Commit Graph

1073 Commits

Author SHA1 Message Date
Nikita Popov 5065076698 [CodeGen] Rename deprecated Address constructor
To make uses of the deprecated constructor easier to spot, and to
ensure that no new uses are introduced, rename it to
Address::deprecated().

While doing the rename, I've filled in element types in cases
where it was relatively obvious, but we're still left with 135
calls to the deprecated constructor.
2022-02-17 11:26:42 +01:00
Nikita Popov f208644ed3 [CGBuilder] Remove CreateBitCast() method
Use CreateElementBitCast() instead, or don't work on Address
where not necessary.
2022-02-14 15:06:04 +01:00
Bill Wendling deaf22bc0e [X86] Implement -fzero-call-used-regs option
The "-fzero-call-used-regs" option tells the compiler to zero out
certain registers before the function returns. It's also available as a
function attribute: zero_call_used_regs.

The two upper categories are:

  - "used": Zero out used registers.
  - "all": Zero out all registers, whether used or not.

The individual options are:

  - "skip": Don't zero out any registers. This is the default.
  - "used": Zero out all used registers.
  - "used-arg": Zero out used registers that are used for arguments.
  - "used-gpr": Zero out used registers that are GPRs.
  - "used-gpr-arg": Zero out used GPRs that are used as arguments.
  - "all": Zero out all registers.
  - "all-arg": Zero out all registers used for arguments.
  - "all-gpr": Zero out all GPRs.
  - "all-gpr-arg": Zero out all GPRs used for arguments.

This is used to help mitigate Return-Oriented Programming exploits.

Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D110869
2022-02-08 17:42:54 -08:00
Nikita Popov 18834dca2d [OpenCL] Mark kernel arguments as ABI aligned
Following the discussion on D118229, this marks all pointer-typed
kernel arguments as having ABI alignment, per section 6.3.5 of
the OpenCL spec:

> For arguments to a __kernel function declared to be a pointer to
> a data type, the OpenCL compiler can assume that the pointee is
> always appropriately aligned as required by the data type.

Differential Revision: https://reviews.llvm.org/D118894
2022-02-08 16:12:51 +01:00
Arthur Eubanks 45084eab5e [clang] Fix some clang->llvm type cache invalidation issues
Take the following as an example

  struct z {
    z (*p)();
  };

  z f();

When we attempt to get the LLVM type of f, we recurse into z. z itself
has a function pointer with the same type as f. Given the recursion,
Clang simply treats z::p as a pointer to an empty struct `{}*`. The
LLVM type of f is as expected. So we have two different potential
LLVM types for a given Clang type. If we store one of those into the
cache, when we access the cache with a different context (e.g. we
are/aren't recursing on z) we may get an incorrect result. There is some
attempt to clear the cache in these cases, but it doesn't seem to handle
all cases.

This change makes it so we only use the cache when we are not in any
sort of function context, i.e. `noRecordsBeingLaidOut() &&
FunctionsBeingProcessed.empty()`, which are the cases where we may
decide to choose a different LLVM type for a given Clang type. LLVM
types for builtin types are never recursive so they're always ok.

This allows us to clear the type cache less often (as seen with the
removal of one of the calls to `TypeCache.clear()`). We
still need to clear it when we use a placeholder type then replace it
later with the final type and other dependent types need to be
recalculated.

I've added a check that the cached type matches what we compute. It
triggered in this test case without the fix. It's currently not
check-clang clean so it's not on by default for something like expensive
checks builds.

This change uncovered another issue where the LLVM types for an argument
and its local temporary don't match. For example in type-cache-3, when
expanding z::dc's argument into a temporary alloca, we ConvertType() the
type of z::p which is `void ({}*)*`, which doesn't match the alloca GEP
type of `{}*`.

No noticeable compile time changes:
https://llvm-compile-time-tracker.com/compare.php?from=3918dd6b8acf8c5886b9921138312d1c638b2937&to=50bdec9836ed40e38ece0657f3058e730adffc4c&stat=instructions

Fixes #53465.

Reviewed By: rnk

Differential Revision: https://reviews.llvm.org/D118744
2022-02-07 18:59:09 -08:00
James Y Knight caa1ebde70 Don't assume that a new cleanup was added to InnermostEHScope.
After fa87fa97fb, this was no longer guaranteed to be the cleanup
just added by this code, if IsEHCleanup got disabled. Instead, use
stable_begin(), which _is_ guaranteed to be the cleanup just added.

This caused a crash when a object that is callee destroyed (e.g. with the MS ABI) was passed in a call from a noexcept function.

Added a test to verify.

Fixes: fa87fa97fb
2022-02-04 23:39:42 -05:00
Nikita Popov aa97bc116d [NFC] Remove uses of PointerType::getElementType()
Instead use either Type::getPointerElementType() or
Type::getNonOpaquePointerElementType().

This is part of D117885, in preparation for deprecating the API.
2022-01-25 09:44:52 +01:00
Florian Hahn 67aa314bce
[IRGen] Do not overwrite existing attributes in CGCall.
When adding new attributes, existing attributes are dropped. While
this appears to be a longstanding issue, this was highlighted by D105169
which dropped a lot of attributes due to adding the new noundef
attribute.

Ahmed Bougacha (@ab) tracked down the issue and provided the fix in
CGCall.cpp. I bundled it up and updated the tests.
2022-01-20 13:45:19 +00:00
hyeongyu kim 1b1c8d83d3 [Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default
Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.

Test updates are made as a separate patch: D108453

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D105169
2022-01-16 18:54:17 +09:00
Kevin Athey a141e47138 [NFC] Minimize noundef analysis when disabled
Minor adjustment in order of noundef analysis to be a bit more optimal (when disabled).

