Commit Graph

876 Commits

Author SHA1 Message Date
Roman Lebedev e3a4701627
[clang][CodeGen] Lower Likelihood attributes to @llvm.expect intrin instead of branch weights
08196e0b2e exposed LowerExpectIntrinsic's
internal implementation detail in the form of
LikelyBranchWeight/UnlikelyBranchWeight options to the outside.

While this isn't incorrect from the results viewpoint,
this is suboptimal from the layering viewpoint,
and causes confusion - should transforms also use those weights,
or should they use something else, D98898?

So go back to status quo by making LikelyBranchWeight/UnlikelyBranchWeight
internal again, and fixing all the code that used it directly,
which currently is only clang codegen, thankfully,
to emit proper @llvm.expect intrinsics instead.
2021-03-21 22:50:21 +03:00
Roman Lebedev 37d6be9052
Revert "[BranchProbability] move options for 'likely' and 'unlikely'"
Upon reviewing D98898 i've come to realization that these are
implementation detail of LowerExpectIntrinsicPass,
and they should not be exposed to outside of it.

This reverts commit ee8b53815d.
2021-03-21 22:50:21 +03:00
Sanjay Patel ee8b53815d [BranchProbability] move options for 'likely' and 'unlikely'
This makes the settings available for use in other passes by housing
them within the Support lib, but NFC otherwise.

See D98898 for the proposed usage in SimplifyCFG
(where this change was originally included).

Differential Revision: https://reviews.llvm.org/D98945
2021-03-20 14:46:46 -04:00
Nikita Popov 42eb658f65 [OpaquePtrs] Remove some uses of type-less CreateGEP() (NFC)
This removes some (but not all) uses of type-less CreateGEP()
and CreateInBoundsGEP() APIs, which are incompatible with opaque
pointers.

There are a still a number of tricky uses left, as well as many
more variation APIs for CreateGEP.
2021-03-12 21:01:16 +01:00
Nikita Popov 68e01339cc [CGBuilder] Remove type-less CreateAlignedLoad() APIs (NFC)
These are incompatible with opaque pointers. This is in preparation
of dropping this API on the IRBuilder side as well.

Instead explicitly pass the loaded type.
2021-03-11 10:41:23 +01:00
Michael Kruse b119120673 [clang][OpenMP] Use OpenMPIRBuilder for workshare loops.
Initial support for using the OpenMPIRBuilder by clang to generate loops using the OpenMPIRBuilder. This initial support is intentionally limited to:
 * Only the worksharing-loop directive.
 * Recognizes only the nowait clause.
 * No loop nests with more than one loop.
 * Untested with templates, exceptions.
 * Semantic checking left to the existing infrastructure.

This patch introduces a new AST node, OMPCanonicalLoop, which becomes parent of any loop that has to adheres to the restrictions as specified by the OpenMP standard. These restrictions allow OMPCanonicalLoop to provide the following additional information that depends on base language semantics:
 * The distance function: How many loop iterations there will be before entering the loop nest.
 * The loop variable function: Conversion from a logical iteration number to the loop variable.

These allow the OpenMPIRBuilder to act solely using logical iteration numbers without needing to be concerned with iterator semantics between calling the distance function and determining what the value of the loop variable ought to be. Any OpenMP logical should be done by the OpenMPIRBuilder such that it can be reused MLIR OpenMP dialect and thus by flang.

The distance and loop variable function are implemented using lambdas (or more exactly: CapturedStmt because lambda implementation is more interviewed with the parser). It is up to the OpenMPIRBuilder how they are called which depends on what is done with the loop. By default, these are emitted as outlined functions but we might think about emitting them inline as the OpenMPRuntime does.

For compatibility with the current OpenMP implementation, even though not necessary for the OpenMPIRBuilder, OMPCanonicalLoop can still be nested within OMPLoopDirectives' CapturedStmt. Although OMPCanonicalLoop's are not currently generated when the OpenMPIRBuilder is not enabled, these can just be skipped when not using the OpenMPIRBuilder in case we don't want to make the AST dependent on the EnableOMPBuilder setting.

Loop nests with more than one loop require support by the OpenMPIRBuilder (D93268). A simple implementation of non-rectangular loop nests would add another lambda function that returns whether a loop iteration of the rectangular overapproximation is also within its non-rectangular subset.

Reviewed By: jdenny

Differential Revision: https://reviews.llvm.org/D94973
2021-03-04 22:52:59 -06:00
Reid Kleckner 1c2e7d200d [MS] Fix crash involving gnu stmt exprs and inalloca
Use a WeakTrackingVH to cope with the stmt emission logic that cleans up
unreachable blocks. This invalidates the reference to the deferred
replacement placeholder. Cope with it.

Fixes PR25102 (from 2015!)
2021-03-04 13:57:46 -08:00
Gui Andrade 10264a1b21 Introduce noundef attribute at call sites for stricter poison analysis
This change adds a new IR noundef attribute, which denotes when a function call argument or return val may never contain uninitialized bits.

In MemorySanitizer, this attribute enables optimizations which decrease instrumented code size by up to 17% (measured with an instrumented build of clang) . I'll introduce the change allowing msan to take advantage of this information in a separate patch.

Differential Revision: https://reviews.llvm.org/D81678
2021-03-04 12:15:12 -08:00
Dávid Bolvanský 053dc95839 Reduce the number of attributes attached to each function
Patch takes advantage of the implicit default behavior to reduce the number of attributes, which in turns reduces compilation time.

Reviewed By: serge-sans-paille

Differential Revision: https://reviews.llvm.org/D97116
2021-02-24 07:08:44 +01:00
Melanie Blower e64fcdf8d5 [clang][patch] Inclusive language, modify filename SanitizerBlacklist.h to NoSanitizeList.h
This patch responds to a comment from @vitalybuka in D96203: suggestion to
do the change incrementally, and start by modifying this file name. I modified
the file name and made the other changes that follow from that rename.

