218 Commits

Author SHA1 Message Date
Andrew Gozillon
2e634367be [Flang][OpenMP][Driver][MLIR] Port fopenmp-host-ir-file-path flag and add MLIR module attribute to proliferate to OpenMP IR lowering
This patch ports the fopenmp-host-ir-file-path flag from Clang to Flang-new, this flag
is added by the driver to the device pass when doing two phase compilation (device + host).

This flag is then applied to the module when compiling during the OpenMP device phase.
This file can then be utilised during lowering of the OpenMP dialect to LLVM-IR, which
allows the device and host to maintain 1:1 mapping of OpenMP metadata for variables
during lowering via the OpenMPIRBuilders loadOffloadInfoMetadata facilities
(which is used for declare target and I believe target regions as well).

Reviewer: awarzynski

Differential Revision: https://reviews.llvm.org/D148038
2023-04-24 10:06:21 -05:00
Mats Petersson
efae695d52 Add -f[no-]loop-versioning option
Add flags for loop-versioning pass enable/disable

Reviewed By: awarzynski, tblah

Differential Revision: https://reviews.llvm.org/D141307
2023-04-18 09:47:54 +01:00
Andrew Gozillon
53152f12a4 [OpenMP][MLIR][Flang][bbc][Driver] Add OpenMP RTL Flags to Flang and generate omp.FlagsAttr from them
This patch ports OpenMP RTL flags from the shared Clang compiler
options to Flang. As well as adding a limited subset to bbc.

This patch enables the flags below (and any equals or inverse variants)
for Flang that exist in Clang:

-fopenmp-target-debug
-fopenmp-assume-threads-oversubscription
-fopenmp-assume-teams-oversubscription
-fopenmp-assume-no-nested-parallelism
-fopenmp-assume-no-thread-state

For the bbc tool it only utilises the primary variants to minimize
additional complexity in the tool.

The patch also provides FlagAttr generation from these flags. Which
will be lowered to LLVM-IR in a subsequent patch.

Reviewers: kiranchandramohan, awarzynski

Differential Revision: https://reviews.llvm.org/D147324
2023-04-05 12:50:32 -05:00
Sacha Ballantyne
e2b7424d06 [Flang] Add debug flag to enable current debug information pass
While a pass exists to generate basic debug information, currently there is not a corresponding flag to enable it.
This patch adds support for activating this pass at any debug level >= -g1, as well as emiting a warning for higher levels that the functionality is not yet fully implemented.

This patch also adds -g and -gline-tables-only to appear when `flang-new` --help is run

Depends on D142347.

Reviewed By: awarzynski

Differential Revision: https://reviews.llvm.org/D146814
2023-03-29 12:21:26 +00:00
Sergio Afonso
33be83415c [flang][driver][openmp] Write MLIR for -save-temps
This patch adds support for producing MLIR files when using -save-temps on
flang. One MLIR file will be produced before lowering and optimization passes,
containing the operations produced by the PFT-to-MLIR lowering bridge, and
another at the end of the process, just before LLVM IR generation.

This is accomplished by forwarding the -save-temps flag from the driver to the
frontend, and modifying it to output MLIR files accordingly.

Differential Revision: https://reviews.llvm.org/D146075
2023-03-24 17:13:40 +00:00
Tom Eccles
acf6a32249 [flang] add -flang-experimental-hlfir flag to flang-new
This flag instructs flang-new to use the new HLFIR lowering. It is
marked as experimental and not included in --help.

This was added to make it more convenient to test the performance of
code generated by the HLFIR lowering.

Extra diffs are from running clang-format on CLOptions.inc (which was
being forced by CI).

Differential Revision: https://reviews.llvm.org/D146278
2023-03-22 13:36:54 +00:00
Nadeem, Usman
0fdfb65e26 [Flang] Add support to use LTO specific pipelines
Thin and full LTO modes use different pre-link pipelines compared to
regular compilation. This patch adds support for calling those pipelines.

This patch closely mimics Clang's implementation with the exception that I
changed the codegen option name from `PrepareForLTO` to `PrepareForFullLTO`
to be more precise.

With this patch:
  - Compilation for full LTO should be as we expect (except possibly
  missing optimizations enabled by module summaries which we do not
  produce yet).
  - thinLTO uses the correct prelink pipeline but will use the postlink
  backend for fullLTO due to missing metadata and summary in the llvm
  module. I have added a warning regarding this: `flang-new: warning: the
  option '-flto=thin' is a work in progress`.