Reviewed By: vitalybuka

Differential Revision: https://reviews.llvm.org/D117078
2022-01-12 17:21:19 -08:00
Serge Guelton d2cc6c2d0c Use a sorted array instead of a map to store AttrBuilder string attributes
Using and std::map<SmallString, SmallString> for target dependent attributes is
inefficient: it makes its constructor slightly heavier, and involves extra
allocation for each new string attribute. Storing the attribute key/value as
strings implies extra allocation/copy step.

Use a sorted vector instead. Given the low number of attributes generally
involved, this is cheaper, as showcased by

https://llvm-compile-time-tracker.com/compare.php?from=5de322295f4ade692dc4f1823ae4450ad3c48af2&to=05bc480bf641a9e3b466619af43a2d123ee3f71d&stat=instructions

Differential Revision: https://reviews.llvm.org/D116599
2022-01-10 14:49:53 +01:00
Nikita Popov 53f0538181 [CodeGen] Use correct element type for store to sret
sret is special in that it does not use the memory type
representation. Manually construct the LValue using ConvertType
instead of ConvertTypeForMem here.

This fixes matrix-lowering-opt-levels.c on s390x.
2021-12-23 13:02:49 +01:00
Sanjay Patel 1965cc4695 [CodeGen] remove creation of FP cast function attribute
This is the last cleanup step resulting from D115804 .
Now that clang uses intrinsics when we're in the special FP mode,
we don't need a function attribute as an indicator to the backend.
The LLVM part of the change is in D115885.

Differential Revision: https://reviews.llvm.org/D115886
2021-12-19 11:55:00 -05:00
Kazu Hirata 713ee230f8 [clang] Use llvm::reverse (NFC) 2021-12-17 16:51:42 -08:00
Nikita Popov 9bf917394e [CodeGen] Avoid more pointer element type accesses 2021-12-17 12:11:50 +01:00
Nikita Popov 2d89382b5a [CodeGen] Avoid more pointer element type accesses
This is enough to build sqlite3 with opaque pointers.
2021-12-16 16:34:09 +01:00
Nikita Popov 58c8c53263 [CodeGen] Avoid more pointer element type accesses 2021-12-16 15:26:21 +01:00
Nikita Popov b9492ec649 [CodeGen] Avoid some pointer element type accesses 2021-12-15 14:46:10 +01:00
Nikita Popov b8d121eb1d [CodeGen] Require use of Address::invalid() for invalid address (NFC)
This no longer allows creating an invalid Address through the regular
constructor. There were only two places that did this (AggValueSlot
and EHCleanupScope) which did this by converting a potential nullptr
into an Address. I've fixed both of these by directly storing an
Address instead.

This is intended as a bit of preliminary cleanup for D103465.

Differential Revision: https://reviews.llvm.org/D115630
2021-12-14 12:06:05 +01:00
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
Joseph Huber 4b5c3e591d [OpenMP] Remove doing assumption propagation in the front end.
This patch removes the assumption propagation that was added in D110655
primarily to get assumption informatino on opaque call sites for
optimizations. The analysis done in D111445 allows us to do this more
intelligently in the back-end.

Depends on D111445

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D111463
2021-11-09 17:39:24 -05:00
hyeongyu kim fd9b099906 Revert "[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default"
This reverts commit aacfbb953e.

Revert "Fix lit test failures in CodeGenCoroutines"

This reverts commit 63fff0f5bf.
2021-11-09 02:15:55 +09:00
hyeongyukim aacfbb953e [Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default
Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.

Test updates are made as a separate patch: D108453

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D105169

[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default (2)

This patch updates test files after D105169.
Autogenerated test codes are changed by `utils/update_cc_test_checks.py,` and non-autogenerated test codes are changed as follows:

(1) I wrote a python script that (partially) updates the tests using regex: {F18594904} The script is not perfect, but I believe it gives hints about which patterns are updated to have `noundef` attached.

(2) The remaining tests are updated manually.

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D108453

Resolve lit failures in clang after 8ca4b3e's land

Fix lit test failures in clang-ppc* and clang-x64-windows-msvc

Fix missing failures in clang-ppc64be* and retry fixing clang-x64-windows-msvc

Fix internal_clone(aarch64) inline assembly
2021-11-06 19:19:22 +09:00
Juneyoung Lee 89ad2822af Revert "[Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default"
This reverts commit 7584ef766a.
2021-11-06 15:39:19 +09:00
Juneyoung Lee 7584ef766a [Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default
Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.

Test updates are made as a separate patch: D108453

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D105169
2021-11-06 15:36:42 +09:00
Juneyoung Lee f193bcc701 Revert D105169 due to the two-stage failure in ASAN
This reverts the following commits:
37ca7a795b
9aa6c72b92
705387c507
8ca4b3ef19
80dba72a66
2021-10-18 23:52:46 +09:00
Juneyoung Lee 80dba72a66 [Clang/Test]: Rename enable_noundef_analysis to disable-noundef-analysis and turn it off by default
Turning on `enable_noundef_analysis` flag allows better codegen by removing freeze instructions.
I modified clang by renaming `enable_noundef_analysis` flag to `disable-noundef-analysis` and turning it off by default.

Test updates are made as a separate patch: D108453

Reviewed By: eugenis

Differential Revision: https://reviews.llvm.org/D105169
2021-10-16 12:01:37 +09:00
Qiu Chaofan 8a714722e2 [NFC] [Clang] Use global enum for explicit float mode
Currently, there're multiple float types that can be represented by
__attribute__((mode(xx))). It's parsed, and then a corresponding type is
created if available.

