[flang]Add vscale argument parsing

Leporacanthicus · Leporacanthicus · commit 17e128e808ec · 2023-09-29T23:23:02.000+01:00
Support for vector scale range arguments, for AArch64 scalable vector
extension (SVE) support.

Adds -msve-vector-bits to the flang frontend, and for flang fc1 the
options are -mvscale-min and -mvscale-max (optional). These match the
clang and clang cc1 options for the same purposes.

A further patch will actually USE these arguments.
diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td
@@ -4550,18 +4550,19 @@ foreach i = {8-15,18} in
     HelpText<"Make the x"#i#" register call-saved (AArch64 only)">;
 
 def msve_vector_bits_EQ : Joined<["-"], "msve-vector-bits=">, Group<m_aarch64_Features_Group>,
+  Visibility<[ClangOption, FlangOption]>,
   HelpText<"Specify the size in bits of an SVE vector register. Defaults to the"
            " vector length agnostic value of \"scalable\". (AArch64 only)">;
 } // let Flags = [TargetSpecific]
 
 def mvscale_min_EQ : Joined<["-"], "mvscale-min=">,
   Group<m_aarch64_Features_Group>, Flags<[NoXarchOption]>,
-  Visibility<[ClangOption, CC1Option]>,
+  Visibility<[ClangOption, CC1Option, FC1Option]>,
   HelpText<"Specify the vscale minimum. Defaults to \"1\". (AArch64/RISC-V only)">,
   MarshallingInfoInt<LangOpts<"VScaleMin">>;
 def mvscale_max_EQ : Joined<["-"], "mvscale-max=">,
   Group<m_aarch64_Features_Group>, Flags<[NoXarchOption]>,
-  Visibility<[ClangOption, CC1Option]>,
+  Visibility<[ClangOption, CC1Option, FC1Option]>,
   HelpText<"Specify the vscale maximum. Defaults to the"
            " vector length agnostic value of \"0\". (AArch64/RISC-V only)">,
   MarshallingInfoInt<LangOpts<"VScaleMax">>;
diff --git a/clang/lib/Driver/ToolChains/Flang.cpp b/clang/lib/Driver/ToolChains/Flang.cpp
@@ -170,6 +170,39 @@ void Flang::addPicOptions(const ArgList &Args, ArgStringList &CmdArgs) const {
   }
 }
 
+
+void Flang::AddAArch64TargetArgs(const ArgList &Args,
+                                 ArgStringList &CmdArgs) const {
+  // Handle -msve_vector_bits=<bits>
+  if (Arg *A = Args.getLastArg(options::OPT_msve_vector_bits_EQ)) {
+    StringRef Val = A->getValue();
+    const Driver &D = getToolChain().getDriver();
+    if (Val.equals("128") || Val.equals("256") || Val.equals("512") ||
+        Val.equals("1024") || Val.equals("2048") || Val.equals("128+") ||
+        Val.equals("256+") || Val.equals("512+") || Val.equals("1024+") ||
+        Val.equals("2048+")) {
+      unsigned Bits = 0;
+      if (Val.endswith("+"))
+        Val = Val.substr(0, Val.size() - 1);
+      else {
+        bool Invalid = Val.getAsInteger(10, Bits); (void)Invalid;
+        assert(!Invalid && "Failed to parse value");
+        CmdArgs.push_back(
+            Args.MakeArgString("-mvscale-max=" + llvm::Twine(Bits / 128)));
+      }
+
+      bool Invalid = Val.getAsInteger(10, Bits); (void)Invalid;
+      assert(!Invalid && "Failed to parse value");
+      CmdArgs.push_back(
+          Args.MakeArgString("-mvscale-min=" + llvm::Twine(Bits / 128)));
+    // Silently drop requests for vector-length agnostic code as it's implied.
+    } else if (!Val.equals("scalable"))
+      // Handle the unsupported values passed to msve-vector-bits.
+      D.Diag(diag::err_drv_unsupported_option_argument)
+          << A->getSpelling() << Val;
+  }
+}
+
 void Flang::addTargetOptions(const ArgList &Args,
                              ArgStringList &CmdArgs) const {
   const ToolChain &TC = getToolChain();
@@ -186,9 +219,13 @@ void Flang::addTargetOptions(const ArgList &Args,
   switch (TC.getArch()) {
   default:
     break;
+  case llvm::Triple::aarch64:
+    getTargetFeatures(D, Triple, Args, CmdArgs, /*ForAs*/ false);
+    AddAArch64TargetArgs(Args, CmdArgs);
+    break;
+
   case llvm::Triple::r600:
   case llvm::Triple::amdgcn:
-  case llvm::Triple::aarch64:
   case llvm::Triple::riscv64:
   case llvm::Triple::x86_64:
     getTargetFeatures(D, Triple, Args, CmdArgs, /*ForAs*/ false);
diff --git a/clang/lib/Driver/ToolChains/Flang.h b/clang/lib/Driver/ToolChains/Flang.h
@@ -56,6 +56,13 @@ class LLVM_LIBRARY_VISIBILITY Flang : public Tool {
   void addTargetOptions(const llvm::opt::ArgList &Args,
                         llvm::opt::ArgStringList &CmdArgs) const;
 
