623 Commits

Author SHA1 Message Date
Valentin Clement
fdc3dd70c7
[flang] Add runtime default initialization for polymorphic intent(out) dummy
This patch adds runtime default initialization for polymorphic
dummy argument. The dynamic type might require default initialization
but not the declared type.

Reviewed By: jeanPerier, PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D141278
2023-01-09 17:53:41 +01:00
Kazu Hirata
0db88db5d9 flang] Remove remaining uses of llvm::Optional (NFC)
This patch removes the unused "using" declaration and removes #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
2023-01-07 22:32:38 -08:00
Kazu Hirata
c09215860f [flang] 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
2023-01-07 22:26:48 -08:00
Kazu Hirata
4d4d4785e0 [flang] 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
2023-01-07 20:55:47 -08:00
Jean Perier
2d9b4a50ca [flang][NFC] share Constant<SomeDerived> lowering
A previous patch (https://reviews.llvm.org/D136955) already refactored
intrinsic constant lowering to place in its own file and allow using it from
both the current lowering and the new lowering to HLFIR.

This patch does the same for derived types. The core function
"genStructComponentInInitializer" is moved from ConvertExpr.cpp and
renamed "genInlinedStructureCtorLitImpl" into ConvertConstant.cpp
without significant logic change.

Then, genScalarLit, genArrayLit (and genInlinedArrayLit/genOutlinedArrayLit)
are updated to support derived types.

The core aspect of derived type constant lowering that differs between
the current lowering and the HLFIR update is the way
addresses/initial target descriptors are built when part of a derived
type constant. This part happens in ConvertVariable.cpp (since the
address of a variable is taken in an initializer and is left TODO).

The mangling of derived type global literal constant is fixed: it did not embed
the derived type name and could cause "conflicts" between unrelated
derived types containing the same data. However, the hash remains
unstable between two compilation of the same file. This is not a
correctness issue and would require a lot of work to hash the derived
type constant data without hashing some irrelevant (but not out of bound)
data in the compile time data structure that holds derived type
constants (Constant<SomeDerived>). This may have to be revisited later.

Differential Revision: https://reviews.llvm.org/D140986
2023-01-05 14:45:34 +01:00
V Donaldson
609b789170 [flang] Control flow graph issues
Address several issues involving control flow graph generation and
structured code ops.

 - Fix a problem with constructs nested inside unstructured selection
   constructs. This is a general problem involving branches that are
   implied rather than explicit. It is addressed in the generic genFIR
   "wrapper" function that calls individual statement-specific genFIR calls.

 - The previous fix requires some compensating changes in IF and DO
   construct code lowering.

 - Streamline the code to generate explicit DO loop variable updates.

 - Fix a problem with the individual detailed genFIR calls made in the
   genFIR(SelectTypeConstruct) call.

 - Modify control flow graph generation to support the insertion of
   deallocation and finalization code when lowering most END <construct>
   statements.
2023-01-03 14:46:25 -08:00
Peter Klausler
a8234196c5 [flang] Restore checking for some optional values before use
Recent commits (2098ad7f00324ee0f2a6538f418a6f81dfdd2edb and
15a9a72ee68166c0cff3f036cacd3c82be66c729) replaced usage of "o.value()"
on optionals with "*o".  Those optional values are expected to be
present -- but now, if it ever turns out that they're not,
compilation will proceed with garbage data rather than crashing
immediately (and more debuggably) with an uncaught exception.

Add asserts for presence to restore the previous level of safety.
(I could have revert these patches so as to resume used of .value()
but I didn't want to just have them get broken again.)

Differential Revision: https://reviews.llvm.org/D140340
2022-12-29 09:37:34 -08:00
Slava Zakharin
2b60ed405b [flang] Use Assign() runtime for copy-in/copy-out.
The loops generated under IsContiguous check for copy-in/copy-out
result in LLVM backend spending too much time optimizing them.
At the same time, the copy loops do not provide any optimization
opportunities with the surrounding code (since they are executed
under runtime IsContiguous check), so the copy code may be optimized
on its own and this can be done in runtime.

