Commit Graph

479 Commits

Author SHA1 Message Date
Fraser Cormack f3e9047249 [VP] Add vector-predicated reduction intrinsics
This patch adds vector-predicated ("VP") reduction intrinsics corresponding to
each of the existing unpredicated `llvm.vector.reduce.*` versions. Unlike the
unpredicated reductions, all VP reductions have a start value. This start value
is returned when the no vector element is active.

Support for expansion on targets without native vector-predication support is
included.

This patch is based on the ["reduction
slice"](https://reviews.llvm.org/D57504#1732277) of the LLVM-VP reference patch
(https://reviews.llvm.org/D57504).

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D104308
2021-08-17 17:56:35 +01:00
Florian Hahn f999312872
Recommit "[Matrix] Overload stride arg in matrix.columnwise.load/store."
This reverts the revert 28c04794df.

The failing MLIR test that caused the revert should be fixed  in this
version.

Also includes a PPC test fix previously in 1f87c7c478.
2021-08-12 18:31:57 +01:00
Mehdi Amini 28c04794df Revert "[Matrix] Overload stride arg in matrix.columnwise.load/store."
This reverts commit a1ef81de35.

Broke the MLIR buildbot.
2021-08-12 11:57:19 +00:00
Florian Hahn a1ef81de35
[Matrix] Overload stride arg in matrix.columnwise.load/store.
This patch adjusts the intrinsics definition of
llvm.matrix.column.major.load and llvm.matrix.column.major.store to
allow overloading the type of the stride. The bitwidth of the stride is
used to perform the offset computation.

This fixes a crash when using __builtin_matrix_column_major_load or
__builtin_matrix_column_major_store on 32 bit platforms. The stride argument
of the builtins are defined as `size_t`, which is 32 bits wide on 32 bit
platforms.

Note that we still perform offset computations with 64 bit width on 32
bit platforms for accesses that do not take a user-specified stride.
This can be fixed separately.

Fixes PR51304.

Reviewed By: erichkeane

Differential Revision: https://reviews.llvm.org/D107349
2021-08-12 10:45:25 +01:00
Nikita Popov 1f8d3fd42b [Verifier] Check byval/etc type when comparing ABI attributes
For musttail calls, ABI attributes between the function and the
musttail call must match. The current check discards the type of
type attributes like byval, which means that it will consider
byval(i32) and byval(i64) (or similar) as compatible.

I assume this is a leftover from before these attributes had a
type argument. Ran into this while trying to tighten an assertion
in AttrBuilder.

Differential Revision: https://reviews.llvm.org/D105841
2021-07-20 20:19:47 +02:00
Nikita Popov be5af50e7d [BPF] Use elementtype attribute for preserve.array/struct.index intrinsics
Use the elementtype attribute introduced in D105407 for the
llvm.preserve.array/struct.index intrinsics. It carries the
element type of the GEP these intrinsics effectively encode.

This patch:

 * Adds a verifier check that the attribute is required.
 * Adds it in the IRBuilder methods for these intrinsics.
 * Autoupgrades old bitcode without the attribute.
 * Updates the lowering code to use the attribute rather than
   the pointer element type.
 * Updates lots of tests to specify the attribute.
 * Adds -force-opaque-pointers to the intrinsic-array.ll test
   to demonstrate they work now.

https://reviews.llvm.org/D106184
2021-07-17 11:09:18 +02:00
Nikita Popov 4d188a6524 [Verifier] Require same signature for intrinsic calls
As suggested on D105733, this adds a verifier rule that calls to
intrinsics must match the signature of the intrinsic.

Without opaque pointers this is automatically enforced for all
calls, because the pointer types need to match. If the signatures
don't match, a pointer bitcast has to be inserted. For intrinsics
in particular, such bitcasts are not legal, because the address of
intrinsics cannot be taken.

With opaque pointers, there are no more pointer bitcasts, so it's
generally possible for the call and the callee signature to differ.
However, for intrinsics we still want to enforce that the signatures
must match, the same as was done before through the address taken
check.

We can't enforce this more generally for non-intrinsics, because
calls with mismatched signatures at the very least can legally
occur in unreachable code, and might also be valid in some other
cases, depending on how exactly the signatures differ.

