[flang] Adding support of -fcoarray flang and init PRIF

[JDPailleux]

In relation to the approval and merge of the PRIF specification about multi-image features in Flang, here is a first PR to add support for the -fcoarray compilation flag and the initialization of the PRIF environment.
Other PRs will follow for adding support of lowering to PRIF.

[llvmbot]

@llvm/pr-subscribers-clang-driver
@llvm/pr-subscribers-flang-fir-hlfir

@llvm/pr-subscribers-flang-driver

Author: Jean-Didier PAILLEUX (JDPailleux)

Changes

In relation to the approval and merge of the PRIF specification about multi-image features in Flang, here is a first PR to add support for the -fcoarray compilation flag and the initialization of the PRIF environment.
Other PRs will follow for adding support of lowering to PRIF.

---

Full diff: https://github.com/llvm/llvm-project/pull/151675.diff

11 Files Affected:

• (modified) clang/include/clang/Driver/Options.td (+9-1)
• (modified) clang/lib/Driver/ToolChains/Flang.cpp (+2)
• (modified) flang/include/flang/Lower/LoweringOptions.def (+4)
• (added) flang/include/flang/Optimizer/Builder/Runtime/Coarray.h (+50)
• (modified) flang/include/flang/Optimizer/Builder/Runtime/Main.h (+1-1)
• (modified) flang/lib/Frontend/CompilerInvocation.cpp (+4)
• (modified) flang/lib/Lower/Bridge.cpp (+2-1)
• (modified) flang/lib/Optimizer/Builder/CMakeLists.txt (+1)
• (added) flang/lib/Optimizer/Builder/Runtime/Coarray.cpp (+35)
• (modified) flang/lib/Optimizer/Builder/Runtime/Main.cpp (+5-2)
• (added) flang/test/Lower/Coarray/coarray-init.f90 (+11)

diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index eb53821bbf4d5..a8611a8114de1 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -6962,7 +6962,6 @@ def static_libgfortran : Flag<["-"], "static-libgfortran">, Group<gfortran_Group
 // "f" options with values for gfortran.
 def fblas_matmul_limit_EQ : Joined<["-"], "fblas-matmul-limit=">, Group<gfortran_Group>;
 def fcheck_EQ : Joined<["-"], "fcheck=">, Group<gfortran_Group>;
-def fcoarray_EQ : Joined<["-"], "fcoarray=">, Group<gfortran_Group>;
 def ffpe_trap_EQ : Joined<["-"], "ffpe-trap=">, Group<gfortran_Group>;
 def ffree_line_length_VALUE : Joined<["-"], "ffree-line-length-">, Group<gfortran_Group>;
 def finit_character_EQ : Joined<["-"], "finit-character=">, Group<gfortran_Group>;
@@ -8670,6 +8669,15 @@ def fopenmp_host_ir_file_path : Separate<["-"], "fopenmp-host-ir-file-path">,
 
 } // let Visibility = [CC1Option, FC1Option]
 
+//===----------------------------------------------------------------------===//
+// Coarray Options
+//===----------------------------------------------------------------------===//
+
+def fcoarray : Flag<["-"], "fcoarray">,
+               Group<f_Group>,
+               Visibility<[FlangOption, FC1Option]>,
+               HelpText<"Enable Coarray features">;
+
 //===----------------------------------------------------------------------===//
 // SYCL Options
 //===----------------------------------------------------------------------===//
diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
index 7ab41e9b85a04..d5074818de27c 100644
--- a/clang/lib/Driver/ToolChains/Flang.cpp
+++ b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -178,6 +178,8 @@ void Flang::addCodegenOptions(const ArgList &Args,
        options::OPT_fstack_repack_arrays, options::OPT_fno_stack_repack_arrays,
        options::OPT_ftime_report, options::OPT_ftime_report_EQ,
        options::OPT_funroll_loops, options::OPT_fno_unroll_loops});
+  if (Args.hasArg(clang::driver::options::OPT_fcoarray))
+    CmdArgs.push_back("-fcoarray");
 }
 
