Commit Graph

234 Commits

Author SHA1 Message Date
Chandler Carruth edb12a838a [TI removal] Make variables declared as `TerminatorInst` and initialized
by `getTerminator()` calls instead be declared as `Instruction`.

This is the biggest remaining chunk of the usage of `getTerminator()`
that insists on the narrow type and so is an easy batch of updates.
Several files saw more extensive updates where this would cascade to
requiring API updates within the file to use `Instruction` instead of
`TerminatorInst`. All of these were trivial in nature (pervasively using
`Instruction` instead just worked).

llvm-svn: 344502
2018-10-15 10:04:59 +00:00
Fangrui Song 0cac726a00 llvm::sort(C.begin(), C.end(), ...) -> llvm::sort(C, ...)
Summary: The convenience wrapper in STLExtras is available since rL342102.

Reviewers: dblaikie, javed.absar, JDevlieghere, andreadb

Subscribers: MatzeB, sanjoy, arsenm, dschuff, mehdi_amini, sdardis, nemanjai, jvesely, nhaehnle, sbc100, jgravelle-google, eraman, aheejin, kbarton, JDevlieghere, javed.absar, gbedwell, jrtc27, mgrang, atanasyan, steven_wu, george.burgess.iv, dexonsmith, kristina, jsji, llvm-commits

Differential Revision: https://reviews.llvm.org/D52573

llvm-svn: 343163
2018-09-27 02:13:45 +00:00
Chijun Sima 21a8b605a1 [Dominators] Convert existing passes and utils to use the DomTreeUpdater class
Summary:
This patch is the second in a series of patches related to the [[ http://lists.llvm.org/pipermail/llvm-dev/2018-June/123883.html | RFC - A new dominator tree updater for LLVM ]].

It converts passes (e.g. adce/jump-threading) and various functions which currently accept DDT in local.cpp and BasicBlockUtils.cpp to use the new DomTreeUpdater class.
These converted functions in utils can accept DomTreeUpdater with either UpdateStrategy and can deal with both DT and PDT held by the DomTreeUpdater.

Reviewers: brzycki, kuhar, dmgreen, grosser, davide

Reviewed By: brzycki

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D48967

llvm-svn: 338814
2018-08-03 05:08:17 +00:00
Fangrui Song f78650a8de Remove trailing space
sed -Ei 's/[[:space:]]+$//' include/**/*.{def,h,td} lib/**/*.{cpp,h}

llvm-svn: 338293
2018-07-30 19:41:25 +00:00
Hiroshi Inoue f209649dfc [NFC] fix trivial typos in comments
llvm-svn: 334687
2018-06-14 05:41:49 +00:00
David Blaikie 31b98d2e99 Move Analysis/Utils/Local.h back to Transforms
Review feedback from r328165. Split out just the one function from the
file that's used by Analysis. (As chandlerc pointed out, the original
change only moved the header and not the implementation anyway - which
was fine for the one function that was used (since it's a
template/inlined in the header) but not in general)

llvm-svn: 333954
2018-06-04 21:23:21 +00:00
Eric Christopher 563d0b9cb9 Fix up a few grammar issues.
llvm-svn: 332835
2018-05-21 10:27:36 +00:00
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.

In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.

Differential Revision: https://reviews.llvm.org/D43624

llvm-svn: 332240
2018-05-14 12:53:11 +00:00
Vedant Kumar e0b5f86b30 [STLExtras] Add distance() for ranges, pred_size(), and succ_size()
This commit adds a wrapper for std::distance() which works with ranges.
As it would be a common case to write `distance(predecessors(BB))`, this
also introduces `pred_size()` and `succ_size()` helpers to make that
easier to write.

Differential Revision: https://reviews.llvm.org/D46668

llvm-svn: 332057
2018-05-10 23:01:54 +00:00
Mandeep Singh Grang 636d94db3b [Transforms] Change std::sort to llvm::sort in response to r327219
Summary:
r327219 added wrappers to std::sort which randomly shuffle the container before sorting.
This will help in uncovering non-determinism caused due to undefined sorting
order of objects having the same key.

To make use of that infrastructure we need to invoke llvm::sort instead of std::sort.

