Print to dbgs() any taken action.
Also, read-only scalars do not require any action unless
-polly-analyze-read-only-scalars=true is used. Better refect this by
using ForwardingAction::triviallyForwardable and thus not bumping the
statistics.
ScopBuilder distributes independent instructions between statements.
Only modeled (e.g. not synthesizable) instructions are represented.
To compute independence, non-modeled instructions were used in some
parts of determining instruction independence, which could lead to the
re-introduction of non-model instructions.
In particular, required invariant loads could be added to instruction
list, which then led to redundant MemoryAccesses for such a load.
This fixes llvm.org/PR48059.
If we've got an SCEVPtrToIntExpr(op), where op is not an SCEVUnknown,
we want to sink the SCEVPtrToIntExpr into an operand,
so that the operation is performed on integers,
and eventually we end up with just an `SCEVPtrToIntExpr(SCEVUnknown)`.
Reviewed By: mkazantsev
Differential Revision: https://reviews.llvm.org/D89692
And use it to model LLVM IR's `ptrtoint` cast.
This is essentially an alternative to D88806, but with no chance for
all the problems it caused due to having the cast as implicit there.
(see rG7ee6c402474a2f5fd21c403e7529f97f6362fdb3)
As we've established by now, there are at least two reasons why we want this:
* It will allow SCEV to actually model the `ptrtoint` casts
and their operands, instead of treating them as `SCEVUnknown`
* It should help with initial problem of PR46786 - this should eventually allow us
to not loose pointer-ness of an expression in more cases
As discussed in [[ https://bugs.llvm.org/show_bug.cgi?id=46786 | PR46786 ]], in principle,
we could just extend `SCEVUnknown` with a `is ptrtoint` cast, because `ScalarEvolution::getPtrToIntExpr()`
should sink the cast as far down into the expression as possible,
so in the end we should always end up with `SCEVPtrToIntExpr` of `SCEVUnknown`.
But i think that it isn't the best solution, because it doesn't really matter
from memory consumption side - there probably won't be *that* many `SCEVPtrToIntExpr`s
for it to matter, and it allows for much better discoverability.
Reviewed By: mkazantsev
Differential Revision: https://reviews.llvm.org/D89456
This is a long-delayed follow-up to
5e5b85098d.
`TempMDNode` includes a bunch of machinery for RAUW, and should only be
used when necessary. RAUW wasn't being used in any of these cases... it
was just a placeholder for a self-reference.
Where the real node was using `MDNode::getDistinct`, just replace the
temporary argument with `nullptr`.
Where the real node was using `MDNode::get`, the `replaceOperandWith`
call was "promoting" the node to a distinct one implicitly due to
self-reference detection in `MDNode::handleChangedOperand`. The
`TempMDNode` was serving a purpose by delaying uniquing, but it's way
simpler to just call `MDNode::getDistinct` in the first place.
Note that using a self-reference at all in these places is a hold-over
from before `distinct` metadata existed. It was an old trick to create
distinct nodes. It would be intrusive to change, including bitcode
upgrades, etc., and it's harmless so I'm not sure there's much value in
removing it from existing schemas. After this commit it still has a tiny
memory cost (in the extra metadata operand) but no more overhead in
construction.
Differential Revision: https://reviews.llvm.org/D90079
Recursively traversing the operand tree leads to an exponential blowup
if instructions are used multiple times due to every path leading to an
additional copy of the instructions after forwarding. This problem was
marked as a TODO in the code and was reported as a bug in llvm.org/PR47340.
Fix by caching already visited instructions and returning the cached
version when already visited. Instead of calling forwardTree() twice,
return a ForwardingAction structure that contains a lambda which will
carry-out the forwarding when requested. The lambdas are executed in
reverse-postorder to mimic the previous recursive calls unless there
is a reuse.
Fixes llvm.org/PR47340
getVectorPtrTy is private to VectorBlockGenerator, and all uses query
the address space from the passed-in pointer prior to calling it.
Reviewed By: efriedma
Differential Revision: https://reviews.llvm.org/D89745
Polly incorrectly dropped the address space specified for a load instruction when it vectorized the code.
Reviewed By: Meinersbur
Differential Revision: https://reviews.llvm.org/D88907
While we haven't encountered an earth-shattering problem with this yet,
by now it is pretty evident that trying to model the ptr->int cast
implicitly leads to having to update every single place that assumed
no such cast could be needed. That is of course the wrong approach.