Differential Revision: https://reviews.llvm.org/D106013
2021-07-16 18:33:16 +02:00
Nikita Popov ff59a1cfe6 [Verifier] Extend address taken check for unknown intrinsics
Intrinsics can only be called directly, taking their address is not
legal. This is currently only enforced for intrinsics that have an
ID, rather than all intrinsics. Adjust the check to cover all
intrinsics.

This came up in D106013.

Differential Revision: https://reviews.llvm.org/D106095
2021-07-15 23:16:14 +02:00
Nikita Popov c191035f42 [IR] Add elementtype attribute
This implements the elementtype attribute specified in D105407. It
just adds the attribute and the specified verifier rules, but
doesn't yet make use of it anywhere.

Differential Revision: https://reviews.llvm.org/D106008
2021-07-15 18:04:26 +02:00
Nikita Popov f59209a86e [AsmParser] Unify parsing of attributes
Continuing on from D105780, this should be the last major bit of
attribute cleanup. Currently, LLParser implements attribute parsing
for functions, parameters and returns separately, enumerating all
supported (and unsupported) attributes each time. This patch
extracts the common parsing logic, and performs a check afterwards
whether the attribute is valid in the given position. Parameters
and returns are handled together, while function attributes need
slightly different logic to support attribute groups.

Differential Revision: https://reviews.llvm.org/D105938
2021-07-15 17:51:11 +02:00
Nikita Popov 5e4b33fe92 [Verifier] Improve incompatible attribute type check
A couple of attributes had explicit checks for incompatibility
with pointer types. However, this is already handled generically
by the typeIncompatible() check. We can drop these after adding
SwiftError to typeIncompatible().

However, the previous implementation of the check prints out all
attributes that are incompatible with a given type, even though
those attributes aren't actually used. This has the annoying
result that the error message changes every time a new attribute
is added to the list. Improve this by explicitly finding which
attribute isn't compatible and printing just that.
2021-07-14 21:02:10 +02:00
Nikita Popov 460dfbd9f8 [OpaquePtr] Support VecOfAnyPtrsToElt intrinsics
In this case the pointer type is part of the mangled name, so we
can allow on opaque pointer outside --force-opaque-pointers mode
as well.
2021-07-01 20:35:33 +02:00
Akira Hatanaka f85b9d6443 [ObjC][ARC] Ignore operand bundle "clang.arc.attachedcall" on a call if
the call's return type is void

Instead of trying hard to prevent global optimization passes such as
deadargelim from changing the return type to void, just ignore the
bundle if the return type is void. clang currently emits calls to
@llvm.objc.clang.arc.noop.use, which consumes the function call result,
immediately after the function call to prevent changes to the return
type, but optimization passes can delete the call to
@llvm.objc.clang.arc.noop.use if the function call doesn't return, which
enables deadargelim to change the return type.

rdar://76671438

Differential Revision: https://reviews.llvm.org/D103062
2021-06-28 11:02:30 -07:00
Nikita Popov 8c2d4621d9 [Verifier] Support masked load/store with opaque pointers 2021-06-26 18:11:59 +02:00
Zequan Wu ec08f03be3 [OpaquePtr] Mangle intrinsics with opaque pointers arguments
Mangling intrinsics with opaque pointer arguments using "op"+{address space}.

Differential Revision: https://reviews.llvm.org/D104272
2021-06-23 10:52:13 -07:00
Joe Ellis 3c4dbf6ea9 [Verifier] Fail on overrunning and invalid indices for {insert,extract} vector intrinsics
With regards to overrunning, the langref (llvm/docs/LangRef.rst)
specifies:

   (llvm.experimental.vector.insert)
   Elements ``idx`` through (``idx`` + num_elements(``subvec``) - 1)
   must be valid ``vec`` indices. If this condition cannot be determined
   statically but is false at runtime, then the result vector is
   undefined.

   (llvm.experimental.vector.extract)
   Elements ``idx`` through (``idx`` + num_elements(result_type) - 1)
   must be valid vector indices. If this condition cannot be determined
   statically but is false at runtime, then the result vector is
   undefined.

For the non-mixed cases (e.g. inserting/extracting a scalable into/from
another scalable, or inserting/extracting a fixed into/from another
fixed), it is possible to statically check whether or not the above
conditions are met. This was previously missing from the verifier, and
if the conditions were found to be false, the result of the
insertion/extraction would be replaced with an undef.

