[HLSL]Add -O and -Od option for dxc mode.

[python3kgae]

Summary

Two new dxc mode options -O and -Od are added for dxc mode.
-O is just alias of existing cc1 -O option.
-Od will be lowered into -O0 and -dxc-opt-disable.

-dxc-opt-disable is cc1 option added to for build ShaderFlags.

[python3kgae]

Fix test fail.

[pow2clk]

Looks good apart from my uncertainty as to what -fcgl should or shouldn't imply

clang/test/Driver/dxc_O.hlsl

9

It looks to me that these are added when -Od is specified, not -fcgl (aka pristine-llvm I guess ;))

Is the comment wrong or should these be added as part of pristine-llvm too?

[beanz]

clang/lib/Frontend/CompilerInvocation.cpp

575

Is there a way to tie this to using the DXC driver instead of the language option?

It would be nice in the future to have a more clang-conformant driver mode.

[python3kgae]

Change default to O3 implement to HLSL driver and update test.

[python3kgae]

Use CLDXCOption for opt level.

[python3kgae]

Rebase and fix test fail.

[beanz]

clang/lib/CodeGen/CGHLSLRuntime.cpp

46

What does this translate to in codegen?

clang/lib/Driver/ToolChains/HLSL.cpp

164

Since dxc_opt_disable is paired with passing -O0 do we need the flag at all, or can we just set the module flag if OptimizationLevel is 0?

[python3kgae]

clang/lib/CodeGen/CGHLSLRuntime.cpp

46

DisableOptimizations in ShaderFlags.

https://github.com/microsoft/DirectXShaderCompiler/blob/main/lib/DXIL/DxilShaderFlags.cpp#L192

clang/lib/Driver/ToolChains/HLSL.cpp

164

-O0 and -Od will generate different ShaderFlags in dxc.

[python3kgae]

Make O0 the same as Od.

[beanz]

clang/include/clang/Basic/TargetOptions.h

117

If Od and O0 are the same you shouldn't need to track this, or have the extra command line option to set the flag, you should imply the shader flag from the optimization level.

[python3kgae]

Use O0 instead of DxcOptDisable since Od is same as O0.

[beanz]

Two nits, please fix them before merging otherwise looks good.

clang/include/clang/Driver/Options.td

6857

nit: remove extra whitespace change.

clang/test/Driver/dxc_O.hlsl

12

nit: out of date comment.

[python3kgae]

Cleanup per comments.

clang/include/clang/Basic/TargetOptions.h

public:
   std::string DarwinTargetVariantTriple;
 
   /// The version of the darwin target variant SDK which was used during the
   /// compilation.
   llvm::VersionTuple DarwinTargetVariantSDKVersion;
 
   /// The validator version for dxil.
   std::string DxilValidatorVersion;
+
+  /// Keep the information about disable optimization for ShaderFlags.
+  bool DxcOptDisable = false;
 };
 
