[clang] ce9cef7 - [flang] Add support for -mprefer-vector-width=<value> (#142073)
via cfe-commits
cfe-commits at lists.llvm.org
Fri May 30 06:50:24 PDT 2025
Author: Cameron McInally
Date: 2025-05-30T07:50:18-06:00
New Revision: ce9cef79ea3f1ee86e4dc674d4c05b2fa8b3c7a8
URL: https://github.com/llvm/llvm-project/commit/ce9cef79ea3f1ee86e4dc674d4c05b2fa8b3c7a8
DIFF: https://github.com/llvm/llvm-project/commit/ce9cef79ea3f1ee86e4dc674d4c05b2fa8b3c7a8.diff
LOG: [flang] Add support for -mprefer-vector-width=<value> (#142073)
This patch adds support for the -mprefer-vector-width= command line
option. The parsing of this options is equivalent to Clang's and it is
implemented by setting the "prefer-vector-width" function attribute.
Co-authored-by: Cameron McInally <cmcinally at nvidia.com>
Added:
flang/test/Driver/prefer-vector-width.f90
mlir/test/Target/LLVMIR/Import/prefer-vector-width.ll
mlir/test/Target/LLVMIR/prefer-vector-width.mlir
Modified:
clang/include/clang/Driver/Options.td
flang/include/flang/Frontend/CodeGenOptions.h
flang/include/flang/Optimizer/Transforms/Passes.td
flang/include/flang/Tools/CrossToolHelpers.h
flang/lib/Frontend/CompilerInvocation.cpp
flang/lib/Frontend/FrontendActions.cpp
flang/lib/Optimizer/Passes/Pipelines.cpp
flang/lib/Optimizer/Transforms/FunctionAttr.cpp
mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
mlir/lib/Target/LLVMIR/ModuleImport.cpp
mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
Removed:
################################################################################
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
index 6e72576862890..5ca31c253ed8f 100644
--- a/clang/include/clang/Driver/Options.td
+++ b/clang/include/clang/Driver/Options.td
@@ -5480,7 +5480,7 @@ def mrecip_EQ : CommaJoined<["-"], "mrecip=">, Group<m_Group>,
"<value> = ( ['!'] ['vec-'] ('rcp'|'sqrt') [('h'|'s'|'d')] [':'<n>] ) | 'all' | 'default' | 'none'">,
MarshallingInfoStringVector<CodeGenOpts<"Reciprocals">>;
def mprefer_vector_width_EQ : Joined<["-"], "mprefer-vector-width=">, Group<m_Group>,
- Visibility<[ClangOption, CC1Option]>,
+ Visibility<[ClangOption, CC1Option, FlangOption, FC1Option]>,
HelpText<"Specifies preferred vector width for auto-vectorization. Defaults to 'none' which allows target specific decisions.">,
MarshallingInfoString<CodeGenOpts<"PreferVectorWidth">>;
def mstack_protector_guard_EQ : Joined<["-"], "mstack-protector-guard=">, Group<m_Group>,
diff --git a/flang/include/flang/Frontend/CodeGenOptions.h b/flang/include/flang/Frontend/CodeGenOptions.h
index 2b4e823b3fef4..61e56e51c4bbb 100644
--- a/flang/include/flang/Frontend/CodeGenOptions.h
+++ b/flang/include/flang/Frontend/CodeGenOptions.h
@@ -53,6 +53,9 @@ class CodeGenOptions : public CodeGenOptionsBase {
/// The paths to the pass plugins that were registered using -fpass-plugin.
std::vector<std::string> LLVMPassPlugins;
+ // The prefered vector width, if requested by -mprefer-vector-width.
