[flang-commits] [clang] [flang] [Flang][OpenMP] Add -fdo-concurrent alias for -fdo-concurrent-to-openmp (PR #195007)
Kareem Ergawy via flang-commits
flang-commits at lists.llvm.org
Wed Apr 29 22:56:47 PDT 2026
https://github.com/ergawy updated https://github.com/llvm/llvm-project/pull/195007
>From 2fa34a84e09c484cb4a5b88983f1bbcdea3a6167 Mon Sep 17 00:00:00 2001
From: Kareem Ergawy <kareem.ergawy at amd.com>
Date: Wed, 29 Apr 2026 17:40:47 +0200
Subject: [PATCH] [Flang][OpenMP] Add -fdo-concurrent alias for
-fdo-concurrent-to-openmp
Adds the shorter -fdo-concurrent alias to map DO CONCURRENT loops to
OpenMP.
Co-authored-by: Gemini 3.1 Pro
---
clang/include/clang/Options/Options.td | 3 ++-
clang/lib/Driver/ToolChains/Flang.cpp | 9 ++++++--
flang/docs/DoConcurrentConversionToOpenMP.md | 8 +++++--
flang/lib/Frontend/CompilerInvocation.cpp | 3 +--
.../test/Driver/do_concurrent_to_omp_cli.f90 | 23 ++++++++++++++-----
flang/tools/bbc/bbc.cpp | 6 ++++-
6 files changed, 38 insertions(+), 14 deletions(-)
diff --git a/clang/include/clang/Options/Options.td b/clang/include/clang/Options/Options.td
index c16c41ad4057d..6403453ccc5b4 100644
--- a/clang/include/clang/Options/Options.td
+++ b/clang/include/clang/Options/Options.td
@@ -7768,9 +7768,10 @@ defm unsafe_cray_pointers : BoolOptionWithoutMarshalling<"f", "unsafe-cray-point
def fhermetic_module_files : Flag<["-"], "fhermetic-module-files">, Group<f_Group>,
HelpText<"Emit hermetic module files (no nested USE association)">;
-def fdo_concurrent_to_openmp_EQ : Joined<["-"], "fdo-concurrent-to-openmp=">,
+def fdo_concurrent_EQ : Joined<["-"], "fdo-concurrent=">,
HelpText<"Try to map `do concurrent` loops to OpenMP [none|host|device]">,
Values<"none, host, device">;
+def fdo_concurrent_to_openmp_EQ : Joined<["-"], "fdo-concurrent-to-openmp=">, Flags<[HelpHidden]>, HelpText<"Alias for -fdo-concurrent">, Alias<fdo_concurrent_EQ>;
} // let Visibility = [FC1Option, FlangOption]
def J : JoinedOrSeparate<["-"], "J">,
diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
index ce503b74295e4..bfd9b24c40c55 100644
--- a/clang/lib/Driver/ToolChains/Flang.cpp
+++ b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -249,10 +249,15 @@ void Flang::addCodegenOptions(const ArgList &Args,
<< "-frepack-arrays-contiguity=" << arg;
}
+ // -fdo-concurrent and -fdo-concurrent-to-openmp are aliases. Make sure the
+ // correct alias (spelling) is added to the list of command arguments.
+ if (const Arg *A = Args.getLastArg(options::OPT_fdo_concurrent_EQ)) {
+ CmdArgs.push_back(Args.MakeArgString(A->getAsString(Args)));
+ }
+
Args.addAllArgs(
CmdArgs,
- {options::OPT_fdo_concurrent_to_openmp_EQ,
- options::OPT_flang_experimental_hlfir,
+ {options::OPT_flang_experimental_hlfir,
options::OPT_flang_deprecated_no_hlfir,
options::OPT_fno_ppc_native_vec_elem_order,
options::OPT_fppc_native_vec_elem_order, options::OPT_finit_global_zero,
diff --git a/flang/docs/DoConcurrentConversionToOpenMP.md b/flang/docs/DoConcurrentConversionToOpenMP.md
index 78c5eb30cceb7..162dab9f4340d 100644
--- a/flang/docs/DoConcurrentConversionToOpenMP.md
+++ b/flang/docs/DoConcurrentConversionToOpenMP.md
@@ -27,7 +27,7 @@ are:
## Usage
In order to enable `do concurrent` to OpenMP mapping, `flang` adds a new
-compiler flag: `-fdo-concurrent-to-openmp`. This flag has 3 possible values:
+compiler flag: `-fdo-concurrent` (and its alias `-fdo-concurrent-to-openmp`). This flag has 3 possible values:
1. `host`: this maps `do concurrent` loops to run in parallel on the host CPU.
This maps such loops to the equivalent of `omp parallel do`.
2. `device`: this maps `do concurrent` loops to run in parallel on a target device.
@@ -36,10 +36,14 @@ compiler flag: `-fdo-concurrent-to-openmp`. This flag has 3 possible values:
3. `none`: this disables `do concurrent` mapping altogether. In that case, such
loops are emitted as sequential loops.