This refactor moves the enum for mode into a global enum class visible
to ASTContext.

Reviewed By: aaron.ballman, erichkeane

Differential Revision: https://reviews.llvm.org/D111391
2021-10-09 10:39:10 +08:00
Arthur Eubanks a6891d2104 [clang] Set max allowed alignment to 2^32
Followup to D110451 which set LLVM's max allowed alignment to 2^32.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D111250
2021-10-08 11:44:15 -07:00
Masoud Ataei b0f68791f0 [clang] Option control afn flag
Clang option to set/unset afn fast-math flag.

 Differential: https://reviews.llvm.org/D106191
 Reviewd with: aaron.ballman, erichkeane, and others
2021-10-08 14:26:14 -04:00
Arthur Eubanks 05392466f0 Reland [IR] Increase max alignment to 4GB
Currently the max alignment representable is 1GB, see D108661.
Setting the align of an object to 4GB is desirable in some cases to make sure the lower 32 bits are clear which can be used for some optimizations, e.g. https://crbug.com/1016945.

This uses an extra bit in instructions that carry an alignment. We can store 15 bits of "free" information, and with this change some instructions (e.g. AtomicCmpXchgInst) use 14 bits.
We can increase the max alignment representable above 4GB (up to 2^62) since we're only using 33 of the 64 values, but I've just limited it to 4GB for now.

The one place we have to update the bitcode format is for the alloca instruction. It stores its alignment into 5 bits of a 32 bit bitfield. I've added another field which is 8 bits and should be future proof for a while. For backward compatibility, we check if the old field has a value and use that, otherwise use the new field.

Updating clang's max allowed alignment will come in a future patch.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D110451
2021-10-06 13:29:23 -07:00
Arthur Eubanks 569346f274 Revert "Reland [IR] Increase max alignment to 4GB"
This reverts commit 8d64314ffe.
2021-10-06 11:38:11 -07:00
Arthur Eubanks 8d64314ffe Reland [IR] Increase max alignment to 4GB
Currently the max alignment representable is 1GB, see D108661.
Setting the align of an object to 4GB is desirable in some cases to make sure the lower 32 bits are clear which can be used for some optimizations, e.g. https://crbug.com/1016945.

This uses an extra bit in instructions that carry an alignment. We can store 15 bits of "free" information, and with this change some instructions (e.g. AtomicCmpXchgInst) use 14 bits.
We can increase the max alignment representable above 4GB (up to 2^62) since we're only using 33 of the 64 values, but I've just limited it to 4GB for now.

The one place we have to update the bitcode format is for the alloca instruction. It stores its alignment into 5 bits of a 32 bit bitfield. I've added another field which is 8 bits and should be future proof for a while. For backward compatibility, we check if the old field has a value and use that, otherwise use the new field.

Updating clang's max allowed alignment will come in a future patch.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D110451
2021-10-06 11:03:51 -07:00
Arthur Eubanks 72cf8b6044 Revert "[IR] Increase max alignment to 4GB"
This reverts commit df84c1fe78.

Breaks some bots
2021-10-06 10:21:35 -07:00
Arthur Eubanks df84c1fe78 [IR] Increase max alignment to 4GB
Currently the max alignment representable is 1GB, see D108661.
Setting the align of an object to 4GB is desirable in some cases to make sure the lower 32 bits are clear which can be used for some optimizations, e.g. https://crbug.com/1016945.

This uses an extra bit in instructions that carry an alignment. We can store 15 bits of "free" information, and with this change some instructions (e.g. AtomicCmpXchgInst) use 14 bits.
We can increase the max alignment representable above 4GB (up to 2^62) since we're only using 33 of the 64 values, but I've just limited it to 4GB for now.

The one place we have to update the bitcode format is for the alloca instruction. It stores its alignment into 5 bits of a 32 bit bitfield. I've added another field which is 8 bits and should be future proof for a while. For backward compatibility, we check if the old field has a value and use that, otherwise use the new field.

Updating clang's max allowed alignment will come in a future patch.

Reviewed By: hans

Differential Revision: https://reviews.llvm.org/D110451
2021-10-06 09:54:14 -07:00
Joseph Huber d12502a3ab [OpenMP] Apply OpenMP assumptions to applicable call sites
This patch adds OpenMP assumption attributes to call sites in applicable
regions. Currently this applies the caller's assumption attributes to
any calls contained within it. So, if a call occurs inside an OpenMP
assumes region to a function outside that region, we will assume that
call respects the assumptions. This is primarily useful for inline
assembly calls used heavily in the OpenMP GPU device runtime, which
allows us to then make judgements about what the ASM will do.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D110655
2021-09-29 16:08:21 -04:00
Roman Lebedev 85ba583eba
[NFCI][clang] Move allocation alignment manifestation for malloc-like into Sema from Codegen
... so that it happens right next to `AddKnownFunctionAttributesForReplaceableGlobalAllocationFunction()`,
which is good for consistency.
2021-09-10 20:49:28 +03:00
Nick Desaulniers 846e562dcc [Clang] add support for error+warning fn attrs
Add support for the GNU C style __attribute__((error(""))) and
__attribute__((warning(""))). These attributes are meant to be put on
declarations of functions whom should not be called.

They are frequently used to provide compile time diagnostics similar to
_Static_assert, but which may rely on non-ICE conditions (ie. relying on
compiler optimizations). This is also similar to diagnose_if function
attribute, but can diagnose after optimizations have been run.

While users may instead simply call undefined functions in such cases to
get a linkage failure from the linker, these provide a much more
ergonomic and actionable diagnostic to users and do so at compile time
rather than at link time. Users instead may be able use inline asm .err
directives.