Reviewers: vitalybuka, echristo, MaskRay, jansvoboda11, aaron.ballman

Differential Revision: https://reviews.llvm.org/D96974
2021-02-22 15:11:37 -05:00
Dávid Bolvanský ee51c42e00 Reduce the number of attributes attached to each function
This takes advantage of the implicit default behavior to reduce the number of
attributes.
2021-02-20 06:57:47 +01:00
Petr Hosek bb9eb19829 Support for instrumenting only selected files or functions
This change implements support for applying profile instrumentation
only to selected files or functions. The implementation uses the
sanitizer special case list format to select which files and functions
to instrument, and relies on the new noprofile IR attribute to exclude
functions from instrumentation.

Differential Revision: https://reviews.llvm.org/D94820
2021-01-26 17:13:34 -08:00
Petr Hosek 1e634f3952 Revert "Support for instrumenting only selected files or functions"
This reverts commit 4edf35f11a because
the test fails on Windows bots.
2021-01-26 12:25:28 -08:00
Petr Hosek 4edf35f11a Support for instrumenting only selected files or functions
This change implements support for applying profile instrumentation
only to selected files or functions. The implementation uses the
sanitizer special case list format to select which files and functions
to instrument, and relies on the new noprofile IR attribute to exclude
functions from instrumentation.

Differential Revision: https://reviews.llvm.org/D94820
2021-01-26 11:11:39 -08:00
Fangrui Song b88c8f1aab CGDebugInfo: Delete unused parameters 2021-01-11 13:39:03 -08:00
Alan Phipps 9f2967bcfe [Coverage] Add support for Branch Coverage in LLVM Source-Based Code Coverage
This is an enhancement to LLVM Source-Based Code Coverage in clang to track how
many times individual branch-generating conditions are taken (evaluate to TRUE)
and not taken (evaluate to FALSE).  Individual conditions may comprise larger
boolean expressions using boolean logical operators.  This functionality is
very similar to what is supported by GCOV except that it is very closely
anchored to the ASTs.

Differential Revision: https://reviews.llvm.org/D84467
2021-01-05 09:51:51 -06:00
James Y Knight 4ddf140c00 Fix PR35902: incorrect alignment used for ubsan check.
UBSan was using the complete-object align rather than nv alignment
when checking the "this" pointer of a method.

Furthermore, CGF.CXXABIThisAlignment was also being set incorrectly,
due to an incorrectly negated test. The latter doesn't appear to have
had any impact, due to it not really being used anywhere.

Differential Revision: https://reviews.llvm.org/D93072
2020-12-28 18:11:17 -05:00
Kevin P. Neal 2069403cdf [FPEnv] Use strictfp metadata in casting nodes
The strictfp metadata was added to the casting AST nodes in D85960, but
we aren't using that metadata yet. This patch adds that support.

In order to avoid lots of ad-hoc passing around of the strictfp bits I
updated the IRBuilder when moving from a function that has the Expr* to a
function that lacks it. I believe we should switch to this pattern to keep
the strictfp support from being overly invasive.

For the purpose of testing that we're picking up the right metadata, I
also made my tests use a pragma to make the AST's strictfp metadata not
match the global strictfp metadata. This exposes issues that we need to
deal with in subsequent patches, and I believe this is the right method
for most all of our clang strictfp tests.

Differential Revision: https://reviews.llvm.org/D88913
2020-11-06 11:56:12 -05:00
Atmn Patel ac73b73c16 [clang] Add mustprogress and llvm.loop.mustprogress attribute deduction
Since C++11, the C++ standard has a forward progress guarantee
[intro.progress], so all such functions must have the `mustprogress`
requirement. In addition, from C11 and onwards, loops without a non-zero
constant conditional or no conditional are also required to make
progress (C11 6.8.5p6). This patch implements these attribute deductions
so they can be used by the optimization passes.

Differential Revision: https://reviews.llvm.org/D86841
2020-11-04 22:03:14 -05:00
Mark de Wever b46fddf75f [CodeGen] Implement [[likely]] and [[unlikely]] for while and for loop.
The attribute has no effect on a do statement since the path of execution
will always include its substatement.

It adds a diagnostic when the attribute is used on an infinite while loop
since the codegen omits the branch here. Since the likelihood attributes
have no effect on a do statement no diagnostic will be issued for
do [[unlikely]] {...} while(0);

Differential Revision: https://reviews.llvm.org/D89899
2020-10-31 17:51:29 +01:00
Liu, Chen3 00090a2b82 Support complex target features combinations
This patch is mainly doing two things:

1. Adding support for parentheses, making the combination of target features
   more diverse;
2. Making the priority of ’,‘ is higher than that of '|' by default. So I need
   to make some change with PTX Builtin function.

Differential Revision: https://reviews.llvm.org/D89184
2020-10-30 10:32:53 +08:00
Tyker d3205bbca3 [Annotation] Allows annotation to carry some additional constant arguments.
This allows using annotation in a much more contexts than it currently has.
especially when annotation with template or constexpr.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D88645
2020-10-26 10:50:05 +01:00
Melanie Blower 2e204e2391 [clang] Enable support for #pragma STDC FENV_ACCESS
Reviewers: rjmccall, rsmith, sepavloff

Differential Revision: https://reviews.llvm.org/D87528
2020-10-25 06:46:25 -07:00
Mark de Wever 2bcda6bb28 [Sema, CodeGen] Implement [[likely]] and [[unlikely]] in SwitchStmt
This implements the likelihood attribute for the switch statement. Based on the
discussion in D85091 and D86559 it only handles the attribute when placed on
the case labels or the default labels.

It also marks the likelihood attribute as feature complete. There are more QoI
patches in the pipeline.

Differential Revision: https://reviews.llvm.org/D89210
2020-10-18 13:48:42 +02:00
Mark de Wever 1113fbf44c [CodeGen] Improve likelihood branch weights
Bruno De Fraine discovered some issues with D85091. The branch weights
generated for `logical not` and `ternary conditional` were wrong. The
`logical and` and `logical or` differed from the code generated of
`__builtin_predict`.

Adjusted the generated code for the likelihood to match
`__builtin_predict`. The patch is based on Bruno's suggestions.

Differential Revision: https://reviews.llvm.org/D88363
2020-10-04 14:24:27 +02:00
Ian Levesque 6f7fbdd285 [xray] Function coverage groups
Add the ability to selectively instrument a subset of functions by dividing the functions into N logical groups and then selecting a group to cover. By selecting different groups over time you could cover the entire application incrementally with lower overhead than instrumenting the entire application at once.

