211 Commits

Author SHA1 Message Date
Alex Voicu
4d680f5647 [HIP][Clang][Sema] Add Sema support for hipstdpar
This patch adds the Sema changes needed for enabling HIP parallel algorithm offload on AMDGPU targets. This change impacts the CUDA / HIP language specific checks, and only manifests if compiling in `hipstdpar` mode. In this case, we essentially do three things:

1. Allow device side callers to call host side callees - since the user visible HLL would be standard C++, with no annotations / restriction mechanisms, we cannot unambiguously establish that such a call is an error, so we conservatively allow all such calls, deferring actual cleanup to a subsequent pass over IR;
2. Allow host formed lambdas to capture by reference;
3. Allow device functions to use host global variables.

Reviewed by: yaxunl

Differential Revision: https://reviews.llvm.org/D155833
2023-10-03 13:29:12 +01:00
Elliot Goodrich
b0abd4893f [llvm] Add missing StringExtras.h includes
In preparation for removing the `#include "llvm/ADT/StringExtras.h"`
from the header to source file of `llvm/Support/Error.h`, first add in
all the missing includes that were previously included transitively
through this header.
2023-06-25 15:42:22 +01:00
Kazu Hirata
6ad0788c33 [clang] Use std::optional instead of llvm::Optional (NFC)
This patch replaces (llvm::|)Optional< with std::optional<.  I'll post
a separate patch to remove #include "llvm/ADT/Optional.h".

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 12:31:01 -08:00
Kazu Hirata
a1580d7b59 [clang] Add #include <optional> (NFC)
This patch adds #include <optional> to those files containing
llvm::Optional<...> or Optional<...>.

I'll post a separate patch to actually replace llvm::Optional with
std::optional.

This is part of an effort to migrate from llvm::Optional to
std::optional:

https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716
2023-01-14 11:07:21 -08:00
Saleem Abdulrasool
707cc06e15 Sema: diagnose PMFs passed through registers to inline assembly
The itanium ABI represents the PMF as a pair of pointers.  As such the
structure cannot be passed through a single register.  Diagnose such
cases in the frontend rather than trying to generate IR to perform this
operation.

Fixes: 59033

Differential Revision: https://reviews.llvm.org/D13851
Reviewed By: aaron.ballman
2022-12-09 16:58:46 +00:00
Tom Honermann
0982db188b [Clang] reject bit-fields as instruction operands in Microsoft style inline asm blocks.
MSVC allows bit-fields to be specified as instruction operands in inline asm
blocks. Such references are resolved to the address of the allocation unit that
the named bitfield is a part of. The result is that reads and writes of such
operands will read or mutate nearby bit-fields stored in the same allocation
unit. This is a surprising behavior for which MSVC issues warning C4401,
"'<identifier>': member is bit field". Intel's icc compiler also allows such
bit-field references, but does not issue a diagnostic.

Prior to this change, Clang fails the following assertion when a bit-field is
referenced in such instructions:
  clang/lib/CodeGen/CGValue.h:338: llvm::Value* clang::CodeGen::LValue::getPointer(clang::CodeGen::CodeGenFunction&) const: Assertion `isSimple()' failed.
In non-assert enabled builds, Clang's behavior appears to match the behavior
of the MSVC and icc compilers, though it is unknown if that is by design or
happenstance.

Following this change, attempts to use a bit-field as an instruction operand
in Microsoft style asm blocks is diagnosed as an error due to the risk of
unintentionally reading or writing nearby bit-fields.

Fixes https://github.com/llvm/llvm-project/issues/57791

Reviewed By: erichkeane, aaron.ballman

Differential Revision: https://reviews.llvm.org/D135500
2022-10-10 15:45:02 -04:00
Fangrui Song
3f18f7c007 [clang] LLVM_FALLTHROUGH => [[fallthrough]]. NFC
With C++17 there is no Clang pedantic warning or MSVC C5051.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D131346
2022-08-08 09:12:46 -07:00
Corentin Jabot
a9a60f20e6 [Clang] Rename StringLiteral::isAscii() => isOrdinary() [NFC]
"Ascii" StringLiteral instances are actually narrow strings
that are UTF-8 encoded and do not have an encoding prefix.
(UTF8 StringLiteral are also UTF-8 encoded strings, but with
the u8 prefix.

