Commit Graph

9003 Commits

Author SHA1 Message Date
Teresa Johnson f9ca75f19b [Inliner] Inlining should honor nobuiltin attributes
Summary:
Final patch in series to fix inlining between functions with different
nobuiltin attributes/options, which was specifically an issue in LTO.
See discussion on D61634 for background.

The prior patch in this series (D67923) enabled per-Function TLI
construction that identified the nobuiltin attributes.

Here I have allowed inlining to proceed if the callee's nobuiltins are a
subset of the caller's nobuiltins, but not in the reverse case, which
should be conservatively correct. This is controlled by a new option,
-inline-caller-superset-nobuiltin, which is enabled by default.

Reviewers: hfinkel, gchatelet, chandlerc, davidxl

Subscribers: arsenm, jvesely, nhaehnle, mehdi_amini, eraman, hiraditya, haicheng, dexonsmith, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74162
2020-02-28 07:34:14 -08:00
serge-sans-paille 6d15c4deab No longer generate calls to *_finite
According to Joseph Myers, a libm maintainer

> They were only ever an ABI (selected by use of -ffinite-math-only or
> options implying it, which resulted in the headers using "asm" to redirect
> calls to some libm functions), not an API. The change means that ABI has
> turned into compat symbols (only available for existing binaries, not for
> anything newly linked, not included in static libm at all, not included in
> shared libm for future glibc ports such as RV32), so, yes, in any case
> where tools generate direct calls to those functions (rather than just
> following the "asm" annotations on function declarations in the headers),
> they need to stop doing so.

As a consequence, we should no longer assume these symbols are available on the
target system.

Still keep the TargetLibraryInfo for constant folding.

Differential Revision: https://reviews.llvm.org/D74712
2020-02-28 10:07:37 +01:00
Bardia Mahjour 1b811ff8a9 [DA] Delinearization of fixed-size multi-dimensional arrays
Summary:
Currently the dependence analysis in LLVM is unable to compute accurate
dependence vectors for multi-dimensional fixed size arrays.
This is mainly because the delinearization algorithm in scalar evolution
relies on parametric terms to be present in the access functions. In the
case of fixed size arrays such parametric terms are not present, but we
can use the indexes from GEP instructions to recover the subscripts for
each dimension of the arrays. This patch adds this ability under the
existing option `-da-disable-delinearization-checks`.

Authored By: bmahjour

Reviewer: Meinersbur, sebpop, fhahn, dmgreen, grosser, etiotto, bollu

Reviewed By: Meinersbur

Subscribers: hiraditya, arphaman, Whitney, ppc-slack, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72178
2020-02-27 10:29:01 -05:00
Jay Foad 5900d3f2e9 [AMDGPU][ConstantFolding] Fold llvm.amdgcn.fract intrinsic
Reviewers: nhaehnle, arsenm, rampitec

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D75179
2020-02-27 14:37:53 +00:00
Kirill Naumov c965fd942f Cost Annotation Writer for InlineCost
Add extra diagnostics for the inline cost analysis under
-print-instruction-deltas cl option. When enabled along with
-debug-only=inline-cost it prints the IR of inline candidate
annotated with cost and threshold change per every instruction.

Reviewed By: apilipenko, davidxl, mtrofin

Differential Revision: https://reviews.llvm.org/D71501
2020-02-26 17:03:52 -08:00
Roman Lebedev 400ceda425
[SCEV][IndVars] Always provide insertion point to the SCEVExpander::isHighCostExpansion()
Summary: This addresses the `llvm/test/Transforms/IndVarSimplify/elim-extend.ll` `@nestedIV` regression from D73728

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73777
2020-02-25 23:05:59 +03:00
Roman Lebedev d6f47aeb51
[SCEV] SCEVExpander::isHighCostExpansionHelper(): cost-model min/max (PR44668)
Summary:
Previosly we simply always said that `SCEVMinMaxExpr` is too costly to expand.
But this isn't really true, it expands into just a comparison+swap pair.
And again much like with add/mul, there will be one less such pair
than the number of operands. And we need to count the cost of operands themselves.

This does change a number of testcases, and as far as i can tell,
all of these changes are improvements, in the sense that
we fixed up more latches to do the [in]equality comparison.