Differential Revision: https://reviews.llvm.org/D87953
2020-09-24 22:09:53 -04:00
Tyker 78de7297ab Reland [AssumeBundles] Use operand bundles to encode alignment assumptions
NOTE: There is a mailing list discussion on this: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

Complemantary to the assumption outliner prototype in D71692, this patch
shows how we could simplify the code emitted for an alignemnt
assumption. The generated code is smaller, less fragile, and it makes it
easier to recognize the additional use as a "assumption use".

As mentioned in D71692 and on the mailing list, we could adopt this
scheme, and similar schemes for other patterns, without adopting the
assumption outlining.
2020-09-12 15:36:06 +02:00
Mark de Wever 08196e0b2e Implements [[likely]] and [[unlikely]] in IfStmt.
This is the initial part of the implementation of the C++20 likelihood
attributes. It handles the attributes in an if statement.

Differential Revision: https://reviews.llvm.org/D85091
2020-09-09 20:48:37 +02:00
Richard Smith 740a164dec PR46377: Fix dependence calculation for function types and typedef
types.

We previously did not treat a function type as dependent if it had a
parameter pack with a non-dependent type -- such a function type depends
on the arity of the pack so is dependent even though none of the
parameter types is dependent. In order to properly handle this, we now
treat pack expansion types as always being dependent types (depending on
at least the pack arity), and always canonically being pack expansion
types, even in the unusual case when the pattern is not a dependent
type. This does mean that we can have canonical types that are pack
expansions that contain no unexpanded packs, which is unfortunate but
not inaccurate.

We also previously did not treat a typedef type as
instantiation-dependent if its canonical type was not
instantiation-dependent. That's wrong because instantiation-dependence
is a property of the type sugar, not of the type; an
instantiation-dependent type can have a non-instantiation-dependent
canonical type.
2020-07-28 13:23:13 -07:00
Eric Christopher 7bfaa40086 Temporarily Revert "[AssumeBundles] Use operand bundles to encode alignment assumptions"
due to the performance bugs filed in https://bugs.llvm.org/show_bug.cgi?id=46753.

An SROA change soon may obviate some of these problems.

This reverts commit 8d09f20798.
2020-07-16 11:54:04 -07:00
Tyker 8d09f20798 [AssumeBundles] Use operand bundles to encode alignment assumptions
Summary:
NOTE: There is a mailing list discussion on this: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

Complemantary to the assumption outliner prototype in D71692, this patch
shows how we could simplify the code emitted for an alignemnt
assumption. The generated code is smaller, less fragile, and it makes it
easier to recognize the additional use as a "assumption use".

As mentioned in D71692 and on the mailing list, we could adopt this
scheme, and similar schemes for other patterns, without adopting the
assumption outlining.

Reviewers: hfinkel, xbolva00, lebedev.ri, nikic, rjmccall, spatel, jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: thopre, yamauchi, kuter, fhahn, merge_guards_bot, hiraditya, bollu, rkruppe, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71739
2020-07-14 01:05:58 +02:00
sstefan1 6aab27ba85 [OpenMPIRBuilder][Fix] Move llvm::omp::types to OpenMPIRBuilder.
Summary:
D82193 exposed a problem with global type definitions in
`OMPConstants.h`. This causes a race when running in thinLTO mode.
Types now live inside of OpenMPIRBuilder to prevent this from happening.

Reviewers: jdoerfert

Subscribers: yaxunl, hiraditya, guansong, dexonsmith, aaron.ballman, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D83176
2020-07-08 17:23:55 +02:00
Roman Lebedev 7ea46aee36
Revert "[AssumeBundles] Use operand bundles to encode alignment assumptions"
Assume bundle can have more than one entry with the same name,
but at least AlignmentFromAssumptionsPass::extractAlignmentInfo() uses
getOperandBundle("align"), which internally assumes that it isn't the
case, and happily crashes otherwise.

Minimal reduced reproducer: run `opt -alignment-from-assumptions` on

target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
target triple = "x86_64-unknown-linux-gnu"

%0 = type { i64, %1*, i8*, i64, %2, i32, %3*, i8* }
%1 = type opaque
%2 = type { i8, i8, i16 }
%3 = type { i32, i32, i32, i32 }

; Function Attrs: nounwind
define i32 @f(%0* noalias nocapture readonly %arg, %0* noalias %arg1) local_unnamed_addr #0 {
bb:
  call void @llvm.assume(i1 true) [ "align"(%0* %arg, i64 8), "align"(%0* %arg1, i64 8) ]
  ret i32 0
}

; Function Attrs: nounwind willreturn
declare void @llvm.assume(i1) #1

attributes #0 = { nounwind "reciprocal-estimates"="none" }
attributes #1 = { nounwind willreturn }


This is what we'd have with -mllvm -enable-knowledge-retention

This reverts commit c95ffadb24.
2020-07-04 23:49:23 +03:00
Melanie Blower f4aaed3bf1 Reland D81869 "Modify FPFeatures to use delta not absolute settings"
This reverts commit defd43a5b3.
with correction to solve msan report

To solve https://bugs.llvm.org/show_bug.cgi?id=46166 where the
floating point settings in PCH files aren't compatible, rewrite
FPFeatures to use a delta in the settings rather than absolute settings.
With this patch, these floating point options can be benign.

Reviewers: rjmccall

Differential Revision: https://reviews.llvm.org/D81869
2020-06-27 01:34:57 -07:00
Melanie Blower defd43a5b3 Revert "Revert "Revert "Modify FPFeatures to use delta not absolute settings"""
This reverts commit 9518763d71.
Memory sanitizer fails in CGFPOptionsRAII::CGFPOptionsRAII dtor
2020-06-26 08:47:04 -07:00
Melanie Blower 9518763d71 Revert "Revert "Modify FPFeatures to use delta not absolute settings""
This reverts commit b55d723ed6.
Reapply Modify FPFeatures to use delta not absolute settings

To solve https://bugs.llvm.org/show_bug.cgi?id=46166 where the
floating point settings in PCH files aren't compatible, rewrite
FPFeatures to use a delta in the settings rather than absolute settings.
With this patch, these floating point options can be benign.

