Summary:
This is the first patch for the loop guard. We introduced
getLoopGuardBranch() and isGuarded().
This currently only works on simplified loop, as it requires a preheader
and a latch to identify the guard.
It will work on loops of the form:
/// GuardBB:
/// br cond1, Preheader, ExitSucc <== GuardBranch
/// Preheader:
/// br Header
/// Header:
/// ...
/// br Latch
/// Latch:
/// br cond2, Header, ExitBlock
/// ExitBlock:
/// br ExitSucc
/// ExitSucc:
Prior discussions leading upto the decision to introduce the loop guard
API: http://lists.llvm.org/pipermail/llvm-dev/2019-May/132607.html
Reviewer: reames, kbarton, hfinkel, jdoerfert, Meinersbur, dmgreen
Reviewed By: reames
Subscribers: wuzish, hiraditya, jsji, llvm-commits, bmahjour, etiotto
Tag: LLVM
Differential Revision: https://reviews.llvm.org/D63885
llvm-svn: 367033
Summary:
SimplifyFPBinOp is a variant of SimplifyBinOp that lets you specify
fast math flags, but the name is misleading because both functions
can simplify both FP and non-FP ops. Instead, overload SimplifyBinOp
so that you can optionally specify fast math flags.
Likewise for SimplifyFPUnOp.
Reviewers: spatel
Reviewed By: spatel
Subscribers: xbolva00, cameron.mcinally, eraman, hiraditya, haicheng, zzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64902
llvm-svn: 366902
It is not safe in general to replace an alias in a GEP with its aliasee
if the alias can be replaced with another definition (i.e. via strong/weak
resolution (linkonce_odr) or via symbol interposition (default visibility
in ELF)) while the aliasee cannot. An example of how this can go wrong is
in the included test case.
I was concerned that this might be a load-bearing misoptimization (it's
possible for us to use aliases to share vtables between base and derived
classes, and on Windows, vtable symbols will always be aliases in RTTI
mode, so this change could theoretically inhibit trivial devirtualization
in some cases), so I built Chromium for Linux and Windows with and without
this change. The file sizes of the resulting binaries were identical, so it
doesn't look like this is going to be a problem.
Differential Revision: https://reviews.llvm.org/D65118
llvm-svn: 366754
Summary:
- As the pointer stripping now tracks through `addrspacecast`, prepare
to handle the bit-width difference from the result pointer.
Reviewers: jdoerfert
Subscribers: jvesely, nhaehnle, hiraditya, arphaman, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64928
llvm-svn: 366470
Summary:
LoopInfoWrapperPass::verify uses DT, which means DT must be alive
even if it has no direct users.
Fixes a crash in expensive checks mode.
Reviewers: pcc, leonardchan
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64896
llvm-svn: 366388
Implement IR intrinsics for stack tagging. Generated code is very
unoptimized for now.
Two special intrinsics, llvm.aarch64.irg.sp and llvm.aarch64.tagp are
used to implement a tagged stack frame pointer in a virtual register.
Differential Revision: https://reviews.llvm.org/D64172
llvm-svn: 366360
Summary:
Since the target has no significant advantage of vectorization,
vector instructions bous threshold bonus should be optional.
amdgpu-inline-arg-alloca-cost parameter default value and the target
InliningThresholdMultiplier value tuned then respectively.
Reviewers: arsenm, rampitec
Subscribers: kzhuravl, jvesely, wdng, nhaehnle, yaxunl, dstuttard, tpr, t-tye, eraman, hiraditya, haicheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64642
llvm-svn: 366348
Summary:
- As the pointer stripping could trace through `addrspacecast` now, need
to sext/trunc the offset to ensure it has the same width as the
pointer after stripping.
Reviewers: jdoerfert
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64768
llvm-svn: 366162
Summary:
There is currently a correctness issue when unrolling loops containing
callbr's where their indirect targets are being updated correctly to the
newly created labels, but their operands are not. This manifests in
unrolled loops where the second and subsequent copies of callbr
instructions have blockaddresses of the label from the first instance of
the unrolled loop, which would result in nonsensical runtime control
flow.
For now, conservatively do not unroll the loop. In the future, I think
we can pursue unrolling such loops provided we transform the cloned
callbr's operands correctly.