With regards to invalid indices, the langref (llvm/docs/LangRef.rst)
specifies:

    (llvm.experimental.vector.insert)
    ``idx`` represents the starting element number at which ``subvec``
    will be inserted. ``idx`` must be a constant multiple of
    ``subvec``'s known minimum vector length.

    (llvm.experimental.vector.extract)
    The ``idx`` specifies the starting element number within ``vec``
    from which a subvector is extracted. ``idx`` must be a constant
    multiple of the known-minimum vector length of the result type.

Similarly, these conditions were not previously enforced in the
verifier. In some circumstances, invalid indices were permitted
silently, and in other circumstances, an undef was spawned where a
verifier error would have been preferred.

This commit adds verifier checks to enforce the constraints above.

Differential Revision: https://reviews.llvm.org/D104468
2021-06-23 10:33:22 +00:00
Nick Desaulniers 8ace121305 [IR] convert warn-stack-size from module flag to fn attr
Otherwise, this causes issues when building with LTO for object files
that use different values.

Link: https://github.com/ClangBuiltLinux/linux/issues/1395

Reviewed By: dblaikie, MaskRay

Differential Revision: https://reviews.llvm.org/D104342
2021-06-21 15:09:25 -07:00
Zequan Wu fad8d4230f [OpaquePtr] Verify Opaque pointer in function parameter
Verifying opaque pointer as function parameter when using with `byval`, `byref`,
`inalloca`, `preallocated`.

Differential Revision: https://reviews.llvm.org/D104309
2021-06-15 14:57:48 -07:00
Simon Moll 74d45b884c [VP] Binary floating-point intrinsics.
This patch implements vector-predicated intrinsics on IR level for fadd,
fsub, fmul, fdiv and frem.  There operate in the default floating-point
environment. We will use constrained fp operand bundles for constrained
vector-predicated fp math (D93455).

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D93470
2021-06-14 08:51:41 +02:00
Philip Reames ac81cb7e6d Allow ptrtoint/inttoptr of non-integral pointer types in IR
I don't like landing this change, but it's an acknowledgement of a practical reality.  Despite not having well specified semantics for inttoptr and ptrtoint involving non-integral pointer types, they are used in practice.  Here's a quick summary of the current pragmatic reality:
* I happen to know that the main external user of non-integral pointers has effectively disabled the verifier rules.
* RS4GC (the lowering pass for abstract GC machine model which is the key motivation for non-integral pointers), even supports them.  We just have all the tests using an integral pointer space to let the verifier run.
* Certain idioms (such as alignment checks for alignment N, where any relocation is guaranteed to be N byte aligned) are fine in practice.
* As implemented, inttoptr/ptrtoint are CSEd and are not control dependent.  This means that any code which is intending to check a particular bit pattern at site of use must be wrapped in an intrinsic or external function call.

This change allows them in the Verifier, and updates the LangRef to specific them as implementation dependent.  This allows us to acknowledge current reality while still leaving ourselves room to punt on figuring out "good" semantics until the future.
2021-06-11 13:38:32 -07:00
Tim Northover 9ff2eb1ea5 SwiftTailCC: teach verifier musttail rules applicable to this CC.
SwiftTailCC has a different set of requirements than the C calling convention
for a tail call. The exact argument sequence doesn't have to match, but fewer
ABI-affecting attributes are allowed.

Also make sure the musttail diagnostic triggers if a musttail call isn't
actually a tail call.
2021-05-28 11:12:00 +01:00
Adrian Prantl f3869a5c32 Support stripping indirectly referenced DILocations from !llvm.loop metadata
in stripDebugInfo().  This patch fixes an oversight in
https://reviews.llvm.org/D96181 and also takes into account loop
metadata pointing to other MDNodes that point into the debug info.

rdar://78487175

Differential Revision: https://reviews.llvm.org/D103220
2021-05-27 13:23:33 -07:00
Arthur Eubanks 1202f559bd [OpaquePtr] Make atomicrmw work with opaque pointers
FullTy is only necessary when we need to figure out what type an
instruction works with given a pointer's pointee type. However, we just
end up using the value operand's type, so FullTy isn't necessary.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102788
2021-05-25 20:16:21 -07:00
Arthur Eubanks 0bbb502daa Revert "[OpaquePtr] Make atomicrmw work with opaque pointers"
This reverts commit 0bebda17be.