These are used throughout the Linux kernel in its implementation of
BUILD_BUG and BUILD_BUG_ON macros. These macros generally cannot be
converted to use _Static_assert because many of the parameters are not
ICEs. The Linux kernel still needs to be modified to make use of these
when building with Clang; I have a patch that does so I will send once
this feature is landed.

To do so, we create a new IR level Function attribute, "dontcall" (both
error and warning boil down to one IR Fn Attr).  Then, similar to calls
to inline asm, we attach a !srcloc Metadata node to call sites of such
attributed callees.

The backend diagnoses these during instruction selection, while we still
know that a call is a call (vs say a JMP that's a tail call) in an arch
agnostic manner.

The frontend then reconstructs the SourceLocation from that Metadata,
and determines whether to emit an error or warning based on the callee's
attribute.

Link: https://bugs.llvm.org/show_bug.cgi?id=16428
Link: https://github.com/ClangBuiltLinux/linux/issues/1173

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D106030
2021-08-25 10:34:18 -07:00
Arthur Eubanks 644f88a25b [NFC] addAttribute(FunctionIndex) => addFnAttribute() 2021-08-20 14:18:59 -07:00
Arthur Eubanks 3f4d00bc3b [NFC] More get/removeAttribute() cleanup 2021-08-17 21:05:41 -07:00
Arthur Eubanks de0ae9e89e [NFC] Cleanup more AttributeList::addAttribute() 2021-08-17 21:05:41 -07:00
Arthur Eubanks ad727ab7d9 [NFC] Migrate some callers away from Function/AttributeLists methods that take an index
These methods can be confusing.
2021-08-17 21:05:40 -07:00
Arthur Eubanks 92ce6db9ee [NFC] Rename AttributeList::hasFnAttribute() -> hasFnAttr()
This is more consistent with similar methods.
2021-08-13 11:09:18 -07:00
Arnold Schwaighofer 9eb99d2e73 CodeGen: No need to check for isExternC if HasStrictReturn is already false
NFC intended.

Differential Revision: https://reviews.llvm.org/D107841
2021-08-11 07:42:48 -07:00
Bradley Smith e57e1e4e00 [clang][AArch64][SVE] Avoid going through memory for fixed/scalable predicate casts
For fixed SVE types, predicates are represented using vectors of i8,
where as for scalable types they are represented using vectors of i1. We
can avoid going through memory for casts between these by bitcasting the
i1 scalable vectors to/from a scalable i8 vector of matching size, which
can then use the existing vector insert/extract logic.

Differential Revision: https://reviews.llvm.org/D106860
2021-08-04 16:10:37 +00:00
Varun Gandhi 92dcb1d2db [Clang] Introduce Swift async calling convention.
This change is intended as initial setup. The plan is to add
more semantic checks later. I plan to update the documentation
as more semantic checks are added (instead of documenting the
details up front). Most of the code closely mirrors that for
the Swift calling convention. Three places are marked as
[FIXME: swiftasynccc]; those will be addressed once the
corresponding convention is introduced in LLVM.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D95561
2021-07-09 11:50:10 -07:00
Nikita Popov a0ea367562 [CodeGen] Avoid nullptr arg to CreateStructGEP (NFC)
For now just make the getPointerElementType() explicit.
2021-07-08 21:21:43 +02:00
Nikita Popov 693251fb2f [CodeGen] Avoid CreateGEP with nullptr type (NFC)
In preparation for dropping support for it. I've replaced it with
a proper type where the correct type was obvious and left an
explicit getPointerElementType() where it wasn't.
2021-07-08 20:38:54 +02:00
Michael Liao 948308ef34 Fix `-Wunused-variable` warning. NFC. 2021-06-28 22:50:36 -04:00
Hongtao Yu 633ca3ff2f [UniqueLinkageName] Use exsiting GlobalDecl object instead of reconstructing one.
C++ constructors/destructors need to go through a different constructor to construct a GlobalDecl object in order to retrieve their linkage type. This causes an assert failure in the default constructor of GlobalDecl. I'm chaning it to using the exsiting GlobalDecl object.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102356
2021-06-28 14:50:41 -07:00
Hsiangkai Wang 2b13ff6979 [Clang][CodeGen] Set the size of llvm.lifetime to unknown for scalable types.
If the memory object is scalable type, we do not know the exact size of
it at compile time. Set the size of lifetime marker to unknown if the
object is scalable one.

Differential Revision: https://reviews.llvm.org/D102822
2021-06-07 23:30:13 +08:00
Tim Northover e94fada045 SwiftAsync: add Clang attribute to apply the LLVM `swiftasync` one.
Expected to be used by Swift runtime developers.
2021-05-28 12:31:12 +01:00
Eli Friedman 698568b74c [clang CodeGen] Don't crash on large atomic function parameter.
I wouldn't recommend writing code like the testcase; a function
parameter isn't atomic, so using an atomic type doesn't really make
sense.  But it's valid, so clang shouldn't crash on it.

The code was assuming hasAggregateEvaluationKind(Ty) implies Ty is a
RecordType, which isn't true.  Just use isRecordType() instead.

Differential Revision: https://reviews.llvm.org/D102015
2021-05-17 13:18:23 -07:00
Roman Lebedev 16d0381841
Return "[CGCall] Annotate `this` argument with alignment"
The original change was reverted because it was discovered
that clang mishandles thunks, and they receive wrong
attributes for their this/return types - the ones for the function
they will call, not the ones they have.

While i have tried to fix this in https://reviews.llvm.org/D100388
that patch has been up and stuck for a month now,
with little signs of progress.