Note: This patch is one of a series of patches to replace *all* std::sort to llvm::sort.
Refer the comments section in D44363 for a list of all the required patches.

Reviewers: kcc, pcc, danielcdh, jmolloy, sanjoy, dberlin, ruiu

Reviewed By: ruiu

Subscribers: ruiu, llvm-commits

Differential Revision: https://reviews.llvm.org/D45142

llvm-svn: 330059
2018-04-13 19:47:57 +00:00
David Blaikie 2be3922807 Fix a couple of layering violations in Transforms
Remove #include of Transforms/Scalar.h from Transform/Utils to fix layering.

Transforms depends on Transforms/Utils, not the other way around. So
remove the header and the "createStripGCRelocatesPass" function
declaration (& definition) that is unused and motivated this dependency.

Move Transforms/Utils/Local.h into Analysis because it's used by
Analysis/MemoryBuiltins.cpp.

llvm-svn: 328165
2018-03-21 22:34:23 +00:00
Daniel Neilson 82daad31fe [RewriteStatepoints] Fix stale parse points
Summary:
RewriteStatepointsForGC collects parse points for further processing.
During the collection if a callsite is found in an unreachable block
(DominatorTree::isReachableFromEntry()) then all unreachable blocks are
removed by removeUnreachableBlocks(). Some of the removed blocks could
have been reachable according to DominatorTree::isReachableFromEntry().
In this case the collected parse points became stale and resulted in a
crash when accessed.

The fix is to unconditionally canonicalize the IR to
removeUnreachableBlocks and then collect the parse points.

The added test crashes with the old version and passes with this patch.

Patch by Yevgeny Rouban!

Reviewed by: Anna

Differential Revision: https://reviews.llvm.org/D43929

llvm-svn: 326748
2018-03-05 22:27:30 +00:00
Daniel Neilson 594f443b06 [RS4GC] Handle call/invoke instructions as base defining values of vectors
Summary:
 There's an asymmetry in the definitions of findBaseDefiningValueOfVector() and
findBaseDefiningValue() of RS4GC. The later handles call and invoke instructions,
and the former does not. This appears to be simple oversight. This patch remedies
the oversight by adding the call and invoke cases to findBaseDefiningValueOfVector().

Reviewers: DaniilSuchkov, anna

Reviewed By: anna

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D42653

llvm-svn: 323764
2018-01-30 14:43:41 +00:00
Ivan A. Kosarev 4d0ff0c74d [Transforms] Support making mutable versions of new-format TBAA access tags
Differential Revision: https://reviews.llvm.org/D41565

llvm-svn: 322650
2018-01-17 13:29:54 +00:00
Max Kazantsev a13e163a27 [RewriteStatepoints] Fix incorrect assertion
`RewriteStatepointsForGC` iterates over function blocks and their predecessors
in order of declaration. One of outcomes of this is that callsites are placed in
arbitrary order which has nothing to do with travelsar order.

On the other hand, function `recomputeLiveInValues` asserts that bases are
added to `Info.PointerToBase` before their deried pointers are updated. But
if call sites are processed in order different from RPOT, this is not necessarily
true. We cannot guarantee that the base was placed there before every
pointer derived from it. All we can guarantee is that this base was marked as
known base by this point.

This patch replaces the fact that we assert from checking that the base was
added to the map with assert that the base was marked as known base.

Differential Revision: https://reviews.llvm.org/D41593

llvm-svn: 321517
2017-12-28 12:03:12 +00:00
Fedor Sergeev 4b86d79048 [PM] port Rewrite Statepoints For GC to the new pass manager.
Summary:
The port is nearly straightforward.
The only complication is related to the analyses handling,
since one of the analyses used in this module pass is domtree,
which is a function analysis. That requires asking for the results
of each function and disallows a single interface for run-on-module
pass action.

Decided to copy-paste the main body of this pass.
Most of its code is requesting analyses anyway, so not that much
of a copy-paste.

The rest of the code movement is to transform all the implementation
helper functions like stripNonValidData into non-member statics.

Extended all the related LLVM tests with new-pass-manager use.
No failures.