 void Flang::addPicOptions(const ArgList &Args, ArgStringList &CmdArgs) const {
diff --git a/flang/include/flang/Lower/LoweringOptions.def b/flang/include/flang/Lower/LoweringOptions.def
index 8135704971aa4..4b70d2df9c2f4 100644
--- a/flang/include/flang/Lower/LoweringOptions.def
+++ b/flang/include/flang/Lower/LoweringOptions.def
@@ -74,5 +74,9 @@ ENUM_LOWERINGOPT(SkipExternalRttiDefinition, unsigned, 1, 0)
 /// If false, lower to the complex dialect of MLIR.
 /// On by default.
 ENUM_LOWERINGOPT(ComplexDivisionToRuntime, unsigned, 1, 1)
+
+/// Enable coarrays feature.
+ENUM_LOWERINGOPT(CoarrayFeature, unsigned, 1, 0)
+
 #undef LOWERINGOPT
 #undef ENUM_LOWERINGOPT
diff --git a/flang/include/flang/Optimizer/Builder/Runtime/Coarray.h b/flang/include/flang/Optimizer/Builder/Runtime/Coarray.h
new file mode 100644
index 0000000000000..83561fffc3ff0
--- /dev/null
+++ b/flang/include/flang/Optimizer/Builder/Runtime/Coarray.h
@@ -0,0 +1,50 @@
+//===-- Coarray.h -- generate Coarray intrinsics runtime calls --*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRAN_OPTIMIZER_BUILDER_RUNTIME_COARRAY_H
+#define FORTRAN_OPTIMIZER_BUILDER_RUNTIME_COARRAY_H
+
+#include "flang/Lower/AbstractConverter.h"
+#include "mlir/Dialect/Func/IR/FuncOps.h"
+
+namespace fir {
+class ExtendedValue;
+class FirOpBuilder;
+} // namespace fir
+
+namespace fir::runtime {
+
+// Get the function type for a prif subroutine with a variable number of
+// arguments
+#define PRIF_FUNCTYPE(...)                                                     \
+  mlir::FunctionType::get(builder.getContext(), /*inputs*/ {__VA_ARGS__},      \
+                          /*result*/ {})
+
+// Default prefix for type of PRIF compiled with LLVM
+#define PRIFTYPE_PREFIX "_QM__prifT"
+#define PRIFTYPE(fmt)                                                          \
+  []() {                                                                       \
+    std::ostringstream oss;                                                    \
+    oss << PRIFTYPE_PREFIX << fmt;                                             \
+    return oss.str();                                                          \
+  }()
+
+// Default prefix for subroutines of PRIF compiled with LLVM
+#define PRIFSUB_PREFIX "_QMprifPprif_"
+#define PRIFNAME_SUB(fmt)                                                      \
+  []() {                                                                       \
+    std::ostringstream oss;                                                    \
+    oss << PRIFSUB_PREFIX << fmt;                                              \
+    return oss.str();                                                          \
+  }()
+
+/// Generate Call to runtime prif_init
+mlir::Value genInitCoarray(fir::FirOpBuilder &builder, mlir::Location loc);
+
+} // namespace fir::runtime
+#endif // FORTRAN_OPTIMIZER_BUILDER_RUNTIME_COARRAY_H
diff --git a/flang/include/flang/Optimizer/Builder/Runtime/Main.h b/flang/include/flang/Optimizer/Builder/Runtime/Main.h
index a0586deade42a..d4067b367f73e 100644
--- a/flang/include/flang/Optimizer/Builder/Runtime/Main.h
+++ b/flang/include/flang/Optimizer/Builder/Runtime/Main.h
@@ -25,7 +25,7 @@ namespace fir::runtime {
 
 void genMain(fir::FirOpBuilder &builder, mlir::Location loc,
              const std::vector<Fortran::lower::EnvironmentDefault> &defs,
-             bool initCuda = false);
+             bool initCuda = false, bool initCoarrayEnv = false);
 }
 
 #endif // FORTRAN_OPTIMIZER_BUILDER_RUNTIME_MAIN_H
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 111c5aa48726f..88065a5b4fb2f 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -1152,6 +1152,10 @@ static bool parseDialectArgs(CompilerInvocation &res, llvm::opt::ArgList &args,
       diags.Report(diagID);
     }
   }
+  // -fcoarray
+  if (args.hasArg(clang::driver::options::OPT_fcoarray))
+    res.getLoweringOpts().setCoarrayFeature(1);
+
   return diags.getNumErrors() == numErrorsBefore;
 }
 
diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index ac3669c907fbc..9d6eed1d4822d 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -475,7 +475,8 @@ class FirConverter : public Fortran::lower::AbstractConverter {
         fir::runtime::genMain(*builder, toLocation(),
                               bridge.getEnvironmentDefaults(),
                               getFoldingContext().languageFeatures().IsEnabled(
-                                  Fortran::common::LanguageFeature::CUDA));
+                                  Fortran::common::LanguageFeature::CUDA),
+                              getLoweringOptions().getCoarrayFeature());
       });
 