+  /// Add specific options for AArch64 target.
+  ///
+  /// \param [in] Args The list of input driver arguments
+  /// \param [out] CmdArgs The list of output command arguments
+  void AddAArch64TargetArgs(const llvm::opt::ArgList &Args,
+                            llvm::opt::ArgStringList &CmdArgs) const;
+
   /// Extract offload options from the driver arguments and add them to
   /// the command arguments.
   /// \param [in] C The current compilation for the driver invocation
diff --git a/flang/include/flang/Frontend/LangOptions.def b/flang/include/flang/Frontend/LangOptions.def
@@ -53,5 +53,8 @@ LANGOPT(OpenMPNoThreadState, 1, 0)
 /// Assume that no thread in a parallel region will encounter a parallel region
 LANGOPT(OpenMPNoNestedParallelism, 1, 0)
 
+LANGOPT(VScaleMin, 32, 0)  ///< Minimum vscale range value
+LANGOPT(VScaleMax, 32, 0)  ///< Maximum vscale range value
+
 #undef LANGOPT
 #undef ENUM_LANGOPT
diff --git a/flang/lib/Frontend/CompilerInvocation.cpp b/flang/lib/Frontend/CompilerInvocation.cpp
@@ -986,6 +986,41 @@ static bool parseFloatingPointArgs(CompilerInvocation &invoc,
   return true;
 }
 
+/// Parses vscale range options and populates the CompilerInvocation
+/// accordingly.
+/// Returns false if new errors are generated.
+///
+/// \param [out] invoc Stores the processed arguments
+/// \param [in] args The compiler invocation arguments to parse
+/// \param [out] diags DiagnosticsEngine to report erros with
+static bool parseVScaleArgs(CompilerInvocation &invoc, llvm::opt::ArgList &args,
+                            clang::DiagnosticsEngine &diags) {
+  LangOptions &opts = invoc.getLangOpts();
+  if (const auto arg =
+          args.getLastArg(clang::driver::options::OPT_mvscale_min_EQ)) {
+    llvm::StringRef argValue = llvm::StringRef(arg->getValue());
+    unsigned VScaleMin;
+    if (argValue.getAsInteger(/*Radix=*/10, VScaleMin)) {
+      diags.Report(clang::diag::err_drv_unsupported_option_argument)
+          << arg->getSpelling() << argValue;
+      return false;
+    }
+    opts.VScaleMin = VScaleMin;
+  }
+  if (const auto arg =
+          args.getLastArg(clang::driver::options::OPT_mvscale_max_EQ)) {
+    llvm::StringRef argValue = llvm::StringRef(arg->getValue());
+    unsigned VScaleMax;
+    if (argValue.getAsInteger(/*Radix=w*/ 10, VScaleMax)) {
+      diags.Report(clang::diag::err_drv_unsupported_option_argument)
+          << arg->getSpelling() << argValue;
+      return false;
+    }
+    opts.VScaleMax = VScaleMax;
+  }
+  return true;
+}
+
 bool CompilerInvocation::createFromArgs(
     CompilerInvocation &res, llvm::ArrayRef<const char *> commandLineArgs,
     clang::DiagnosticsEngine &diags, const char *argv0) {
@@ -1079,6 +1114,8 @@ bool CompilerInvocation::createFromArgs(
 
   success &= parseFloatingPointArgs(res, args, diags);
 