To avoid possible confusion both with actuall ASCII strings,
and with future works extending the set of literal encodings
supported by clang, this rename StringLiteral::isAscii() to
isOrdinary(), matching C++ standard terminology.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D128762
2022-06-29 18:28:51 +02:00
Akira Hatanaka
8fc3d719ee Stop wrapping GCCAsmStmts inside StmtExprs to destruct temporaries
Instead, just pop the cleanups at the end of the asm statement.

This fixes an assertion failure in BuildStmtExpr. It also fixes a bug
where blocks and C compound literals were destructed at the end of the
asm statement instead of at the end of the enclosing scope.

Differential Revision: https://reviews.llvm.org/D125936
2022-06-17 17:28:00 -07:00
Kazu Hirata
4969a6924d Use llvm::less_first (NFC) 2022-06-04 21:23:18 -07:00
Balazs Benics
a73b50ad06 Revert "[llvm][clang][bolt][NFC] Use llvm::less_first() when applicable"
This reverts commit 3988bd13988aad72ec979beb2361e8738584926b.

Did not build on this bot:
https://lab.llvm.org/buildbot#builders/215/builds/6372

/usr/include/c++/9/bits/predefined_ops.h:177:11: error: no match for call to
‘(llvm::less_first) (std::pair<long unsigned int, llvm::bolt::BinaryBasicBlock*>&, const std::pair<long unsigned int, std::nullptr_t>&)’
  177 |  { return bool(_M_comp(*__it, __val)); }
2022-05-27 11:19:18 +02:00
Balazs Benics
3988bd1398 [llvm][clang][bolt][NFC] Use llvm::less_first() when applicable
One could reuse this functor instead of rolling out your own version.
There were a couple other cases where the code was similar, but not
quite the same, such as it might have an assertion in the lambda or other
constructs. Thus, I've not touched any of those, as it might change the
behavior in some way.

As per https://discourse.llvm.org/t/submitting-simple-nfc-patches/62640/3?u=steakhal
Chris Lattner
> LLVM intentionally has a “yes, you can apply common sense judgement to
> things” policy when it comes to code review. If you are doing mechanical
> patches (e.g. adopting less_first) that apply to the entire monorepo,
> then you don’t need everyone in the monorepo to sign off on it. Having
> some +1 validation from someone is useful, but you don’t need everyone
> whose code you touch to weigh in.

Differential Revision: https://reviews.llvm.org/D126068
2022-05-27 11:15:23 +02:00
Phoebe Wang
32103608fc [Inline-asm] Add diagnosts for unsupported inline assembly arguments
GCC supports power-of-2 size structures for the arguments. Clang supports fewer than GCC. But Clang always crashes for the unsupported cases.

This patch adds sema checks to do the diagnosts to solve these crashes.

Reviewed By: jyu2

Differential Revision: https://reviews.llvm.org/D107141
2022-03-23 11:25:19 +08:00
Aaron Ballman
6c75ab5f66 Introduce _BitInt, deprecate _ExtInt
WG14 adopted the _ExtInt feature from Clang for C23, but renamed the
type to be _BitInt. This patch does the vast majority of the work to
rename _ExtInt to _BitInt, which accounts for most of its size. The new
type is exposed in older C modes and all C++ modes as a conforming
extension. However, there are functional changes worth calling out:

* Deprecates _ExtInt with a fix-it to help users migrate to _BitInt.
* Updates the mangling for the type.
* Updates the documentation and adds a release note to warn users what
is going on.
* Adds new diagnostics for use of _BitInt to call out when it's used as
a Clang extension or as a pre-C23 compatibility concern.
* Adds new tests for the new diagnostic behaviors.

I want to call out the ABI break specifically. We do not believe that
this break will cause a significant imposition for early adopters of
the feature, and so this is being done as a full break. If it turns out
there are critical uses where recompilation is not an option for some
reason, we can consider using ABI tags to ease the transition.
2021-12-06 12:52:01 -05:00
Jason Liu
fe177a1773 Fix assertion when passing function into inline asm's input operand
This seem to be a regression caused by this change:
https://reviews.llvm.org/D60943.
Since we delayed report the error, we would run into some invalid
state in clang and llvm.

Without this fix, clang would assert when passing function into
inline asm's input operand.

