[flang-commits] [clang] [flang] [mlir] [flang][flang-driver] atomic control support (PR #143441)
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Mon Jun 9 14:02:54 PDT 2025
llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT-->
@llvm/pr-subscribers-flang-driver
Author: Anchu Rajendran S (anchuraj)
<details>
<summary>Changes</summary>
Atomic Control Options are used to specify architectural characteristics to help lowering of atomic operations. The options used are:
`-f[no-]atomic-remote-memory`, `-f[no-]atomic-fine-grained-memory`,
`-f[no-]atomic-ignore-denormal-mode`.
Legacy option `-m[no-]unsafe-fp-atomics` is aliased to
`-f[no-]ignore-denormal-mode`.
More details can be found in https://github.com/llvm/llvm-project/pull/102569. This PR implements the frontend support for these options with OpenMP atomic in flang
---
Full diff: https://github.com/llvm/llvm-project/pull/143441.diff
11 Files Affected:
- (modified) clang/include/clang/Driver/Options.td (+11-11)
- (modified) flang/include/flang/Frontend/TargetOptions.h (+5)
- (modified) flang/include/flang/Optimizer/Dialect/Support/FIRContext.h (+14)
- (modified) flang/lib/Frontend/CompilerInvocation.cpp (+12)
- (modified) flang/lib/Lower/Bridge.cpp (+6)
- (modified) flang/lib/Lower/OpenMP/OpenMP.cpp (+6-1)
- (modified) flang/lib/Optimizer/Dialect/Support/FIRContext.cpp (+40)
- (added) flang/test/Lower/OpenMP/atomic-control-options.f90 (+37)
- (modified) mlir/include/mlir/Dialect/OpenMP/OpenMPAttrDefs.td (+14)
- (modified) mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td (+5-3)
- (modified) mlir/test/Dialect/OpenMP/ops.mlir (+9)
``````````diff
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index fd6deb22d404e..c6d8f9106341a 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -2299,21 +2299,21 @@ def fsymbol_partition_EQ : Joined<["-"], "fsymbol-partition=">, Group<f_Group>,
defm atomic_remote_memory : BoolFOption<"atomic-remote-memory",
LangOpts<"AtomicRemoteMemory">, DefaultFalse,
- PosFlag<SetTrue, [], [ClangOption, CC1Option], "May have">,
- NegFlag<SetFalse, [], [ClangOption], "Assume no">,
- BothFlags<[], [ClangOption], " atomic operations on remote memory">>;
+ PosFlag<SetTrue, [], [ClangOption, CC1Option, FlangOption, FC1Option], "May have">,
+ NegFlag<SetFalse, [], [ClangOption, FlangOption], "Assume no">,
+ BothFlags<[], [ClangOption, FlangOption], " atomic operations on remote memory">>;
defm atomic_fine_grained_memory : BoolFOption<"atomic-fine-grained-memory",
LangOpts<"AtomicFineGrainedMemory">, DefaultFalse,
- PosFlag<SetTrue, [], [ClangOption, CC1Option], "May have">,
- NegFlag<SetFalse, [], [ClangOption], "Assume no">,
- BothFlags<[], [ClangOption], " atomic operations on fine-grained memory">>;
+ PosFlag<SetTrue, [], [ClangOption, CC1Option, FlangOption, FC1Option], "May have">,
+ NegFlag<SetFalse, [], [ClangOption, FlangOption], "Assume no">,
+ BothFlags<[], [ClangOption, FlangOption], " atomic operations on fine-grained memory">>;
defm atomic_ignore_denormal_mode : BoolFOption<"atomic-ignore-denormal-mode",
LangOpts<"AtomicIgnoreDenormalMode">, DefaultFalse,