     finalizeOpenMPLowering(globalOmpRequiresSymbol);
diff --git a/flang/lib/Optimizer/Builder/CMakeLists.txt b/flang/lib/Optimizer/Builder/CMakeLists.txt
index 31ae395805faf..8fb36a750d433 100644
--- a/flang/lib/Optimizer/Builder/CMakeLists.txt
+++ b/flang/lib/Optimizer/Builder/CMakeLists.txt
@@ -16,6 +16,7 @@ add_flang_library(FIRBuilder
   Runtime/Allocatable.cpp
   Runtime/ArrayConstructor.cpp
   Runtime/Assign.cpp
+  Runtime/Coarray.cpp
   Runtime/Character.cpp
   Runtime/Command.cpp
   Runtime/CUDA/Descriptor.cpp
diff --git a/flang/lib/Optimizer/Builder/Runtime/Coarray.cpp b/flang/lib/Optimizer/Builder/Runtime/Coarray.cpp
new file mode 100644
index 0000000000000..bcc4d63e22f26
--- /dev/null
+++ b/flang/lib/Optimizer/Builder/Runtime/Coarray.cpp
@@ -0,0 +1,35 @@
+//===-- Coarray.cpp -- runtime API for coarray intrinsics -----------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+
+#include "flang/Optimizer/Builder/Runtime/Coarray.h"
+#include "flang/Optimizer/Builder/FIRBuilder.h"
+#include "flang/Optimizer/Builder/Runtime/RTBuilder.h"
+#include "flang/Optimizer/HLFIR/HLFIROps.h"
+#include "flang/Optimizer/Support/InternalNames.h"
+#include "flang/Semantics/scope.h"
+#include "flang/Semantics/tools.h"
+#include "mlir/Dialect/Func/IR/FuncOps.h"
+#include "mlir/Dialect/LLVMIR/LLVMDialect.h"
+#include "llvm/ADT/TypeSwitch.h"
+
+using namespace Fortran::runtime;
+using namespace Fortran::semantics;
+
+/// Generate Call to runtime prif_init
+mlir::Value fir::runtime::genInitCoarray(fir::FirOpBuilder &builder,
+                                         mlir::Location loc) {
+  mlir::Type i32Ty = builder.getI32Type();
+  mlir::Value result = builder.createTemporary(loc, i32Ty);
+  mlir::FunctionType ftype = PRIF_FUNCTYPE(builder.getRefType(i32Ty));
+  mlir::func::FuncOp funcOp =
+      builder.createFunction(loc, PRIFNAME_SUB("init"), ftype);
+  llvm::SmallVector<mlir::Value> args =
+      fir::runtime::createArguments(builder, loc, ftype, result);
+  builder.create<fir::CallOp>(loc, funcOp, args);
+  return builder.create<fir::LoadOp>(loc, result);
+}
diff --git a/flang/lib/Optimizer/Builder/Runtime/Main.cpp b/flang/lib/Optimizer/Builder/Runtime/Main.cpp
index d35f687167b05..d303e0ad63842 100644
--- a/flang/lib/Optimizer/Builder/Runtime/Main.cpp
+++ b/flang/lib/Optimizer/Builder/Runtime/Main.cpp
@@ -10,6 +10,7 @@
 #include "flang/Lower/EnvironmentDefault.h"
 #include "flang/Optimizer/Builder/BoxValue.h"
 #include "flang/Optimizer/Builder/FIRBuilder.h"
+#include "flang/Optimizer/Builder/Runtime/Coarray.h"
 #include "flang/Optimizer/Builder/Runtime/EnvironmentDefaults.h"
 #include "flang/Optimizer/Builder/Runtime/RTBuilder.h"
 #include "flang/Optimizer/Dialect/FIROps.h"
@@ -23,8 +24,8 @@ using namespace Fortran::runtime;
 /// Create a `int main(...)` that calls the Fortran entry point
 void fir::runtime::genMain(
     fir::FirOpBuilder &builder, mlir::Location loc,
-    const std::vector<Fortran::lower::EnvironmentDefault> &defs,
-    bool initCuda) {
+    const std::vector<Fortran::lower::EnvironmentDefault> &defs, bool initCuda,
+    bool initCoarrayEnv) {
   auto *context = builder.getContext();
   auto argcTy = builder.getDefaultIntegerType();
   auto ptrTy = mlir::LLVM::LLVMPointerType::get(context);
@@ -69,6 +70,8 @@ void fir::runtime::genMain(
         loc, RTNAME_STRING(CUFInit), mlir::FunctionType::get(context, {}, {}));
     fir::CallOp::create(builder, loc, initFn);
   }
+  if (initCoarrayEnv)
+    fir::runtime::genInitCoarray(builder, loc);
 
   fir::CallOp::create(builder, loc, qqMainFn);
   fir::CallOp::create(builder, loc, stopFn);
diff --git a/flang/test/Lower/Coarray/coarray-init.f90 b/flang/test/Lower/Coarray/coarray-init.f90
new file mode 100644
index 0000000000000..055bc0fc4da72
--- /dev/null
+++ b/flang/test/Lower/Coarray/coarray-init.f90
@@ -0,0 +1,11 @@
+! RUN: %flang_fc1 -emit-hlfir -fcoarray %s -o - | FileCheck %s --check-prefixes=ALL,COARRAY
+! RUN: %flang_fc1 -emit-hlfir %s -o - | FileCheck %s --check-prefixes=ALL,NOCOARRAY
+
+program test_init
+
+end 
+
+! ALL-LABEL: func.func @main
+! ALL: fir.call @_FortranAProgramStart
+! COARRAY: fir.call @_QMprifPprif_init(%[[ARG:.*]]) fastmath<contract> : (!fir.ref<i32>) -> ()
+! NOCOARRAY-NOT: fir.call @_QMprifPprif_init(%[[ARG:.*]]) fastmath<contract> : (!fir.ref<i32>) -> ()