Differential Revision: https://reviews.llvm.org/D107941
2021-08-27 13:39:41 -04:00
Simon Pilgrim
61cdaf66fe [ADT] Remove APInt/APSInt toString() std::string variants
<string> is currently the highest impact header in a clang+llvm build:

https://commondatastorage.googleapis.com/chromium-browser-clang/llvm-include-analysis.html

One of the most common places this is being included is the APInt.h header, which needs it for an old toString() implementation that returns std::string - an inefficient method compared to the SmallString versions that it actually wraps.

This patch replaces these APInt/APSInt methods with a pair of llvm::toString() helpers inside StringExtras.h, adjusts users accordingly and removes the <string> from APInt.h - I was hoping that more of these users could be converted to use the SmallString methods, but it appears that most end up creating a std::string anyhow. I avoided trying to use the raw_ostream << operators as well as I didn't want to lose having the integer radix explicit in the code.

Differential Revision: https://reviews.llvm.org/D103888
2021-06-11 13:19:15 +01:00
Matheus Izvekov
aef5d8fdc7 [clang] NFC: Rename rvalue to prvalue
This renames the expression value categories from rvalue to prvalue,
keeping nomenclature consistent with C++11 onwards.

C++ has the most complicated taxonomy here, and every other language
only uses a subset of it, so it's less confusing to use the C++ names
consistently, and mentally remap to the C names when working on that
context (prvalue -> rvalue, no xvalues, etc).

Renames:
* VK_RValue -> VK_PRValue
* Expr::isRValue -> Expr::isPRValue
* SK_QualificationConversionRValue -> SK_QualificationConversionPRValue
* JSON AST Dumper Expression nodes value category: "rvalue" -> "prvalue"

Signed-off-by: Matheus Izvekov <mizvekov@gmail.com>

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D103720
2021-06-09 12:27:10 +02:00
cynecx
8ec9fd4839 Support unwinding from inline assembly
I've taken the following steps to add unwinding support from inline assembly:

1) Add a new `unwind` "attribute" (like `sideeffect`) to the asm syntax:

```
invoke void asm sideeffect unwind "call thrower", "~{dirflag},~{fpsr},~{flags}"()
    to label %exit unwind label %uexit
```

2.) Add Bitcode writing/reading support + LLVM-IR parsing.

3.) Emit EHLabels around inline assembly lowering (SelectionDAGBuilder + GlobalISel) when `InlineAsm::canThrow` is enabled.

4.) Tweak InstCombineCalls/InlineFunction pass to not mark inline assembly "calls" as nounwind.

5.) Add clang support by introducing a new clobber: "unwind", which lower to the `canThrow` being enabled.

6.) Don't allow unwinding callbr.

Reviewed By: Amanieu

Differential Revision: https://reviews.llvm.org/D95745
2021-05-13 19:13:03 +01:00
Thorsten Schütt
2fd11e0b1e Revert "[NFC, Refactor] Modernize StorageClass from Specifiers.h to a scoped enum (II)"
This reverts commit efc82c4ad2bcb256a4f4c20238d08cd3afba4d2d.
2021-01-04 23:17:45 +01:00
Thorsten Schütt
efc82c4ad2 [NFC, Refactor] Modernize StorageClass from Specifiers.h to a scoped enum (II)
Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D93765
2021-01-04 22:58:26 +01:00
Yaxun (Sam) Liu
52bcd691cb Recommit "[CUDA][HIP] Defer overloading resolution diagnostics for host device functions"
This recommits 7f1f89ec8d9944559042bb6d3b1132eabe3409de and
40df06cdafc010002fc9cfe1dda73d689b7d27a6 with bug fixes for
memory sanitizer failure and Tensile build failure.
2020-10-19 17:48:04 -04:00
Reid Kleckner
3453b6928d Revert "Recommit "[CUDA][HIP] Defer overloading resolution diagnostics for host device functions""
This reverts commit e39da8ab6a286ac777d5fe7799f1eb782cf99938.

This depends on a change that needs additional design review and needs
to be reverted.
2020-09-24 11:16:54 -07:00
Yaxun (Sam) Liu
e39da8ab6a Recommit "[CUDA][HIP] Defer overloading resolution diagnostics for host device functions"
This recommits 7f1f89ec8d9944559042bb6d3b1132eabe3409de and
40df06cdafc010002fc9cfe1dda73d689b7d27a6 after fixing memory
sanitizer failure.
2020-09-24 08:44:37 -04:00
Yaxun (Sam) Liu
772bd8a7d9 Revert "[CUDA][HIP] Defer overloading resolution diagnostics for host device functions"
This reverts commit 7f1f89ec8d9944559042bb6d3b1132eabe3409de.