- PosFlag<SetTrue, [], [ClangOption, CC1Option], "Allow">,
- NegFlag<SetFalse, [], [ClangOption], "Disallow">,
- BothFlags<[], [ClangOption], " atomic operations to ignore denormal mode">>;
+ PosFlag<SetTrue, [], [ClangOption, CC1Option, FlangOption, FC1Option], "Allow">,
+ NegFlag<SetFalse, [], [ClangOption, FlangOption], "Disallow">,
+ BothFlags<[], [ClangOption, FlangOption], " atomic operations to ignore denormal mode">>;
defm memory_profile : OptInCC1FFlag<"memory-profile", "Enable", "Disable", " heap memory profiling">;
def fmemory_profile_EQ : Joined<["-"], "fmemory-profile=">,
@@ -5270,9 +5270,9 @@ defm amdgpu_precise_memory_op
" precise memory mode (AMDGPU only)">;
def munsafe_fp_atomics : Flag<["-"], "munsafe-fp-atomics">,
- Visibility<[ClangOption, CC1Option]>, Alias<fatomic_ignore_denormal_mode>;
+ Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>, Alias<fatomic_ignore_denormal_mode>;
def mno_unsafe_fp_atomics : Flag<["-"], "mno-unsafe-fp-atomics">,
- Visibility<[ClangOption]>, Alias<fno_atomic_ignore_denormal_mode>;
+ Visibility<[ClangOption, FlangOption]>, Alias<fno_atomic_ignore_denormal_mode>;
def faltivec : Flag<["-"], "faltivec">, Group<f_Group>;
def fno_altivec : Flag<["-"], "fno-altivec">, Group<f_Group>;
diff --git a/flang/include/flang/Frontend/TargetOptions.h b/flang/include/flang/Frontend/TargetOptions.h
index 002d8d158abd4..26256fd775f11 100644
--- a/flang/include/flang/Frontend/TargetOptions.h
+++ b/flang/include/flang/Frontend/TargetOptions.h
@@ -53,6 +53,11 @@ class TargetOptions {
/// Print verbose assembly
bool asmVerbose = false;
+
+ /// Atomic Control Options for AMD GPU
+ bool amdgpuIgnoreDenormalMode = false;
+ bool amdgpuRemoteMemory = false;
+ bool amdgpuFineGrainedMemory = false;
};
} // end namespace Fortran::frontend
diff --git a/flang/include/flang/Optimizer/Dialect/Support/FIRContext.h b/flang/include/flang/Optimizer/Dialect/Support/FIRContext.h
index 2df14f83c11e1..ac563bcc402c7 100644
--- a/flang/include/flang/Optimizer/Dialect/Support/FIRContext.h
+++ b/flang/include/flang/Optimizer/Dialect/Support/FIRContext.h
@@ -58,10 +58,24 @@ void setTargetCPU(mlir::ModuleOp mod, llvm::StringRef cpu);
/// Get the target CPU string from the Module or return a null reference.
llvm::StringRef getTargetCPU(mlir::ModuleOp mod);
+// Setters and Getters for atomic control options
+void setAmdgpuIgnoreDenormalMode(mlir::ModuleOp mod);
+bool getAmdgpuIgnoreDenormalMode(mlir::ModuleOp mod);
+void setAmdgpuFineGrainedMemory(mlir::ModuleOp mod);
+bool getAmdgpuFineGrainedMemory(mlir::ModuleOp mod);
+void setAmdgpuRemoteMemory(mlir::ModuleOp mod);
+bool getAmdgpuRemoteMemory(mlir::ModuleOp mod);
+
/// Set the tune CPU for the module. `cpu` must not be deallocated while
/// module `mod` is still live.
void setTuneCPU(mlir::ModuleOp mod, llvm::StringRef cpu);
+// set Atomic control options for amd gpu.
+void setAmdgpuAtomicControlOptions(mlir::ModuleOp mod,
+ bool amdgpuIgnoreDenormalMode,
+ bool amdgpuNoFineGrainedMemory,
+ bool amdgpuNoRemoteMemory);
+
/// Get the tune CPU string from the Module or return a null reference.