Differential Revision: https://reviews.llvm.org/D142420

Change-Id: I6b94b775b5b8e93340e520c5cd4bf60834b2e209
2023-03-09 13:27:43 -08:00
Andrew Gozillon
e002a38b20 [Flang][OpenMP][MLIR][Driver][bbc] Add -fopenmp-is-device flag to Flang -fc1 & the bbc tool, and omp.is_device attribute
Adds the -fopenmp-is-device flag to bbc and Flang's -fc1 (but not flang-new) and in addition adds an omp.is_device attribute onto the module when fopenmp is passed, this is a boolean attribute that is set to false or true dependent on if fopenmp-is-device is specified alongside the fopenmp flag on the commandline when invoking flang or bbc.

Reviewers:
awarzynski
kiranchandramohan

Differential Revision: https://reviews.llvm.org/D144864
2023-03-07 12:57:58 -06:00
Ethan Luis McDonough
ce3a1c59e1
[flang] Handle unsupported warning flags
This PR makes flang emit a warning when the user passes an unsupported gfortran warning flag in as a CLI arg.  This PR also checks each `-W` argument instead of just looking at the last one passed in.

Reviewed By: awarzynski

Differential Revision: https://reviews.llvm.org/D143301
2023-02-21 16:14:19 -06:00
Mark Danial
1360bfb05b [Flang] Add user option -funderscoring/-fnounderscoring to control trailing underscore added to external names
This patch adds user option -funderscoring/-fnounderscoring  to control the trailing underscore being appended to external names (e.g. procedure names, common block names). The option in gfortran is documented in https://gcc.gnu.org/onlinedocs/gfortran/Code-Gen-Options.html.

Reviewed By: clementval

Differential Revision: https://reviews.llvm.org/D140795
2023-02-21 16:34:26 -05:00
Archibald Elliott
d768bf994f [NFC][TargetParser] Replace uses of llvm/Support/Host.h
The forwarding header is left in place because of its use in
`polly/lib/External/isl/interface/extract_interface.cc`, but I have
added a GCC warning about the fact it is deprecated, because it is used
in `isl` from where it is included by Polly.
2023-02-10 09:59:46 +00:00
Archibald Elliott
62c7f035b4 [NFC][TargetParser] Remove llvm/ADT/Triple.h
I also ran `git clang-format` to get the headers in the right order for
the new location, which has changed the order of other headers in two
files.
2023-02-07 12:39:46 +00:00
Tom Eccles
bf81ba3726 [flang] add -fstack-arrays flag
The implementation of -fstack-arrays was added in
https://reviews.llvm.org/D140415

The new macro BoolOptionWithoutMarshalling in Options.td avoids
generating code to store the flags in clang data structures. For
example, writing something like

  defm stack_arrays : BoolOption<"f", "stack-arrays",
                                 CodeGenOpts<"StackArrays">, [...]

Would generate code referring to `clang::CodeGenOpts::StackArrays`, which
does not exist.

Differential Revision: https://reviews.llvm.org/D140972
2023-02-07 10:27:52 +00:00
Jan Sjodin
40d8c0666f [flang][driver] Add support for -embed-offload-object flag in flang
This patch adds support for the -embed-offload-object flag to embed offloading
binaries in host code. This flag is identical to the clang flag with the same name.

Differential Revision: https://reviews.llvm.org/D142244

Reviewed By: awarzynski, jhuber6
2023-01-31 10:56:45 -05:00
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
Tom Eccles
e7b6660243 [flang] Add -ffast-math and -Ofast
clang -cc1 accepts -Ofast. I did not add it to flang -fc1 because this
seems redundant because the compiler driver will always resolve -Ofast
into -O3 -ffast-math (I added a test for this).

-menable-infs is removed from the frontend-forwarding test because if
all of the fast-math component flags are present, these will be resolved
into the fast-math flag. Instead -menable-infs is tested in the
fast-math test.

Specifying -ffast-math to the compiler driver causes linker invocations
to include crtfastmath.o.