Reviewers: rjmccall

Differential Revision: https://reviews.llvm.org/D81869
2020-06-26 08:00:08 -07:00
Melanie Blower b55d723ed6 Revert "Modify FPFeatures to use delta not absolute settings"
This reverts commit 3a748cbf86.
I'm reverting this commit because I forgot to format the commit message
propertly. Sorry for the thrash.
2020-06-26 07:52:57 -07:00
Melanie Blower 3a748cbf86 Modify FPFeatures to use delta not absolute settings 2020-06-26 07:41:09 -07:00
Tyker c95ffadb24 [AssumeBundles] Use operand bundles to encode alignment assumptions
Summary:
NOTE: There is a mailing list discussion on this: http://lists.llvm.org/pipermail/llvm-dev/2019-December/137632.html

Complemantary to the assumption outliner prototype in D71692, this patch
shows how we could simplify the code emitted for an alignemnt
assumption. The generated code is smaller, less fragile, and it makes it
easier to recognize the additional use as a "assumption use".

As mentioned in D71692 and on the mailing list, we could adopt this
scheme, and similar schemes for other patterns, without adopting the
assumption outlining.

Reviewers: hfinkel, xbolva00, lebedev.ri, nikic, rjmccall, spatel, jdoerfert, sstefan1

Reviewed By: jdoerfert

Subscribers: yamauchi, kuter, fhahn, merge_guards_bot, hiraditya, bollu, rkruppe, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D71739
2020-06-25 12:59:44 +02:00
Akira Hatanaka c9a52de002 [CodeGen] Simplify the way lifetime of block captures is extended
Rather than pushing inactive cleanups for the block captures at the
entry of a full expression and activating them during the creation of
the block literal, just call pushLifetimeExtendedDestroy to ensure the
cleanups are popped at the end of the scope enclosing the block
expression.

rdar://problem/63996471

Differential Revision: https://reviews.llvm.org/D81624
2020-06-11 16:06:22 -07:00
John McCall 7fac1acc61 Set the LLVM FP optimization flags conservatively.
Functions can have local pragmas that override the global settings.
We set the flags eagerly based on global settings, but if we emit
an expression under the influence of a pragma, we clear the
appropriate flags from the function.

In order to avoid doing a ton of redundant work whenever we emit
an FP expression, configure the IRBuilder to default to global
settings, and only reconfigure it when we see an FP expression
that's not using the global settings.

Patch by Michele Scandale!

https://reviews.llvm.org/D80462
2020-06-11 18:16:41 -04:00
Wei Mi 7a6c89427c [SampleFDO] Add use-sample-profile function attribute.
When sampleFDO is enabled, people may expect they can use
-fno-profile-sample-use to opt-out using sample profile for a certain file.
That could be either for debugging purpose or for performance tuning purpose.
However, when thinlto is enabled, if a function in file A compiled with
-fno-profile-sample-use is imported to another file B compiled with
-fprofile-sample-use, the inlined copy of the function in file B may still
get its profile annotated.

The inconsistency may even introduce profile unused warning because if the
target is not compiled with explicit debug information flag, the function
in file A won't have its debug information enabled (debug information will
be enabled implicitly only when -fprofile-sample-use is used). After it is
imported into file B which is compiled with -fprofile-sample-use, profile
annotation for the outline copy of the function will fail because the
function has no debug information, and that will trigger  profile unused
warning.

We add a new attribute use-sample-profile to control whether a function
will use its sample profile no matter for its outline or inline copies.
That will make the behavior of -fno-profile-sample-use consistent.

Differential Revision: https://reviews.llvm.org/D79959
2020-06-02 17:23:17 -07:00
John McCall 8a8d703be0 Fix how cc1 command line options are mapped into FP options.
Canonicalize on storing FP options in LangOptions instead of
redundantly in CodeGenOptions.  Incorporate -ffast-math directly
into the values of those LangOptions rather than considering it
separately when building FPOptions.  Build IR attributes from
those options rather than a mix of sources.

We should really simplify the driver/cc1 interaction here and have
the driver pass down options that cc1 directly honors.  That can
happen in a follow-up, though.

Patch by Michele Scandale!
https://reviews.llvm.org/D80315
2020-06-01 22:00:30 -04:00
Eli Friedman 62f3ef2b53 [CGCall] Annotate references with "align" attribute.
If we're going to assume references are dereferenceable, we should also
assume they're aligned: otherwise, we can't actually dereference them.

See also D80072.

Differential Revision: https://reviews.llvm.org/D80166
2020-05-19 20:21:30 -07:00
Florian Hahn 1065869195 [Matrix] Add matrix type to Clang.
This patch adds a matrix type to Clang as described in the draft
specification in clang/docs/MatrixSupport.rst. It introduces a new option
-fenable-matrix, which can be used to enable the matrix support.

The patch adds new MatrixType and DependentSizedMatrixType types along
with the plumbing required. Loads of and stores to pointers to matrix
values are lowered to memory operations on 1-D IR arrays. After loading,
the loaded values are cast to a vector. This ensures matrix values use
the alignment of the element type, instead of LLVM's large vector
alignment.

The operators and builtins described in the draft spec will will be added in
follow-up patches.