llvm::StringRef getTuneCPU(mlir::ModuleOp mod);
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index 89aaee9f13853..78d44d76744dc 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -494,6 +494,18 @@ static void parseTargetArgs(TargetOptions &opts, llvm::opt::ArgList &args) {
args.getLastArg(clang::driver::options::OPT_triple))
opts.triple = a->getValue();
+ if (llvm::Triple(opts.triple).isAMDGPU()) {
+ opts.amdgpuIgnoreDenormalMode = args.hasFlag(
+ clang::driver::options::OPT_fatomic_ignore_denormal_mode,
+ clang::driver::options::OPT_fno_atomic_ignore_denormal_mode, false);
+ opts.amdgpuFineGrainedMemory = args.hasFlag(
+ clang::driver::options::OPT_fatomic_fine_grained_memory,
+ clang::driver::options::OPT_fno_atomic_fine_grained_memory, false);
+ opts.amdgpuRemoteMemory = args.hasFlag(
+ clang::driver::options::OPT_fatomic_remote_memory,
+ clang::driver::options::OPT_fno_atomic_remote_memory, false);
+ }
+
if (const llvm::opt::Arg *a =
args.getLastArg(clang::driver::options::OPT_target_cpu))
opts.cpu = a->getValue();
diff --git a/flang/lib/Lower/Bridge.cpp b/flang/lib/Lower/Bridge.cpp
index 64b16b3abe991..b045556565613 100644
--- a/flang/lib/Lower/Bridge.cpp
+++ b/flang/lib/Lower/Bridge.cpp
@@ -6648,6 +6648,12 @@ Fortran::lower::LoweringBridge::LoweringBridge(
fir::setKindMapping(*module, kindMap);
fir::setTargetCPU(*module, targetMachine.getTargetCPU());
fir::setTuneCPU(*module, targetOpts.cpuToTuneFor);
+ if (targetOpts.amdgpuIgnoreDenormalMode)
+ fir::setAmdgpuIgnoreDenormalMode(*module);
+ if (targetOpts.amdgpuFineGrainedMemory)
+ fir::setAmdgpuFineGrainedMemory(*module);
+ if (targetOpts.amdgpuRemoteMemory)
+ fir::setAmdgpuRemoteMemory(*module);
fir::setTargetFeatures(*module, targetMachine.getTargetFeatureString());
fir::support::setMLIRDataLayout(*module, targetMachine.createDataLayout());
fir::setIdent(*module, Fortran::common::getFlangFullVersion());
diff --git a/flang/lib/Lower/OpenMP/OpenMP.cpp b/flang/lib/Lower/OpenMP/OpenMP.cpp
index 6892e571e62a3..bd09073100f1d 100644
--- a/flang/lib/Lower/OpenMP/OpenMP.cpp
+++ b/flang/lib/Lower/OpenMP/OpenMP.cpp
@@ -2911,8 +2911,13 @@ static void genAtomicUpdateStatement(
if (rightHandClauseList)
genOmpAtomicHintAndMemoryOrderClauses(converter, *rightHandClauseList, hint,
memoryOrder);
+ auto module = firOpBuilder.getModule();
+ auto atomicControlAttr = mlir::omp::AtomicControlAttr::get(
+ firOpBuilder.getContext(), fir::getAmdgpuIgnoreDenormalMode(module),
+ fir::getAmdgpuFineGrainedMemory(module),
+ fir::getAmdgpuRemoteMemory(module));
atomicUpdateOp = firOpBuilder.create<mlir::omp::AtomicUpdateOp>(
- currentLocation, lhsAddr, hint, memoryOrder);
+ currentLocation, lhsAddr, atomicControlAttr, hint, memoryOrder);
processOmpAtomicTODO(varType, loc);
diff --git a/flang/lib/Optimizer/Dialect/Support/FIRContext.cpp b/flang/lib/Optimizer/Dialect/Support/FIRContext.cpp
index 01c0be66d1ecc..b961793dbdfd5 100644
--- a/flang/lib/Optimizer/Dialect/Support/FIRContext.cpp
+++ b/flang/lib/Optimizer/Dialect/Support/FIRContext.cpp
@@ -88,6 +88,46 @@ void fir::setTuneCPU(mlir::ModuleOp mod, llvm::StringRef cpu) {
mod->setAttr(tuneCpuName, mlir::StringAttr::get(ctx, cpu));
}
+static constexpr const char *amdgpuIgnoreDenormalModeName =
+ "fir.amdgpu.ignore.denormal.mode";
+void fir::setAmdgpuIgnoreDenormalMode(mlir::ModuleOp mod) {
+ auto *ctx = mod.getContext();