+ std::string PreferVectorWidth;
+
/// List of filenames passed in using the -fembed-offload-object option. These
/// are offloading binaries containing device images and metadata.
std::vector<std::string> OffloadObjects;
diff --git a/flang/include/flang/Optimizer/Transforms/Passes.td b/flang/include/flang/Optimizer/Transforms/Passes.td
index 71493535db8ba..1b1970412676d 100644
--- a/flang/include/flang/Optimizer/Transforms/Passes.td
+++ b/flang/include/flang/Optimizer/Transforms/Passes.td
@@ -429,6 +429,10 @@ def FunctionAttr : Pass<"function-attr", "mlir::func::FuncOp"> {
"module.">,
Option<"unsafeFPMath", "unsafe-fp-math", "bool", /*default=*/"false",
"Set the unsafe-fp-math attribute on functions in the module.">,
+ Option<"preferVectorWidth", "prefer-vector-width", "std::string",
+ /*default=*/"",
+ "Set the prefer-vector-width attribute on functions in the "
+ "module.">,
Option<"tuneCPU", "tune-cpu", "std::string", /*default=*/"",
"Set the tune-cpu attribute on functions in the module.">,
Option<"setNoCapture", "set-nocapture", "bool", /*default=*/"false",
diff --git a/flang/include/flang/Tools/CrossToolHelpers.h b/flang/include/flang/Tools/CrossToolHelpers.h
index 118695bbe2626..058024a4a04c5 100644
--- a/flang/include/flang/Tools/CrossToolHelpers.h
+++ b/flang/include/flang/Tools/CrossToolHelpers.h
@@ -102,6 +102,7 @@ struct MLIRToLLVMPassPipelineConfig : public FlangEPCallBacks {
UnsafeFPMath = mathOpts.getAssociativeMath() &&
mathOpts.getReciprocalMath() && NoSignedZerosFPMath &&
ApproxFuncFPMath && mathOpts.getFPContractEnabled();
+ PreferVectorWidth = opts.PreferVectorWidth;
if (opts.InstrumentFunctions) {
InstrumentFunctionEntry = "__cyg_profile_func_enter";
InstrumentFunctionExit = "__cyg_profile_func_exit";
@@ -126,6 +127,8 @@ struct MLIRToLLVMPassPipelineConfig : public FlangEPCallBacks {
bool NoSignedZerosFPMath =
false; ///< Set no-signed-zeros-fp-math attribute for functions.
bool UnsafeFPMath = false; ///< Set unsafe-fp-math attribute for functions.
+ std::string PreferVectorWidth = ""; ///< Set prefer-vector-width attribute for
+ ///< functions.
bool NSWOnLoopVarInc = true; ///< Add nsw flag to loop variable increments.
bool EnableOpenMP = false; ///< Enable OpenMP lowering.
std::string InstrumentFunctionEntry =
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
index ba2531819ee5e..90a002929eff0 100644
--- a/flang/lib/Frontend/CompilerInvocation.cpp
+++ b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -309,6 +309,20 @@ static void parseCodeGenArgs(Fortran::frontend::CodeGenOptions &opts,
for (auto *a : args.filtered(clang::driver::options::OPT_fpass_plugin_EQ))
opts.LLVMPassPlugins.push_back(a->getValue());
+ // -mprefer_vector_width option
+ if (const llvm::opt::Arg *a = args.getLastArg(
+ clang::driver::options::OPT_mprefer_vector_width_EQ)) {
+ llvm::StringRef s = a->getValue();
+ unsigned width;
+ if (s == "none")
+ opts.PreferVectorWidth = "none";
+ else if (s.getAsInteger(10, width))
+ diags.Report(clang::diag::err_drv_invalid_value)
+ << a->getAsString(args) << a->getValue();
+ else
+ opts.PreferVectorWidth = s.str();
+ }
+
// -fembed-offload-object option
