Modify structurize returns option to use opt-enable (#3052)

This conforms to the established -opt-enable -opt-disable flag standard
to enable this optimization as well as tying in with the semantic
defines mechanism.

include/dxc/Support/HLSLOptions.h

@@ -165,7 +165,6 @@ public:
   bool UseHexLiterals = false; // OPT_Lx
   bool UseInstructionByteOffsets = false; // OPT_No
   bool UseInstructionNumbers = false; // OPT_Ni
-  bool StructurizeReturns = false;      // OPT_structurize_returns
   bool NotUseLegacyCBufLoad = false;  // OPT_no_legacy_cbuf_layout
   bool PackPrefixStable = false;  // OPT_pack_prefix_stable
   bool PackOptimized = false;  // OPT_pack_optimized

include/dxc/Support/HLSLOptions.td

@@ -234,8 +234,6 @@ def flegacy_macro_expansion : Flag<["-", "/"], "flegacy-macro-expansion">, Group
     HelpText<"Expand the operands before performing token-pasting operation (fxc behavior)">;
 def flegacy_resource_reservation : Flag<["-", "/"], "flegacy-resource-reservation">, Group<hlslcomp_Group>, Flags<[CoreOption, DriverOption]>,
     HelpText<"Reserve unused explicit register assignments for compatibility with shader model 5.0 and below">;
-def structurize_returns : Flag<["-", "/"], "structurize-returns">, Group<hlslcomp_Group>, Flags<[CoreOption]>,
-  HelpText<"structurize return control flow for functions with multiple returns.">;
 def no_legacy_cbuf_layout : Flag<["-", "/"], "no-legacy-cbuf-layout">, Group<hlslcomp_Group>, Flags<[CoreOption]>,
   HelpText<"Do not use legacy cbuffer load">;
 def not_use_legacy_cbuf_load_ : Flag<["-", "/"], "not_use_legacy_cbuf_load">, Group<hlslcomp_Group>, Flags<[CoreOption, HelpHidden]>,

lib/DxcSupport/HLSLOptions.cpp

@@ -612,7 +612,6 @@ int ReadDxcOpts(const OptTable *optionTable, unsigned flagsToInclude,
   opts.DefaultRowMajor = Args.hasFlag(OPT_Zpr, OPT_INVALID, false);
   opts.DefaultColMajor = Args.hasFlag(OPT_Zpc, OPT_INVALID, false);
   opts.DumpBin = Args.hasFlag(OPT_dumpbin, OPT_INVALID, false);
-  opts.StructurizeReturns = Args.hasFlag(OPT_structurize_returns, OPT_INVALID, false);
   opts.NotUseLegacyCBufLoad = Args.hasFlag(OPT_no_legacy_cbuf_layout, OPT_INVALID, false);
   opts.NotUseLegacyCBufLoad = Args.hasFlag(OPT_not_use_legacy_cbuf_load_, OPT_INVALID, opts.NotUseLegacyCBufLoad);
   opts.PackPrefixStable = Args.hasFlag(OPT_pack_prefix_stable, OPT_INVALID, false);

tools/clang/include/clang/Frontend/CodeGenOptions.h

@@ -214,8 +214,6 @@ public:
   std::vector<std::string> HLSLLibraryExports;
   /// ExportShadersOnly limits library export functions to shaders
   bool ExportShadersOnly = false;
-  /// Structurize control flow for function has multiple returns.
-  bool HLSLStructurizeReturns = false;
   /// DefaultLinkage Internal, External, or Default.  If Default, default
   /// function linkage is determined by library target.
   hlsl::DXIL::DefaultLinkage DefaultLinkage = hlsl::DXIL::DefaultLinkage::Default;

tools/clang/lib/CodeGen/CGHLSLMS.cpp

@@ -3301,7 +3301,14 @@ void CGMSHLSLRuntime::FinishCodeGen() {
   bool bWaveEnabledStage = m_pHLModule->GetShaderModel()->IsPS() ||
                            m_pHLModule->GetShaderModel()->IsCS() ||
                            m_pHLModule->GetShaderModel()->IsLib();
-  if (CGM.getCodeGenOpts().HLSLStructurizeReturns)
+
+  // Handle lang extensions if provided.
+  if (CGM.getCodeGenOpts().HLSLExtensionsCodegen) {
+    ExtensionCodeGen(HLM, CGM);
+  }
+
+  if (CGM.getCodeGenOpts().HLSLOptimizationToggles.count("structurize-returns") &&
+      CGM.getCodeGenOpts().HLSLOptimizationToggles.find("structurize-returns")->second)
     StructurizeMultiRet(M, m_ScopeMap, bWaveEnabledStage, m_DxBreaks);
 
   FinishEntries(HLM, Entry, CGM, entryFunctionMap, HSEntryPatchConstantFuncAttr,
@@ -3341,10 +3348,6 @@ void CGMSHLSLRuntime::FinishCodeGen() {
   // Add dx.break function and make appropriate breaks conditional on it.
   AddDxBreak(M, m_DxBreaks);
 
-  // Handle lang extensions if provided.
-  if (CGM.getCodeGenOpts().HLSLExtensionsCodegen) {
-    ExtensionCodeGen(HLM, CGM);
-  }
   // At this point, we have a high-level DXIL module - record this.
   SetPauseResumePasses(*m_pHLModule->GetModule(), "hlsl-hlemit",
                        "hlsl-hlensure");

tools/clang/test/HLSLFileCheck/hlsl/control_flow/return/multi_ret.hlsl

@@ -1,4 +1,4 @@
-// RUN: %dxc -E main -fcgl -structurize-returns -T ps_6_0 %s | FileCheck %s
+// RUN: %dxc -E main -fcgl -opt-enable structurize-returns -T ps_6_0 %s | FileCheck %s
 
 int i;
 

tools/clang/test/HLSLFileCheck/hlsl/control_flow/return/whole_scope_returned_if.hlsl

@@ -1,4 +1,4 @@
-// RUN: %dxc -E main -fcgl -structurize-returns -T ps_6_0 %s | FileCheck %s
+// RUN: %dxc -E main -fcgl -opt-enable structurize-returns -T ps_6_0 %s | FileCheck %s
 
 float main(float4 a:A) : SV_Target {
 // Init bReturned.

tools/clang/test/HLSLFileCheck/hlsl/control_flow/return/whole_scope_returned_loop.hlsl

@@ -1,4 +1,4 @@
-// RUN: %dxc -E main -fcgl -structurize-returns -T ps_6_0 %s | FileCheck %s
+// RUN: %dxc -E main -fcgl -opt-enable structurize-returns -T ps_6_0 %s | FileCheck %s
 
 int i;
 // CHECK:define float @main

tools/clang/test/HLSLFileCheck/hlsl/control_flow/return/whole_scope_returned_switch.hlsl

@@ -1,4 +1,4 @@
-// RUN: %dxc -E main -fcgl -structurize-returns -T ps_6_0 %s | FileCheck %s
+// RUN: %dxc -E main -fcgl -opt-enable structurize-returns -T ps_6_0 %s | FileCheck %s
 
 int i;
 

tools/clang/tools/dxcompiler/dxcompilerobj.cpp

@@ -1109,7 +1109,6 @@ public:
       compiler.getCodeGenOpts().HLSLFloat32DenormMode = DXIL::Float32DenormMode::Preserve;
     }
 
-    compiler.getCodeGenOpts().HLSLStructurizeReturns = Opts.StructurizeReturns;
     if (Opts.DisableOptimizations)
       compiler.getCodeGenOpts().DisableLLVMOpts = true;