Reviewers: martong, rsmith, Bigcheese, anemet, dexonsmith, rjmccall, aaron.ballman

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D72281
2020-05-11 18:55:45 +01:00
Melanie Blower f5360d4bb3 Reapply "Add support for #pragma float_control" with buildbot fixes
Add support for #pragma float_control

Reviewers: rjmccall, erichkeane, sepavloff

Differential Revision: https://reviews.llvm.org/D72841

This reverts commit fce82c0ed3.
2020-05-04 05:51:25 -07:00
Melanie Blower fce82c0ed3 Revert "Reapply "Add support for #pragma float_control" with improvements to"
This reverts commit 69aacaf699.
2020-05-01 10:31:09 -07:00
Melanie Blower 69aacaf699 Reapply "Add support for #pragma float_control" with improvements to
test cases
Add support for #pragma float_control

Reviewers: rjmccall, erichkeane, sepavloff

Differential Revision: https://reviews.llvm.org/D72841

This reverts commit 85dc033cac, and makes
corrections to the test cases that failed on buildbots.
2020-05-01 10:03:30 -07:00
Melanie Blower 85dc033cac Revert "Add support for #pragma float_control"
This reverts commit 4f1e9a17e9.
due to fail on buildbot, sorry for the noise
2020-05-01 06:36:58 -07:00
Melanie Blower 4f1e9a17e9 Add support for #pragma float_control
Reviewers: rjmccall, erichkeane, sepavloff

Differential Revision: https://reviews.llvm.org/D72841
2020-05-01 06:14:24 -07:00
Craig Topper a58b62b4a2 [IR] Replace all uses of CallBase::getCalledValue() with getCalledOperand().
This method has been commented as deprecated for a while. Remove
it and replace all uses with the equivalent getCalledOperand().

I also made a few cleanups in here. For example, to removes use
of getElementType on a pointer when we could just use getFunctionType
from the call.

Differential Revision: https://reviews.llvm.org/D78882
2020-04-27 22:17:03 -07:00
Erich Keane 5f0903e9be Reland Implement _ExtInt as an extended int type specifier.
I fixed the LLDB issue, so re-applying the patch.

This reverts commit a4b88c0449.
2020-04-17 10:45:48 -07:00
Sterling Augustine a4b88c0449 Revert "Implement _ExtInt as an extended int type specifier."
This reverts commit 61ba1481e2.

I'm reverting this because it breaks the lldb build with
incomplete switch coverage warnings. I would fix it forward,
but am not familiar enough with lldb to determine the correct
fix.

lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:3958:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
          ^
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:4633:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
          ^
lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp:4889:11: error: enumeration values 'DependentExtInt' and 'ExtInt' not handled in switch [-Werror,-Wswitch]
  switch (qual_type->getTypeClass()) {
2020-04-17 10:29:40 -07:00
Erich Keane 61ba1481e2 Implement _ExtInt as an extended int type specifier.
Introduction/Motivation:
LLVM-IR supports integers of non-power-of-2 bitwidth, in the iN syntax.
Integers of non-power-of-two aren't particularly interesting or useful
on most hardware, so much so that no language in Clang has been
motivated to expose it before.

However, in the case of FPGA hardware normal integer types where the
full bitwidth isn't used, is extremely wasteful and has severe
performance/space concerns.  Because of this, Intel has introduced this
functionality in the High Level Synthesis compiler[0]
under the name "Arbitrary Precision Integer" (ap_int for short). This
has been extremely useful and effective for our users, permitting them
to optimize their storage and operation space on an architecture where
both can be extremely expensive.

We are proposing upstreaming a more palatable version of this to the
community, in the form of this proposal and accompanying patch.  We are
proposing the syntax _ExtInt(N).  We intend to propose this to the WG14
committee[1], and the underscore-capital seems like the active direction
for a WG14 paper's acceptance.  An alternative that Richard Smith
suggested on the initial review was __int(N), however we believe that
is much less acceptable by WG14.  We considered _Int, however _Int is
used as an identifier in libstdc++ and there is no good way to fall
back to an identifier (since _Int(5) is indistinguishable from an
unnamed initializer of a template type named _Int).

[0]https://www.intel.com/content/www/us/en/software/programmable/quartus-prime/hls-compiler.html)
[1]http://www.open-std.org/jtc1/sc22/wg14/www/docs/n2472.pdf

Differential Revision: https://reviews.llvm.org/D73967
2020-04-17 07:10:57 -07:00
Serge Pavlov c7ff5b38f2 [FPEnv] Use single enum to represent rounding mode
Now compiler defines 5 sets of constants to represent rounding mode.
These are:

1. `llvm::APFloatBase::roundingMode`. It specifies all 5 rounding modes
defined by IEEE-754 and is used in `APFloat` implementation.

2. `clang::LangOptions::FPRoundingModeKind`. It specifies 4 of 5 IEEE-754
rounding modes and a special value for dynamic rounding mode. It is used
in clang frontend.

3. `llvm::fp::RoundingMode`. Defines the same values as
`clang::LangOptions::FPRoundingModeKind` but in different order. It is
used to specify rounding mode in in IR and functions that operate IR.

4. Rounding mode representation used by `FLT_ROUNDS` (C11, 5.2.4.2.2p7).
Besides constants for rounding mode it also uses a special value to
indicate error. It is convenient to use in intrinsic functions, as it
represents platform-independent representation for rounding mode. In this
role it is used in some pending patches.

5. Values like `FE_DOWNWARD` and other, which specify rounding mode in
library calls `fesetround` and `fegetround`. Often they represent bits
of some control register, so they are target-dependent. The same names
(not values) and a special name `FE_DYNAMIC` are used in
`#pragma STDC FENV_ROUND`.

The first 4 sets of constants are target independent and could have the
same numerical representation. It would simplify conversion between the
representations. Also now `clang::LangOptions::FPRoundingModeKind` and
`llvm::fp::RoundingMode` do not contain the value for IEEE-754 rounding
direction `roundTiesToAway`, although it is supported natively on
some targets.

This change defines all the rounding mode type via one `llvm::RoundingMode`,
which also contains rounding mode for IEEE rounding direction `roundTiesToAway`.

Differential Revision: https://reviews.llvm.org/D77379
2020-04-09 13:26:47 +07:00
Erich Keane 30588a7395 Make target features check work with ctor and dtor-
The problem was reported in PR45468, applying target features to an
always_inline constructor/destructor runs afoul of GlobalDecl
construction assert when checking for target-feature compatibility.

The core problem is fixed by using the version of the check that takes a
FunctionDecl rather than the GlobalDecl. However, while writing the
test, I discovered that source locations weren't properly set for this
check on ctors/dtors. This patch also fixes constructors and CALLED destructors.