RFC: https://discourse.llvm.org/t/rfc-the-meaning-of-ofast/66554

Differential Revision: https://reviews.llvm.org/D138675
2022-12-09 19:55:58 +00:00
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
Usman Nadeem
3951a73490 [Flang][Driver] Handle target CPU and features
This patch:

- Adds target-feature and target-cpu to FC1Options.
- Moves getTargetFeatures() from Clang.cpp to CommonArgs.cpp.
- Processes target cpu and features in the flang driver. Right now
  features are only added for AArch64/x86 because I only did basic
  testing on them but it should generally work for others as well.
  Option handling is similar to clang.
- Adds appropriate structures in TargetOptions and passes them to
  the target machine.

What's missing:

- Adding the CPU info and the features as attributes in the LLVM IR
  module.
- Processing target specific flags, e.g. SVE vector bits for AArch64,
  ABI etc.

Differential Revision: https://reviews.llvm.org/D137995

Change-Id: Ib081a74ea98617674845518a5d2754edba596418
2022-12-02 09:37:53 -08:00
Tom Eccles
3a1b409254 [flang] fix unused variables 2022-11-30 10:37:23 +00:00
Tom Eccles
6841c43f36 [flang] Remove warnings that fast-math options are unimplemented
These are now fully implemented, see
https://reviews.llvm.org/D137390
https://reviews.llvm.org/D137391
https://reviews.llvm.org/D137456
https://reviews.llvm.org/D137580
https://reviews.llvm.org/D137602
https://reviews.llvm.org/D138048

These flags are still tested in
flang/test/Driver/frontend-forwarding.f90 and
flang/test/Lower/fast-math-arithmetic.f90

Differential revision: https://reviews.llvm.org/D138907
2022-11-29 17:15:05 +00:00
Valentin Clement
fa3587d63e
[flang] Remove debug option
Remove debug option added by mistake in D138587
2022-11-25 09:30:17 +01:00
Valentin Clement
c1b7e9c962
[flang] Adapt descriptor codegen to support unlimited polymorphic entities
Code generation to create and populate the descriptor (element size and
type code) is based on the boxed result type. This does not work well with
unlimited polymorphic entities since the fir type does not represent what is
actually emboxed or reboxed.
In the case of emboxing, the input type will be used to populate
the descriptor element size and type code.
When reboxing an unlimited polymorphic to a unlimited polymorphic entities, the
element size and type code is retrieve from the input box.

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D138587
2022-11-24 20:47:21 +01:00
Tarun Prabhu
c3821b8d2a [flang] Add -fpass-plugin option to flang
This patch adds the -fpass-plugin option to flang which dynamically loads LLVM
passes from the shared object passed as the argument to the flag. The behavior
of the option is designed to replicate that of the same option in clang and
thus has the same capabilities and limitations.

Features:

  Multiple instances of -fpass-plugin=path-to-file can be specified and each
  of the files will be loaded in that order.

  The flag can be passed to both flang-new and flang-new -fc1.

  The flag will be listed when the -help flag is passed to both flang-new and
  flang-new -fc1. It will also be listed when the --help-hidden flag is passed.

Limitations:

  Dynamically loaded plugins are not supported in clang on Windows and are not
  supported in flang either.

Addenda:

  Some minor stylistic changes are made in the files that were modified to
  enable this functionality. Those changes make the naming of functions more
  consistent, but do not change any functionality that is not directly
  related to enabling -fpass-plugin.

Differential Revision: https://reviews.llvm.org/D129156
2022-11-10 08:03:46 -07:00
Slava Zakharin
3538ca3f1b [flang] Propagate more FastMath flags to lowering.
Plugged in propagation of nnan/nsz/arcp/afn/reassoc related options
to lowering/FirOpBuilder.

Reviewed By: jeanPerier, tblah, awarzynski

Differential Revision: https://reviews.llvm.org/D137580
2022-11-09 15:01:47 -08:00
Fangrui Song
8c2c62282f [Driver] Refactor err_drv_unsupported_option_argument call sites to use llvm::opt::Arg::getSpelling
For `-foo=bar`, getSpelling return `-foo=` which is exactly what we need from
the diagnostic. Drop `-` from the err_drv_unsupported_option_argument template.
This change makes `--` long option diagnostics more convenient.