for (auto *a :
args.filtered(clang::driver::options::OPT_fembed_offload_object_EQ))
diff --git a/flang/lib/Frontend/FrontendActions.cpp b/flang/lib/Frontend/FrontendActions.cpp
index 38dfaadf1dff9..012d0fdfe645f 100644
--- a/flang/lib/Frontend/FrontendActions.cpp
+++ b/flang/lib/Frontend/FrontendActions.cpp
@@ -741,6 +741,8 @@ void CodeGenAction::generateLLVMIR() {
config.VScaleMax = vsr->second;
}
+ config.PreferVectorWidth = opts.PreferVectorWidth;
+
if (ci.getInvocation().getFrontendOpts().features.IsEnabled(
Fortran::common::LanguageFeature::OpenMP))
config.EnableOpenMP = true;
diff --git a/flang/lib/Optimizer/Passes/Pipelines.cpp b/flang/lib/Optimizer/Passes/Pipelines.cpp
index 378913fcb1329..0c774eede4c9a 100644
--- a/flang/lib/Optimizer/Passes/Pipelines.cpp
+++ b/flang/lib/Optimizer/Passes/Pipelines.cpp
@@ -358,7 +358,7 @@ void createDefaultFIRCodeGenPassPipeline(mlir::PassManager &pm,
{framePointerKind, config.InstrumentFunctionEntry,
config.InstrumentFunctionExit, config.NoInfsFPMath, config.NoNaNsFPMath,
config.ApproxFuncFPMath, config.NoSignedZerosFPMath, config.UnsafeFPMath,
- /*tuneCPU=*/"", setNoCapture, setNoAlias}));
+ config.PreferVectorWidth, /*tuneCPU=*/"", setNoCapture, setNoAlias}));
if (config.EnableOpenMP) {
pm.addNestedPass<mlir::func::FuncOp>(
diff --git a/flang/lib/Optimizer/Transforms/FunctionAttr.cpp b/flang/lib/Optimizer/Transforms/FunctionAttr.cpp
index c8cdba0d6f9c4..041aa8717d20e 100644
--- a/flang/lib/Optimizer/Transforms/FunctionAttr.cpp
+++ b/flang/lib/Optimizer/Transforms/FunctionAttr.cpp
@@ -107,6 +107,10 @@ void FunctionAttrPass::runOnOperation() {
func->setAttr(
mlir::LLVM::LLVMFuncOp::getUnsafeFpMathAttrName(llvmFuncOpName),
mlir::BoolAttr::get(context, true));
+ if (!preferVectorWidth.empty())
+ func->setAttr(
+ mlir::LLVM::LLVMFuncOp::getPreferVectorWidthAttrName(llvmFuncOpName),
+ mlir::StringAttr::get(context, preferVectorWidth));
LLVM_DEBUG(llvm::dbgs() << "=== End " DEBUG_TYPE " ===\n");
}
diff --git a/flang/test/Driver/prefer-vector-width.f90 b/flang/test/Driver/prefer-vector-width.f90
new file mode 100644
index 0000000000000..d0f5fd28db826
--- /dev/null
+++ b/flang/test/Driver/prefer-vector-width.f90
@@ -0,0 +1,16 @@
+! Test that -mprefer-vector-width works as expected.
+
+! RUN: %flang_fc1 -emit-llvm -o - %s 2>&1| FileCheck %s --check-prefix=CHECK-DEF
+! RUN: %flang_fc1 -mprefer-vector-width=none -emit-llvm -o - %s 2>&1| FileCheck %s --check-prefix=CHECK-NONE
+! RUN: %flang_fc1 -mprefer-vector-width=128 -emit-llvm -o - %s 2>&1| FileCheck %s --check-prefix=CHECK-128
+! RUN: %flang_fc1 -mprefer-vector-width=256 -emit-llvm -o - %s 2>&1| FileCheck %s --check-prefix=CHECK-256
+! RUN: not %flang_fc1 -mprefer-vector-width=xxx -emit-llvm -o - %s 2>&1| FileCheck %s --check-prefix=CHECK-INVALID
+
+subroutine func
+end subroutine func
+
+! CHECK-DEF-NOT: attributes #0 = { "prefer-vector-width"={{.*}} }
+! CHECK-NONE: attributes #0 = { "prefer-vector-width"="none" }
+! CHECK-128: attributes #0 = { "prefer-vector-width"="128" }
+! CHECK-256: attributes #0 = { "prefer-vector-width"="256" }
+! CHECK-INVALID:error: invalid value 'xxx' in '-mprefer-vector-width=xxx'