Unfortunately, it doesn't seem too possible to get a meaningful source
location for a 'cleanup' destructor, so those are still 'frontend' level
errors unfortunately. A fixme was added to the test to cover that
situation.
2020-04-08 13:19:55 -07:00
Ian Levesque bb3111cbaf [clang][xray] Add xray attributes to functions without decls too
Summary: This allows instrumenting things like global initializers

Reviewers: dberris, MaskRay, smeenai

Subscribers: cfe-commits, johnislarry

Tags: #clang

Differential Revision: https://reviews.llvm.org/D77191
2020-04-01 00:02:39 -04:00
Sander de Smalen 5087ace651 [Clang][SVE] Parse builtin type string for scalable vectors
This patch adds 'q' to mean 'scalable vector' in the builtin
type string, and for SVE will return the matching builtin
type as defined in the C/C++ language extensions for SVE.

This patch also adds some scaffolding to generate the arm_sve.h
header file, and some builtin definitions (+CodeGen) to be able
to implement some simple masked load intrinsics that use the
ACLE types, such as:

 svint8_t test_svld1_s8(svbool_t pg, const int8_t *base) {
   return svld1_s8(pg, base);
 }

Reviewers: efriedma, rjmccall, rovka, rsandifo-arm, rengolin

Reviewed By: efriedma

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75298
2020-03-15 14:34:52 +00:00
Yaxun (Sam) Liu fb44b9db95 [OpenCL][CUDA][HIP][SYCL] Add norecurse
norecurse function attr indicates the function is not called recursively
directly or indirectly.

Add norecurse to OpenCL functions, SYCL functions in device compilation
and CUDA/HIP kernels.

Although there is LLVM pass adding norecurse to functions, it only works
for whole-program compilation. Also FE adding norecurse can make that
pass run faster since functions with norecurse do not need to be checked
again.

Differential Revision: https://reviews.llvm.org/D73651
2020-02-16 20:41:00 -05:00
Fangrui Song 1d49eb00d9 [AsmPrinter] De-capitalize all AsmPrinter::Emit* but EmitInstruction
Similar to rL328848.
2020-02-13 17:06:24 -08:00
Johannes Doerfert 70cac41a2b Reapply "[OpenMP][IRBuilder] Perform finalization (incl. outlining) late"
Reapply 8a56d64d76 with minor fixes.

The problem was that cancellation can cause new edges to the parallel
region exit block which is not outlined. The CodeExtractor will encode
the information which "exit" was taken as a return value. The fix is to
ensure we do not return any value from the outlined function, to prevent
control to value conversion we ensure a single exit block for the
outlined region.

This reverts commit 3aac953afa.
2020-02-12 22:29:07 -06:00
Johannes Doerfert 3aac953afa Revert "[OpenMP][IRBuilder] Perform finalization (incl. outlining) late"
This reverts commit 8a56d64d76.

Will be recommitted once the clang test problem is addressed.
2020-02-12 18:50:43 -06:00
Johannes Doerfert 8a56d64d76 [OpenMP][IRBuilder] Perform finalization (incl. outlining) late
In order to fix PR44560 and to prepare for loop transformations we now
finalize a function late, which will also do the outlining late. The
logic is as before but the actual outlining step happens now after the
function was fully constructed. Once we have loop transformations we
can apply them in the finalize step before the outlining.

Reviewed By: JonChesterfield

Differential Revision: https://reviews.llvm.org/D74372
2020-02-12 17:55:01 -06:00
Ian Levesque 14f870366a [xray][clang] Always add xray-skip-entry/exit and xray-ignore-loops attrs
The function attributes xray-skip-entry, xray-skip-exit, and
xray-ignore-loops were only being applied if a function had an
xray-instrument attribute, but they should apply if xray is enabled
globally too.

Differential Revision: https://reviews.llvm.org/D73842
2020-02-11 14:00:41 -08:00
Fangrui Song 69bf40c45f [Driver][CodeGen] Support -fpatchable-function-entry=N,M and __attribute__((patchable_function_entry(N,M))) where M>0
Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D73072
2020-01-23 17:02:54 -08:00
Ian Levesque 97ba483026 [xray] Allow instrumenting only function entry and/or only function exit
Extend -fxray-instrumentation-bundle to split function-entry and
function-exit into two separate options, so that it is possible to
instrument only function entry or only function exit.  For use cases
that only care about one or the other this will save significant overhead
and code size.

Differential Revision: https://reviews.llvm.org/D72890
2020-01-17 13:32:34 -08:00
Ian Levesque 1d62be2441 [clang][xray] Add -fxray-ignore-loops option
XRay allows tuning by minimum function size, but also always instruments
functions with loops in them. If the minimum function size is set to a
large value the loop instrumention ends up causing most functions to be
instrumented anyway. This adds a new flag, -fxray-ignore-loops, to disable
the loop detection logic.

Differential Revision: https://reviews.llvm.org/D72873
2020-01-17 13:32:24 -08:00
Amy Huang 53539bb032 [DebugInfo] Add another level to DebugInfoKind called Constructor
The option will limit debug info by only emitting complete class
type information when its constructor is emitted.
This patch changes comparisons with LimitedDebugInfo to use the new
level instead.

Differential Revision: https://reviews.llvm.org/D72427
2020-01-13 15:59:03 -08:00
Fangrui Song f17ae668a9 [Driver][CodeGen] Add -fpatchable-function-entry=N[,0]
In the backend, this feature is implemented with the function attribute
"patchable-function-entry". Both the attribute and XRay use
TargetOpcode::PATCHABLE_FUNCTION_ENTER, so the two features are
incompatible.

Reviewed By: ostannard, MaskRay

Differential Revision: https://reviews.llvm.org/D72222
2020-01-10 09:57:39 -08:00
Fangrui Song a44c434b68 Support function attribute patchable_function_entry
This feature is generic. Make it applicable for AArch64 and X86 because
the backend has only implemented NOP insertion for AArch64 and X86.

Reviewed By: nickdesaulniers, aaron.ballman

Differential Revision: https://reviews.llvm.org/D72221
2020-01-10 09:57:34 -08:00
Jim Lin ab1bcda851 [NFC] Use isX86() instead of getArch()
Summary: This is a clean up for https://reviews.llvm.org/D72247.

