugs.llvm.org/show_bug.cgi?id=14613

  Name: uaddsat, -1 fval
  %notx = xor i32 %x, -1
  %a = add i32 %x, %y
  %c = icmp ugt i32 %notx, %y
  %r = select i1 %c, i32 %a, i32 -1
  =>
  %a = add i32 %x, %y
  %c2 = icmp ugt i32 %y, %a
  %r = select i1 %c2, i32 -1, i32 %a

  Name: uaddsat, -1 fval + ult
  %notx = xor i32 %x, -1
  %a = add i32 %x, %y
  %c = icmp ult i32 %y, %notx
  %r = select i1 %c, i32 %a, i32 -1
  =>
  %a = add i32 %x, %y
  %c2 = icmp ugt i32 %y, %a
  %r = select i1 %c2, i32 -1, i32 %a

https://rise4fun.com/Alive/nTp

llvm-svn: 354393

This is no-functional-change-intended, but that was also
true when it was part of rL354276, and I managed to lose
2 predicates for the fold with constant...causing much bot
distress. So this time I'm adding a couple of negative tests
to avoid that.

llvm-svn: 354384

We are planning to be able to delete the current loop in LoopSimplifyCFG
in the future. Add API to notify the loop pass manager that it happened.

llvm-svn: 354314

llvm-svn: 354313

This reverts commit 079b610c.
Bots are failing after this change on a stage 2 compile of clang.

llvm-svn: 354277

We want to use the sum in the icmp to allow matching with
m_UAddWithOverflow and eliminate the 'not'. This is discussed
in D51929 and is another step towards solving PR14613:
https://bugs.llvm.org/show_bug.cgi?id=14613

  Name: uaddsat, -1 fval
  %notx = xor i32 %x, -1
  %a = add i32 %x, %y
  %c = icmp ugt i32 %notx, %y
  %r = select i1 %c, i32 %a, i32 -1
  =>
  %a = add i32 %x, %y
  %c2 = icmp ugt i32 %y, %a
  %r = select i1 %c2, i32 -1, i32 %a

  Name: uaddsat, -1 fval + ult
  %notx = xor i32 %x, -1
  %a = add i32 %x, %y
  %c = icmp ult i32 %y, %notx
  %r = select i1 %c, i32 %a, i32 -1
  =>
  %a = add i32 %x, %y
  %c2 = icmp ugt i32 %y, %a
  %r = select i1 %c2, i32 -1, i32 %a

https://rise4fun.com/Alive/nTp

llvm-svn: 354276

This should be NFC in current use case of this method, but it will
help to use it for solving more compex tasks in follow-up patches.

llvm-svn: 354227

We want to use the sum in the icmp to allow matching with
m_UAddWithOverflow and eliminate the 'not'. This is discussed
in D51929 and is another step towards solving PR14613:
https://bugs.llvm.org/show_bug.cgi?id=14613

  Name: not op
  %notx = xor i32 %x, -1
  %a = add i32 %x, %y
  %c = icmp ult i32 %notx, %y
  %r = select i1 %c, i32 -1, i32 %a
  =>
  %a = add i32 %x, %y
  %c2 = icmp ult i32 %a, %y
  %r = select i1 %c2, i32 -1, i32 %a

  Name: not op ugt
  %notx = xor i32 %x, -1
  %a = add i32 %x, %y
  %c = icmp ugt i32 %y, %notx
  %r = select i1 %c, i32 -1, i32 %a
  =>
  %a = add i32 %x, %y
  %c2 = icmp ult i32 %a, %y
  %r = select i1 %c2, i32 -1, i32 %a

https://rise4fun.com/Alive/niom

(The matching here is still incomplete.)

llvm-svn: 354224

We want to use the sum in the icmp to allow matching with
m_UAddWithOverflow and eliminate the 'not'. This is discussed
in D51929 and is another step towards solving PR14613:
https://bugs.llvm.org/show_bug.cgi?id=14613

(The matching here is incomplete. Trying to take minimal steps
to make sure we don't induce infinite looping from existing
canonicalizations of the 'select'.)

llvm-svn: 354221

llvm-svn: 354220

llvm-svn: 354218

Summary:
Unlimitted number of calls to getClobberingAccess can lead to high
compile times in pathological cases.
Limitting getClobberingAccess to a fairly high number. Can be adjusted
based on users/need.
Note: this is the only user of MemorySSA currently enabled by default.
The same handling exists in LICM (disabled atm). As MemorySSA gains more
users, this logic of capping will need to move inside MemorySSA.

Reviewers: george.burgess.iv

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D58248

llvm-svn: 354182

Better addressing comments from https://reviews.llvm.org/D58290.

llvm-svn: 354171

Implement two more transforms of atomicrmw:
1) We can convert an atomicrmw which produces a known value in memory into an xchg instead.
2) We can convert an atomicrmw xchg w/o users into a store for some orderings.

Differential Revision: https://reviews.llvm.org/D58290

llvm-svn: 354170

If a lifetime.end marker occurs along one path through the extraction
region, but not another, then it's still incorrect to lift the marker,
because there is some path through the extracted function which would
ordinarily not reach the marker. If the call to the extracted function
is in a loop, unrolling can cause inputs to the function to become
optimized out as undef after the first iteration.

To prevent incorrect stack slot merging in the calling function, it
should be sufficient to lift lifetime.start markers for region inputs.
I've tested this theory out by doing a stage2 check-all with randomized
splitting enabled.

This is a follow-up to r353973, and there's additional context for this
change in https://reviews.llvm.org/D57834.

rdar://47896986

Differential Revision: https://reviews.llvm.org/D58253

llvm-svn: 354159

With or without PGO data applied, splitting early in the pipeline
(either before the inliner or shortly after it) regresses performance
across SPEC variants. The cause appears to be that splitting hides
context for subsequent optimizations.

Schedule splitting late again, in effect reversing r352080, which
scheduled the splitting pass early for code size benefits (documented in
https://reviews.llvm.org/D57082).

Differential Revision: https://reviews.llvm.org/D58258

llvm-svn: 354158

https://bugs.llvm.org/show_bug.cgi?id=40734

llvm-svn: 354144

Summary:
The idea is that we now manipulate bases through a `unsigned BaseID` based on
order of appearance in the comparison chain rather than through the `Value*`.

Fixes 40714.

Reviewers: gchatelet

Subscribers: mgrang, jfb, jdoerfert, llvm-commits, hans

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D58274

llvm-svn: 354131

llvm-svn: 354128

llvm-svn: 354124

llvm-svn: 354123

llvm-svn: 354118

llvm-svn: 354107