diff --git a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
index 6fde45ce5c556..c0324d561b77b 100644
--- a/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
+++ b/mlir/include/mlir/Dialect/LLVMIR/LLVMOps.td
@@ -1893,6 +1893,7 @@ def LLVM_LLVMFuncOp : LLVM_Op<"func", [
OptionalAttr<FramePointerKindAttr>:$frame_pointer,
OptionalAttr<StrAttr>:$target_cpu,
OptionalAttr<StrAttr>:$tune_cpu,
+ OptionalAttr<StrAttr>:$prefer_vector_width,
OptionalAttr<LLVM_TargetFeaturesAttr>:$target_features,
OptionalAttr<BoolAttr>:$unsafe_fp_math,
OptionalAttr<BoolAttr>:$no_infs_fp_math,
diff --git a/mlir/lib/Target/LLVMIR/ModuleImport.cpp b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
index b049064fbd31c..85417da798b22 100644
--- a/mlir/lib/Target/LLVMIR/ModuleImport.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleImport.cpp
@@ -2636,6 +2636,10 @@ void ModuleImport::processFunctionAttributes(llvm::Function *func,
funcOp.setTargetFeaturesAttr(
LLVM::TargetFeaturesAttr::get(context, attr.getValueAsString()));
+ if (llvm::Attribute attr = func->getFnAttribute("prefer-vector-width");
+ attr.isStringAttribute())
+ funcOp.setPreferVectorWidth(attr.getValueAsString());
+
if (llvm::Attribute attr = func->getFnAttribute("unsafe-fp-math");
attr.isStringAttribute())
funcOp.setUnsafeFpMath(attr.getValueAsBool());
diff --git a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
index e3264985ecd6e..4cc419c7cde5b 100644
--- a/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
+++ b/mlir/lib/Target/LLVMIR/ModuleTranslation.cpp
@@ -1549,6 +1549,9 @@ LogicalResult ModuleTranslation::convertOneFunction(LLVMFuncOp func) {
if (auto tuneCpu = func.getTuneCpu())
llvmFunc->addFnAttr("tune-cpu", *tuneCpu);
+ if (auto preferVectorWidth = func.getPreferVectorWidth())
+ llvmFunc->addFnAttr("prefer-vector-width", *preferVectorWidth);
+
if (auto attr = func.getVscaleRange())
llvmFunc->addFnAttr(llvm::Attribute::getWithVScaleRangeArgs(
getLLVMContext(), attr->getMinRange().getInt(),
diff --git a/mlir/test/Target/LLVMIR/Import/prefer-vector-width.ll b/mlir/test/Target/LLVMIR/Import/prefer-vector-width.ll
new file mode 100644
index 0000000000000..e30ef04924b81
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/Import/prefer-vector-width.ll
@@ -0,0 +1,9 @@
+; RUN: mlir-translate -import-llvm -split-input-file %s | FileCheck %s
+
+; CHECK-LABEL: llvm.func @prefer_vector_width()
+; CHECK-SAME: prefer_vector_width = "128"
+define void @prefer_vector_width() #0 {
+ ret void
+}
+
+attributes #0 = { "prefer-vector-width"="128" }
diff --git a/mlir/test/Target/LLVMIR/prefer-vector-width.mlir b/mlir/test/Target/LLVMIR/prefer-vector-width.mlir
new file mode 100644
index 0000000000000..7410e8139fd31
--- /dev/null
+++ b/mlir/test/Target/LLVMIR/prefer-vector-width.mlir
@@ -0,0 +1,8 @@
+// RUN: mlir-translate -mlir-to-llvmir %s | FileCheck %s
+
+// CHECK: define void @prefer_vector_width() #[[ATTRS:.*]] {
+// CHECK: attributes #[[ATTRS]] = { "prefer-vector-width"="128" }
+
+llvm.func @prefer_vector_width() attributes {prefer_vector_width = "128"} {
+ llvm.return
+}
More information about the cfe-commits
mailing list