I thought I could implement and use new APIs for packing/unpacking
non-contiguous data (interfaces added in D136378), but then I found
that Assign() is already doing what is needed. If performance
becomes an issue for these loops, we can optimize code in Assign()
rather than creating new APIs.

Thus, this change makes use of Assign() for copy-in/copy-out
of boxed objects, and this is done only if the objects
are non-contiguous during execution. Copies for non-boxed
objects (e.g. for passing as VALUE dummy argument) are still
done inline, because they can potentially be optimized with
surrounding loops.

I added internal -inline-copyinout-for-boxes option to revert to the old
behavior just to make it easier to triage performance regressions,
if any appear after the change.

CPU2017/521.wrf compiles for 2179 seconds without the change and
the module_dm.f90 compiled with -O0 (without -O0 this single
module compiles for 5775 seconds). With the change total compilation
time of the benchmark reduces to 722 seconds.

Differential Revision: https://reviews.llvm.org/D140446
2022-12-21 09:55:33 -08:00
Jean Perier
93129ca8d1 [flang] Do not convey captured globals through host link
Addresses and properties (bounds, length parameters) of host
variables associated in an internal procedure were all passed via
an extra tuple argument of the internal procedure.
This extra tuple is in general an overhead: it must be created and
passed, and require creating thunks when taking the address of the
internal procedure.
This patch allows not using the tuple for host global variables
(from modules, common block, or local saved variables) since they can
be instantiated from the fir.global symbol in the internal procedure
instead.
Add a fir.internal_proc attribute to mlir::FuncOp for internal procedures
so that ArrayValueCopy can still detect internal procedures even if they
do not have a tuple argument.

Differential Revision: https://reviews.llvm.org/D140288
2022-12-20 13:52:53 +01:00
Jean Perier
d0018c959a [flang] Finish substring lowering
Hlfir.designate was made to support substrings but so far substrings
were not yet lowered to it. Implement support for them.

Differential Revision: https://reviews.llvm.org/D140310
2022-12-20 08:47:14 +01:00
Tarun Prabhu
bef2bb34bf [flang] Lowering and runtime support for F08 transformational intrinsics: BESSEL_JN and BESSEL_YN
The runtime implementation uses the recurrence relations

`J(n-1, x) = (2.0 / x) * n * J(n, x) - J(n+1, x)`
`Y(n+1, x) = (2.0 / x) * n * Y(n, x) - Y(n-1, x)`

(see https://dlmf.nist.gov/10.74.iv and https://dlmf.nist.gov/10.6.E1).

Although the standard requires that `N1` and `N2` in `BESSEL_JN(N1, N2, x)`
and `BESSEL_YN(N1, N2, x)` be non-negative, this is not checked in the
runtime functions. This is in keeping with some other compilers which also
return some results when `N1` and/or `N2` are negative.

The special case for `x == 0` is  handled in different runtime functions
for each of `BESSEL_JN` and `BESSEL_YN`. The lowering code checks for this
case and inserts the checks and the appropriate runtime calls in FIR.

The existing tests for the two intrinsics was modified to keep the style
consistent with the additional lowering tests that were added.
2022-12-19 07:59:38 -07:00
Jean Perier
fc61400cb8 [flang] Fix llvm::Optional warning caused by D140220
Using llvm::Optional::value() was just deprecated in LLVM.
Remove the usage that was added by D140220 and replace it by an assert.

https://lab.llvm.org/buildbot/#/builders/160/builds/14222
2022-12-19 11:43:36 +01:00
Jean Perier
8febe67851 [flang] Lower statement function references in HLFIR
Enable lowering of statement function references in HLFIR.  This follows
the same principle as statement function lowering with the current
lowering:
- Actual arguments are lowered and mapped to the statement function
  dummy symbols.
- "HostAssociated" symbols are mapped to their host values (these are
  the symbols referred to inside the statement function expressions that
  are not statement function dummies. e.g: `x` in `stmt_func(i) =
  x(i)`).
- The statement function expression is evaluated.

evaluate::SetLength has to be lowered to deal with statement functions
returning characters since the front-end is generating one to ensure the
statement function expression value is trimmed/padded to match the statement
function declared type.