This concludes cost-modelling changes, no other SCEV expressions exist as of now.

This is a part of addressing [[ https://bugs.llvm.org/show_bug.cgi?id=44668 | PR44668 ]].

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: hiraditya, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73744
2020-02-25 23:05:59 +03:00
Roman Lebedev 0f3c9b54e6
[SCEV] SCEVExpander::isHighCostExpansionHelper(): cost-model polynomial recurrence
Summary:
So, i wouldn't call this *obviously* correct,
but i think i got it right this time :)

Roughly, we have
```
Op0*x^0 + Op1*x^1 + Op2*x^2 ...
```
where `Op_{n} * x^{n}` is called term, and `n` the degree of term.

Due to the way they are stored internally in `SCEVAddRecExpr`,
i believe we can have `Op_{n}` to be `0`, so we should not charge for those.

I think it is most straight-forward to count the cost in 4 steps:
1. First, count it the same way we counted `scAddExpr`, but be sure to skip terms with zero constants.
   Much like with `add` expr we will have one less addition than number of terms.
2. Each non-constant term (term degree >= 1) requires a multiplication between the `Op_{n}` and `x^{n}`.
   But again, only charge for it if it is required - `Op_{n}` must not be 0 (no term) or 1 (no multiplication needed),
   and obviously don't charge constant terms (`x^0 == 1`).
3. We must charge for all the `x^0`..`x^{poly_degree}` themselves.
   Since `x^{poly_degree}` is `x * x * ...  * x`, i.e. `poly_degree` `x`'es multiplied,
   for final `poly_degree` term we again require `poly_degree-1` multiplications.
   Note that all the `x^{0}`..`x^{poly_degree-1}` will be computed for the free along the way there.
4. And finally, the operands themselves.

Here, much like with add/mul exprs, we really don't look for preexisting instructions..

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: hiraditya, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73741
2020-02-25 23:05:58 +03:00
Roman Lebedev 756af2f88b
[SCEV] SCEVExpander::isHighCostExpansionHelper(): cost-model add/mul
Summary:
While this resolves the regression from D73722 in `llvm/test/Transforms/IndVarSimplify/exit_value_test2.ll`,
this now regresses `llvm/test/Transforms/IndVarSimplify/elim-extend.ll` `@nestedIV` test,
we no longer can perform that expansion within default budget of `4`, but require budget of `6`.
That regression is being addressed by D73777.

The basic idea here is simple.
```
Op0,  Op1, Op2 ...
 |     |    |
 \--+--/    |
    |       |
    \---+---/
```
I.e. given N operands, we will have N-1 operations,
so we have to add cost of an add (mul) for **every** Op processed,
**except** the first one, plus we need to recurse into *every* Op.

I'm guessing there's already canonicalization that ensures we won't
have `1` operand in `scMulExpr`, and no `0` in `scAddExpr`/`scMulExpr`.

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73728
2020-02-25 23:05:58 +03:00
Roman Lebedev cc29600b90
[SCEV] SCEVExpander::isHighCostExpansionHelper(): cost-model plain UDiv
Summary:
If we don't believe this UDiv is actually a LShr in disguise, things are much worse.
First, we try to see if this UDiv actually originates from user code,
by looking for `S + 1`, and if found considering this UDiv to be free.
But otherwise, we always considered this UDiv to be high-cost.

However that is no longer the case with TTI-driven cost model:
our default budget is 4, which matches the default cost of UDiv,
so now we allow a single UDiv to not be counted as high-cost.

While that is the case, it is evident this is actually a regression
due to the fact that cost-modelling is incomplete - we did not account
for the `add`, `mul` costs yet. That is being addressed in D73728.

Cost-modelling for UDiv also seems pretty straight-forward:
subtract cost of the UDiv itself, and recurse into both the LHS and RHS.

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73722
2020-02-25 23:05:58 +03:00
Roman Lebedev b8793f0dab
[SCEV] SCEVExpander::isHighCostExpansionHelper(): cost-model UDiv by power-of-two as LShr
Summary:
Like with casts, we need to subtract the cost of `lshr` instruction
from budget, and recurse into LHS operand.
Seems "pretty obviously correct" to me?