So while it will be good to solve this for real,
for now we can simply avoid introducing the bug,
by not annotating this/return for thunks.

This reverts commit 6270b3a1ea,
relanding 0aa0458f14.
2021-05-13 20:33:14 +03:00
Roman Lebedev a624cec56d
[Clang][Codegen] Do not annotate thunk's this/return types with align/deref/nonnull attrs
As it was discovered in post-commit feedback
for 0aa0458f14,
we handle thunks incorrectly, and end up annotating
their this/return with attributes that are valid
for their callees, not for thunks themselves.

While it would be good to fix this properly,
and keep annotating them on thunks,
i've tried doing that in https://reviews.llvm.org/D100388
with little success, and the patch is stuck for a month now.

So for now, as a stopgap measure, subj.
2021-05-13 20:33:08 +03:00
Dávid Bolvanský 2cae7025c1 Reland "[Clang] Propagate guaranteed alignment for malloc and others"
This relands commit 6914a0ed2b. Crash in InstCombine was fixed.
2021-04-23 14:05:57 +02:00
Dávid Bolvanský 6914a0ed2b Revert "[Clang] Propagate guaranteed alignment for malloc and others"
This reverts commit c2297544c0. Some buildbots are broken.
2021-04-23 11:33:33 +02:00
Dávid Bolvanský c2297544c0 [Clang] Propagate guaranteed alignment for malloc and others
LLVM should be smarter about *known* malloc's alignment and this knowledge may enable other optimizations.

Originally started as LLVM patch - https://reviews.llvm.org/D100862 but this logic should be really in Clang.

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D100879
2021-04-23 11:07:14 +02:00
Joshua Haberman 8344675908 Implemented [[clang::musttail]] attribute for guaranteed tail calls.
This is a Clang-only change and depends on the existing "musttail"
support already implemented in LLVM.

The [[clang::musttail]] attribute goes on a return statement, not
a function definition. There are several constraints that the user
must follow when using [[clang::musttail]], and these constraints
are verified by Sema.

Tail calls are supported on regular function calls, calls through a
function pointer, member function calls, and even pointer to member.

Future work would be to throw a warning if a users tries to pass
a pointer or reference to a local variable through a musttail call.

Reviewed By: rsmith

Differential Revision: https://reviews.llvm.org/D99517
2021-04-15 17:12:21 -07:00
Momchil Velikov f9d932e673 [clang][AArch64] Correctly align HFA arguments when passed on the stack
When we pass a AArch64 Homogeneous Floating-Point
Aggregate (HFA) argument with increased alignment
requirements, for example

    struct S {
      __attribute__ ((__aligned__(16))) double v[4];
    };

Clang uses `[4 x double]` for the parameter, which is passed
on the stack at alignment 8, whereas it should be at
alignment 16, following Rule C.4 in
AAPCS (https://github.com/ARM-software/abi-aa/blob/master/aapcs64/aapcs64.rst#642parameter-passing-rules)

Currently we don't have a way to express in LLVM IR the
alignment requirements of the function arguments. The align
attribute is applicable to pointers only, and only for some
special ways of passing arguments (e..g byval). When
implementing AAPCS32/AAPCS64, clang resorts to dubious hacks
of coercing to types, which naturally have the needed
alignment. We don't have enough types to cover all the
cases, though.

This patch introduces a new use of the stackalign attribute
to control stack slot alignment, when and if an argument is
passed in memory.

The attribute align is left as an optimizer hint - it still
applies to pointer types only and pertains to the content of
the pointer, whereas the alignment of the pointer itself is
determined by the stackalign attribute.

For byval arguments, the stackalign attribute assumes the
role, previously perfomed by align, falling back to align if
stackalign` is absent.

On the clang side, when passing arguments using the "direct"
style (cf. `ABIArgInfo::Kind`), now we can optionally
specify an alignment, which is emitted as the new
`stackalign` attribute.

Patch by Momchil Velikov and Lucas Prates.

Differential Revision: https://reviews.llvm.org/D98794
2021-04-15 22:58:14 +01:00
Roman Lebedev 6270b3a1ea
Temporairly revert "[CGCall] Annotate `this` argument with alignment"
As per @jyknight, "It seems like there's a bug with vtable thunks getting the wrong information."
See https://reviews.llvm.org/D99790#2680857, https://godbolt.org/z/MxhYMe1q7

This reverts commit 0aa0458f14.
2021-04-10 10:43:16 +03:00
Roman Lebedev 0aa0458f14
[CGCall] Annotate `this` argument with alignment
As it is being noted in D99249, lack of alignment information on `this`
has been preventing LICM from happening.

For some time now, lack of alignment attribute does *not* imply
natural alignment, but an alignment of `1`.
Also, we used to treat dereferenceable as implying alignment,
but we no longer do, so it's a bugfix.

Differential Revision: https://reviews.llvm.org/D99790
2021-04-07 11:02:01 +03:00
Matt Arsenault 9a0c9402fa Reapply "OpaquePtr: Turn inalloca into a type attribute"
This reverts commit 07e46367ba.
2021-03-29 08:55:30 -04:00
Oliver Stannard 07e46367ba Revert "Reapply "OpaquePtr: Turn inalloca into a type attribute""
Reverting because test 'Bindings/Go/go.test' is failing on most
buildbots.