Reviewers: sanjoy, anna, reames

Reviewed By: anna

Subscribers: skatkov, llvm-commits

Differential Revision: https://reviews.llvm.org/D41162

llvm-svn: 320796
2017-12-15 09:32:11 +00:00
Anna Thomas 729dafc16b Strip off invariant.start because memory locations arent invariant
The original change was reverted in rL317217 because of the failure in
the RS4GC testcase. I couldn't reproduce the failure on my local machine
(macbook) but could reproduce it on a linux box.

The failure was around removing the uses of invariant.start. The fix
here is to just RAUW undef (which was the first implementation in D39388).
This is perfectly valid IR as discussed in the review.

llvm-svn: 317225
2017-11-02 18:24:04 +00:00
Anna Thomas ebe429d99f Revert "[RS4GC] Strip off invariant.start because memory locations arent invariant"
This reverts commit r317215, investigating the test failure.

llvm-svn: 317217
2017-11-02 16:45:51 +00:00
Anna Thomas 486a7aaa31 [RS4GC] Strip off invariant.start because memory locations arent invariant
Summary:
Invariant.start on memory locations has the property that the memory
location is unchanging. However, this is not true in the face of
rewriting statepoints for GC.
Teach RS4GC about removing invariant.start so that optimizations after
RS4GC does not incorrect sink a load from the memory location past a
statepoint.

Added test showcasing the issue.

Reviewers: reames, apilipenko, dneilson

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D39388

llvm-svn: 317215
2017-11-02 16:23:31 +00:00
Daniel Neilson fa14ebd138 [RS4GC] Look through vector bitcasts when looking for base pointer
Summary:
 In RS4GC it is possible that a base pointer is contained in a vector that
has undergone a bitcast from one element-pointertype to another. We teach
RS4GC how to look through bitcasts of vector types when looking for a base
pointer.

Reviewers: anna

Reviewed By: anna

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D38849

llvm-svn: 315694
2017-10-13 15:59:13 +00:00
Eugene Zelenko 75075efe5e [Analysis, Transforms] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 312383
2017-09-01 21:37:29 +00:00
Daniel Neilson 2574d7cbf6 All libcalls should be considered to be GC-leaf functions.
Summary:
It is possible for some passes to materialize a call to a libcall (ex: ldexp, exp2, etc),
but these passes will not mark the call as a gc-leaf-function. All libcalls are
actually gc-leaf-functions, so we change llvm::callsGCLeafFunction() to tell us that
available libcalls are equivalent to gc-leaf-function calls.

Reviewers: sanjoy, anna, reames

Reviewed By: anna

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D35840

llvm-svn: 309291
2017-07-27 16:49:39 +00:00
Hiroshi Inoue bb703e8960 fix trivial typos; NFC
suport -> support

llvm-svn: 306968
2017-07-02 03:24:54 +00:00
Hiroshi Inoue ef1c2ba22a fix trivial typos, NFC
llvm-svn: 306952
2017-07-01 07:12:15 +00:00
Anna Thomas 4b027e8f89 [RS4GC] Drop invalid metadata after pointers are relocated
Summary:
After RS4GC, we should drop metadata that is no longer valid. These metadata
is used by optimizations scheduled after RS4GC, and can cause a miscompile.
One such metadata is invariant.load which is used by LICM sinking transform.
After rewriting statepoints, the address of a load maybe relocated. With
invariant.load metadata on a load instruction, LICM sinking assumes the
loaded value (from a dererenceable address) to be invariant, and
rematerializes the load operand and the load at the exit block.
This transforms the IR to have an unrelocated use of the
address after a statepoint, which is incorrect.
Other metadata we conservatively remove are related to
dereferenceability and noalias metadata.

This patch drops such metadata on store and load instructions after
rewriting statepoints.

