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

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.

Reviewed By: beanz

Differential Revision: https://reviews.llvm.org/D128845

Author: python3kgae

clang/include/clang/Driver/Options.td

@@ -6402,6 +6402,9 @@ def cl_ignored_Group : OptionGroup<"<clang-cl ignored options>">,
 class CLFlag<string name> : Option<["/", "-"], name, KIND_FLAG>,
   Group<cl_Group>, Flags<[CLOption, NoXarchOption]>;
 
+class CLDXCFlag<string name> : Option<["/", "-"], name, KIND_FLAG>,
+  Group<cl_Group>, Flags<[CLDXCOption, NoXarchOption]>;
+
 class CLCompileFlag<string name> : Option<["/", "-"], name, KIND_FLAG>,
   Group<cl_compile_Group>, Flags<[CLOption, NoXarchOption]>;
 
@@ -6411,6 +6414,9 @@ class CLIgnoredFlag<string name> : Option<["/", "-"], name, KIND_FLAG>,
 class CLJoined<string name> : Option<["/", "-"], name, KIND_JOINED>,
   Group<cl_Group>, Flags<[CLOption, NoXarchOption]>;
 
+class CLDXCJoined<string name> : Option<["/", "-"], name, KIND_JOINED>,
+  Group<cl_Group>, Flags<[CLDXCOption, NoXarchOption]>;
+
 class CLCompileJoined<string name> : Option<["/", "-"], name, KIND_JOINED>,
   Group<cl_compile_Group>, Flags<[CLOption, NoXarchOption]>;
 
@@ -6507,7 +6513,7 @@ def _SLASH_J : CLFlag<"J">, HelpText<"Make char type unsigned">,
 
 // The _SLASH_O option handles all the /O flags, but we also provide separate
 // aliased options to provide separate help messages.
-def _SLASH_O : CLJoined<"O">,
+def _SLASH_O : CLDXCJoined<"O">,
   HelpText<"Set multiple /O flags at once; e.g. '/O2y-' for '/O2 /Oy-'">,
   MetaVarName<"<flags>">;
 def : CLFlag<"O1">, Alias<_SLASH_O>, AliasArgs<["1"]>,
@@ -6520,7 +6526,7 @@ def : CLFlag<"Ob1">, Alias<_SLASH_O>, AliasArgs<["b1"]>,
   HelpText<"Only inline functions explicitly or implicitly marked inline">;
 def : CLFlag<"Ob2">, Alias<_SLASH_O>, AliasArgs<["b2"]>,
   HelpText<"Inline functions as deemed beneficial by the compiler">;
-def : CLFlag<"Od">, Alias<_SLASH_O>, AliasArgs<["d"]>,
+def : CLDXCFlag<"Od">, Alias<_SLASH_O>, AliasArgs<["d"]>,
   HelpText<"Disable optimization">;
 def : CLFlag<"Og">, Alias<_SLASH_O>, AliasArgs<["g"]>,
   HelpText<"No effect">;

clang/lib/CodeGen/CGHLSLRuntime.cpp

@@ -46,6 +46,11 @@ void addDxilValVersion(StringRef ValVersionStr, llvm::Module &M) {
   auto *DXILValMD = M.getOrInsertNamedMetadata(DXILValKey);
   DXILValMD->addOperand(Val);
 }
+void addDisableOptimizations(llvm::Module &M) {
+  StringRef Key = "dx.disable_optimizations";
+  M.addModuleFlag(llvm::Module::ModFlagBehavior::Override, Key, 1);
+}
+
 } // namespace
 
 void CGHLSLRuntime::finishCodeGen() {
@@ -56,6 +61,8 @@ void CGHLSLRuntime::finishCodeGen() {
     addDxilValVersion(TargetOpts.DxilValidatorVersion, M);
 
   generateGlobalCtorDtorCalls();
+  if (CGM.getCodeGenOpts().OptimizationLevel == 0)
+    addDisableOptimizations(M);
 }
 