This reverts commit fc9df30991.
2021-03-29 11:32:22 +01:00
Matt Arsenault fc9df30991 Reapply "OpaquePtr: Turn inalloca into a type attribute"
This reverts commit 20d5c42e0e.
2021-03-28 13:35:21 -04:00
Nico Weber 20d5c42e0e Revert "OpaquePtr: Turn inalloca into a type attribute"
This reverts commit 4fefed6563.
Broke check-clang everywhere.
2021-03-28 13:02:52 -04:00
Matt Arsenault 4fefed6563 OpaquePtr: Turn inalloca into a type attribute
I think byval/sret and the others are close to being able to rip out
the code to support the missing type case. A lot of this code is
shared with inalloca, so catch this up to the others so that can
happen.
2021-03-28 11:12:23 -04:00
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
serge-sans-paille ea8e5b87ac [NFC] Remove duplicate isNoBuiltinFunc method
It's available both in CodeGenOptions and in LangOptions, and LangOptions
implementation is slightly better as it uses a StringRef instead of a char
pointer, so use it.

Differential Revision: https://reviews.llvm.org/D98175
2021-03-10 09:18:55 +01:00
Sriraman Tallam 78d0e91865 Refactor -funique-internal-linakge-names implementation.
The option -funique-internal-linkage-names was added in D73307 and D78243 as a
LLVM early pass to insert a unique suffix to internal linkage functions and
vars. The unique suffix was the hash of the module path. However, we found
that this can be done more cleanly in clang early and the fixes that need to
be done later can be completely avoided. The fixes in particular are trying
to modify the DW_AT_linkage_name and finding the right place to insert the
pass.

This patch ressurects the original implementation proposed in D73307 which
was reviewed and then ditched in favor of the pass based approach.

Differential Revision: https://reviews.llvm.org/D96109
2021-03-05 13:32:17 -08:00
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 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
Jeroen Dobbelaere 46757ccb49 [clang] functions with the 'const' or 'pure' attribute must always return.
As described in
* https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-pure-function-attribute
* https://gcc.gnu.org/onlinedocs/gcc/Common-Function-Attributes.html#index-const-function-attribute

An `__attribute__((pure))` function must always return, as well as an `__attribute__((const))` function.

Reviewed By: jdoerfert

Differential Revision: https://reviews.llvm.org/D96960
2021-02-18 17:29:46 +01:00
serge-sans-paille 3c8bf29f14
Reduce the number of attributes attached to each function
This takes advantage of the implicit default behavior to reduce the number of
attributes, which in turns reduces compilation time. I've observed -3% in
instruction count when compiling sqlite3 amalgamation with -O0

Differential Revision: https://reviews.llvm.org/D96400
2021-02-16 16:19:54 +01:00
Zequan Wu e53bbd9951 [IR] move nomerge attribute from function declaration/definition to callsites
Move nomerge attribute from function declaration/definition to callsites to
allow virtual function calls attach the attribute.

Differential Revision: https://reviews.llvm.org/D94537
2021-01-12 12:10:46 -08:00
Joe Ellis 8ea72b3887 [clang][AArch64][SVE] Avoid going through memory for coerced VLST return values
VLST return values are coerced to VLATs in the function epilog for
consistency with the VLAT ABI. Previously, this coercion was done
through memory. It is preferable to use the
llvm.experimental.vector.insert intrinsic to avoid going through memory
here.

Reviewed By: c-rhodes

Differential Revision: https://reviews.llvm.org/D94290
2021-01-11 12:10:59 +00:00
Joe Ellis 3d5b18a3fd [clang][AArch64][SVE] Avoid going through memory for coerced VLST arguments
VLST arguments are coerced to VLATs at the function boundary for
consistency with the VLAT ABI. They are then bitcast back to VLSTs in
the function prolog. Previously, this conversion is done through memory.
With the introduction of the llvm.vector.{insert,extract} intrinsic, we
can avoid going through memory here.

Depends on D92761

Differential Revision: https://reviews.llvm.org/D92762
2021-01-05 15:18:21 +00:00
Rong Xu 3733463dbb [IR][PGO] Add hot func attribute and use hot/cold attribute in func section
Clang FE currently has hot/cold function attribute. But we only have
cold function attribute in LLVM IR.

This patch adds support of hot function attribute to LLVM IR.  This
attribute will be used in setting function section prefix/suffix.
Currently .hot and .unlikely suffix only are added in PGO (Sample PGO)
compilation (through isFunctionHotInCallGraph and
isFunctionColdInCallGraph).

This patch changes the behavior. The new behavior is:
(1) If the user annotates a function as hot or isFunctionHotInCallGraph
    is true, this function will be marked as hot. Otherwise,
(2) If the user annotates a function as cold or
    isFunctionColdInCallGraph is true, this function will be marked as
    cold.

The changes are:
(1) user annotated function attribute will used in setting function
    section prefix/suffix.
(2) hot attribute overwrites profile count based hotness.
(3) profile count based hotness overwrite user annotated cold attribute.

The intention for these changes is to provide the user a way to mark
certain function as hot in cases where training input is hard to cover
all the hot functions.

Differential Revision: https://reviews.llvm.org/D92493
2020-12-17 18:41:12 -08:00
Zequan Wu fb0f728805 [Clang] Make nomerge attribute a function attribute as well as a statement attribute.
Differential Revision: https://reviews.llvm.org/D92800
2020-12-17 07:45:38 -08:00
Johannes Doerfert b9c77542e2 [Clang][Attr] Introduce the `assume` function attribute
The `assume` attribute is a way to provide additional, arbitrary
information to the optimizer. For now, assumptions are restricted to
strings which will be accumulated for a function and emitted as comma
separated string function attribute. The key of the LLVM-IR function
attribute is `llvm.assume`. Similar to `llvm.assume` and
`__builtin_assume`, the `assume` attribute provides a user defined
assumption to the compiler.

A follow up patch will introduce an LLVM-core API to query the
assumptions attached to a function. We also expect to add more options,
e.g., expression arguments, to the `assume` attribute later on.

