Address PR comments on gatherGlobalModuleFlags

Author: Icohedron

llvm/lib/Target/DirectX/DXILShaderFlags.cpp

@@ -208,9 +208,12 @@ void ModuleShaderFlags::updateFunctionFlags(ComputedShaderFlags &CSF,
 }
 
 /// Set shader flags that apply to all functions within the module
-void ModuleShaderFlags::gatherGlobalModuleFlags(
-    ComputedShaderFlags &CSF, const Module &M, const DXILResourceMap &DRM,
-    const ModuleMetadataInfo &MMDI) {
+ComputedShaderFlags
+ModuleShaderFlags::gatherGlobalModuleFlags(const Module &M,
+                                           const DXILResourceMap &DRM,
+                                           const ModuleMetadataInfo &MMDI) {
+
+  ComputedShaderFlags CSF;
 
   // Set DisableOptimizations flag based on the presence of OptimizeNone
   // attribute of entry functions.
@@ -249,27 +252,28 @@ void ModuleShaderFlags::gatherGlobalModuleFlags(
     if (MMDI.ShaderModelVersion >= VersionTuple(6, 2))
       CSF.NativeLowPrecisionMode = NativeLowPrec->getValue().getBoolValue();
 
-  CanSetResMayNotAlias = MMDI.DXILVersion >= VersionTuple(1, 7);
-  // The command line option -res-may-alias will set the dx.resmayalias module
-  // flag to 1, thereby disabling the ability to set the ResMayNotAlias flag
-  if (auto *ResMayAlias = mdconst::extract_or_null<ConstantInt>(
-          M.getModuleFlag("dx.resmayalias")))
-    if (ResMayAlias->getValue().getBoolValue())
-      CanSetResMayNotAlias = false;
-
   // Set ResMayNotAlias to true if DXIL validator version < 1.8 and there
   // are UAVs present globally.
   if (CanSetResMayNotAlias && MMDI.ValidatorVersion < VersionTuple(1, 8))
     CSF.ResMayNotAlias = !DRM.uavs().empty();
+
+  return CSF;
 }
 
 /// Construct ModuleShaderFlags for module Module M
 void ModuleShaderFlags::initialize(Module &M, DXILResourceTypeMap &DRTM,
                                    const DXILResourceMap &DRM,
                                    const ModuleMetadataInfo &MMDI) {
 
-  ComputedShaderFlags GlobalSFMask;
-  gatherGlobalModuleFlags(GlobalSFMask, M, DRM, MMDI);
+  CanSetResMayNotAlias = MMDI.DXILVersion >= VersionTuple(1, 7);
+  // The command line option -res-may-alias will set the dx.resmayalias module
+  // flag to 1, thereby disabling the ability to set the ResMayNotAlias flag
+  if (auto *ResMayAlias = mdconst::extract_or_null<ConstantInt>(
+          M.getModuleFlag("dx.resmayalias")))
+    if (ResMayAlias->getValue().getBoolValue())
+      CanSetResMayNotAlias = false;
+
+  ComputedShaderFlags GlobalSFMask = gatherGlobalModuleFlags(M, DRM, MMDI);
 
   CallGraph CG(M);
 

llvm/lib/Target/DirectX/DXILShaderFlags.h

@@ -101,9 +101,9 @@ struct ModuleShaderFlags {
   DenseMap<const Function *, ComputedShaderFlags> FunctionFlags;
   /// Combined Shader Flag Mask of all functions of the module
   ComputedShaderFlags CombinedSFMask{};
-  void gatherGlobalModuleFlags(ComputedShaderFlags &, const Module &M,
-                               const DXILResourceMap &,
-                               const ModuleMetadataInfo &);
+  ComputedShaderFlags gatherGlobalModuleFlags(const Module &M,
+                                              const DXILResourceMap &,
+                                              const ModuleMetadataInfo &);
   void updateFunctionFlags(ComputedShaderFlags &, const Instruction &,
                            DXILResourceTypeMap &, const ModuleMetadataInfo &);
 };