Reviewers: reames, sanjoy, apilipenko

Reviewed by: reames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D33756

llvm-svn: 305234
2017-06-12 21:26:53 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Philip Reames b70cecd60a [Statepoint] Be consistent about using deopt naming [NFCI]
We'd called this "vm state" in the early days, but have long since standardized on calling it "deopt" in line with the operand bundle tag.  Fix a few cases we'd missed.

llvm-svn: 304607
2017-06-02 23:03:26 +00:00
Philip Reames ae80045deb [RS4GC] Comment clarification
llvm-svn: 304514
2017-06-02 01:52:06 +00:00
Reid Kleckner a0b45f4bfc [IR] Abstract away ArgNo+1 attribute indexing as much as possible
Summary:
Do three things to help with that:
- Add AttributeList::FirstArgIndex, which is an enumerator currently set
  to 1. It allows us to change the indexing scheme with fewer changes.
- Add addParamAttr/removeParamAttr. This just shortens addAttribute call
  sites that would otherwise need to spell out FirstArgIndex.
- Remove some attribute-specific getters and setters from Function that
  take attribute list indices.  Most of these were only used from
  BuildLibCalls, and doesNotAlias was only used to test or set if the
  return value is malloc-like.

I'm happy to split the patch, but I think they are probably easier to
review when taken together.

This patch should be NFC, but it sets the stage to change the indexing
scheme to this, which is more convenient when indexing into an array:
  0: func attrs
  1: retattrs
  2...: arg attrs

Reviewers: chandlerc, pete, javed.absar

Subscribers: david2050, llvm-commits

Differential Revision: https://reviews.llvm.org/D32811

llvm-svn: 302060
2017-05-03 18:17:31 +00:00
Reid Kleckner ee4930b688 Re-land r301697 "[IR] Make add/remove Attributes use AttrBuilder instead of AttributeList"
This time, I fixed, built, and tested clang.

This reverts r301712.

llvm-svn: 301981
2017-05-02 22:07:37 +00:00
Hans Wennborg 0f88d863b4 Revert r301697 "[IR] Make add/remove Attributes use AttrBuilder instead of AttributeList"
This broke the Clang build. (Clang-side patch missing?)

Original commit message:

> [IR] Make add/remove Attributes use AttrBuilder instead of
> AttributeList
>
> This change cleans up call sites and avoids creating temporary
> AttributeList objects.
>
> NFC

llvm-svn: 301712
2017-04-28 23:01:32 +00:00
Reid Kleckner 608c8b63b3 [IR] Make add/remove Attributes use AttrBuilder instead of AttributeList
This change cleans up call sites and avoids creating temporary
AttributeList objects.

NFC

llvm-svn: 301697
2017-04-28 21:48:28 +00:00
Reid Kleckner 99351967c7 [RS4GC] Simplify attribute handling code NFC
Avoids use of AttributeList::getNumSlots, making it easier to change the
underlying implementation.

llvm-svn: 301671
2017-04-28 19:22:40 +00:00
Jonas Paulsson fccc7d66c3 [SystemZ] TargetTransformInfo cost functions implemented.
getArithmeticInstrCost(), getShuffleCost(), getCastInstrCost(),
getCmpSelInstrCost(), getVectorInstrCost(), getMemoryOpCost(),
getInterleavedMemoryOpCost() implemented.

Interleaved access vectorization enabled.

BasicTTIImpl::getCastInstrCost() improved to check for legal extending loads,
in which case the cost of the z/sext instruction becomes 0.

Review: Ulrich Weigand, Renato Golin.
https://reviews.llvm.org/D29631

llvm-svn: 300052
2017-04-12 11:49:08 +00:00
Reid Kleckner eb9dd5b87f Reland "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies"
This re-lands r299875.

I introduced a bug in Clang code responsible for replacing K&R, no
prototype declarations with a real function definition with a prototype.
The bug was here:

       // Collect any return attributes from the call.
  -    if (oldAttrs.hasAttributes(llvm::AttributeList::ReturnIndex))
  -      newAttrs.push_back(llvm::AttributeList::get(newFn->getContext(),
  -                                                  oldAttrs.getRetAttributes()));
  +    newAttrs.push_back(oldAttrs.getRetAttributes());

Previously getRetAttributes() carried AttributeList::ReturnIndex in its
AttributeList. Now that we return the AttributeSetNode* directly, it no
longer carries that index, and we call this overload with a single node:
  AttributeList::get(LLVMContext&, ArrayRef<AttributeSetNode*>)

That aborted with an assertion on x86_32 targets. I added an explicit
triple to the test and added CHECKs to help find issues like this in the
future sooner.

llvm-svn: 299899
2017-04-10 23:31:05 +00:00
Matt Arsenault 3c1fc768ed Allow DataLayout to specify addrspace for allocas.
LLVM makes several assumptions about address space 0. However,
alloca is presently constrained to always return this address space.
There's no real way to avoid using alloca, so without this
there is no way to opt out of these assumptions.