 } // end namespace clang
 
 #endif

clang/include/clang/Driver/Options.td

Values<"ps_6_0, ps_6_1, ps_6_2, ps_6_3, ps_6_4, ps_6_5, ps_6_6, ps_6_7,"
          "hs_6_0, hs_6_1, hs_6_2, hs_6_3, hs_6_4, hs_6_5, hs_6_6, hs_6_7,"
          "ds_6_0, ds_6_1, ds_6_2, ds_6_3, ds_6_4, ds_6_5, ds_6_6, ds_6_7,"
          "cs_6_0, cs_6_1, cs_6_2, cs_6_3, cs_6_4, cs_6_5, cs_6_6, cs_6_7,"
          "lib_6_3, lib_6_4, lib_6_5, lib_6_6, lib_6_7, lib_6_x,"
          "ms_6_5, ms_6_6, ms_6_7,"
          "as_6_5, as_6_6, as_6_7">;
 def dxc_D : Option<["--", "/", "-"], "D", KIND_JOINED_OR_SEPARATE>,
   Group<dxc_Group>, Flags<[DXCOption, NoXarchOption]>, Alias<D>;
+def dxc_O : Option<["--", "/", "-"], "O", KIND_JOINED>,
+  Group<dxc_Group>, Flags<[DXCOption, NoXarchOption]>, Alias<O>;
+def dxc_Od : Option<["--", "/", "-"], "Od", KIND_FLAG>,
+  Group<dxc_Group>, Flags<[DXCOption, NoXarchOption]>,
+  HelpText<"Disable optimizations.">;
+def dxc_opt_disable : Flag<["-"], "dxc-opt-disable">, Group<dxc_Group>, Flags<[CC1Option]>,
+  MarshallingInfoFlag<TargetOpts<"DxcOptDisable">>,
+  HelpText<"HLSL only. This option disables all optimizations. By default optimizations are enabled.">;
 def emit_pristine_llvm : DXCFlag<"emit-pristine-llvm">,
   HelpText<"Emit pristine LLVM IR from the frontend by not running any LLVM passes at all."
            "Same as -S + -emit-llvm + -disable-llvm-passes.">;
 def fcgl : DXCFlag<"fcgl">, Alias<emit_pristine_llvm>;
 def enable_16bit_types : DXCFlag<"enable-16bit-types">, Alias<fnative_half_type>,
   HelpText<"Enable 16-bit types and disable min precision types."
            "Available in HLSL 2018 and shader model 6.2.">;

clang/lib/CodeGen/CGHLSLRuntime.cpp

void addDxilValVersion(StringRef ValVersionStr, llvm::Module &M) {
 
   auto &Ctx = M.getContext();
   IRBuilder<> B(M.getContext());
   MDNode *Val = MDNode::get(Ctx, {ConstantAsMetadata::get(B.getInt32(Major)),
                                   ConstantAsMetadata::get(B.getInt32(Minor))});
   StringRef DxilValKey = "dx.valver";
   M.addModuleFlag(llvm::Module::ModFlagBehavior::AppendUnique, DxilValKey, Val);
 }
+void addDisableOptimizations(llvm::Module &M) {
+  StringRef Key = "dx.disable_optimizations";
+  M.addModuleFlag(llvm::Module::ModFlagBehavior::Override, Key, 1);
+}
+
 } // namespace
 
 void CGHLSLRuntime::finishCodeGen() {
   auto &TargetOpts = CGM.getTarget().getTargetOpts();
 
   llvm::Module &M = CGM.getModule();
   addDxilValVersion(TargetOpts.DxilValidatorVersion, M);
+  if (TargetOpts.DxcOptDisable)
+    addDisableOptimizations(M);
 }

clang/lib/Driver/ToolChains/Clang.cpp

static void RenderOpenCLOptions(const ArgList &Args, ArgStringList &CmdArgs,
   }
 }
 
 static void RenderHLSLOptions(const ArgList &Args, ArgStringList &CmdArgs,
                               types::ID InputType) {
   const unsigned ForwardedArguments[] = {options::OPT_dxil_validator_version,
                                          options::OPT_D,
                                          options::OPT_S,
+                                         options::OPT_O,
+                                         options::OPT_dxc_opt_disable,
                                          options::OPT_emit_llvm,
                                          options::OPT_disable_llvm_passes,
                                          options::OPT_fnative_half_type};
 
   for (const auto &Arg : ForwardedArguments)
     if (const auto *A = Args.getLastArg(Arg))
       A->renderAsInput(Args, CmdArgs);
   // Add the default headers if dxc_no_stdinc is not set.