Reviewers: MaskRay, craig.topper, jhenderson

Reviewed By: MaskRay

Subscribers: hiraditya, rupprecht, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D72320
2020-01-07 17:35:44 +08:00
Craig Topper d35bcbbb5d [Sema][X86] Consider target attribute into the checks in validateOutputSize and validateInputSize.
The validateOutputSize and validateInputSize need to check whether
AVX or AVX512 are enabled. But this can be affected by the
target attribute so we need to factor that in.

This patch moves some of the code from CodeGen to create an
appropriate feature map that we can pass to the function.

Differential Revision: https://reviews.llvm.org/D68627
2019-12-23 11:23:30 -08:00
Fangrui Song 0792ef7256 [Driver] Verify -mrecord-mcount in Driver, instead of CodeGen after D71627
GCC's x86 and s390 ports support -mrecord-mcount. Other ports reject the
option.

  aarch64-linux-gnu-gcc: error: unrecognized command line option ‘-mrecord-mcount’

Allowing this option can cause failures when building Linux kernel for
aarch64, powerpc64, etc, which will think the feature is available if
the clang command returns 0.
2019-12-21 22:47:24 -08:00
Jonas Paulsson 2520bef865 [Clang FE, SystemZ] Recognize -mrecord-mcount CL option.
Recognize -mrecord-mcount from the command line and add a function attribute
"mrecord-mcount" when passed.

Only valid on SystemZ (when used with -mfentry).

Review: Ulrich Weigand
https://reviews.llvm.org/D71627
2019-12-19 08:51:55 -08:00
Jonas Paulsson ca520592c0 [Clang FE, SystemZ] Don't add "true" value for the "mnop-mcount" attribute.
Let the "mnop-mcount" function attribute simply be present or non-present.
Update SystemZ backend as well to use hasFnAttribute() instead.

Review: Ulrich Weigand
https://reviews.llvm.org/D71669
2019-12-18 11:04:13 -08:00
Jonas Paulsson 599d1cc07a [Clang FE, SystemZ] Recognize -mpacked-stack CL option
Recognize -mpacked-stack from the command line and add a function attribute
"mpacked-stack" when passed. This is needed for building the Linux kernel.

If this option is passed for any other target than SystemZ, an error is
generated.

Review: Ulrich Weigand
https://reviews.llvm.org/D71441
2019-12-17 11:26:17 -08:00
Reid Kleckner 9803178a78 Avoid Attr.h includes, CodeGen edition
This saves around 20 includes of Attr.h. Not much.
2019-12-09 16:17:18 -08:00
Craig Topper 505aa2410d [Attr] Move ParsedTargetAttr out of the TargetAttr class
Need to forward declare it in ASTContext.h for D68627, so it can't be a nested struct.

Differential Revision: https://reviews.llvm.org/D71159
2019-12-09 12:40:41 -08:00
Reid Kleckner eff08f4097 Revert "[Sema][X86] Consider target attribute into the checks in validateOutputSize and validateInputSize."
This reverts commit e1578fd2b7.

It introduces a dependency on Attr.h which I am removing from
ASTContext.h.
2019-12-06 15:42:14 -08:00
Craig Topper e1578fd2b7 [Sema][X86] Consider target attribute into the checks in validateOutputSize and validateInputSize.
The validateOutputSize and validateInputSize need to check whether
AVX or AVX512 are enabled. But this can be affected by the
target attribute so we need to factor that in.

This patch copies some of the code from CodeGen to create an
appropriate feature map that we can pass to the function. Probably
need some refactoring here to share more code with Codegen. Is
there a good place to do that? Also need to support the cpu_specific
attribute as well.

Differential Revision: https://reviews.llvm.org/D68627
2019-12-06 15:30:59 -08:00
Adrian Prantl 338588d7cf Debug Info: Apply a default location for cleanups if none is available.
This unbreaks the debuginfo-tests testsuite by replacing the assertion
with a default location. There are cleanups in helper functions that
don't have a valid source location such as block copy helpers and it's
not worth tracking each of them down.

rdar://57630879
2019-12-05 13:30:23 -08:00
Adrian Prantl ce7d35988d Debug Info: Assert that location is available for cleanups
rdar://57630879

Differential Revision: https://reviews.llvm.org/D71042
2019-12-05 12:45:10 -08:00
Melanie Blower 7f9b513847 Reapply af57dbf12e "Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior="
Patch was reverted because https://bugs.llvm.org/show_bug.cgi?id=44048
        The original patch is modified to set the strictfp IR attribute
        explicitly in CodeGen instead of as a side effect of IRBuilder.
        In the 2nd attempt to reapply there was a windows lit test fail, the
        tests were fixed to use wildcard matching.

        Differential Revision: https://reviews.llvm.org/D62731
2019-12-05 03:48:04 -08:00
Melanie Blower 5412913631 Revert " Reapply af57dbf12e "Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior=""
This reverts commit cdbed2dd85.
Build break on Windows (lit fail)
2019-12-04 12:21:23 -08:00
Melanie Blower cdbed2dd85 Reapply af57dbf12e "Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior="
Patch was reverted because https://bugs.llvm.org/show_bug.cgi?id=44048
        The original patch is modified to set the strictfp IR attribute
        explicitly in CodeGen instead of as a side effect of IRBuilder

        Differential Revision: https://reviews.llvm.org/D62731
2019-12-04 11:32:33 -08:00
Akira Hatanaka f139ae3d93 [NFC] Pass a reference to CodeGenFunction to methods of LValue and
AggValueSlot

This reapplies 8a5b7c3570 after a null
dereference bug in CGOpenMPRuntime::emitUserDefinedMapper.

Original commit message:

This is needed for the pointer authentication work we plan to do in the
near future.

a63a81bd99/clang/docs/PointerAuthentication.rst
2019-12-03 15:22:13 -08:00
Akira Hatanaka 9f37c0e703 Revert "[NFC] Pass a reference to CodeGenFunction to methods of LValue and"
This reverts commit 8a5b7c3570. This seems
to have broken UBSan because of a null dereference.
2019-12-03 13:08:01 -08:00
Akira Hatanaka 8a5b7c3570 [NFC] Pass a reference to CodeGenFunction to methods of LValue and
AggValueSlot

This is needed for the pointer authentication work we plan to do in the
near future.

a63a81bd99/clang/docs/PointerAuthentication.rst
2019-12-03 11:30:09 -08:00
Erich Keane 0213adde21 [NFC] Fix 'target' condition in checkTargetFeatures
checkTargetFeatures was incorrectly checking for cpu_specific instead of
just 'target'. While this function was never called in that situation,
it seemed correct to fix the condition.  Additionally, multiversion
functions can never be always_inline, but if any function accidentially
ended up here we shouldn't diagnose.