Causing "Invalid record" errors.
2021-05-25 10:14:58 -07:00
Arthur Eubanks 0bebda17be [OpaquePtr] Make atomicrmw work with opaque pointers
FullTy is only necessary when we need to figure out what type an
instruction works with given a pointer's pointee type. However, we just
end up using the value operand's type, so FullTy isn't necessary.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102788
2021-05-19 12:49:28 -07:00
Arthur Eubanks 1b25fce404 [OpaquePtr] Make cmpxchg work with opaque pointers
Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102745
2021-05-19 12:44:10 -07:00
Arthur Eubanks 6013d84392 [OpaquePtr] Make loads and stores work with opaque pointers
Don't check that types match when the pointer operand is an opaque
pointer.

I would separate the Assembler and Verifier changes, but
verify-uselistorder in the Assembler test ends up running the verifier.

Reviewed By: dblaikie

Differential Revision: https://reviews.llvm.org/D102450
2021-05-18 13:43:50 -07:00
Tim Northover ea0eec69f1 IR+AArch64: add a "swiftasync" argument attribute.
This extends any frame record created in the function to include that
parameter, passed in X22.

The new record looks like [X22, FP, LR] in memory, and FP is stored with 0b0001
in bits 63:60 (CodeGen assumes they are 0b0000 in normal operation). The effect
of this is that tools walking the stack should expect to see one of three
values there:

  * 0b0000 => a normal, non-extended record with just [FP, LR]
  * 0b0001 => the extended record [X22, FP, LR]
  * 0b1111 => kernel space, and a non-extended record.

All other values are currently reserved.

If compiling for arm64e this context pointer is address-discriminated with the
discriminator 0xc31a and the DB (process-specific) key.

There is also an "i8** @llvm.swift.async.context.addr()" intrinsic providing
front-ends access to this slot (and forcing its creation initialized to nullptr
if necessary).
2021-05-14 11:43:58 +01:00
Roman Lebedev b01f499861
[NFC][Verifier] Split token1.ll into two, assert/non-assert versions 2021-04-28 13:58:38 +03:00
Hans Wennborg e9fe387ac5 Require asserts for llvm/test/Verifier/token1.ll
The test expects and assert, and that only works in asserts-enabled builds.
2021-04-28 09:58:36 +02:00
Roman Lebedev be935f2888
[NFC][Verifier] Fixup token PHINode test cases
It would still pass in non-assert build,
but with asserts it would now crash.

I haven't checked, but hopefully `not`'s `--crash` argument
should be enough to support both paths.
2021-04-27 21:09:43 +03:00
Luo, Yuanke bcdaccfe34 [X86][AMX] Verify illegal types or instructions for x86_amx.
This patch is related to https://reviews.llvm.org/D100032 which define
some illegal types or operations for x86_amx. There are no arguments,
arrays, pointers, vectors or constants of x86_amx.

Reviewed By: pengfei

Differential Revision: https://reviews.llvm.org/D100472
2021-04-20 16:14:22 +08:00
Serge Guelton d6de1e1a71 Normalize interaction with boolean attributes
Such attributes can either be unset, or set to "true" or "false" (as string).
throughout the codebase, this led to inelegant checks ranging from

        if (Fn->getFnAttribute("no-jump-tables").getValueAsString() == "true")

to

        if (Fn->hasAttribute("no-jump-tables") && Fn->getFnAttribute("no-jump-tables").getValueAsString() == "true")

Introduce a getValueAsBool that normalize the check, with the following
behavior:

no attributes or attribute set to "false" => return false
attribute set to "true" => return true

Differential Revision: https://reviews.llvm.org/D99299
2021-04-17 08:17:33 +02:00
Alok Kumar Sharma 9fb0025f70 [DebugInfo] Upgrade DISubragne::count to accept DIExpression also
This is needed for Fortran assumed shape arrays whose dimensions are
defined as,
  - 'count' is taken from array descriptor passed as parameter by
    caller, access from descriptor is defined by type DIExpression.
  - 'lowerBound' is defined by callee.
The current alternate way represents using upperBound in place of
count, where upperBound is calculated in callee in a temp variable
using lowerBound and count

Representation with count (DIExpression) is not only clearer as
compared to upperBound (DIVariable) but it has another advantage that
variable count is accessed by being parameter has better chance of
survival at higher optimization level than upperBound being local
variable.