To be noted, there is a number of other shortcuts we //could// cost-model:
* `... + (-1 * ...)` -> `... - ...` <-  likely very frequent case
* `x - (rem x, power-of-2)`, which is currently `(x udiv power-of-2) * power-of-2` -> `x & -log2(power-of-2)`
* `rem x, power-of-2`, which is currently `x - ((x udiv power-of-2) * power-of-2)` -> `x & log2(power-of-2)-1`
* `... * power-of-2` -> `... << log2(power-of-2)` <- likely not very beneficial

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73718
2020-02-25 23:05:58 +03:00
Roman Lebedev f90973f486
[SCEV] SCEVExpander::isHighCostExpansionHelper(): begin cost modelling - model cast cost
Summary:
This is not a NFC, although it does not change any of the existing tests.
I'm not really sure if we should have specific tests for the cost modelling itself.

This is the first patch that actually makes `SCEVExpander::isHighCostExpansionHelper()`
account for the cost of the SCEV expression, and consider the budget available,
by modelling cast expressions.

I believe the logic itself is "pretty obviously correct" - from budget,
we need to subtract the cost of the cast expression from inner type `Op->getType()`
to the `S->getType()` type, and recurse into the expression we are casting.

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: xbolva00, hiraditya, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73716
2020-02-25 23:05:57 +03:00
Roman Lebedev 2d8275d72e
[SCEV] SCEVExpander::isHighCostExpansion(): assert if TTI is not provided
Summary:
Currently, as per `check-llvm`, we never call `SCEVExpander::isHighCostExpansion()` with null TTI,
so this appears to be a safe restriction.

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: javed.absar, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73712
2020-02-25 23:05:57 +03:00
Roman Lebedev 1622f3e074
[NFC][SCEV] SCEVExpander::isHighCostExpansionHelper(): check that we processed expression first
Summary:
As far as i can tell this is still NFC.
Initially in rL146438 it was added at the top of the function,
later rL238507 dethroned it, and rL244474 did it again.

I'm not sure if we have already checked the cost of this expansion, we should be doing that again.

Reviewers: reames, mkazantsev, wmi, sanjoy, atrick, igor-laevsky

Reviewed By: mkazantsev

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73706
2020-02-25 23:05:57 +03:00
Roman Lebedev b99c91a087
[NFC][SCEV] Piping to pass new SCEVCheapExpansionBudget option into SCEVExpander::isHighCostExpansionHelper()
Summary:
In future patches`SCEVExpander::isHighCostExpansionHelper()` will respect the budget allocated by performing TTI cost modelling.
This is a fully NFC patch to make things reviewable.

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: hiraditya, zzheng, javed.absar, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73705
2020-02-25 23:05:57 +03:00
Roman Lebedev 0789f28048
[NFC][SCEV] Piping to pass TTI into SCEVExpander::isHighCostExpansionHelper()
Summary:
Future patches will make use of TTI to perform cost-model-driven `SCEVExpander::isHighCostExpansionHelper()`
This is a fully NFC patch to make things reviewable.

Reviewers: reames, mkazantsev, wmi, sanjoy

Reviewed By: mkazantsev

Subscribers: hiraditya, zzheng, javed.absar, dmgreen, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73704
2020-02-25 23:05:56 +03:00
Bardia Mahjour cf9dae122e [NFC] [DA] Refactoring getIndexExpressionsFromGEP
Summary:
This patch moves the getIndexExpressionsFromGEP function from polly
into ScalarEvolution so that both polly and DependenceAnalysis can
use it for the purpose of subscript delinearization when the array
sizes are not parametric.

Authored By: bmahjour

Reviewer: Meinersbur, sebpop, fhahn, dmgreen, grosser, etiotto, bollu

Reviewed By: Meinersbur

Subscribers: hiraditya, arphaman, Whitney, ppc-slack, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73995
2020-02-24 17:32:30 -05:00
Kirill Naumov e33c9bb245 Flags for displaying only hot nodes in CFGPrinter graph
Added two flags to omit uncommon or dead paths in the CFG graphs:
  -cfg-hide-unreachable-paths
  -cfg-hide-deoptimize-paths

The main purpose is performance analysis when such block are not
"interesting" from perspective of common path performance.