+ mod->setAttr(amdgpuIgnoreDenormalModeName, mlir::UnitAttr::get(ctx));
+}
+
+bool fir::getAmdgpuIgnoreDenormalMode(mlir::ModuleOp mod) {
+ if (auto attr =
+ mod->getAttrOfType<mlir::UnitAttr>(amdgpuIgnoreDenormalModeName))
+ return true;
+ return false;
+}
+
+static constexpr const char *amdgpuFineGrainedMemoryName =
+ "fir.amdgpu.fine.grained.memory";
+void fir::setAmdgpuFineGrainedMemory(mlir::ModuleOp mod) {
+ auto *ctx = mod.getContext();
+ mod->setAttr(amdgpuFineGrainedMemoryName, mlir::UnitAttr::get(ctx));
+}
+
+bool fir::getAmdgpuFineGrainedMemory(mlir::ModuleOp mod) {
+ if (auto attr =
+ mod->getAttrOfType<mlir::UnitAttr>(amdgpuFineGrainedMemoryName))
+ return true;
+ return false;
+}
+static constexpr const char *amdgpuRemoteMemoryName =
+ "fir.amdgpu.remote.memory";
+void fir::setAmdgpuRemoteMemory(mlir::ModuleOp mod) {
+ auto *ctx = mod.getContext();
+ mod->setAttr(amdgpuRemoteMemoryName, mlir::UnitAttr::get(ctx));
+}
+
+bool fir::getAmdgpuRemoteMemory(mlir::ModuleOp mod) {
+ if (auto attr = mod->getAttrOfType<mlir::UnitAttr>(amdgpuRemoteMemoryName))
+ return true;
+ return false;
+}
+
llvm::StringRef fir::getTuneCPU(mlir::ModuleOp mod) {
if (auto attr = mod->getAttrOfType<mlir::StringAttr>(tuneCpuName))
return attr.getValue();
diff --git a/flang/test/Lower/OpenMP/atomic-control-options.f90 b/flang/test/Lower/OpenMP/atomic-control-options.f90
new file mode 100644
index 0000000000000..1eb0f617f365e
--- /dev/null
+++ b/flang/test/Lower/OpenMP/atomic-control-options.f90
@@ -0,0 +1,37 @@
+! RUN: %flang_fc1 -emit-hlfir -triple amdgcn-amd-amdhsa -fopenmp -fopenmp-is-device -munsafe-fp-atomics %s -o - | FileCheck -check-prefix=UNSAFE-FP-ATOMICS %s
+! RUN: %flang_fc1 -emit-hlfir -triple amdgcn-amd-amdhsa -fopenmp -fopenmp-is-device -fatomic-ignore-denormal-mode %s -o - | FileCheck -check-prefix=IGNORE-DENORMAL %s
+! RUN: %flang_fc1 -emit-hlfir -triple amdgcn-amd-amdhsa -fopenmp -fopenmp-is-device -fatomic-fine-grained-memory %s -o - | FileCheck -check-prefix=FINE-GRAINED-MEMORY %s
+! RUN: %flang_fc1 -emit-hlfir -triple amdgcn-amd-amdhsa -fopenmp -fopenmp-is-device -fatomic-remote-memory %s -o - | FileCheck -check-prefix=REMOTE-MEMORY %s
+program test
+ implicit none
+ integer :: A, B, threads
+ threads = 128
+ A = 0
+ B = 0
+ !UNSAFE-FP-ATOMICS: omp.atomic.update %{{.*}} : !fir.ref<i32> {
+ !UNSAFE-FP-ATOMICS: } {atomic_control = #omp.atomic_control<amdgpu_ignore_denormal_mode = true>}
+ !IGNORE-DENORMAL: omp.atomic.update %{{.*}} : !fir.ref<i32> {
+ !IGNORE-DENORMAL: } {atomic_control = #omp.atomic_control<amdgpu_ignore_denormal_mode = true>}
+ !FINE-GRAINED-MEMORY: omp.atomic.update %{{.*}} : !fir.ref<i32> {
+ !FINE-GRAINED-MEMORY: } {atomic_control = #omp.atomic_control<amdgpu_fine_grained_memory = true>}
+ !REMOTE-MEMORY: omp.atomic.update %{{.*}} : !fir.ref<i32> {
+ !REMOTE-MEMORY: } {atomic_control = #omp.atomic_control<amdgpu_remote_memory = true>}
+ !$omp target parallel num_threads(threads)
+ !$omp atomic
+ A = A + 1
+ !$omp end target parallel
+ !UNSAFE-FP-ATOMICS: omp.atomic.update %{{.*}} : !fir.ref<i32> {
+ !UNSAFE-FP-ATOMICS: } {atomic_control = #omp.atomic_control<amdgpu_ignore_denormal_mode = true>}
+ !IGNORE-DENORMAL: omp.atomic.update %{{.*}} : !fir.ref<i32> {
+ !IGNORE-DENORMAL: } {atomic_control = #omp.atomic_control<amdgpu_ignore_denormal_mode = true>}
+ !FINE-GRAINED-MEMORY: omp.atomic.update %{{.*}} : !fir.ref<i32> {