Reviewed By: lenary

Differential Revision: https://reviews.llvm.org/D137659
2022-11-08 14:39:09 -08:00
Slava Zakharin
8f3f15c1a2 [flang] Configure FirOpBuilder based on math driver options.
Added MathOptionsBase to share fastmath config between different
components. Frontend driver translates LangOptions into MathOptionsBase.
FirConverter configures FirOpBuilder using MathOptionsBase
config passed to it via LoweringOptions.

Depends on D137390

Reviewed By: jeanPerier

Differential Revision: https://reviews.llvm.org/D137391
2022-11-07 09:26:46 -08:00
Tom Eccles
d0d4b63578 [flang] add -f[no-]reciprocal-math
Only add the option processing and store the result. No attributes are
added to FIR yet.

Differential Revision: https://reviews.llvm.org/D137330
2022-11-04 17:22:35 +00:00
Tom Eccles
c4dc3c0294 [flang] Add -f[no-]associative-math and -mreassociate
Only add the option processing and store the result. No attributes are
added to FIR yet.

Clang only forwards -mreassociate
if (AssociativeMath && !SignedZeros && !TrappingMath)

Flang doesn't have -f[no-]trapping-math, so this part of the condition
has been omitted. !TrappingMath is the default.

Differential Revision: https://reviews.llvm.org/D137329
2022-11-04 17:22:35 +00:00
Tom Eccles
b5b8a8cfbe [flang] Add -f[no-]signed-zeros
Only add the option processing and store the result. No attributes are
added to FIR yet.

Differential Revision: https://reviews.llvm.org/D137328
2022-11-04 17:22:34 +00:00
Tom Eccles
36b37a1ed5 [flang] Add -f[no-]approx-func
Only add the option processing and store the result. No attributes are
added to FIR yet.

Differential Revision: https://reviews.llvm.org/D137326
2022-11-04 17:22:34 +00:00
Tom Eccles
b5e93e390c [flang] Add -f[no-]honor-nans and -menable-no-nans
Only add the option processing and store the result. No attributes are
added to FIR yet.

Differential Revision: https://reviews.llvm.org/D137325
2022-11-04 17:22:34 +00:00
Peter Steinfeld
74d5c3c0f0 [Flang] Run clang-format on all flang files
This will make it easier for me to do reviews.

Differential Revision: https://reviews.llvm.org/D137291
2022-11-03 09:26:22 -07:00
Tom Eccles
0fb763e7d0 [flang] Add -f[no-]honor-infinities and -menable-no-infs
Only add the option processing and store the result. No attributes are
added to FIR yet.

This patch follows Clang in forwarding -fno-honor-infinities as
-menable-no-infs.

Reviewed By: kiranchandramohan awarzynski vzakhari

Differential Revision: https://reviews.llvm.org/D137072
2022-11-03 10:38:09 +00:00
Tom Eccles
a784de783a [flang] Add -ffp-contract option processing
Only add the option processing and store the result. No attributes are
added to FIR yet.

Only the "off" and "fast" options are supported. "fast-honor-pragmas" is not applicable because we do not implement `#pragma clang fp contract()` in Fortran [1]. "on" is not supported because it is unclear how to fuse only within individual statements. gfortran also does not implement "on": treating it as an "off".

Currently the default value is "off" to preserve existing behavior. gfortran uses "fast" by default and that may be the right thing for flang-new after further discussion in the future, but that can be changed separately. gfortran's documentation is available [[ https://gcc.gnu.org/onlinedocs/gcc/Optimize-Options.html | here ]].

[1] https://clang.llvm.org/docs/LanguageExtensions.html#extensions-to-specify-floating-point-flags

Reviewed By: vzakhari, awarzynski

Differential Revision: https://reviews.llvm.org/D136080
2022-10-31 11:32:31 +00:00
Valentin Clement
4515dd3495
[flang] Remove debug flag added in D136824 2022-10-27 22:23:40 +02:00
Valentin Clement
ea1e767a06
[flang] Carry dynamic type when emboxing polymorphic pointer
In order to be passed as passed-object in the dynamic dispatch, the
polymorphic pointer entity are emboxed. In this process, the dynamic
type must be preserve and pass to fir.embox as the tdesc operand. This
patch introduce a new ExtendedValue that allow to carry over the
dynamic type when the value is unboxed.