Differential Revision: https://reviews.llvm.org/D140220
2022-12-19 11:11:37 +01:00
Jean Perier
a1fae71f85 [flang][NFC] move getIntIfConstant into FIROpsSupport.h
The motivation is to have it accessible in HLFIROps.cpp to
use it in hlfir.set_length builder to build the result length
type as best as possible.

Differential Revision: https://reviews.llvm.org/D140214
2022-12-19 09:49:23 +01:00
Fangrui Song
15a9a72ee6 [flang] llvm::Optional::value() => => operator*/operator->
std::optional::value() has undesired exception checking semantics and is
unavailable in older Xcode (see _LIBCPP_AVAILABILITY_BAD_OPTIONAL_ACCESS). The
call sites block std::optional migration.
2022-12-17 22:22:47 +00:00
Slava Zakharin
1a9dec0dda [flang] Fixed buildbot failured after D140236.
Removed unused functions searchFunctionInLibrary and getFuncOp.

Differential Revision: https://reviews.llvm.org/D140236
2022-12-17 13:09:08 -08:00
Slava Zakharin
b6ef76a1ec [NFC][flang] Removed pgmath handling from lowering.
I kept the possibility to use pgmath in constant folding
just in case. We can remove it later, if it is proven to be redundant.

Differential Revision: https://reviews.llvm.org/D140236
2022-12-17 12:33:33 -08:00
Ramkumar Ramachandra
22426110c5 mlir/tblgen: use std::optional in generation
This is part of an effort to migrate from llvm::Optional to
std::optional. This patch changes the way mlir-tblgen generates .inc
files, and modifies tests and documentation appropriately. It is a "no
compromises" patch, and doesn't leave the user with an unpleasant mix of
llvm::Optional and std::optional.

A non-trivial change has been made to ControlFlowInterfaces to split one
constructor into two, relating to a build failure on Windows.

See also: https://discourse.llvm.org/t/deprecating-llvm-optional-x-hasvalue-getvalue-getvalueor/63716

Signed-off-by: Ramkumar Ramachandra <r@artagnon.com>

Differential Revision: https://reviews.llvm.org/D138934
2022-12-17 11:13:26 +01:00
Valentin Clement
b2b680a5ab
[flang] Unlimited polymoprhic allocation with intrinsic type spec
An unlimited polymoprhic entity can be allocated with a derived type
spec or an intrinsic type spec. This patch add the generation of the
runtime function call when the allocation is done with an intrinsic
type spec.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D140207
2022-12-16 21:20:28 +01:00
Jean Perier
4203b062fb [flang] Lower procedure ref to user defined elemental procedures (part 1)
Lower procedure ref to user defined elemental procedure when:
- there are no arguments that may be dynamically optional
- for functions, the result has no length parameters
- the reference can be unordered
- there are not character by value arguments

This uses the recently added hlfir.elemental operation and tools.
The "core" of the argument preparation is shared between elemental
and non elemental calls (genUserCalls is code moved without any
functional changes)

Differential Revision: https://reviews.llvm.org/D140118
2022-12-16 13:04:04 +01:00
Jean Perier
3191e8e19f [flang] Lower binary and unary elemental array operations
Lower binary and unary elemental operations with an array argument
using hlfir.elemental, hlfir.yield_element, and hlfir.apply.

Concat implementation, which is a binary operation, is moved to a
BinaryOp struct so that it can leverage this new code.

This patch implements the "not yet implemented: character array
expression temp with dynamic length" TODO of the current lowering
by splitting the result length computation from the result value
computation. That way, the result length computation can be done
before lowering the operation to an hlfir.elemental, and the length
of the hlfir.elemental is known and storage for it can later be
allocated.