Reviewed By: apilipenko, davidxl

Differential Revision: https://reviews.llvm.org/D74346
2020-02-21 17:20:00 -08:00
Evgeniy Brevnov b0761bbc76 [DependenceAnalysis] Memory dependence analysis internal caching mechanism is broken in presence of TBAA (PR42733).
Summary:
There is a flaw in memory dependence analysis caching mechanism when memory accesses with TBAA are involved. Assume we first analysed and cached results for access with TBAA. Later we request dependence for the same memory but without TBAA (or different TBAA). By design these two queries should share one entry in the internal cache which corresponds to a general access (without TBAA).  Thus upon second request internal cached is cleared and we continue analysis for access as if there is no TBAA.

The problem is that even though internal cache is cleared the set of visited nodes is not. That means we won't traverse visited nodes again and populate internal cache with the corresponding dependence results. So we end up  with internal cache in an incomplete state. Current implementation tries to signal that situation by resetting CacheInfo->Pair at line 1104. But that doesn't actually help since later code ignores this invalidation and relies on 'Cache->empty()' property to decide on cache completeness.

Reviewers: reames, hfinkel, chandlerc, fedor.sergeev, asbirlea, fhahn, john.brawn, Prazek, sunfish

Reviewed By: john.brawn

Subscribers: DaniilSuchkov, kosarev, jfb, dantrushin, hiraditya, bmahjour, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73032
2020-02-21 20:20:36 +07:00
Hideto Ueno e253cdda35 [MustExecute] Add backward exploration for must-be-executed-context
Summary:
As mentioned in D71974, it is useful for must-be-executed-context to explore CFG backwardly.
This patch is ported from parts of D64975. We use a dominator tree to find the previous context if
a dominator tree is available.

Reviewers: jdoerfert, hfinkel, baziotis, sstefan1

Reviewed By: jdoerfert

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74817
2020-02-20 14:49:30 +09:00
Bardia Mahjour 0a2626d0cd [DDG] Data Dependence Graph - Graph Simplification
Summary:
This is the last functional patch affecting the representation of DDG.
Here we try to simplify the DDG to reduce the number of nodes and edges by
iteratively merging pairs of nodes that satisfy the following conditions,
until no such pair can be identified. A pair of nodes consisting of a and b
can be merged if:

    1. the only edge from a is a def-use edge to b and
    2. the only edge to b is a def-use edge from a and
    3. there is no cyclic edge from b to a and
    4. all instructions in a and b belong to the same basic block and
    5. both a and b are simple (single or multi instruction) nodes.

These criteria allow us to fold many uninteresting def-use edges that
commonly exist in the graph while avoiding the risk of introducing
dependencies that didn't exist before.

Authored By: bmahjour

Reviewer: Meinersbur, fhahn, myhsu, xtian, dmgreen, kbarton, jdoerfert

Reviewed By: Meinersbur

Subscribers: ychen, arphaman, simoll, a.elovikov, mgorny, hiraditya, jfb, wuzish, llvm-commits, jsji, Whitney, etiotto, ppc-slack

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72350
2020-02-19 13:41:51 -05:00
Jonas Paulsson 0eddeeab29 [ValueTracking] Improve isKnownNonNaN() to recognize zero splats.
isKnownNonNaN() could not recognize a zero splat because that is a
ConstantAggregateZero which is-a ConstantData but not a ConstantDataVector.

Patch makes a ConstantAggregateZero return true.

Review: Thomas Lively

Differential Revision: https://reviews.llvm.org/D74263
2020-02-19 09:35:36 -08:00
Jay Foad b329d1b06e [AMDGPU][ConstantFolding] Fold llvm.amdgcn.fmul.legacy intrinsic
Reviewers: arsenm, rampitec, nhaehnle