This reverts commit 40df06cdafc010002fc9cfe1dda73d689b7d27a6.
2020-09-17 13:55:31 -04:00
Yaxun (Sam) Liu
40df06cdaf [CUDA][HIP] Defer overloading resolution diagnostics for host device functions
In CUDA/HIP a function may become implicit host device function by
pragma or constexpr. A host device function is checked in both
host and device compilation. However it may be emitted only
on host or device side, therefore the diagnostics should be
deferred until it is known to be emitted.

Currently clang is only able to defer certain diagnostics. This causes
false alarms and limits the usefulness of host device functions.

This patch lets clang defer all overloading resolution diagnostics for host device functions.

An option -fgpu-defer-diag is added to control this behavior. By default
it is off.

It is NFC for other languages.

Differential Revision: https://reviews.llvm.org/D84364
2020-09-17 11:30:42 -04:00
Erich Keane
5f1f4a5d01 Prohibit capture of _ExtInt in inline assembly.
The backends don't seem to properly handle the _ExtInt type in inline
assembly with crashes occurring in many. While the ones I tested seem to
work for powers of 2 < 64 (and some any multiple of 64 greater than
that), it seemed like a better idea to just use of this type in inline
assembly prohibited.
2020-05-14 07:21:09 -07:00
Bill Wendling
50cac24877 Support output constraints on "asm goto"
Summary:
Clang's "asm goto" feature didn't initially support outputs constraints. That
was the same behavior as gcc's implementation. The decision by gcc not to
support outputs was based on a restriction in their IR regarding terminators.
LLVM doesn't restrict terminators from returning values (e.g. 'invoke'), so
it made sense to support this feature.

Output values are valid only on the 'fallthrough' path. If an output value's used
on an indirect branch, then it's 'poisoned'.

In theory, outputs *could* be valid on the 'indirect' paths, but it's very
difficult to guarantee that the original semantics would be retained. E.g.
because indirect labels could be used as data, we wouldn't be able to split
critical edges in situations where two 'callbr' instructions have the same
indirect label, because the indirect branch's destination would no longer be
the same.

Reviewers: jyknight, nickdesaulniers, hfinkel

Reviewed By: jyknight, nickdesaulniers

Subscribers: MaskRay, rsmith, hiraditya, llvm-commits, cfe-commits, craig.topper, rnk

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D69876
2020-02-24 18:51:29 -08:00
Eric Astor
4a7aa252a3 [X86][AsmParser] re-introduce 'offset' operator
Summary:
Amend MS offset operator implementation, to more closely fit with its MS counterpart:

    1. InlineAsm: evaluate non-local source entities to their (address) location
    2. Provide a mean with which one may acquire the address of an assembly label via MS syntax, rather than yielding a memory reference (i.e. "offset asm_label" and "$asm_label" should be synonymous
    3. address PR32530

Based on http://llvm.org/D37461

Fix broken test where the break appears unrelated.

- Set up appropriate memory-input rewrites for variable references.

- Intel-dialect assembly printing now correctly handles addresses by adding "offset".

- Pass offsets as immediate operands (using "r" constraint for offsets of locals).

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D71436
2019-12-30 14:35:26 -05:00
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
Reid Kleckner
eff08f4097 Revert "[Sema][X86] Consider target attribute into the checks in validateOutputSize and validateInputSize."
This reverts commit e1578fd2b79fe5af5f80c0c166a8abd0f816c022.

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
Bill Wendling
ce29291fc3 Delay diagnosing asm constraints that require immediates until after inlining
Summary:
An inline asm call may result in an immediate input value after inlining.
Therefore, don't emit a diagnostic here if the input isn't an immediate.