Such a transform and its legalities are being discussed in:
https://reviews.llvm.org/D64101
Link: https://bugs.llvm.org/show_bug.cgi?id=42489
Link: https://groups.google.com/forum/#!topic/clang-built-linux/z-hRWP9KqPI
Reviewers: fhahn, hfinkel, efriedma
Reviewed By: fhahn, hfinkel, efriedma
Subscribers: efriedma, hiraditya, zzheng, dmgreen, llvm-commits, pirama, kees, nathanchance, E5ten, craig.topper, chandlerc, glider, void, srhines
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64368
llvm-svn: 366130
Summary: Vector of the same value with few undefs will sill be considered "Bytewise"
Reviewers: eugenis, pcc, jfb
Reviewed By: jfb
Subscribers: dexonsmith, hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64031
llvm-svn: 365971
Summary:
This helps with more efficient use of memset for pattern initialization
From @pcc prototype for -ftrivial-auto-var-init=pattern optimizations
Binary size change on CTMark, (with -fuse-ld=lld -Wl,--icf=all, similar results with default linker options)
```
master patch diff
Os 8.238864e+05 8.238864e+05 0.0
O3 1.054797e+06 1.054797e+06 0.0
Os zero 8.292384e+05 8.292384e+05 0.0
O3 zero 1.062626e+06 1.062626e+06 0.0
Os pattern 8.579712e+05 8.338048e+05 -0.030299
O3 pattern 1.090502e+06 1.067574e+06 -0.020481
```
Zero vs Pattern on master
```
zero pattern diff
Os 8.292384e+05 8.579712e+05 0.036578
O3 1.062626e+06 1.090502e+06 0.025124
```
Zero vs Pattern with the patch
```
zero pattern diff
Os 8.292384e+05 8.338048e+05 0.003333
O3 1.062626e+06 1.067574e+06 0.003193
```
Reviewers: pcc, eugenis
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D63967
llvm-svn: 365858
The interface predates CallBase, so both it and implementation were
significantly more complicated than they needed to be. There was even
some redundancy that could be eliminated.
Should also help with OpaquePointers by not trying to derive a
function's type from it's PointerType.
llvm-svn: 365767
This patch replaces the three almost identical "strip & accumulate"
implementations for constant pointer offsets with a single one,
combining the respective functionalities. The old interfaces are kept
for now.
Differential Revision: https://reviews.llvm.org/D64468
llvm-svn: 365723
Summary:
We will need to handle IntToPtr which I will submit in a separate patch as it's
not going to be NFC.
Reviewers: eugenis, pcc
Reviewed By: eugenis
Subscribers: hiraditya, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D63940
llvm-svn: 365709
This makes the functions in Loads.h require a type to be specified
independently of the pointer Value so that when pointers have no structure
other than address-space, it can still do its job.
Most callers had an obvious memory operation handy to provide this type, but a
SROA and ArgumentPromotion were doing more complicated analysis. They get
updated to merge the properties of the various instructions they were
considering.
llvm-svn: 365468
This patch adds a function attribute, nofree, to indicate that a function does
not, directly or indirectly, call a memory-deallocation function (e.g., free,
C++'s operator delete).
Reviewers: jdoerfert
Differential Revision: https://reviews.llvm.org/D49165
llvm-svn: 365336
It's possible that some function can load and store the same
variable using the same constant expression:
store %Derived* @foo, %Derived** bitcast (%Base** @bar to %Derived**)
%42 = load %Derived*, %Derived** bitcast (%Base** @bar to %Derived**)
The bitcast expression was mistakenly cached while processing loads,
and never examined later when processing store. This caused @bar to
be mistakenly treated as read-only variable. See load-store-caching.ll.
llvm-svn: 365188
This reverts r365040 (git commit 5cacb91475)
Speculatively reverting, since this appears to have broken check-lld on
Linux. Partial analysis in https://crbug.com/981168.
llvm-svn: 365097
We haven't changed the set of users, just specialized an operand for those users. Given that, the previous wrap flags must still be correct.
Sorry for the lack of test case. Noticed this while working on something else, and haven't figured out to exercise this standalone.
llvm-svn: 365053
On some occasions ReuseOrCreateCast may convert previously
expanded value to undefined. That value may be passed by
SCEVExpander as an argument to InsertBinop making IV chain
undefined.
Differential revision: https://reviews.llvm.org/D63928
llvm-svn: 365009
This reverts r364422 (git commit 1a3dc76186)
The inlining cost calculation is incorrect, leading to stack overflow due to large stack frames from heavy inlining.
llvm-svn: 365000
Summary:
If LTOUnit splitting is disabled, the module summary analysis computes
the summary information necessary to perform single implementation
devirtualization during the thin link with the index and no IR. The
information collected from the regular LTO IR in the current hybrid WPD
algorithm is summarized, including:
1) For vtable definitions, record the function pointers and their offset
within the vtable initializer (subsumes the information collected from
IR by tryFindVirtualCallTargets).
2) A record for each type metadata summarizing the vtable definitions
decorated with that metadata (subsumes the TypeIdentiferMap collected
from IR).
Also added are the necessary bitcode records, and the corresponding
assembly support.
The follow-on index-based WPD patch is D55153.
Depends on D53890.