Note that the adding of target-features to the list is unnecessary since
the getFunctionFeatureMap actually considers attribute target,
however adding it results in significantly better error messages by
putting the 'target' features first (and thus first to fail).
Otherwise, the error message would be the first feature 'implied' by the
target attribute, and not necessarily the feature listed in the
attribute itself.
2019-11-18 13:43:52 -08:00
Eric Christopher 30e7ee3c4b Temporarily Revert "Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior="
and a follow-up NFC rearrangement as it's causing a crash on valid. Testcase is on the original review thread.

This reverts commits af57dbf12e and e6584b2b7b
2019-11-18 10:46:48 -08:00
Serge Pavlov e6584b2b7b Move floating point related entities to namespace level
Enumerations that describe rounding mode and exception behavior were
defined inside ConstrainedFPIntrinsic. It makes sense to use the same
definitions to represent the same properties in other cases, not only
in constrained intrinsics. It was however inconvenient as required to
include constrained intrinsics definitions even if they were not needed.
Also using long scope prefix reduced readability.

This change moves these definitioins to the namespace llvm::fp.
No functional changes.

Differential Revision: https://reviews.llvm.org/D69552
2019-11-15 19:56:33 +07:00
Adrian Prantl 2073dd2da7 Redeclare Objective-C property accessors inside the ObjCImplDecl in which they are synthesized.
This patch is motivated by (and factored out from)
https://reviews.llvm.org/D66121 which is a debug info bugfix. Starting
with DWARF 5 all Objective-C methods are nested inside their
containing type, and that patch implements this for synthesized
Objective-C properties.

1. SemaObjCProperty populates a list of synthesized accessors that may
   need to inserted into an ObjCImplDecl.

2. SemaDeclObjC::ActOnEnd inserts forward-declarations for all
   accessors for which no override was provided into their
   ObjCImplDecl. This patch does *not* synthesize AST function
   *bodies*. Moving that code from the static analyzer into Sema may
   be a good idea though.

3. Places that expect all methods to have bodies have been updated.

I did not update the static analyzer's inliner for synthesized
properties to point back to the property declaration (see
test/Analysis/Inputs/expected-plists/nullability-notes.m.plist), which
I believed to be more bug than a feature.

Differential Revision: https://reviews.llvm.org/D68108

rdar://problem/53782400
2019-11-08 08:23:22 -08:00
Melanie Blower af57dbf12e Add support for options -frounding-math, ftrapping-math, -ffp-model=, and -ffp-exception-behavior=
Add options to control floating point behavior: trapping and
    exception behavior, rounding, and control of optimizations that affect
    floating point calculations. More details in UsersManual.rst.

    Reviewers: rjmccall

    Differential Revision: https://reviews.llvm.org/D62731
2019-11-07 07:22:45 -08:00
Jonas Paulsson 9376714314 [Clang FE] Recognize -mnop-mcount CL option (SystemZ only).
Recognize -mnop-mcount from the command line and add a function attribute
"mnop-mcount"="true" when passed.

When this option is used, a nop is added instead of a call to fentry. This
is used when building the Linux Kernel.

If this option is passed for any other target than SystemZ, an error is
generated.

Review: Ulrich Weigand
https://reviews.llvm.org/D67763
2019-11-05 12:12:36 +01:00
Amy Huang ab76cfdd20 Recommit "[CodeView] Add option to disable inline line tables."
This reverts commit 004ed2b0d1.
Original commit hash 6d03890384

Summary:
This adds a clang option to disable inline line tables. When it is used,
the inliner uses the call site as the location of the inlined function instead of
marking it as an inline location with the function location.

https://reviews.llvm.org/D67723
2019-11-04 09:15:26 -08:00
Amy Huang 004ed2b0d1 Revert "[CodeView] Add option to disable inline line tables."
because it breaks compiler-rt tests.

This reverts commit 6d03890384.
2019-10-30 17:31:12 -07:00
Amy Huang 6d03890384 [CodeView] Add option to disable inline line tables.
Summary:
This adds a clang option to disable inline line tables. When it is used,
the inliner uses the call site as the location of the inlined function instead of
marking it as an inline location with the function location.

See https://bugs.llvm.org/show_bug.cgi?id=42344

Reviewers: rnk

Subscribers: hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D67723
2019-10-30 16:52:39 -07:00
Erich Keane f759395994 Reland r374450 with Richard Smith's comments and test fixed.
The behavior from the original patch has changed, since we're no longer
allowing LLVM to just ignore the alignment.  Instead, we're just
assuming the maximum possible alignment.

Differential Revision: https://reviews.llvm.org/D68824

llvm-svn: 374562
2019-10-11 14:59:44 +00:00
Nico Weber b556085d81 Revert 374450 "Fix __builtin_assume_aligned with too large values."
The test fails on Windows, with

  error: 'warning' diagnostics expected but not seen:
    File builtin-assume-aligned.c Line 62: requested alignment
        must be 268435456 bytes or smaller; assumption ignored
  error: 'warning' diagnostics seen but not expected:
    File builtin-assume-aligned.c Line 62: requested alignment
        must be 8192 bytes or smaller; assumption ignored

llvm-svn: 374456
2019-10-10 21:34:32 +00:00
Erich Keane 31e454c1ec Fix __builtin_assume_aligned with too large values.
Code to handle __builtin_assume_aligned was allowing larger values, but
would convert this to unsigned along the way. This patch removes the
EmitAssumeAligned overloads that take unsigned to do away with this
problem.

Additionally, it adds a warning that values greater than 1 <<29 are
ignored by LLVM.

Differential Revision: https://reviews.llvm.org/D68824

llvm-svn: 374450
2019-10-10 21:08:28 +00:00