+ !FINE-GRAINED-MEMORY: } {atomic_control = #omp.atomic_control<amdgpu_fine_grained_memory = true>}
+ !REMOTE-MEMORY: omp.atomic.update %{{.*}} : !fir.ref<i32> {
+ !REMOTE-MEMORY: } {atomic_control = #omp.atomic_control<amdgpu_remote_memory = true>}
+ !$omp target parallel num_threads(threads)
+ !$omp atomic capture
+ A = A + B
+ B = A
+ !$omp end atomic
+ !$omp end target parallel
+end program test
diff --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPAttrDefs.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPAttrDefs.td
index 704d0b2220e8a..84887dfd2c6f9 100644
--- a/mlir/include/mlir/Dialect/OpenMP/OpenMPAttrDefs.td
+++ b/mlir/include/mlir/Dialect/OpenMP/OpenMPAttrDefs.td
@@ -54,6 +54,20 @@ def FlagsAttr : OpenMP_Attr<"Flags", "flags"> {
let assemblyFormat = "`<` struct(params) `>`";
}
+//===----------------------------------------------------------------------===//
+// AtomicControlAttr
+//===----------------------------------------------------------------------===//
+
+// Runtime library flags attribute that holds information for lowering to LLVM.
+def AtomicControlAttr : OpenMP_Attr<"AtomicControl", "atomic_control"> {
+ let parameters =
+ (ins DefaultValuedParameter<"bool", "false">:$amdgpu_ignore_denormal_mode,
+ DefaultValuedParameter<"bool", "false">:$amdgpu_fine_grained_memory,
+ DefaultValuedParameter<"bool", "false">:$amdgpu_remote_memory);
+
+ let assemblyFormat = "`<` struct(params) `>`";
+}
+
//===----------------------------------------------------------------------===//
// TaskDependArrayAttr
//===----------------------------------------------------------------------===//
diff --git a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
index 036c6a6e350a8..d7d14e96233ae 100644
--- a/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
+++ b/mlir/include/mlir/Dialect/OpenMP/OpenMPOps.td
@@ -1543,9 +1543,11 @@ def AtomicUpdateOp : OpenMP_Op<"atomic.update", traits = [
operations.
}] # clausesDescription;
- let arguments = !con((ins Arg<OpenMP_PointerLikeType,
- "Address of variable to be updated",
- [MemRead, MemWrite]>:$x), clausesArgs);
+ let arguments = !con(
+ (ins Arg<OpenMP_PointerLikeType,
+ "Address of variable to be updated", [MemRead, MemWrite]>:$x,
+ OptionalAttr<AtomicControlAttr>:$atomic_control),
+ clausesArgs);
// Override region definition.
let regions = (region SizedRegion<1>:$region);
diff --git a/mlir/test/Dialect/OpenMP/ops.mlir b/mlir/test/Dialect/OpenMP/ops.mlir
index 47cfc5278a5d0..e377b7aab3e43 100644
--- a/mlir/test/Dialect/OpenMP/ops.mlir
+++ b/mlir/test/Dialect/OpenMP/ops.mlir
@@ -1562,6 +1562,15 @@ func.func @omp_atomic_update(%x : memref<i32>, %expr : i32, %xBool : memref<i1>,
omp.yield(%newval : i32)
}
+ // CHECK: omp.atomic.update %[[X]] : memref<i32> {
+ // CHECK-NEXT: (%[[XVAL:.*]]: i32):
+ // CHECK-NEXT: omp.yield(%{{.+}} : i32)
+ // CHECK-NEXT: } {atomic_control_attr = #omp.atomic_control<amdgpu_ignore_denormal_mode = true, amdgpu_fine_grained_memory = true, amdgpu_remote_memory = true>}
+ omp.atomic.update %x : memref<i32> {
+ ^bb0(%xval:i32):
+ omp.yield(%const:i32)
+ } {atomic_control_attr = #omp.atomic_control<amdgpu_ignore_denormal_mode = true, amdgpu_fine_grained_memory = true, amdgpu_remote_memory = true>}
+
return
}
``````````
</details>
https://github.com/llvm/llvm-project/pull/143441
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