Reviewed By: aprantl

Differential Revision: https://reviews.llvm.org/D99335
2021-03-30 09:16:55 +05:30
Adrian Prantl 8573c28a51 Add debug support for set types
This commit adds debugging support for set types defined in languages
such as Pascal and Modula-2.

Patch by Peter McKinna!

Differential Revision: https://reviews.llvm.org/D76115
2021-03-29 18:04:48 -07:00
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
David Sherwood 748ae5281d [IR][SVE] Add new llvm.experimental.stepvector intrinsic
This patch adds a new llvm.experimental.stepvector intrinsic,
which takes no arguments and returns a linear integer sequence of
values of the form <0, 1, ...>. It is primarily intended for
scalable vectors, although it will work for fixed width vectors
too. It is intended that later patches will make use of this
new intrinsic when vectorising induction variables, currently only
supported for fixed width. I've added a new CreateStepVector
method to the IRBuilder, which will generate a call to this
intrinsic for scalable vectors and fall back on creating a
ConstantVector for fixed width.

For scalable vectors this intrinsic is lowered to a new ISD node
called STEP_VECTOR, which takes a single constant integer argument
as the step. During lowering this argument is set to a value of 1.
The reason for this additional argument at the codegen level is
because in future patches we will introduce various generic DAG
combines such as

  mul step_vector(1), 2 -> step_vector(2)
  add step_vector(1), step_vector(1) -> step_vector(2)
  shl step_vector(1), 1 -> step_vector(2)
  etc.

that encourage a canonical format for all targets. This hopefully
means all other targets supporting scalable vectors can benefit
from this too.

I've added cost model tests for both fixed width and scalable
vectors:

  llvm/test/Analysis/CostModel/AArch64/neon-stepvector.ll
  llvm/test/Analysis/CostModel/AArch64/sve-stepvector.ll

as well as codegen lowering tests for fixed width and scalable
vectors:

  llvm/test/CodeGen/AArch64/neon-stepvector.ll
  llvm/test/CodeGen/AArch64/sve-stepvector.ll

See this thread for discussion of the intrinsic:
https://lists.llvm.org/pipermail/llvm-dev/2021-January/147943.html
2021-03-23 10:43:35 +00:00
Bradley Smith 48f5a392cb [IR] Add vscale_range IR function attribute
This attribute represents the minimum and maximum values vscale can
take. For now this attribute is not hooked up to anything during
codegen, this will be added in the future when such codegen is
considered stable.

Additionally hook up the -msve-vector-bits=<x> clang option to emit this
attribute.

Differential Revision: https://reviews.llvm.org/D98030
2021-03-22 12:05:06 +00:00
Akira Hatanaka 1900503595 [ObjC][ARC] Use operand bundle 'clang.arc.attachedcall' instead of
explicitly emitting retainRV or claimRV calls in the IR

This reapplies ed4718eccb, which was reverted
because it was causing a miscompile. The bug that was causing the miscompile
has been fixed in 75805dce5f.

Original commit message:

Background:

This fixes a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end adds operand bundle "clang.arc.attachedcall" to calls,
  which indicates the call is implicitly followed by a marker
  instruction and an implicit retainRV/claimRV call that consumes the
  call result. In addition, it emits a call to
  @llvm.objc.clang.arc.noop.use, which consumes the call result, to
  prevent the middle-end passes from changing the return type of the
  called function. This is currently done only when the target is arm64
  and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
  with the operand bundle in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the call with the
  operand bundle. It doesn't remove the operand bundle on the call since
  the backend needs it to emit the marker instruction. The retainRV and
  claimRV calls are emitted late in the pipeline to prevent optimization
  passes from transforming the IR in a way that makes it harder for the
  ARC middle-end passes to figure out the def-use relationship between
  the call and the retainRV/claimRV calls (which is the cause of
  PR31925).

- The function inliner removes an autoreleaseRV call in the callee if
  nothing in the callee prevents it from being paired up with the
  retainRV/claimRV call in the caller. It then inserts a release call if
  claimRV is attached to the call since autoreleaseRV+claimRV is
  equivalent to a release. If it cannot find an autoreleaseRV call, it
  tries to transfer the operand bundle to a function call in the callee.
  This is important since the ARC optimizer can remove the autoreleaseRV
  returning the callee result, which makes it impossible to pair it up
  with the retainRV/claimRV call in the caller. If that fails, it simply
  emits a retain call in the IR if retainRV is attached to the call and
  does nothing if claimRV is attached to it.