The problematic assumptions include:
- That the pointer size used for the stack is the same size as
  the code size pointer, which is also the maximum sized pointer.

- That 0 is an invalid, non-dereferencable pointer value.

These are problems for AMDGPU because alloca is used to
implement the private address space, which uses a 32-bit
index as the pointer value. Other pointers are 64-bit
and behave more like LLVM's notion of generic address
space. By changing the address space used for allocas,
we can change our generic pointer type to be LLVM's generic
pointer type which does have similar properties.

llvm-svn: 299888
2017-04-10 22:27:50 +00:00
Reid Kleckner 211b1f324f Revert "[IR] Make AttributeSetNode public, avoid temporary AttributeList copies"
This reverts r299875. A Linux bot came back with a test failure:
http://bb.pgr.jp/builders/test-clang-i686-linux-RA/builds/741/steps/test_clang/logs/Clang%20%3A%3A%20CodeGen__2006-05-19-SingleEltReturn.c

llvm-svn: 299878
2017-04-10 20:34:19 +00:00
Reid Kleckner 324c99dee5 [IR] Make AttributeSetNode public, avoid temporary AttributeList copies
Summary:
AttributeList::get(Fn|Ret|Param)Attributes no longer creates a temporary
AttributeList just to hide the AttributeSetNode type.

I've also added a factory method to create AttributeLists from a
parallel array of AttributeSetNodes. I think this simplifies
construction of AttributeLists when rewriting function prototypes.
Previously we would test if a particular index had attributes, and
conditionally add a temporary attribute list to a vector. Now the
attribute set vector is parallel to the argument vector already that
these passes already construct.

My long term vision is to wrap AttributeSetNode* inside an AttributeSet
type that holds the enum attributes, but that will come in a follow up
change.

I haven't done any performance measurements for this change because
profiling hasn't shown that any of the affected code is hot.

Reviewers: pete, chandlerc, sanjoy, hfinkel

Reviewed By: pete

Subscribers: jfb, llvm-commits

Differential Revision: https://reviews.llvm.org/D31198

llvm-svn: 299875
2017-04-10 20:18:10 +00:00
Reid Kleckner b518054b87 Rename AttributeSet to AttributeList
Summary:
This class is a list of AttributeSetNodes corresponding the function
prototype of a call or function declaration. This class used to be
called ParamAttrListPtr, then AttrListPtr, then AttributeSet. It is
typically accessed by parameter and return value index, so
"AttributeList" seems like a more intuitive name.

Rename AttributeSetImpl to AttributeListImpl to follow suit.

It's useful to rename this class so that we can rename AttributeSetNode
to AttributeSet later. AttributeSet is the set of attributes that apply
to a single function, argument, or return value.

Reviewers: sanjoy, javed.absar, chandlerc, pete

Reviewed By: pete

Subscribers: pete, jholewinski, arsenm, dschuff, mehdi_amini, jfb, nhaehnle, sbc100, void, llvm-commits

Differential Revision: https://reviews.llvm.org/D31102

llvm-svn: 298393
2017-03-21 16:57:19 +00:00
Sanjoy Das c4e4dcdf64 [RSForGC] Handle vector GEPs
We were not handling getelemenptr instructions of vector type before.
Since getelemenptr instructions for vector types follow the same rule as
getelementptr instructions for non-vector types, we can just handle them
in the same way.

llvm-svn: 298028
2017-03-17 00:55:53 +00:00
Benjamin Kramer 061f4a5fe6 Apply clang-tidy's performance-unnecessary-value-param to LLVM.
With some minor manual fixes for using function_ref instead of
std::function. No functional change intended.

llvm-svn: 291904
2017-01-13 14:39:03 +00:00
Daniel Jasper aec2fa352f Revert @llvm.assume with operator bundles (r289755-r289757)
This creates non-linear behavior in the inliner (see more details in
r289755's commit thread).