 void CGHLSLRuntime::annotateHLSLResource(const VarDecl *D, GlobalVariable *GV) {

clang/lib/Driver/ToolChains/Clang.cpp

@@ -3520,6 +3520,7 @@ static void RenderHLSLOptions(const ArgList &Args, ArgStringList &CmdArgs,
                                          options::OPT_D,
                                          options::OPT_I,
                                          options::OPT_S,
+                                         options::OPT_O,
                                          options::OPT_emit_llvm,
                                          options::OPT_emit_obj,
                                          options::OPT_disable_llvm_passes,

clang/lib/Driver/ToolChains/HLSL.cpp

@@ -164,6 +164,18 @@ HLSLToolChain::TranslateArgs(const DerivedArgList &Args, StringRef BoundArch,
       A->claim();
       continue;
     }
+    if (A->getOption().getID() == options::OPT__SLASH_O) {
+      StringRef OStr = A->getValue();
+      if (OStr == "d") {
+        DAL->AddFlagArg(nullptr, Opts.getOption(options::OPT_O0));
+        A->claim();
+        continue;
+      } else {
+        DAL->AddJoinedArg(nullptr, Opts.getOption(options::OPT_O), OStr);
+        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));
@@ -192,6 +204,9 @@ HLSLToolChain::TranslateArgs(const DerivedArgList &Args, StringRef BoundArch,
                         Opts.getOption(options::OPT_dxil_validator_version),
                         DefaultValidatorVer);
   }
+  if (!DAL->hasArg(options::OPT_O_Group)) {
+    DAL->AddJoinedArg(nullptr, Opts.getOption(options::OPT_O), "3");
+  }
   // FIXME: add validation for enable_16bit_types should be after HLSL 2018 and
   // shader model 6.2.
   return DAL;

clang/test/CodeGenHLSL/disable_opt.hlsl

@@ -0,0 +1,12 @@
+// RUN: %clang -cc1 -S -triple dxil-pc-shadermodel6.3-library -O0 -emit-llvm -xhlsl  -o - %s | FileCheck %s
+// RUN: %clang -cc1 -S -triple dxil-pc-shadermodel6.3-library -O3 -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

@@ -0,0 +1,18 @@
+// RUN: %clang_dxc -T lib_6_7  foo.hlsl -### %s 2>&1 | FileCheck %s
+// RUN: %clang_dxc -T lib_6_7 -Od foo.hlsl -### %s 2>&1 | FileCheck %s --check-prefix=Od
+// RUN: %clang_dxc -T lib_6_7 -O0 foo.hlsl -### %s 2>&1 | FileCheck %s --check-prefix=O0
+// RUN: %clang_dxc -T lib_6_7 -O1 foo.hlsl -### %s 2>&1 | FileCheck %s --check-prefix=O1
+// RUN: %clang_dxc -T lib_6_7 -O2 foo.hlsl -### %s 2>&1 | FileCheck %s --check-prefix=O2
+// RUN: %clang_dxc -T lib_6_7 -O3 foo.hlsl -### %s 2>&1 | FileCheck %s --check-prefix=O3
+
+// Make sure default is O3.
+// CHECK: "-O3"
+
+// Make sure Od/O0 option flag which translated into "-O0".
+// Od: "-O0"
+// O0: "-O0"
+
+// Make sure O1/O2/O3 is send to cc1.
+// O1: "-O1"
+// O2: "-O2"
+// O3: "-O3"

clang/test/Driver/dxc_fcgl.hlsl

@@ -1,5 +1,6 @@
 // RUN: %clang_dxc -fcgl -T lib_6_7 foo.hlsl -### %s 2>&1 | FileCheck %s
 
 // Make sure fcgl option flag which translated into "-S" "-emit-llvm" "-disable-llvm-passes".
-// CHECK:"-S" "-emit-llvm" "-disable-llvm-passes"
+// CHECK:"-S"
+// CHECK-SAME:"-emit-llvm" "-disable-llvm-passes"