Subscribers: kzhuravl, jvesely, wdng, yaxunl, dstuttard, tpr, t-tye, hiraditya, kerbowa, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74835
2020-02-19 16:01:30 +00:00
Brian Gesiak 26f356350b [LazyCallGraph] Fix ambiguous index value
After having committed https://reviews.llvm.org/D72226, 2 buildbots
running GCC 5.4.0 began failing. The cause was the order in which those
compilers evaluated the left- and right-hand sides of the expression
`RC.SCCIndices[C] = RC.SCCIndices.size();`. This commit splits the
expression into multiple statements to avoid ambiguity, and adds a test
case that exercises the code that caused the test failures on those
older compilers (which was originally included in the reviewed patch,
https://reviews.llvm.org/D72226).
2020-02-18 23:32:55 -05:00
Reid Kleckner 0c2b09a9b6 [IR] Lazily number instructions for local dominance queries
Essentially, fold OrderedBasicBlock into BasicBlock, and make it
auto-invalidate the instruction ordering when new instructions are
added. Notably, we don't need to invalidate it when removing
instructions, which is helpful when a pass mostly delete dead
instructions rather than transforming them.

The downside is that Instruction grows from 56 bytes to 64 bytes.  The
resulting LLVM code is substantially simpler and automatically handles
invalidation, which makes me think that this is the right speed and size
tradeoff.

The important change is in SymbolTableTraitsImpl.h, where the numbering
is invalidated. Everything else should be straightforward.

We probably want to implement a fancier re-numbering scheme so that
local updates don't invalidate the ordering, but I plan for that to be
future work, maybe for someone else.

Reviewed By: lattner, vsk, fhahn, dexonsmith

Differential Revision: https://reviews.llvm.org/D51664
2020-02-18 14:44:24 -08:00
Nikita Popov f37e899fd7 [VectorUtils] Accept IRBuilderBase; NFC 2020-02-18 18:02:04 +01:00
Jim Lin 466f8843f5 [NFC] Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h,td}
2020-02-18 10:49:13 +08:00
Brian Gesiak 0deef2e164 Re-land "Add LazyCallGraph API to add function to RefSCC"
This re-commits https://reviews.llvm.org/D70927, which I reverted in
https://reviews.llvm.org/rG28213680b2a7d1fdeea16aa3f3a368879472c72a due
to a buildbot error:
http://lab.llvm.org:8011/builders/clang-cmake-x86_64-avx2-linux/builds/13251

I no longer include a test case that appears to crash when built with the
buildbot's compiler, GCC 5.4.0.
2020-02-17 16:59:25 -05:00
Brian Gesiak 28213680b2 Revert "Add LazyCallGraph API to add function to RefSCC"
This reverts commit https://reviews.llvm.org/rG449a13509190b1c57e5fcf5cd7e8f0f647f564b4,
due to buildbot failures such as
http://lab.llvm.org:8011/builders/clang-cmake-x86_64-avx2-linux/builds/13251.
2020-02-17 14:25:10 -05:00
Nikita Popov 3eaa53e805 Reapply "[IRBuilder] Virtualize IRBuilder"
Relative to the original commit, this fixes some warnings,
and is based on the deletion of the IRBuilder copy constructor
in D74693. The automatic copy constructor would no longer be
safe.

-----

Related llvm-dev thread:
http://lists.llvm.org/pipermail/llvm-dev/2020-February/138951.html

This patch moves the IRBuilder from templating over the constant
folder and inserter towards making both of these virtual.
There are a couple of motivations for this:

1. It's not possible to share code between use-sites that use
different IRBuilder folders/inserters (short of templating the code
and moving it into headers).
2. Methods currently defined on IRBuilderBase (which is not templated)
do not use the custom inserter, resulting in subtle bugs (e.g.
incorrect InstCombine worklist management). It would be possible to
move those into the templated IRBuilder, but...
3. The vast majority of the IRBuilder implementation has to live
in the header, because it depends on the template arguments.
4. We have many unnecessary dependencies on IRBuilder.h,
because it is not easy to forward-declare. (Significant parts of
the backend depend on it via TargetLowering.h, for example.)

This patch addresses the issue by making the following changes:

* IRBuilderDefaultInserter::InsertHelper becomes virtual.
  IRBuilderBase accepts a reference to it.
* IRBuilderFolder is introduced as a virtual base class. It is
 implemented by ConstantFolder (default), NoFolder and TargetFolder.
  IRBuilderBase has a reference to this as well.
* All the logic is moved from IRBuilder to IRBuilderBase. This means
  that methods can in the future replace their IRBuilder<> & uses
  (or other specific IRBuilder types) with IRBuilderBase & and thus
  be usable with different IRBuilders.
* The IRBuilder class is now a thin wrapper around IRBuilderBase.
  Essentially it only stores the folder and inserter and takes care
  of constructing the base builder.