Let's back this out, and re-attempt with some another approach,
possibly one originally suggested by Eli Friedman in
https://bugs.llvm.org/show_bug.cgi?id=46786#c20
which should hopefully spare us this pain and more.
This reverts commits 1fb6104293,
7324616660,
aaafe350bb,
e92a8e0c74.
I've kept&improved the tests though.
This relands commit 1c021c64ca which was
reverted in commit 17cec6a11a because
an assertion was being triggered, since `BuildConstantFromSCEV()`
wasn't updated to handle the case where the constant we want to truncate
is actually a pointer. I was unsuccessful in coming up with a test case
where we'd end there with constant zext/sext of a pointer,
so i didn't handle those cases there until there is a test case.
Original commit message:
While we indeed can't treat them as no-ops, i believe we can/should
do better than just modelling them as `unknown`. `inttoptr` story
is complicated, but for `ptrtoint`, it seems straight-forward
to model it just as a zext-or-trunc of unknown.
This may be important now that we track towards
making inttoptr/ptrtoint casts not no-op,
and towards preventing folding them into loads/etc
(see D88979/D88789/D88788)
Reviewed By: mkazantsev
Differential Revision: https://reviews.llvm.org/D88806
> While we indeed can't treat them as no-ops, i believe we can/should
> do better than just modelling them as `unknown`. `inttoptr` story
> is complicated, but for `ptrtoint`, it seems straight-forward
> to model it just as a zext-or-trunc of unknown.
>
> This may be important now that we track towards
> making inttoptr/ptrtoint casts not no-op,
> and towards preventing folding them into loads/etc
> (see D88979/D88789/D88788)
>
> Reviewed By: mkazantsev
>
> Differential Revision: https://reviews.llvm.org/D88806
It caused the following assert during Chromium builds:
llvm/lib/IR/Constants.cpp:1868:
static llvm::Constant *llvm::ConstantExpr::getTrunc(llvm::Constant *, llvm::Type *, bool):
Assertion `C->getType()->isIntOrIntVectorTy() && "Trunc operand must be integer"' failed.
See code review for a link to a reproducer.
This reverts commit 1c021c64ca.
While we indeed can't treat them as no-ops, i believe we can/should
do better than just modelling them as `unknown`. `inttoptr` story
is complicated, but for `ptrtoint`, it seems straight-forward
to model it just as a zext-or-trunc of unknown.
This may be important now that we track towards
making inttoptr/ptrtoint casts not no-op,
and towards preventing folding them into loads/etc
(see D88979/D88789/D88788)
Reviewed By: mkazantsev
Differential Revision: https://reviews.llvm.org/D88806
This removes "VerifyEachPass" parameters from a lot of functions which is nice.
Don't verify after special passes or VerifierPass.
This introduces verification on loop and cgscc passes, verifying the corresponding function/module.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D88764
This is in preparation for supporting -debugify-each, which adds a debug
info pass before and after each pass.
Switch VerifyEach to use this.
Reviewed By: ychen
Differential Revision: https://reviews.llvm.org/D88107
Before this patch, the cmake disabled loadable modules when compiling
with Visual Studio. However, the reason for this is a limitation of the
Windows DLLs, thus this restriction should apply to any compiler for the
Windows platform, such as MinGW, Cygwin, icc, etc.
Differential Revision: https://reviews.llvm.org/D87524
This applies the same fix that D84748 did for macro definitions.
Appropriate include path is now automatically set for all libraries
which link against gtest targets, which avoids the need to set
include_directories in various parts of the project.
Differential Revision: https://reviews.llvm.org/D86616
A build on `sparcv9-sun-solaris2.11` with `-DLLVM_ENABLE_PIC=Off` failed
linking `LLVMPolly.so`:
[2277/2297] Linking CXX shared module lib/LLVMPolly.so
FAILED: lib/LLVMPolly.so
[...]
ld: fatal: relocation error: R_SPARC_H44: file tools/polly/lib/CMakeFiles/obj.Polly.dir/Analysis/DependenceInfo.cpp.o: symbol .data._ZL16__gthread_active (section): invalid shared object relocation type: ABS44 code model unsupported
[...]