Reviewers: joerg, eli.friedman, rsmith

Subscribers: asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, s.egerton, krytarowski, mgorny, riccibruno, eraman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D60943

llvm-svn: 368104
2019-08-06 22:41:22 +00:00
Rui Ueyama
49a3ad21d6 Fix parameter name comments using clang-tidy. NFC.
This patch applies clang-tidy's bugprone-argument-comment tool
to LLVM, clang and lld source trees. Here is how I created this
patch:

$ git clone https://github.com/llvm/llvm-project.git
$ cd llvm-project
$ mkdir build
$ cd build
$ cmake -GNinja -DCMAKE_BUILD_TYPE=Debug \
    -DLLVM_ENABLE_PROJECTS='clang;lld;clang-tools-extra' \
    -DCMAKE_EXPORT_COMPILE_COMMANDS=On -DLLVM_ENABLE_LLD=On \
    -DCMAKE_C_COMPILER=clang -DCMAKE_CXX_COMPILER=clang++ ../llvm
$ ninja
$ parallel clang-tidy -checks='-*,bugprone-argument-comment' \
    -config='{CheckOptions: [{key: StrictMode, value: 1}]}' -fix \
    ::: ../llvm/lib/**/*.{cpp,h} ../clang/lib/**/*.{cpp,h} ../lld/**/*.{cpp,h}

llvm-svn: 366177
2019-07-16 04:46:31 +00:00
Jennifer Yu
b8fee677bf Re-check in clang support gun asm goto after fixing tests.
llvm-svn: 362410
2019-06-03 15:57:25 +00:00
Erich Keane
d0f34fd198 Revert "clang support gnu asm goto."
This reverts commit 954ec09aed4f2be04bb5f4e10dbb4ea8bd19ef9a.

Reverting due to test failures as requested by Jennifer Yu.

Conflicts:
	clang/test/CodeGen/asm-goto.c

llvm-svn: 362106
2019-05-30 15:38:02 +00:00
Jennifer Yu
954ec09aed clang support gnu asm goto.
Syntax:
  asm [volatile] goto ( AssemblerTemplate
                      :
                      : InputOperands
                      : Clobbers
                      : GotoLabels)

https://gcc.gnu.org/onlinedocs/gcc/Extended-Asm.html

New llvm IR is "callbr" for inline asm goto instead "call" for inline asm
For:
asm goto("testl %0, %0; jne %l1;" :: "r"(cond)::label_true, loop);
IR:
callbr void asm sideeffect "testl $0, $0; jne ${1:l};", "r,X,X,~{dirflag},~{fpsr},~{flags}"(i32 %0, i8* blockaddress(@foo, %label_true), i8* blockaddress(@foo, %loop)) #1
          to label %asm.fallthrough [label %label_true, label %loop], !srcloc !3

asm.fallthrough:                                

Compiler need to generate:
1> a dummy constarint 'X' for each label.
2> an unique fallthrough label for each asm goto stmt " asm.fallthrough%number".


Diagnostic 
1>	duplicate asm operand name are used in output, input and label.
2>	goto out of scope.

llvm-svn: 362045
2019-05-30 01:05:46 +00:00
Hans Wennborg
dd1ea8abb7 Inline asm constraints: allow ICE-like pointers for the "n" constraint (PR40890)
Apparently GCC allows this, and there's code relying on it (see bug).

The idea is to allow expression that would have been allowed if they
were cast to int. So I based the code on how such a cast would be done
(the CK_PointerToIntegral case in IntExprEvaluator::VisitCastExpr()).

Differential Revision: https://reviews.llvm.org/D58821

llvm-svn: 355491
2019-03-06 10:26:19 +00:00
Alexey Bataev
305b6b9647 [OPENMP][CUDA]Do not emit warnings for variables in late-reported asm
statements.

If the assembler instruction is not generated and the delayed diagnostic
is emitted, we may end up with extra warning message for variables used
in the asm statement. Since the asm statement is not built, the
variables may be left non-referenced and it may produce a warning about
a use of the non-initialized variables.

llvm-svn: 354928
2019-02-26 21:51:16 +00:00
Alexey Bataev
3167b3035e [CUDA]Delayed diagnostics for the asm instructions.
Adapted targetDiag for the CUDA and used for the delayed diagnostics in
asm constructs. Works for both host and device compilation sides.

Differential Revision: https://reviews.llvm.org/D58463

llvm-svn: 354671
2019-02-22 14:42:48 +00:00
Alexey Bataev
12a21e4b69 Revert "[CUDA]Delayed diagnostics for the asm instructions."
This reverts commit r354593 to fix the problem with the crash on
windows.

llvm-svn: 354596
2019-02-21 16:40:21 +00:00
Alexey Bataev
16d3e1a4d2 [CUDA]Delayed diagnostics for the asm instructions.
Summary:
Adapted targetDiag for the CUDA and used for the delayed diagnostics in
asm constructs. Works for both host and device compilation sides.