+  success &= parseVScaleArgs(res, args, diags);
+
   // Set the string to be used as the return value of the COMPILER_OPTIONS
   // intrinsic of iso_fortran_env. This is either passed in from the parent
   // compiler driver invocation with an environment variable, or failing that
diff --git a/flang/lib/Frontend/FrontendActions.cpp b/flang/lib/Frontend/FrontendActions.cpp
@@ -42,6 +42,7 @@
 #include "mlir/Target/LLVMIR/ModuleTranslation.h"
 #include "clang/Basic/Diagnostic.h"
 #include "clang/Basic/DiagnosticFrontend.h"
+#include "clang/Basic/TargetInfo.h"
 #include "clang/Driver/DriverDiagnostic.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/ADT/StringRef.h"
diff --git a/flang/test/Driver/driver-help-hidden.f90 b/flang/test/Driver/driver-help-hidden.f90
@@ -110,6 +110,8 @@
 ! CHECK-NEXT: -mllvm <value>          Additional arguments to forward to LLVM's option processing
 ! CHECK-NEXT: -mmlir <value>          Additional arguments to forward to MLIR's option processing
 ! CHECK-NEXT: -module-dir <dir>       Put MODULE files in <dir>
+! CHECK-NEXT: -msve-vector-bits=<value>
+! CHECK-NEXT:                          Specify the size in bits of an SVE vector register. Defaults to the vector length agnostic value of "scalable". (AArch64 only)
 ! CHECK-NEXT: --no-offload-arch=<value>
 ! CHECK-NEXT:                         Remove CUDA/HIP offloading device architecture (e.g. sm_35, gfx906) from the list of devices to compile for. 'all' resets the list to its default value.
 ! CHECK-NEXT: -nocpp                  Disable predefined and command line preprocessor macros
diff --git a/flang/test/Driver/driver-help.f90 b/flang/test/Driver/driver-help.f90
@@ -98,6 +98,8 @@
 ! HELP-NEXT: -mllvm <value>          Additional arguments to forward to LLVM's option processing
 ! HELP-NEXT: -mmlir <value>          Additional arguments to forward to MLIR's option processing
 ! HELP-NEXT: -module-dir <dir>       Put MODULE files in <dir>
+! HELP-NEXT: -msve-vector-bits=<value>
+! HELP-NEXT:                          Specify the size in bits of an SVE vector register. Defaults to the vector length agnostic value of "scalable". (AArch64 only)
 ! HELP-NEXT: --no-offload-arch=<value>
 ! HELP-NEXT:                         Remove CUDA/HIP offloading device architecture (e.g. sm_35, gfx906) from the list of devices to compile for. 'all' resets the list to its default value.
 ! HELP-NEXT: -nocpp                  Disable predefined and command line preprocessor macros
@@ -228,6 +230,8 @@
 ! HELP-FC1-NEXT: -mreassociate           Allow reassociation transformations for floating-point instructions
 ! HELP-FC1-NEXT: -mrelocation-model <value>
 ! HELP-FC1-NEXT:                         The relocation model to use
+! HELP-FC1-NEXT: -mvscale-max=<value>    Specify the vscale maximum. Defaults to the vector length agnostic value of "0". (AArch64/RISC-V only)
+! HELP-FC1-NEXT: -mvscale-min=<value>    Specify the vscale minimum. Defaults to "1". (AArch64/RISC-V only)
 ! HELP-FC1-NEXT: -nocpp                  Disable predefined and command line preprocessor macros
 ! HELP-FC1-NEXT: -opt-record-file <value>
 ! HELP-FC1-NEXT:                         File name to use for YAML optimization record output