Reviewers: pcc
Subscribers: mehdi_amini, Prazek, inglorion, eraman, steven_wu, dexonsmith, arphaman, llvm-commits
Differential Revision: https://reviews.llvm.org/D54815
llvm-svn: 364960
I'm currently working on a GSoC project that aims to improve the the bug reports
of the analyzer. The main heuristic I plan to use is to explain values that are
a control dependency of the bug location better.
01 bool b = messyComputation();
02 int i = 0;
03 if (b) // control dependency of the bug site, let's explain why we assume val
04 // to be true
05 10 / i; // warn: division by zero
Because of this, I'd like to generalize IDFCalculator so that I could use it for
Clang's CFG: D62883.
In detail:
* Rename IDFCalculator to IDFCalculatorBase, make it take a general CFG node
type as a template argument rather then strictly BasicBlock (but preserve
ForwardIDFCalculator and ReverseIDFCalculator)
* Move IDFCalculatorBase from llvm/include/llvm/Analysis to
llvm/include/llvm/Support (but leave the BasicBlock variants in
llvm/include/llvm/Analysis)
* clang-format the file since this patch messes up git blame anyways
* Change typedef to using
* Add the new type ChildrenGetterTy, and store an instance of it in
IDFCalculatorBase. This is important because I'll have to specialize it for
Clang's CFG to filter out nullpointer successors, similarly to D62507.
Differential Revision: https://reviews.llvm.org/D63389
llvm-svn: 364911
The `willreturn` function attribute guarantees that a function call will
come back to the call site if the call is also known not to throw.
Therefore, this attribute can be used in
`isGuaranteedToTransferExecutionToSuccessor`.
Patch by Hideto Ueno (@uenoku)
Reviewers: jdoerfert, sstefan1
Reviewed By: jdoerfert
Subscribers: hiraditya, jfb, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63372
llvm-svn: 364580
The previous output was next to useless if *any* exit was not computable. If we have more than one exit, show the exit count for each so that it's easier to see what's going from with SCEV analysis when debugging.
llvm-svn: 364579
Summary:
Doing better separation of Cost and Threshold.
Cost counts the abstract complexity of live instructions, while Threshold is an upper bound of complexity that inlining is comfortable to pay.
There are two parts:
- huge 15K last-call-to-static bonus is no longer subtracted from Cost
but rather is now added to Threshold.
That makes much more sense, as the cost of inlining (Cost) is not changed by the fact
that internal function is called once. It only changes the likelyhood of this inlining
being profitable (Threshold).
- bonus for calls proved-to-be-inlinable into callee is no longer subtracted from Cost
but added to Threshold instead.
While calculations are somewhat different, overall InlineResult should stay the same since Cost >= Threshold compares the same.
Reviewers: eraman, greened, chandlerc, yrouban, apilipenko
Reviewed By: apilipenko
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D60740
llvm-svn: 364422
Summary:
Handle smul.fix.sat in the scalarizer. This is done by
adding smul.fix.sat to the set of "isTriviallyVectorizable"
intrinsics.
The addition of smul.fix.sat in isTriviallyVectorizable and
hasVectorInstrinsicScalarOpd can also be seen as a preparation
to be able to use hasVectorInstrinsicScalarOpd in ConstantFolding.
Reviewers: rengolin, RKSimon, dblaikie
Reviewed By: rengolin
Subscribers: hiraditya, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63704
llvm-svn: 364177
As discussed in PR42314:
https://bugs.llvm.org/show_bug.cgi?id=42314
Improving the canonicalization for these patterns:
rL363956
...means we should adjust/enhance the related simplification.
https://rise4fun.com/Alive/w1cp
Name: isPow2 or zero
%x = and i32 %xx, 2048
%a = add i32 %x, -1
%r = and i32 %a, %x
=>
%r = i32 0
llvm-svn: 363997
Summary:
This is unfortunately needed for correctness, if we are to extend the tolerance of the update API to the way simple loop unswitch is doing cloning.
In simple loop unswitch (as opposed to loop unswitch), not all blocks are cloned. This can create unreachable cloned blocks (no predecessor), which are later cleaned up.
In MemorySSA, the APIs for supporting these kind of updates (clone + update exit blocks), make certain assumption on the integrity of the CFG. When cloning, if something was not cloned, it's values in MemorySSA default to LiveOnEntry. When updating exit blocks, it is safe to assume that we can first insert phis in the blocks merging two clones, then add additional phis in the IDF of the blocks that received phis. This no longer holds true if one of the clones being merged comes from an unreachable block. We'd conservatively need to add all phis before filling in their incoming definitions. In practice this restriction can be relaxed if we clean up trivial phis after the first round of insertion.
Reviewers: george.burgess.iv
Subscribers: jlebar, Prazek, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63354
llvm-svn: 363880
Whitney Tsang