The `omp [begin] asssumes` pragma will leverage this attribute and
expose the functionality in the absence of OpenMP.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D91979
2020-12-15 16:51:34 -06:00
Rong Xu c36f31c4db [PGO] remove unintentional code in early commit
Remove unintentional code in
commit 54e03d [PGO] Verify BFI counts after loading profile data.
2020-12-14 18:41:49 -08:00
Rong Xu 54e03d03a7 [PGO] Verify BFI counts after loading profile data
This patch adds the functionality to compare BFI counts with real
profile
counts right after reading the profile. It will print remarks under
-Rpass-analysis=pgo, or the internal option -pass-remarks-analysis=pgo.

Differential Revision: https://reviews.llvm.org/D91813
2020-12-14 15:56:10 -08:00
Gulfem Savrun Yeniceri 7c0e3a77bc [clang][IR] Add support for leaf attribute
This patch adds support for leaf attribute as an optimization hint
in Clang/LLVM.

Differential Revision: https://reviews.llvm.org/D90275
2020-12-14 14:48:17 -08:00
Reid Kleckner df282215d4 Don't setup inalloca for swiftcc on i686-windows-msvc
Swiftcall does it's own target-independent argument type classification,
since it is not designed to be ABI compatible with anything local on the
target that isn't LLVM-based. This means it never uses inalloca.
However, we have duplicate logic for checking for inalloca parameters
that runs before call argument setup. This logic needs to know ahead of
time if inalloca will be used later, and we can't move the
CGFunctionInfo calculation earlier.

This change gets the calling convention from either the
FunctionProtoType or ObjCMethodDecl, checks if it is swift, and if so
skips the stackbase setup.

Depends on D92883.

Differential Revision: https://reviews.llvm.org/D92944
2020-12-09 11:08:48 -08:00
Reid Kleckner d7098ff29c De-templatify EmitCallArgs argument type checking, NFCI
This template exists to abstract over FunctionPrototype and
ObjCMethodDecl, which have similar APIs for storing parameter types. In
place of a template, use a PointerUnion with two cases to handle this.
Hopefully this improves readability, since the type of the prototype is
easier to discover. This allows me to sink this code, which is mostly
assertions, out of the header file and into the cpp file. I can also
simplify the overloaded methods for computing isGenericMethod, and get
rid of the second EmitCallArgs overload.

Differential Revision: https://reviews.llvm.org/D92883
2020-12-09 11:08:00 -08:00
Fangrui Song 164410324d [CodeGen] -fno-delete-null-pointer-checks: change dereferenceable to dereferenceable_or_null
After D17993, with -fno-delete-null-pointer-checks we add the dereferenceable attribute to the `this` pointer.

We have observed that one internal target which worked before fails even with -fno-delete-null-pointer-checks.
Switching to dereferenceable_or_null fixes the problem.

dereferenceable currently does not always respect NullPointerIsValid and may
imply nonnull and lead to aggressive optimization. The optimization may be
related to `CallBase::isReturnNonNull`, `Argument::hasNonNullAttr`, or
`Value::getPointerDereferenceableBytes`. See D66664 and D66618 for some discussions.

Reviewed By: bkramer, rsmith

Differential Revision: https://reviews.llvm.org/D92297
2020-11-30 12:44:35 -08:00
Simon Pilgrim eb7ea5aa1a CGCall.cpp - use castAs<> instead of getAs<> as we dereference the pointer directly. NFCI.
castAs<> will assert the correct cast type instead of just returning null, which we then try to dereference immediately in the setUsedBits call.
2020-11-25 11:38:29 +00:00
CJ Johnson 69cd776e1e [CodeGen] Apply 'nonnull' and 'dereferenceable(N)' to 'this' pointer
arguments.

* Adds 'nonnull' and 'dereferenceable(N)' to 'this' pointer arguments
* Gates 'nonnull' on -f(no-)delete-null-pointer-checks
* Introduces this-nonnull.cpp and microsoft-abi-this-nullable.cpp tests to
  explicitly test the behavior of this change
* Refactors hundreds of over-constrained clang tests to permit these
  attributes, where needed
* Updates Clang12 patch notes mentioning this change

Reviewed-by: rsmith, jdoerfert

Differential Revision: https://reviews.llvm.org/D17993
2020-11-16 17:39:17 -08:00
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
Matt Arsenault 0a7cd99a70 Reapply "OpaquePtr: Add type to sret attribute"
This reverts commit eb9f7c28e5.

Previously this was incorrectly handling linking of the contained
type, so this merges the fixes from D88973.
2020-10-16 11:05:02 -04:00
Bevin Hansson 101309fe04 [AST] Change return type of getTypeInfoInChars to a proper struct instead of std::pair.
Followup to D85191.

This changes getTypeInfoInChars to return a TypeInfoChars
struct instead of a std::pair of CharUnits. This lets the
interface match getTypeInfo more closely.

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D86447
2020-10-13 13:26:56 +02:00
Michael Liao 8c36eaf037 [clang][opencl][codegen] Remove the insertion of `correctly-rounded-divide-sqrt-fp-math` fn-attr.
- `-cl-fp32-correctly-rounded-divide-sqrt` is already handled in a
  per-instruction manner by annotating the accuracy required. There's no
  need to add that fn-attr. So far, there's no in-tree backend handling
  that attr and that OpenCL specific option.
- In case that out-of-tree backends are broken, this change could be
  reverted if those backends could not be fixed.

Differential Revision: https://reviews.llvm.org/D88424
2020-10-01 11:07:39 -04:00
Tres Popp eb9f7c28e5 Revert "OpaquePtr: Add type to sret attribute"
This reverts commit 55c4ff91bd.