Depends on D136820

Reviewed By: PeteSteinfeld

Differential Revision: https://reviews.llvm.org/D136824
2022-10-27 20:57:09 +02:00
Peter Steinfeld
1cfae76ed9 [Flang] Adjust preprocessing to build modules correctly
Several module files in .../llvm-project/flang/module check for the
existence of the macro "__x86_64__" to conditionally compile Fortran
code.  Unfortunately, this macro was not being defined anywhere.  This
patch fixes that for compilations targeting 64 bit x86 machines.

I made the following changes --
  -- Removed the test for 32 bit X86 targets.  The rest of the compiler and
  runtime do not support X86 32 bits.
  -- Added predefined macros to define "__x86_64__"  and "__x86__64" to
  be 1 when the target architecture is 64 bit x86 and the "-cpp" option
  is on the command line.
  -- Changed the cmake file for creating the Fortran module files to use the
  "-cpp" option so that the macro "__x86_64__" will be defined when building
  the module files.
  -- Added a test.

Differential Revision: https://reviews.llvm.org/D135810
2022-10-14 12:27:48 -07:00
Jonathon Penix
0ec3ac9b7f [Flang] Add -fconvert option to swap endianness for unformatted files.
To accomplish this, this patch creates an optional list of environment
variable default values to be set by the runtime to allow directly using
the existing runtime implementation of FORT_CONVERT for I/O conversions.
2022-10-12 16:57:37 -07:00
Mats Petersson
4d1460c77d Revert "[flang] Add -fpass-plugin option to Flang frontend"
This reverts commit 43fe6f7cc35ded691bbc2fa844086d321e705d46.

Reverting this as CI breaks.

To reproduce, run check-flang, and it will fail with an error saying
.../lib/Bye.so not found in pass-plugin.f90
2022-10-05 19:43:02 +01:00
Tarun Prabhu
43fe6f7cc3 [flang] Add -fpass-plugin option to Flang frontend
Add the -fpass-plugin option to flang which dynamically loads LLVM passes from the
shared object passed as the argument to the flag. The behavior of the option is
designed to replicate that of the same option in clang and thus has the same
capabilities and limitations.

- Multiple instances of -fpass-plugin=path-to-file can be specified and each of the
  files will be loaded in that order.

- The flag can be passed to both flang-new and flang-new -fc1.

Differential Revision: https://reviews.llvm.org/D129156
2022-10-04 17:02:45 -06:00
Peixin Qiao
c4f04a126a [flang] Make real type of kind 10 target dependent
The real(10) is supported on x86_64. On aarch64, the value of
selected_real_kind(16) should be 16 rather than 10 since real(10)
is not supported on x86_64. Previously, the real type support check
is not target dependent. Support it now through the target triple
information.

Reviewed By: clementval

Differential Revision: https://reviews.llvm.org/D134021
2022-10-03 15:24:39 +08:00
Peixin Qiao
3f0ad8558a Revert "[flang] Make real type of kind 10 target dependent"
This reverts commit d11e406e369fc90be5e2e2a0798ea7b7d2625882.
2022-10-02 17:45:03 +08:00
Peixin Qiao
d11e406e36 [flang] Make real type of kind 10 target dependent
The real(10) is supported on x86_64. On aarch64, the value of
selected_real_kind(16) should be 16 rather than 10 since real(10)
is not supported on x86_64. Previously, the real type support check
is not target dependent. Support it now through the target triple
information.

Reviewed By: clementval

Differential Revision: https://reviews.llvm.org/D134021
2022-10-02 10:30:49 +08:00
Kazu Hirata
d0f1283e6b [flang] Simplify string comparisons (NFC)
Identified with readability-string-compare.
2022-08-27 21:21:04 -07:00
Usman Nadeem
ef5ede52ef [Flang][Driver] Add support for PIC
This patch does the following:

 - Consumes the PIC flags (fPIC/fPIE/fropi/frwpi etc) in flang-new.
   tools::ParsePICArgs() in ToolChains/CommonArgs.cpp is used for this.
 - Adds FC1Option to "-mrelocation-model", "-pic-level", and "-pic-is-pie"
   command line options.
 - Adds the above options to flang/Frontend/CodeGenOptions' data structure.
 - Sets the relocation model in the target machine, and
 - Sets module flags for the respective PIC/PIE type in LLVM IR.

I have tried my best to replicate how clang does things.