It adds a DesignatorOp builder to make "dumb" indexing (without triplets,
component, substrings or derived type component ref) easier since indexing
needs to be generated for array variables in elemental expression (in
the added hlfir::genElementAt helper).

Differential Revision: https://reviews.llvm.org/D140040
2022-12-15 13:15:12 +01:00
Valentin Clement
9379ca0a25
[flang] Fix associating entity when selector is an array, pointer or allocatable
In SELECT TYPE, within the block following TYPE IS, the associating entity is not polymorphic.
It has the type named in the type guard and other properties taken from the
selector. Within the block following a CLASS IS type guard statement, the
associating entity is polymorphic and has the declared type named in the type
guard statement.
This patch makes sure the associating entity matches the selector if it is
an array, a pointer or an allocatable.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D140017
2022-12-15 12:02:38 +01:00
Jean Perier
b22fa8659a [flang][NFC] add builder to simplify fir.shape creation
Differential Revision: https://reviews.llvm.org/D140031
2022-12-15 11:14:14 +01:00
Slava Zakharin
9e8f677299 [flang] Lower exponentiation without using pgmath.
Exponentiation is lowered to either math::FPowI or Fortran runtime
call (in case of --math-runtime=precise).

MathToFuncs convertor will convert math::FPowI operations with
exponent width >32 to calls of outlined implementations and otherwise
will leave the operation to MathToLLVM convertor.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D139806
2022-12-14 15:32:51 -08:00
Kazu Hirata
bfe4c5cc0b [flang] Fix a warning
This patch fixes:

  flang/lib/Lower/PFTBuilder.cpp:1042:6: error: function 'dumpScope'
  is not needed and will not be emitted
  [-Werror,-Wunneeded-internal-declaration]
2022-12-13 17:36:56 -08:00
V Donaldson
9b35843e93 [flang] Fix build failure 2022-12-13 15:10:59 -08:00
V Donaldson
518e6f12f3 [flang] Submodules
A submodule is a program unit that may contain the implementions of procedures
declared in an ancestor module or submodule.

Processing for the equivalence groups and variables declared in a submodule
scope is similar to existing processing for the equivalence groups and
variables in module and procedure scopes. However, module and procedure scopes
are tied directly to code in the Pre-FIR Tree (PFT), whereas processing for a
submodule must have access to an ancestor module scope that is guaranteed
to be present in a .mod file, but is not guaranteed to be in the PFT. This
difference is accommodated by tying processing directly to a front end scope.
Function scopes that can be processed on the fly are done that way; the
resulting variable information is never stored. Module and submodule scopes
whose symbol information may be needed during lowering of any number of module
procedures are instead cached on first use, and reused as needed.

These changes are a direct extension of current code. All module and submodule
variables in scope are processed, whether referenced or not. A possible
alternative would be to instead process symbols only when first used. While
this could ultimately be beneficial, such an approach must account for the
presence of equivalence groups. That information is not currently available
for on-the-fly variable processing.

Some additional changes are needed to include submodules in places where
modules must be considered, and to include separate module procedures in
places where other subprogram variants are considered. There is also a fix
for a bug involving the use of variables in an equivalence group in a
namelist group, which also involves scope processing code.
2022-12-13 13:06:07 -08:00
Valentin Clement
7602e09b1c
[flang] Handle type generation for unlimited polymorphic function result
An unlimited polymorphic entity is considered to have a derived category
in its dynamic type but no type descriptor. Avoid a nullptr dereference when
an unlimited polymorphic type needs to be generated.

Reviewed By: PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D139923
2022-12-13 15:00:08 +01:00
Jonathon Penix
1ee9080d6b [flang] Preserve bound info for pointer assignments through derived types
Doing a pointer assignment to another pointer which is a derived type component
could result in the bound information being lost, potentially leading to
incorrect array accesses. Fix this by trying to retain the bound info during
the assignment.