Issues were introduced as discussed in https://reviews.llvm.org/D88241
where this change made previous bugs in the linker and BitCodeWriter
visible.
2020-09-29 10:31:04 +02:00
Vedant Kumar 06bc685fa2 [ubsan] nullability-arg: Fix crash on C++ member pointers
Extend -fsanitize=nullability-arg to handle call sites which accept C++
member pointers.

rdar://62476022

Differential Revision: https://reviews.llvm.org/D88336
2020-09-28 09:41:18 -07:00
Michael Liao 5dbf80cad9 [clang][codegen] Annotate `correctly-rounded-divide-sqrt-fp-math` fn-attr for OpenCL only.
- `-cl-fp32-correctly-rounded-divide-sqrt` is an OpenCL-specific option
  and `correctly-rounded-divide-sqrt-fp-math` should be added for OpenCL
  at most.

Differential revision: https://reviews.llvm.org/D88303
2020-09-28 11:40:32 -04:00
Matt Arsenault 55c4ff91bd OpaquePtr: Add type to sret attribute
Make the corresponding change that was made for byval in
b7141207a4. Like byval, this requires a
bulk update of the test IR tests to include the type before this can
be mandatory.
2020-09-25 14:07:30 -04:00
Florian Hahn a874d63344 [Clang] Add option to allow marking pass-by-value args as noalias.
After the recent discussion on cfe-dev 'Can indirect class parameters be
noalias?' [1], it seems like using using noalias is problematic for
current C++, but should be allowed for C-only code.

This patch introduces a new option to let the user indicate that it is
safe to mark indirect class parameters as noalias. Note that this also
applies to external callers, e.g. it might not be safe to use this flag
for C functions that are called by C++ functions.

In targets that allocate indirect arguments in the called function, this
enables more agressive optimizations with respect to memory operations
and brings a ~1% - 2% codesize reduction for some programs.

[1] : http://lists.llvm.org/pipermail/cfe-dev/2020-July/066353.html

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D85473
2020-09-12 14:56:13 +01:00
Cullen Rhodes 2ddf795e8c Reland "[CodeGen][AArch64] Support arm_sve_vector_bits attribute"
This relands D85743 with a fix for test
CodeGen/attr-arm-sve-vector-bits-call.c that disables the new pass
manager with '-fno-experimental-new-pass-manager'. Test was failing due
to IR differences with the new pass manager which broke the Fuchsia
builder [1]. Reverted in 2e7041f.

[1] http://lab.llvm.org:8011/builders/fuchsia-x86_64-linux/builds/10375

Original summary:

This patch implements codegen for the 'arm_sve_vector_bits' type
attribute, defined by the Arm C Language Extensions (ACLE) for SVE [1].
The purpose of this attribute is to define vector-length-specific (VLS)
versions of existing vector-length-agnostic (VLA) types.

VLSTs are represented as VectorType in the AST and fixed-length vectors
in the IR everywhere except in function args/return. Implemented in this
patch is codegen support for the following:

  * Implicit casting between VLA <-> VLS types.
  * Coercion of VLS types in function args/return.
  * Mangling of VLS types.

Casting is handled by the CK_BitCast operation, which has been extended
to support the two new vector kinds for fixed-length SVE predicate and
data vectors, where the cast is implemented through memory rather than a
bitcast which is unsupported. Implementing this as a normal bitcast
would require relaxing checks in LLVM to allow bitcasting between
scalable and fixed types. Another option was adding target-specific
intrinsics, although codegen support would need to be added for these
intrinsics. Given this, casting through memory seemed like the best
approach as it's supported today and existing optimisations may remove
unnecessary loads/stores, although there is room for improvement here.

Coercion of VLSTs in function args/return from fixed to scalable is
implemented through the AArch64 ABI in TargetInfo.

The VLA and VLS types are defined by the ACLE to map to the same
machine-level SVE vectors. VLS types are mangled in the same way as:

  __SVE_VLS<typename, unsigned>

where the first argument is the underlying variable-length type and the
second argument is the SVE vector length in bits. For example:

  #if __ARM_FEATURE_SVE_BITS==512
  // Mangled as 9__SVE_VLSIu11__SVInt32_tLj512EE
  typedef svint32_t vec __attribute__((arm_sve_vector_bits(512)));
  // Mangled as 9__SVE_VLSIu10__SVBool_tLj512EE
  typedef svbool_t pred __attribute__((arm_sve_vector_bits(512)));
  #endif

The latest ACLE specification (00bet5) does not contain details of this
mangling scheme, it will be specified in the next revision.  The
mangling scheme is otherwise defined in the appendices to the Procedure
Call Standard for the Arm Architecture, see [2] for more information.

[1] https://developer.arm.com/documentation/100987/latest
[2] https://github.com/ARM-software/abi-aa/blob/master/aapcs64/aapcs64.rst#appendix-c-mangling

Reviewed By: efriedma

Differential Revision: https://reviews.llvm.org/D85743
2020-08-28 15:57:09 +00:00
Cullen Rhodes 2e7041fdc2 Revert "[CodeGen][AArch64] Support arm_sve_vector_bits attribute"
Test CodeGen/attr-arm-sve-vector-bits-call.c is failing on some builders
[1][2]. Reverting whilst I investigate.

[1] http://lab.llvm.org:8011/builders/fuchsia-x86_64-linux/builds/10375
[2] https://luci-milo.appspot.com/p/fuchsia/builders/ci/clang-linux-x64/b8870800848452818112

This reverts commit 42587345a3.
2020-08-27 21:31:05 +00:00