As on many other targets, one cannot link non-PIC objects into a shared
object on Solaris/sparcv9.
The following patch avoids this by not building the library without PIC.
It allowed the build to finish.
Differential Revision: https://reviews.llvm.org/D85627
InstStmtMap became inconsistent with ScopStmt::getInstructions() after
the statement's instructions is modified, e.g. by being considered
unused by the Simplify pass or being moved by ForwardOpTree.
Change ScopStmt::setInstructions() to also update its parent's
InstStmtMap. Also add assertions checking the consistency.
VirtualUse of type UseKind::Inter expects the definition of a
llvm::Value to be represented in another statement. In the bug report
that statement has been removed due to its domain being empty.
Scop::InstStmtMap for the llvm::Value's defintion still pointed to the
removed statement, which resulted in the use-after-free.
The defintion statement was removed by Simplify because it was
considered to not be reachable by other uses; trivially because it is
never executed due to its empty domain. However, no such thing happend
to the using statement using the value altough its domain is also empty.
Fix by always removing statements with empty domains in Simplify since
these are not properly analyzable. A UseKind::Inter should always have a
statement with its defintion due to LLVM's SSA form.
Scop::removeStmtNotInDomainMap() also removes statements with empty
domains but does so without considering the context as used by
Simplify's analyzes.
In another angle, InstStmtMap pointing to removed statements should not
happen either and ForwardOpTree would have bailed out if the llvm::Value
definition was not represented by a statement. This will be corrected in
a followup-commit.
This fixes llvm.org/PR47098
Reuse LLVM's CMakeLists.txt for gtest/gmock instead of reinventing
them in Polly. This fixes a lot of linking errors due to not linking
LLVMSupport in for me.
Differential Revision: https://reviews.llvm.org/D85280
Link ScopPassManager to LLVM dylib target if LLVM_LINK_LLVM_DYLIB
is enabled. This fixes build failures on systems where static LLVM
libraries are not installed.
Differential Revision: https://reviews.llvm.org/D85281
The test failed since commit
bc10888dc "DomTree: Make PostDomTree indifferent to block successors swap"
which is a re-commit of
c35585e20 "DomTree: Make PostDomTree immune to block successors swap"
This reverts the revert commit dc28675768.
It includes a fix for Polly, which uses SCEVExpander on IR that is not
in LCSSA form. Set PreserveLCSSA = false in that case, to ensure we do
not introduce LCSSA phis where there were none before.
This cleans up several CMakeLists.txt's where -Wno-suggest-override was manually specified. These test targets now inherit this flag from the gtest target.
Some unittests CMakeLists.txt's, in particular Flang and LLDB, are not touched by this patch. Flang manually adds the gtest sources itself in some configurations, rather than linking to LLVM's gtest target, so this fix would be insufficient to cover those cases. Similarly, LLDB has subdirectories that manually add the gtest headers to their include path without linking to the gtest target, so those subdirectories still need -Wno-suggest-override to be manually specified to compile without warnings.
Differential Revision: https://reviews.llvm.org/D84554
add_compile_options is more sensitive to its location in the file than add_definitions--it only takes effect for sources that are added after it. This updated patch ensures that the add_compile_options is done before adding any source files that depend on it.
Using add_definitions caused the flag to be passed to rc.exe on Windows and thus broke Windows builds.
After lots of follow-up fixes, there are still problems, such as
-Wno-suggest-override getting passed to the Windows Resource Compiler
because it was added with add_definitions in the CMake file.
Rather than piling on another fix, let's revert so this can be re-landed
when there's a proper fix.
This reverts commit 21c0b4c1e8.
This reverts commit 81d68ad27b.
This reverts commit a361aa5249.
This reverts commit fa42b7cf29.
This reverts commit 955f87f947.
This reverts commit 8b16e45f66.
This reverts commit 308a127a38.
This reverts commit 274b6b0c7a.
This reverts commit 1c7037a2a5.
The schedule of a fused loop has one isl_space per statement, such that
a conversion to a isl_map fails. However, the prevectorization is
interested in the schedule space only: Converting to the non-union
representation only after extracting the schedule range fixes the problem.
This fixes llvm.org/PR46578
The member LastSchedule was never set, such that printScop would always
print "n/a" instead of the last schedule.
To ensure that the isl_ctx lives as least as long as the stored
schedule, also store a shared_ptr.