Fixes #57441

Differential Revision: https://reviews.llvm.org/D139800
2022-12-12 14:22:22 -08:00
Valentin Clement
40cb4fd0b9
[flang] Perform polymorphic pointer association with runtime call
pointer association to a polymorphic pointer needs to potentially
update the element size in the descriptor. Update the pointer association
to polymoprhic pointer with a runtime call to PointerAssociate.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D139825
2022-12-12 14:05:14 +01:00
Valentin Clement
bf773a61ce
[flang] Handle correctly polymorphic descriptor for IO input
Polymorphic entities are already emboxed. Just update
the code to use `BaseBoxType` instead of `BoxType`.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D139707
2022-12-09 16:06:54 +01:00
Valentin Clement
1b41074508
[flang] Embox derived-type when passed to element procedure as passed object
In elemental procedure lowering the passed object is always emboxed. The current code
was not correctly dealing with scalar derived-type used as passed object.

Reviewed By: jeanPerier, PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D139667
2022-12-09 15:37:56 +01:00
Jean Perier
b013ebe059 [flang] Lower intrinsics to HLFIR part 1
This patch adds support for lowering intrinsics that have no dynamic
optionality aspects to handle and that requires argument to be lowered
to value, addr, or box.

It uses the current intrinsic lowering framework that can be re-used in
HLFIR to start with. HLFIR operations for charater/transformational
intrinsics will be added as needed from an optimization point of view.
The current approach will still create temporary variables for their
value directly in lowering.

Later patch will still need to add:
- support for dynamically optional arguments
- inquires
- "moving" the in memory computation of character and transformational
intrinsics to hlfir.expr. This is not needed from a semantic point of
view, but will help optimizing and will probably be required inside
hlfir.elemental returning characters so that the returned element
type is an hlfir.expr and match the result type of later hlfir.apply.

Differential Revision: https://reviews.llvm.org/D139613
2022-12-09 10:11:37 +01:00
Valentin Clement
ee7a62a306
[flang] Generate iteration shape from passed object
When call an elemental subroutine with a monomorphic or polymorphic
passed object, the iteration shape could not be computed. Use the
passed object to infer the implicit iteration shape so the loop
can be constructed.

Reviewed By: PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D139635
2022-12-09 09:18:37 +01:00
Valentin Clement
f1307d78c6
[flang] Handle polymorphic passed object in elemental call
The passed object is placed in the passed arguments by semantics.
When the TBP to be called is an elemental subroutine or function it has to be
handled accordingly.

Reviewed By: jeanPerier, PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D139537
2022-12-08 09:48:17 +01:00
Jean Perier
6e3292fba5 [flang] Lower parentheses with hlfir.as_expr and hlfir.no_reassoc
Differential Revision: https://reviews.llvm.org/D139523
2022-12-07 14:45:55 +01:00
Valentin Clement
0137123846
[flang] Handle polymorphic passed object in host association
Polymorphic entities are always emboxed. This patch
handles host association of polyrmophic entities as passed object.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D139423
2022-12-07 12:01:18 +01:00
Jean Perier
1293b5fe5a [flang] turn fatal error into a TODO for FORALL edge-case
See https://github.com/llvm/llvm-project/issues/59337.
This TODO will be implemented as part of HLFIR work
(see https://github.com/llvm/llvm-project/blob/main/flang/docs/HighLevelFIR.md).

Differential Revision: https://reviews.llvm.org/D139410
2022-12-07 09:47:33 +01:00
Valentin Clement
13cde1129e
[flang] Support fir.class in scalar user defined assignment lowering
Support fir.class in genScalarUserDefinedAssignmentCall so
emboxing is done correctly.

Reviewed By: jeanPerier, PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D139435
2022-12-06 22:02:25 +01:00
Jean Perier
788960d628 [flang] Allow conversion from hlfir.expr to fir::ExtendedValue
For now at least, the plan is to keep hlfir.expr usage limited as
sub-expression operand, assignment rhs, and a few other contexts (
e.g. Associate statements). The rest of lowering (statements lowering
in the bridge) will still expect to get and manipulate characters and
arrays in memory. That means that hlfir.expr must be converted to
variable in converter.genExprAddr/converter.genExprBox.