llvm-svn: 290086
2016-12-19 08:22:17 +00:00
Hal Finkel 3ca4a6bcf1 Remove the AssumptionCache
After r289755, the AssumptionCache is no longer needed. Variables affected by
assumptions are now found by using the new operand-bundle-based scheme. This
new scheme is more computationally efficient, and also we need much less
code...

llvm-svn: 289756
2016-12-15 03:02:15 +00:00
David Majnemer d5648c7a7d Replace some callers of setTailCall with setTailCallKind
We were a little sloppy with adding tailcall markers.  Be more
consistent by using setTailCallKind instead of setTailCall.

llvm-svn: 287955
2016-11-25 22:35:09 +00:00
Anna Thomas 488c05763c [RS4GC] Fix comment to show TODO. NFC
llvm-svn: 283449
2016-10-06 13:24:20 +00:00
Anna Thomas 479cbb9405 [RS4GC] Handle ShuffleVector instruction in findBasePointer
Summary:
This patch modifies the findBasePointer to handle the shufflevector instruction.

Tests run: RS4GC tests, local downstream tests.

Reviewers: reames, sanjoy

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D25197

llvm-svn: 283219
2016-10-04 13:48:37 +00:00
Anna Thomas 82c3717f54 [RS4GC] Remat in presence of phi and use live value
Summary:

Reviewers:

Subscribers:

llvm-svn: 282150
2016-09-22 13:13:06 +00:00
Anna Thomas 8cd7de1d18 [RS4GC] Refactor code for Rematerializing in presence of phi. NFC
Summary:
This is an NFC refactoring change as a precursor to the actual fix for rematerializing in
presence of phi.
https://reviews.llvm.org/D24399

Pasted from review:
findRematerializableChainToBasePointer changed to return the root of the
chain. instead of true or false.
move the PHI matching logic into the caller by inspecting the root return value.
This includes an assertion that the alternate root is in the liveset for the
call.

Tested with current RS4GC tests.

Reviewers: reames, sanjoy

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D24780

llvm-svn: 282023
2016-09-20 21:36:02 +00:00
Philip Reames 2b1084ac93 [statepoints][experimental] Add support for live-in semantics of values in deopt bundles
This is a first step towards supporting deopt value lowering and reporting entirely with the register allocator. I hope to build on this in the near future to support live-on-return semantics, but I have a use case which allows me to test and investigate code quality with just the live-in semantics so I've chosen to start there. For those curious, my use cases is our implementation of the "__llvm_deoptimize" function we bind to @llvm.deoptimize. I'm choosing not to hard code that fact in the patch and instead make it configurable via function attributes.

The basic approach here is modelled on what is done for the "Live In" values on stackmaps and patchpoints. (A secondary goal here is to remove one of the last barriers to merging the pseudo instructions.) We start by adding the operands directly to the STATEPOINT SDNode. Once we've lowered to MI, we extend the remat logic used by the register allocator to fold virtual register uses into StackMap::Indirect entries as needed. This does rely on the fact that the register allocator rematerializes. If it didn't along some code path, we could end up with more vregs than physical registers and fail to allocate.

Today, we *only* fold in the register allocator. This can create some weird effects when combined with arguments passed on the stack because we don't fold them appropriately. I have an idea how to fix that, but it needs this patch in place to work on that effectively. (There's some weird interaction with the scheduler as well, more investigation needed.)

My near term plan is to land this patch off-by-default, experiment in my local tree to identify any correctness issues and then start fixing codegen problems one by one as I find them. Once I have the live-in lowering fully working (both correctness and code quality), I'm hoping to move on to the live-on-return semantics. Note: I don't have any *known* miscompiles with this patch enabled, but I'm pretty sure I'll find at least a couple. Thus, the "experimental" tag and the fact it's off by default.

Differential Revision: https://reviews.llvm.org/D24000

llvm-svn: 280250
2016-08-31 15:12:17 +00:00
Anna Thomas 1aea6da564 [RewriteStatepointsForGC] Update comment for same PHI node check. NFC
llvm-svn: 280052
2016-08-30 02:36:48 +00:00