Also set the schedule tree output style to ISL_YAML_STYLE_BLOCK to avoid
printing everything on a single line.
`opt -polly-opt-isl -analyze` will be used in the next commit.
If we don't know anything about the alignment of a pointer, Align(1) is
still correct: all pointers are at least 1-byte aligned.
Included in this patch is a bugfix for an issue discovered during this
cleanup: pointers with "dereferenceable" attributes/metadata were
assumed to be aligned according to the type of the pointer. This
wasn't intentional, as far as I can tell, so Loads.cpp was fixed to
stop making this assumption. Frontends may need to be updated. I
updated clang's handling of C++ references, and added a release note for
this.
Differential Revision: https://reviews.llvm.org/D80072
Along the lines of D77454 and D79968. Unlike loads and stores, the
default alignment is getPrefTypeAlign, to match the existing handling in
various places, including SelectionDAG and InstCombine.
Differential Revision: https://reviews.llvm.org/D80044
For IR generated by a compiler, this is really simple: you just take the
datalayout from the beginning of the file, and apply it to all the IR
later in the file. For optimization testcases that don't care about the
datalayout, this is also really simple: we just use the default
datalayout.
The complexity here comes from the fact that some LLVM tools allow
overriding the datalayout: some tools have an explicit flag for this,
some tools will infer a datalayout based on the code generation target.
Supporting this properly required plumbing through a bunch of new
machinery: we want to allow overriding the datalayout after the
datalayout is parsed from the file, but before we use any information
from it. Therefore, IR/bitcode parsing now has a callback to allow tools
to compute the datalayout at the appropriate time.
Not sure if I covered all the LLVM tools that want to use the callback.
(clang? lli? Misc IR manipulation tools like llvm-link?). But this is at
least enough for all the LLVM regression tests, and IR without a
datalayout is not something frontends should generate.
This change had some sort of weird effects for certain CodeGen
regression tests: if the datalayout is overridden with a datalayout with
a different program or stack address space, we now parse IR based on the
overridden datalayout, instead of the one written in the file (or the
default one, if none is specified). This broke a few AVR tests, and one
AMDGPU test.
Outside the CodeGen tests I mentioned, the test changes are all just
fixing CHECK lines and moving around datalayout lines in weird places.
Differential Revision: https://reviews.llvm.org/D78403
Due to libPolly now using the component infrastructure, it no longer carries all
dependencies as it used to do.
Differential Revision: https://reviews.llvm.org/D79295
After the update to ISL to isl-0.22.1-87-gfee05a13 and its change of
isl_*_dim returning -1 instead of 0, the -1 got wrapped-around to
UINT_MAX because Polly often uses 'unsigned' type to represent
dimensions, as ISL did before this patch. This may happen in normal
executions after an out-of-quota.
Fix by catching the error-case earlier.
This will allow us to use the datalayout to disambiguate other
constructs in IR, like load alignment. Split off from D78403.
Differential Revision: https://reviews.llvm.org/D78413
This is equivalent in terms of LLVM IR semantics, but we want to
transition away from using MaybeAlign to represent the alignment of
these instructions.
Differential Revision: https://reviews.llvm.org/D77984
The patch introduces the system to distinctively store the information
needed for the Control Flow Graph as well as the instrumentary needed for
the follow-up changes: BlockFrequencyInfo and BranchProbabilityInfo.
The patch is a part of sequence of three patches, related to graphs Heat Coloring.
Reviewers: rcorcs, apilipenko, davidxl, sfertile, fedor.sergeev, eraman, bollu
Differential Revision: https://reviews.llvm.org/D76820
The option is passed as argv to ISL's command line option parser.
Polly's own own command line options take precedence over options passed
as `-polly-isl-arg`. For instance,
`-polly-isl-arg=--schedule-outer-coincidence` will be ignored in favor
of `-polly-opt-outer-coincidence`.
Reviewed By: grosser
Differential Revision: https://reviews.llvm.org/D77303
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
Pass plugins introduced in D61446 do not support dynamic linking on
Windows, hence the option LLVM_${name_upper}_LINK_INTO_TOOLS can only
work being set to "ON". Currently, it defaults to "OFF" such that such
plugins are inoperable by default on Windows. Change the default for
subprojects to follow LLVM_ENABLE_PROJECTS.