This is done using an hlfir.associate, and generating the related
hlfir.end_associate in the statement context.

hlfir::getFirBase of is updated to avoid bringing in the HLFIR
fir.boxchar/fir.box into FIR when the entity was created with
hlfir::AssociateOp.

Differential Revision: https://reviews.llvm.org/D139328
2022-12-06 13:53:16 +01:00
Tarun Prabhu
7fe4abbbc2 [flang] Lower F08 NORM2 intrinsic
The implementation follows the pattern used in comparable intrinsics.
Change the runtime API for Norm2 so it does not expect a mask argument
since the Norm2 intrinsic does not accept a mask in Fortran.

Differential Revision: https://reviews.llvm.org/D138150
2022-12-05 13:53:35 -07:00
Valentin Clement
491b6a9ccb
[flang] Fix pointer association with remap on polymorphic entities
Runtime is expecting a 1d array. This patch fixes the generation
of the array holding the bounds to be passed to the runtime function call.

Reviewed By: jeanPerier, PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D139324
2022-12-05 18:29:06 +01:00
Valentin Clement
42b21ddaad
[flang] Pointer assignment with remapping involcing polymorphic entities
Lower pointer assignment with remapping involving polymorphic entities
to runtime call to PointerAssociateRemapping.
For the time being all pointer assignment involcing polymorphic entities are
done with the runtime call. When lhs is not unlimited polymorphic
we might be able to do it inlined as well.

Reviewed By: jeanPerier, PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D139198
2022-12-05 09:36:11 +01:00
Jean Perier
1981116548 [flang] Lower function return to HLFIR
The only special thing that is needed is to update the bridge symbol
lookup to deal with the HLFIR symbol lookup (symbols are mapped to
fir::FortranVariableInterface operations, not Fortran::Lower::SymbolBox).

Differential Revision: https://reviews.llvm.org/D139201
2022-12-05 09:06:32 +01:00
Kazu Hirata
9a41739565 [flang] Use std::nullopt instead of None (NFC)
This patch mechanically replaces None with std::nullopt where the
compiler would warn if None were deprecated.  The intent is to reduce
the amount of manual work required in migrating from Optional to
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
2022-12-03 12:14:21 -08:00
Peter Klausler
bcba39a56f [flang] Restore ENUM_CLASS() to be compilation-time code
Rework some recent changes to the ENUM_CLASS() macro so that
all of the construction of enumerator-to-name string mapping
data structures is again performed at compilation time.

Differential Revision: https://reviews.llvm.org/D137859
2022-12-02 09:55:45 -08:00
Jean Perier
655d994adc [flang] fix unused-but-set-parameter warning in ConvertExprToHLFIR.cpp
Some named value operands are not used yet (TODOs). Some compilers
complain about it. Remove names of unused parameters.

Differential Revision: https://reviews.llvm.org/D139207
2022-12-02 17:57:12 +01:00
Jean Perier
f24466cf62 [flang] Lower conversions to HLFIR
Differential Revision: https://reviews.llvm.org/D139196
2022-12-02 16:19:38 +01:00
Valentin Clement
f8ea349a6d
[flang] Perform assignment to polymorphic allocatable with runtime call
Lower assignment to polymorphic allocatable to the `Assign` runtime
call.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D139192
2022-12-02 15:51:20 +01:00
Jean Perier
ffdb5f951c [flang] add missing unreachable in D139179
Fix bot failure https://lab.llvm.org/buildbot/#/builders/160/builds/13647
caused by https://reviews.llvm.org/D139179.

Even if the switch is fully covering, adding an unreachable after is
required to cover all path since the switch argument could be a broken
value that does not belong to the enum.
2022-12-02 05:46:22 -08:00