- SCCP refrains from replacing the return value of a call with a
  constant value if the call has the operand bundle. This ensures the
  call always has at least one user (the call to
  @llvm.objc.clang.arc.noop.use).

- This patch also fixes a bug in replaceUsesOfNonProtoConstant where
  multiple operand bundles of the same kind were being added to a call.

Future work:

- Use the operand bundle on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls with the operand bundles.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-03-04 11:22:30 -08:00
Hans Wennborg 0a5dd06718 Revert "[ObjC][ARC] Use operand bundle 'clang.arc.attachedcall' instead of explicitly emitting retainRV or claimRV calls in the IR"
This caused miscompiles of Chromium tests for iOS due clobbering of live
registers. See discussion on the code review for details.

> Background:
>
> This fixes a longstanding problem where llvm breaks ARC's autorelease
> optimization (see the link below) by separating calls from the marker
> instructions or retainRV/claimRV calls. The backend changes are in
> https://reviews.llvm.org/D92569.
>
> https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue
>
> What this patch does to fix the problem:
>
> - The front-end adds operand bundle "clang.arc.attachedcall" to calls,
>   which indicates the call is implicitly followed by a marker
>   instruction and an implicit retainRV/claimRV call that consumes the
>   call result. In addition, it emits a call to
>   @llvm.objc.clang.arc.noop.use, which consumes the call result, to
>   prevent the middle-end passes from changing the return type of the
>   called function. This is currently done only when the target is arm64
>   and the optimization level is higher than -O0.
>
> - ARC optimizer temporarily emits retainRV/claimRV calls after the calls
>   with the operand bundle in the IR and removes the inserted calls after
>   processing the function.
>
> - ARC contract pass emits retainRV/claimRV calls after the call with the
>   operand bundle. It doesn't remove the operand bundle on the call since
>   the backend needs it to emit the marker instruction. The retainRV and
>   claimRV calls are emitted late in the pipeline to prevent optimization
>   passes from transforming the IR in a way that makes it harder for the
>   ARC middle-end passes to figure out the def-use relationship between
>   the call and the retainRV/claimRV calls (which is the cause of
>   PR31925).
>
> - The function inliner removes an autoreleaseRV call in the callee if
>   nothing in the callee prevents it from being paired up with the
>   retainRV/claimRV call in the caller. It then inserts a release call if
>   claimRV is attached to the call since autoreleaseRV+claimRV is
>   equivalent to a release. If it cannot find an autoreleaseRV call, it
>   tries to transfer the operand bundle to a function call in the callee.
>   This is important since the ARC optimizer can remove the autoreleaseRV
>   returning the callee result, which makes it impossible to pair it up
>   with the retainRV/claimRV call in the caller. If that fails, it simply
>   emits a retain call in the IR if retainRV is attached to the call and
>   does nothing if claimRV is attached to it.
>
> - SCCP refrains from replacing the return value of a call with a
>   constant value if the call has the operand bundle. This ensures the
>   call always has at least one user (the call to
>   @llvm.objc.clang.arc.noop.use).
>
> - This patch also fixes a bug in replaceUsesOfNonProtoConstant where
>   multiple operand bundles of the same kind were being added to a call.
>
> Future work:
>
> - Use the operand bundle on x86-64.
>
> - Fix the auto upgrader to convert call+retainRV/claimRV pairs into
>   calls with the operand bundles.
>
> rdar://71443534
>
> Differential Revision: https://reviews.llvm.org/D92808

This reverts commit ed4718eccb.
2021-03-03 15:51:40 +01:00
Sanjay Patel 215bb15791 [IR] restrict vector reduction intrinsic types
The arguments in all cases should be vectors of exactly one of integer or FP.

All of the tests currently pass the verifier because we check for any vector
type regardless of the type of reduction.
This obviously can't work if we mix up integer and FP, and based on current
LangRef text it was not intended to work for pointers either.

The pointer case from https://llvm.org/PR49215 is what led me here. That
example was avoided with 5b250a27ec.