-The `-fdo-concurrent-to-openmp` compiler switch is currently available only when
+The `-fdo-concurrent` (or `-fdo-concurrent-to-openmp`) compiler switch is currently available only when
OpenMP is also enabled. So you need to provide the following options to flang in
order to enable it:
```
+flang ... -fopenmp -fdo-concurrent=[host|device|none] ...
+```
+or using the alias:
+```
flang ... -fopenmp -fdo-concurrent-to-openmp=[host|device|none] ...
```
For mapping to device, the target device architecture must be specified as well.
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index a1508f40bf490..2ec488983de40 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -179,8 +179,7 @@ static bool parseDebugArgs(Fortran::frontend::CodeGenOptions &opts,
static bool parseDoConcurrentMapping(Fortran::frontend::CodeGenOptions &opts,
llvm::opt::ArgList &args,
clang::DiagnosticsEngine &diags) {
- llvm::opt::Arg *arg =
- args.getLastArg(clang::options::OPT_fdo_concurrent_to_openmp_EQ);
+ llvm::opt::Arg *arg = args.getLastArg(clang::options::OPT_fdo_concurrent_EQ);
if (!arg)
return true;
diff --git a/flang/test/Driver/do_concurrent_to_omp_cli.f90 b/flang/test/Driver/do_concurrent_to_omp_cli.f90
index 723f148d2c371..079c4b7d90a6b 100644
--- a/flang/test/Driver/do_concurrent_to_omp_cli.f90
+++ b/flang/test/Driver/do_concurrent_to_omp_cli.f90
@@ -2,24 +2,35 @@
! RUN: %flang --help | FileCheck %s --check-prefix=FLANG
-! FLANG: -fdo-concurrent-to-openmp=<value>
-! FLANG-NEXT: Try to map `do concurrent` loops to OpenMP [none|host|device]
+! FLANG: -fdo-concurrent=<value>
+! FLANG-SAME: Try to map `do concurrent` loops to OpenMP [none|host|device]
! RUN: bbc --help | FileCheck %s --check-prefix=BBC
-! BBC: -fdo-concurrent-to-openmp=<string>
+! BBC: -fdo-concurrent=<string>
! BBC-SAME: Try to map `do concurrent` loops to OpenMP [none|host|device]
-! RUN: %flang -c -fdo-concurrent-to-openmp=host %s 2>&1 \
+! RUN: %flang -c -fdo-concurrent=host %s 2>&1 \
! RUN: | FileCheck %s --check-prefix=OPT
! OPT: warning: OpenMP is required for lowering `do concurrent` loops to OpenMP.
! OPT-SAME: Enable OpenMP using `-fopenmp`.
-! RUN: not %flang -c -fopenmp -fdo-concurrent-to-openmp=devic,e %s 2>&1 \
+! RUN: not %flang -c -fopenmp -fdo-concurrent=devic,e %s 2>&1 \
! RUN: | FileCheck %s --check-prefix=BADVAL
-! BADVAL: error: invalid value 'devic,e' in '-fdo-concurrent-to-openmp{{.*}}'
+! BADVAL: error: invalid value 'devic,e' in '-fdo-concurrent{{.*}}'
+
+! RUN: %flang -c -fdo-concurrent-to-openmp=host %s 2>&1 \
+! RUN: | FileCheck %s --check-prefix=OPT-ALIAS
+
+! OPT-ALIAS: warning: OpenMP is required for lowering `do concurrent` loops to OpenMP.
+! OPT-ALIAS-SAME: Enable OpenMP using `-fopenmp`.
+
+! RUN: not %flang -c -fopenmp -fdo-concurrent-to-openmp=devic,e %s 2>&1 \
+! RUN: | FileCheck %s --check-prefix=BADVAL-ALIAS
+
+! BADVAL-ALIAS: error: invalid value 'devic,e' in '-fdo-concurrent-to-openmp{{.*}}'
program test_cli
end program
diff --git a/flang/tools/bbc/bbc.cpp b/flang/tools/bbc/bbc.cpp
index a21865f9c5ffe..b7b7e71afbb32 100644
--- a/flang/tools/bbc/bbc.cpp
+++ b/flang/tools/bbc/bbc.cpp
@@ -145,11 +145,15 @@ static llvm::cl::opt<bool>
llvm::cl::init(false));
static llvm::cl::opt<std::string> enableDoConcurrentToOpenMPConversion(
- "fdo-concurrent-to-openmp",
+ "fdo-concurrent",
llvm::cl::desc(
"Try to map `do concurrent` loops to OpenMP [none|host|device]"),
llvm::cl::init("none"));
+static llvm::cl::alias enableDoConcurrentToOpenMPConversionAlias(
+ "fdo-concurrent-to-openmp", llvm::cl::desc("Alias for -fdo-concurrent"),
+ llvm::cl::aliasopt(enableDoConcurrentToOpenMPConversion), llvm::cl::Hidden);
+
static llvm::cl::opt<bool>
enableOpenMPGPU("fopenmp-is-gpu",
llvm::cl::desc("enable openmp GPU target codegen"),
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