What this patch doesn't do, but should be simple followups after this change:

* Fixing use of the inserter for creation methods originally defined
  on IRBuilderBase.
* Replacing IRBuilder<> uses in arguments with IRBuilderBase, where useful.
* Moving code from the IRBuilder header to the source file.

From the user perspective, these changes should be mostly transparent:
The only thing that consumers using a custom inserted may need to do is
inherit from IRBuilderDefaultInserter publicly and mark their InsertHelper
as public.

Differential Revision: https://reviews.llvm.org/D73835
2020-02-17 19:04:11 +01:00
Brian Gesiak 449a135091 Add LazyCallGraph API to add function to RefSCC
Summary:
Depends on https://reviews.llvm.org/D70927.

`LazyCallGraph::addNewFunctionIntoSCC` allows users to insert a new
function node into a call graph, into a specific, existing SCC.

Extend this interface such that functions can be added even when they do
not belong in any existing SCC, but instead in a new SCC within an
existing RefSCC.

The ability to insert new functions as part of a RefSCC is necessary for
outlined functions that do not form a strongly connected cycle with the
function they are outlined from. An example of such a function would be the
coroutine funclets 'f.resume', etc., which are outlined from a coroutine 'f'.
Coroutine 'f' only references the funclets' addresses, it does not call
them directly.

Reviewers: jdoerfert, chandlerc, wenlei, hfinkel

Reviewed By: jdoerfert

Subscribers: hfinkel, JonChesterfield, mehdi_amini, hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72226
2020-02-17 12:56:38 -05:00
Nikita Popov af480e8c63 Revert "[IRBuilder] Virtualize IRBuilder"
This reverts commit 0765d3824d.
This reverts commit 1b04866a3d.

Relevant looking crashes observed on:
http://lab.llvm.org:8011/builders/llvm-clang-x86_64-expensive-checks-win
2020-02-16 17:01:10 +01:00
Nikita Popov 0765d3824d [IRBuilder] Virtualize IRBuilder
Related llvm-dev thread:
http://lists.llvm.org/pipermail/llvm-dev/2020-February/138951.html

This patch moves the IRBuilder from templating over the constant
folder and inserter towards making both of these virtual.
There are a couple of motivations for this:

1. It's not possible to share code between use-sites that use
different IRBuilder folders/inserters (short of templating the code
and moving it into headers).
2. Methods currently defined on IRBuilderBase (which is not templated)
do not use the custom inserter, resulting in subtle bugs (e.g.
incorrect InstCombine worklist management). It would be possible to
move those into the templated IRBuilder, but...
3. The vast majority of the IRBuilder implementation has to live
in the header, because it depends on the template arguments.
4. We have many unnecessary dependencies on IRBuilder.h,
because it is not easy to forward-declare. (Significant parts of
the backend depend on it via TargetLowering.h, for example.)

This patch addresses the issue by making the following changes:

* IRBuilderDefaultInserter::InsertHelper becomes virtual.
  IRBuilderBase accepts a reference to it.
* IRBuilderFolder is introduced as a virtual base class. It is
 implemented by ConstantFolder (default), NoFolder and TargetFolder.
  IRBuilderBase has a reference to this as well.
* All the logic is moved from IRBuilder to IRBuilderBase. This means
  that methods can in the future replace their IRBuilder<> & uses
  (or other specific IRBuilder types) with IRBuilderBase & and thus
  be usable with different IRBuilders.
* The IRBuilder class is now a thin wrapper around IRBuilderBase.
  Essentially it only stores the folder and inserter and takes care
  of constructing the base builder.

What this patch doesn't do, but should be simple followups after this change:

* Fixing use of the inserter for creation methods originally defined
  on IRBuilderBase.
* Replacing IRBuilder<> uses in arguments with IRBuilderBase, where useful.
* Moving code from the IRBuilder header to the source file.

From the user perspective, these changes should be mostly transparent:
The only thing that consumers using a custom inserted may need to do is
inherit from IRBuilderDefaultInserter publicly and mark their InsertHelper
as public.