Differential Revision: https://reviews.llvm.org/D96904
2021-02-21 12:37:00 -05:00
Sanjay Patel 38730b0029 [Verifier] add tests for saturating intrinsics; NFC
As noted in D96904, we don't have direct tests for these malformed ops.
2021-02-19 14:58:25 -05:00
Sanjay Patel a1e5388a7c [Verifier] add tests for vector reductions; NFC
Checking existing functionality before D96904.
2021-02-18 10:35:38 -05:00
Akira Hatanaka ed4718eccb [ObjC][ARC] Use operand bundle 'clang.arc.attachedcall' instead of
explicitly emitting retainRV or claimRV calls in the IR

Background:

This fixes a longstanding problem where llvm breaks ARC's autorelease
optimization (see the link below) by separating calls from the marker
instructions or retainRV/claimRV calls. The backend changes are in
https://reviews.llvm.org/D92569.

https://clang.llvm.org/docs/AutomaticReferenceCounting.html#arc-runtime-objc-autoreleasereturnvalue

What this patch does to fix the problem:

- The front-end adds operand bundle "clang.arc.attachedcall" to calls,
  which indicates the call is implicitly followed by a marker
  instruction and an implicit retainRV/claimRV call that consumes the
  call result. In addition, it emits a call to
  @llvm.objc.clang.arc.noop.use, which consumes the call result, to
  prevent the middle-end passes from changing the return type of the
  called function. This is currently done only when the target is arm64
  and the optimization level is higher than -O0.

- ARC optimizer temporarily emits retainRV/claimRV calls after the calls
  with the operand bundle in the IR and removes the inserted calls after
  processing the function.

- ARC contract pass emits retainRV/claimRV calls after the call with the
  operand bundle. It doesn't remove the operand bundle on the call since
  the backend needs it to emit the marker instruction. The retainRV and
  claimRV calls are emitted late in the pipeline to prevent optimization
  passes from transforming the IR in a way that makes it harder for the
  ARC middle-end passes to figure out the def-use relationship between
  the call and the retainRV/claimRV calls (which is the cause of
  PR31925).

- The function inliner removes an autoreleaseRV call in the callee if
  nothing in the callee prevents it from being paired up with the
  retainRV/claimRV call in the caller. It then inserts a release call if
  claimRV is attached to the call since autoreleaseRV+claimRV is
  equivalent to a release. If it cannot find an autoreleaseRV call, it
  tries to transfer the operand bundle to a function call in the callee.
  This is important since the ARC optimizer can remove the autoreleaseRV
  returning the callee result, which makes it impossible to pair it up
  with the retainRV/claimRV call in the caller. If that fails, it simply
  emits a retain call in the IR if retainRV is attached to the call and
  does nothing if claimRV is attached to it.

- SCCP refrains from replacing the return value of a call with a
  constant value if the call has the operand bundle. This ensures the
  call always has at least one user (the call to
  @llvm.objc.clang.arc.noop.use).

- This patch also fixes a bug in replaceUsesOfNonProtoConstant where
  multiple operand bundles of the same kind were being added to a call.

Future work:

- Use the operand bundle on x86-64.

- Fix the auto upgrader to convert call+retainRV/claimRV pairs into
  calls with the operand bundles.

rdar://71443534

Differential Revision: https://reviews.llvm.org/D92808
2021-02-12 09:51:57 -08:00
Adrian Prantl 79f46a30c2 Have stripDebugInfo() also strip !llvm.loop annotations from all
instructions.

The !llvm.loop annotations consist of pointers into the debug info, so
when stripping the debug info (particularly important when it is
malformed!) !llvm.loop annotations need to be stripped as well, or
else the malformed debug info stays around.  This patch applies the
stripping to all instructions, not just terminator instructions.

rdar://73687049

Differential Revision: https://reviews.llvm.org/D96181
2021-02-05 17:22:41 -08:00
Adrian Prantl 57a371d701 Remove overzealous verifier check on DW_OP_LLVM_entry_value and improve the documentation
Based on the comments in the code, the idea is that AsmPrinter is
unable to produce entry value blocks of arbitrary length, such as
DW_OP_entry_value [DW_OP_reg5 DW_OP_lit1 DW_OP_plus]. But the way the
Verifier check is written it also disallows DW_OP_entry_value
[DW_OP_reg5] DW_OP_lit1 DW_OP_plus which seems to overshoot the
target.

Note that this patch does not change any of the safety guards in
LiveDebugValues — there is zero behavior change for clang. It just
allows us to legalize more complex expressions in future patches.

rdar://73907559

Differential Revision: https://reviews.llvm.org/D95990
2021-02-04 10:58:35 -08:00