Reviewers: tra, jlebar

Subscribers: jdoerfert, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58463

llvm-svn: 354593
2019-02-21 15:51:30 +00:00
Alexey Bataev
5c96c1c5aa [OPENMP] Delay emission of the asm target-specific error messages.
Summary:
Added the ability to emit target-specific builtin assembler error
messages only in case if the function is really is going to be emitted
for the device.

Reviewers: rjmccall

Subscribers: guansong, jdoerfert, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D58243

llvm-svn: 354486
2019-02-20 17:42:57 +00:00
Chandler Carruth
2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Bill Wendling
642e140beb Use "EvaluateAsRValue" instead of as a known int, because if it's not a known
integer we want to emit a diagnostic instead of asserting.

llvm-svn: 349604
2018-12-19 04:54:29 +00:00
Bill Wendling
13381fbc29 Revert accidentally included code.
llvm-svn: 349603
2018-12-19 04:36:42 +00:00
Bill Wendling
aa77513bb9 Emit ASM input in a constant context
Summary:
Some ASM input constraints (e.g., "i" and "n") require immediate values. At O0,
very few code transformations are performed. So if we cannot resolve to an
immediate when emitting the ASM input we shouldn't delay its processing.

Reviewers: rsmith, efriedma

Reviewed By: efriedma

Subscribers: rehana, efriedma, craig.topper, jyknight, cfe-commits

Differential Revision: https://reviews.llvm.org/D55616

llvm-svn: 349561
2018-12-18 22:54:03 +00:00
Fangrui Song
407659ab0a Revert "Revert r347417 "Re-Reinstate 347294 with a fix for the failures.""
It seems the two failing tests can be simply fixed after r348037

Fix 3 cases in Analysis/builtin-functions.cpp
Delete the bad CodeGen/builtin-constant-p.c for now

llvm-svn: 348053
2018-11-30 23:41:18 +00:00
Fangrui Song
f5d3335d75 Revert r347417 "Re-Reinstate 347294 with a fix for the failures."
Kept the "indirect_builtin_constant_p" test case in test/SemaCXX/constant-expression-cxx1y.cpp
while we are investigating why the following snippet fails:

  extern char extern_var;
  struct { int a; } a = {__builtin_constant_p(extern_var)};

llvm-svn: 348039
2018-11-30 21:26:09 +00:00
Hans Wennborg
48ee4ad325 Re-commit r347417 "Re-Reinstate 347294 with a fix for the failures."
This was reverted in r347656 due to me thinking it caused a miscompile of
Chromium. Turns out it was the Chromium code that was broken.

llvm-svn: 347756
2018-11-28 14:04:12 +00:00
Hans Wennborg
8c79706e89 Revert r347417 "Re-Reinstate 347294 with a fix for the failures."
This caused a miscompile in Chrome (see crbug.com/908372) that's
illustrated by this small reduction:

  static bool f(int *a, int *b) {
    return !__builtin_constant_p(b - a) || (!(b - a));
  }

  int arr[] = {1,2,3};

  bool g() {
    return f(arr, arr + 3);
  }

  $ clang -O2 -S -emit-llvm a.cc -o -

g() should return true, but after r347417 it became false for some reason.

This also reverts the follow-up commits.

r347417:
> Re-Reinstate 347294 with a fix for the failures.
>
> Don't try to emit a scalar expression for a non-scalar argument to
> __builtin_constant_p().
>
> Third time's a charm!

r347446:
> The result of is.constant() is unsigned.

r347480:
> A __builtin_constant_p() returns 0 with a function type.

r347512:
> isEvaluatable() implies a constant context.
>
> Assume that we're in a constant context if we're asking if the expression can
> be compiled into a constant initializer. This fixes the issue where a
> __builtin_constant_p() in a compound literal was diagnosed as not being
> constant, even though it's always possible to convert the builtin into a
> constant.

r347531:
> A "constexpr" is evaluated in a constant context. Make sure this is reflected
> if a __builtin_constant_p() is a part of a constexpr.

llvm-svn: 347656
2018-11-27 14:01:40 +00:00