clang/lib/Driver/ToolChains/HLSL.cpp

HLSLToolChain::TranslateArgs(const DerivedArgList &Args, StringRef BoundArch,
 
   for (Arg *A : Args) {
     if (A->getOption().getID() == options::OPT_dxil_validator_version) {
       StringRef ValVerStr = A->getValue();
       std::string ErrorMsg;
       if (!isLegalValidatorVersion(ValVerStr, getDriver()))
         continue;
     }
+    if (A->getOption().getID() == options::OPT_dxc_Od) {
+      DAL->AddFlagArg(nullptr, Opts.getOption(options::OPT_dxc_opt_disable));
+      DAL->AddFlagArg(nullptr, Opts.getOption(options::OPT_O0));
+      A->claim();
+      continue;
+    }
     if (A->getOption().getID() == options::OPT_emit_pristine_llvm) {
       // Translate fcgl into -S -emit-llvm and -disable-llvm-passes.
       DAL->AddFlagArg(nullptr, Opts.getOption(options::OPT_S));
       DAL->AddFlagArg(nullptr, Opts.getOption(options::OPT_emit_llvm));
       DAL->AddFlagArg(nullptr,
                       Opts.getOption(options::OPT_disable_llvm_passes));
       A->claim();
       continue;

clang/lib/Frontend/CompilerInvocation.cpp

 static unsigned getOptimizationLevel(ArgList &Args, InputKind IK,
                                      DiagnosticsEngine &Diags) {
   unsigned DefaultOpt = llvm::CodeGenOpt::None;
   if ((IK.getLanguage() == Language::OpenCL ||
        IK.getLanguage() == Language::OpenCLCXX) &&
       !Args.hasArg(OPT_cl_opt_disable))
     DefaultOpt = llvm::CodeGenOpt::Default;
 
+  if (IK.getLanguage() == Language::HLSL)
+    DefaultOpt = llvm::CodeGenOpt::Aggressive;
+
   if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
     if (A->getOption().matches(options::OPT_O0))
       return llvm::CodeGenOpt::None;
 
     if (A->getOption().matches(options::OPT_Ofast))
       return llvm::CodeGenOpt::Aggressive;
 
     assert(A->getOption().matches(options::OPT_O));

clang/test/CodeGenHLSL/disable_opt.hlsl

+// RUN: %clang -cc1 -S -triple dxil-pc-shadermodel6.3-library -dxc-opt-disable -emit-llvm -xhlsl  -o - %s | FileCheck %s
+// RUN: %clang -cc1 -S -triple dxil-pc-shadermodel6.3-library -emit-llvm -xhlsl  -o - %s | FileCheck %s --check-prefix=OPT
+
+// CHECK:!"dx.disable_optimizations", i32 1}
+
+// OPT-NOT:"dx.disable_optimizations"
+
+float bar(float a, float b);
+
+float foo(float a, float b) {
+  return bar(a, b);
+}

clang/test/Driver/dxc_O.hlsl

+// RUN: %clang_dxc -fcgl -T lib_6_7 -Od foo.hlsl -### %s 2>&1 | FileCheck %s
+// RUN: %clang_dxc -fcgl -T lib_6_7 -O0 foo.hlsl -### %s 2>&1 | FileCheck %s --check-prefix=O0
+// RUN: %clang_dxc -fcgl -T lib_6_7 -O1 foo.hlsl -### %s 2>&1 | FileCheck %s --check-prefix=O1
+// RUN: %clang_dxc -fcgl -T lib_6_7 -O2 foo.hlsl -### %s 2>&1 | FileCheck %s --check-prefix=O2
+// RUN: %clang_dxc -fcgl -T lib_6_7 -O3 foo.hlsl -### %s 2>&1 | FileCheck %s --check-prefix=O3
+
+// Make sure fcgl option flag which translated into "-O0" "-dxc-opt-disable"
+// CHECK: "-O0"
+// CHECK-SAME: "-dxc-opt-disable"
+
+// Make sure O0/O1/O2/O3 is send to cc1.
+// O0: "-O0"
+// O1: "-O1"
+// O2: "-O2"
+// O3: "-O3"