Reviewed By: serge-sans-paille, MaskRay
Differential Revision: https://reviews.llvm.org/D72372
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
Simply dropping the createPollyIRBuilder() function here, because
it doesn't do much. Also directly initialize Expander in
ScopExpander instead of going through the copy-constructor.
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
This reverts commit 80a34ae311 with fixes.
Previously, since bots turning on EXPENSIVE_CHECKS are essentially turning on
MachineVerifierPass by default on X86 and the fact that
inline-asm-avx-v-constraint-32bit.ll and inline-asm-avx512vl-v-constraint-32bit.ll
are not expected to generate functioning machine code, this would go
down to `report_fatal_error` in MachineVerifierPass. Here passing
`-verify-machineinstrs=0` to make the intent explicit.
This reverts commit 80a34ae311 with fixes.
On bots llvm-clang-x86_64-expensive-checks-ubuntu and
llvm-clang-x86_64-expensive-checks-debian only,
llc returns 0 for these two tests unexpectedly. I tweaked the RUN line a little
bit in the hope that LIT is the culprit since this change is not in the
codepath these tests are testing.
llvm\test\CodeGen\X86\inline-asm-avx-v-constraint-32bit.ll
llvm\test\CodeGen\X86\inline-asm-avx512vl-v-constraint-32bit.ll
../polly/lib/Transform/ScheduleOptimizer.cpp:812:54: warning: comparison of integers of different signs: 'isl_size' (aka 'int') and 'const unsigned int' [-Wsign-compare]
isl_schedule_node_band_n_member(Node.get()) >
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ^
Static chunked OpenMP scheduling has not been treated correctly.
This patch fixes the problem that threads would not process their
(work-)chunks as intended.
Differential Revision: https://reviews.llvm.org/D61081
The primary motivation is to fix an assertion failure in
isl_basic_map_alloc_equality:
isl_assert(ctx, room_for_con(bmap, 1), return -1);
Although the assertion does not occur anymore, I could not identify
which of ISL's commits fixed it.
Compared to the previous ISL version, Polly requires some changes for this update
* Since ISL commit
20d3574 "perform parameter alignment by modifying both arguments to function"
isl_*_gist_* and similar functions do not always align the paramter
list anymore. This caused the parameter lists in JScop files to
become out-of-sync. Since many regression tests use JScop files with
a fixed parameter list and order, we explicitly call align_params to
ensure a predictable parameter list.
* ISL changed some return types to isl_size, a typedef of (signed) int.
This caused some issues where the return type was unsigned int before:
- No overload for std::max(unsigned,isl_size)
- It cause additional 'mixed signed/unsigned comparison' warnings.
Since they do not break compilation, and sizes larger than 2^31
were never supported, I am going to fix it separately.
* With the change to isl_size, commit
57d547 "isl_*_list_size: return isl_size"
also changed the return value in case of an error from 0 to -1. This
caused undefined looping over isl_iterator since the 'end iterator'
got index -1, never reached from the 'begin iterator' with index 0.
* Some internal changes in ISL caused the number of operations to
increase when determining access ranges to determine aliasing
overlaps. In one test, this caused exceeding the default limit of
800000. The operations-limit was disabled for this test.
The idiom
for (auto i = n - n; i < n; i += 1)
was intended to automatically derive the type of i from n
(signed/unsigned int) and avoid the 'mixed signed/unsigned comparison'
warning. However, almost-always-auto was never used in the LLVM coding
style (although we used it in Polly for some time) and I did never
intended to use this idiom upstream.
PVS Studio may warns about this idiom as 'warning: both sides of
operator are equivalent [misc-redundant-expression]'.
Remove the use of auto and directly use unsigned.
Also see http://llvm.org/PR44768
Commit 777180a "[ADT] Make StringRef's std::string conversion operator explicit"
caused Polly's GPU code generator to not compile anymore. The rest of
Polly has already been fixed in commit
0257a9 "Fix polly build after StringRef change."
Previously, the enums didn't account for all the possible cases, which
could cause misleading results (particularly for a "switch" on
FunctionModRefBehavior).
Fixes regression in polly from recent patch to add writeonly to memset.
While I'm here, also fix a few dubious uses of the FMRB_* enum values.
Differential Revision: https://reviews.llvm.org/D73154