Differential Revision: https://reviews.llvm.org/D73835
2020-02-16 13:48:55 +01:00
Evgeniy Brevnov cae643d596 Reverting D73027 [DependenceAnalysis] Dependecies for loads marked with "ivnariant.load" should not be shared with general accesses(PR42151). 2020-02-14 22:57:23 +07:00
Evgeniy Brevnov 5573abceab [DependenceAnalysis] Dependecies for loads marked with "ivnariant.load" should not be shared with general accesses(PR42151).
Summary:
This is second attempt to fix the problem with incorrect dependencies reported in presence of invariant load. Initial fix (https://reviews.llvm.org/D64405) was reverted due to a regression reported in https://reviews.llvm.org/D70516.

The original fix changed caching behavior for invariant loads. Namely such loads are not put into the second level cache (NonLocalDepInfo). The problem with that fix is the first level cache  (CachedNonLocalPointerInfo) still works as if invariant loads were in the second level cache. The solution is in addition to not putting dependence results into the second level cache avoid putting info about invariant loads into the first level cache as well.

Reviewers: jdoerfert, reames, hfinkel, efriedma

Reviewed By: jdoerfert

Subscribers: DaniilSuchkov, hiraditya, bmahjour, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73027
2020-02-14 12:18:31 +07:00
Nikita Popov f0b57d8071 [MemorySSA] Don't verify MemorySSA unless VerifyMemorySSA enabled
MemorySSA is often taking up an unreasonable fraction of runtime in
assertion enabled builds. Turns out that there is one code-path that
runs verifyMemorySSA() even if VerifyMemorySSA is not enabled. This
patch makes it conditional as well.

Differential Revision: https://reviews.llvm.org/D74505
2020-02-13 18:46:58 +01:00
Jay Foad 32aac25637 [KnownBits] Introduce anyext instead of passing a flag into zext
Summary:
This was a very odd API, where you had to pass a flag into a zext
function to say whether the extended bits really were zero or not. All
callers passed in a literal true or false.

I think it's much clearer to make the function name reflect the
operation being performed on the value we're tracking (rather than on
the KnownBits Zero and One fields), so zext means the value is being
zero extended and new function anyext means the value is being extended
with unknown bits.

NFC.

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74482
2020-02-12 19:06:53 +00:00
Huihui Zhang 5350a48931 [ConstantFold][SVE] Fix constant fold for FoldReinterpretLoadFromConstPtr.
Summary:
Bail out early for scalable vectors. As global variables are not expected
to be scalable.

Use explicit call of getFixedSize() to assert on places where scalable size
doesn't make sense.

Reviewers: sdesmalen, efriedma, apazos, huntergr, willlovett

Reviewed By: sdesmalen

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74424
2020-02-12 10:24:50 -08:00
Alina Sbirlea 4f33a68973 Compute ORE, BPI, BFI in Loop passes.
Summary:
Passes ORE, BPI, BFI are not being preserved by Loop passes, hence it
is incorrect to retrieve these passes as cached.
This patch makes the loop passes in question compute a new instance.

In some of these cases, however, it may be beneficial to change the Loop pass to
a Function pass instead, similar to the change for LoopUnrollAndJam.

Reviewers: chandlerc, dmgreen, jdoerfert, reames

Subscribers: mehdi_amini, hiraditya, zzheng, steven_wu, dexonsmith, Whitney, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D72891
2020-02-12 09:15:18 -08:00
Ehud Katz 2470d2988a [ConstantFolding] Fold calls to FP remainder function
With the fixed implementation of the "remainder" operation in
rG9d0956ebd471, we can now add support to folding calls to it.

Differential Revision: https://reviews.llvm.org/D69777
2020-02-12 13:21:18 +02:00
Huihui Zhang 88de9338f2 [ConstantFold][SVE] Fix constand fold for vector call.
Summary:
Do not iterate on scalable vectors.

Reviewers: sdesmalen, efriedma, apazos, huntergr, willlovett

Reviewed By: sdesmalen

Subscribers: tschuett, hiraditya, rkruppe, psnobl, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74419
2020-02-11 14:06:15 -08:00
Alina Sbirlea 0cecafd647 [BasicAA] Make BasicAA a cfg pass.
Summary:
Part of the changes in D44564 made BasicAA not CFG only due to it using
PhiAnalysisValues which may have values invalidated.
Subsequent patches (rL340613) appear to have addressed this limitation.