Differential Revision: https://reviews.llvm.org/D131533

Change-Id: I68fe64910be28147dc5617826641cea71b92d94d
2022-08-22 11:10:42 -07:00
Slava Zakharin
f1eb945f9a [flang] Propagate lowering options from driver.
This commit addresses concerns raised in D129497.

Propagate lowering options from driver to expressions lowering
via AbstractConverter instance. A single use case so far is
using optimized TRANSPOSE lowering with O1/O2/O3.

bbc does not support optimization level switches, so it uses
default LoweringOptions (e.g. optimized TRANSPOSE lowering
is enabled by default, but an engineering -opt-transpose=false
option can still override this).

Differential Revision: https://reviews.llvm.org/D130204
2022-08-05 11:29:45 -07:00
Peixin Qiao
8df63a23d2 [flang] Support the color diagnostics on scanning, parsing, and semantics
The options -f{no-}color-diagnostics have been supported in driver. This
supports the behaviors in scanning, parsing, and semantics, and the
behaviors are exactly the same as the driver.

To illustrate the added behaviour, consider the following input file:
```! file.f90
program m
  integer :: i = k
end
```
In the following invocations, "error: Must be a constant value" _will be_
formatted:
```
$ flang-new file.f90
error: Semantic errors in file.f90
./file.f90:2:18: error: Must be a constant value
    integer :: i = k
```
Note that "error: Semantic errors in file.f90" is also formatted, which
is supported in https://reviews.llvm.org/D126164.

Also note that only "error", "warning" and "portability" are formatted.
Check the following input file:
```! file2.f90
program m
  integer :: i =
end
```
```
$ flang-new test2.f90
error: Could not parse test2.f90
./test2.f90:2:11: error: expected '('
    integer :: i =
            ^
./test2.f90:2:3: in the context: statement function definition
    integer :: i =
    ^
...
```
The "error: Could not parse test2.f90" and "error: expected '('" are
formatted. Others such as "in the context" are not formatted yet, which
may or may not be supported.

Reviewed By: awarzynski

Differential Revision: https://reviews.llvm.org/D126166
2022-07-27 23:45:41 +08:00
Andrzej Warzynski
bbdf5c37e3 [flang][driver] Fix opt-level option parsing
This update makes sure that `flang-new -O2 -O0` will run at `-O0` rather
than `-O2`.

This bug was identified and originally fixed by Vyacheslav Zakharin in
https://reviews.llvm.org/D130035. I've extracted the fix into a separate
patch.

co-authored by: Vyacheslav Zakharin <vyacheslav.p.zakharin@intel.com>

Differential Revision: https://reviews.llvm.org/D130104
2022-07-20 11:14:29 +00:00
Andrzej Warzynski
869385b11c [flang][driver] Add support for -O{0|1|2|3}
This patch adds support for most common optimisation compiler flags:
`-O{0|1|2|3}`. This is implemented in both the compiler and frontend
drivers. At this point, these options are only used to configure the
LLVM optimisation pipelines (aka middle-end). LLVM backend or MLIR/FIR
optimisations are not supported yet.

Previously, the middle-end pass manager was only required when
generating LLVM bitcode (i.e. for `flang-new -c -emit-llvm <file>` or
`flang-new -fc1 -emit-llvm-bc <file>`). With this change, it becomes
required for all frontend actions that are represented as
`CodeGenAction` and `CodeGenAction::executeAction` is refactored
accordingly (in the spirit of better code re-use).

Additionally, the `-fdebug-pass-manager` option is enabled to facilitate
testing. This flag can be used to configure the pass manager to print
the middle-end passes that are being run. Similar option exists in Clang
and the semantics in Flang are identical. This option translates to
extra configuration when setting up the pass manager. This is
implemented in `CodeGenAction::runOptimizationPipeline`.

This patch also adds some bolier plate code to manage code-gen options
("code-gen" refers to generating machine code in LLVM in this context).
This was extracted from Clang. In Clang, it simplifies defining code-gen
options and enables option marshalling. In Flang, option marshalling is
not yet supported (we might do at some point), but being able to
auto-generate some code with macros is beneficial. This will become
particularly apparent when we start adding more options (at least in
Clang, the list of code-gen options is rather long).

Differential Revision: https://reviews.llvm.org/D128043
2022-06-27 10:06:14 +00:00