BasicAA should not be invalidated by non-CFG-altering passes.
A concrete example is MemCpyOpt which preserves CFG, but we are testing
it invalidates BasicAA.

llvm-dev RFC: https://groups.google.com/forum/#!topic/llvm-dev/eSPXuWnNfzM

Reviewers: john.brawn, sebpop, hfinkel, brzycki

Subscribers: hiraditya, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D74353
2020-02-11 11:30:08 -08:00
Rachel Craik 1f55420065 [LoopCacheAnalysis]: Add support for negative stride
LoopCacheAnalysis currently assumes the loop will be iterated over in
a forward direction. This patch addresses the issue by using the
absolute value of the stride when iterating backwards.

Note: this patch will treat negative and positive array access the
same, resulting in the same cost being calculated for single and
bi-directional access patterns. This should be improved in a
subsequent patch.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D73064
2020-02-10 13:22:35 -05:00
Johannes Doerfert 72277ecd62 Introduce a CallGraph updater helper class
The CallGraphUpdater is a helper that simplifies the process of updating
the call graph, both old and new style, while running an CGSCC pass.

The uses are contained in different commits, e.g. D70767.

More functionality is added as we need it.

Reviewed By: modocache, hfinkel

Differential Revision: https://reviews.llvm.org/D70927
2020-02-08 14:16:48 -06:00
George Burgess IV f8c9ceb1ce [SimplifyLibCalls] Add __strlen_chk.
Bionic has had `__strlen_chk` for a while. Optimizing that into a
constant is quite profitable, when possible.

Differential Revision: https://reviews.llvm.org/D74079
2020-02-08 11:51:00 -08:00
Florian Hahn 14ef87bda6 [ValueTracking] usub(a, b) cannot overflow if a >= b.
If we know that a >= b (unsigned), usub.with.overflow(a, b) cannot
overflow. Similarly, if b > a, the same expression overflows.

Reviewers: nikic, RKSimon, lebedev.ri, spatel

Reviewed By: nikic, Gerolf

Differential Revision: https://reviews.llvm.org/D74066
2020-02-07 10:41:18 +00:00
Florian Hahn 8d5e76ac30 [ValueTracking] Update implied reasoning to accept expanded cmp (NFC).
This patch adds versions of isImpliedCondition and
isImpliedByDomCondition that take a predicate, LHS and RHS operands as
instead of a Value representing the condition.

This allows using those functions to check conditions without having a
concrete ICmp instruction.

Reviewers: nikic, RKSimon, lebedev.ri, spatel

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D74065
2020-02-07 10:27:29 +00:00
Sanjay Patel 686a038ed8 [Analysis] add query to get splat value from array of ints
I was debug stepping through an x86 shuffle lowering and
noticed we were doing an N^2 search for splat index. I
didn't find the equivalent functionality anywhere else in
LLVM, so here's a helper that takes an array of int and
returns a splatted index while ignoring undefs (any
negative value).

This might also be used inside existing
ShuffleVectorInst/ShuffleVectorSDNode functions and/or
help with D72467.

Differential Revision: https://reviews.llvm.org/D74064
2020-02-05 14:55:02 -05:00
Christopher Tetreault b03f3fbd6a Reapply: [SVE] Fix bug in simplification of scalable vector instructions
This reverts commit a05441038a, reapplying
commit 31574d38ac
2020-02-05 10:00:09 -08:00
Teresa Johnson 7f37a8026f [InlineCost] Add flag to allow changing the default inline cost
Summary:
It can be useful to tune the default inline threshold without overriding other inlining thresholds (e.g. in code compiled for size).

The existing `-inline-threshold` flag overrides other thresholds, so it is insufficient in codebases where there is a mix of code compiled for size and speed.

Patch by Michael Holman <michael.holman@microsoft.com>

Reviewers: eraman, tejohnson

Reviewed By: tejohnson

Subscribers: tejohnson, mtrofin, davidxl, hiraditya, haicheng, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D73217
2020-02-04 12:06:20 -08:00