Implement wave size range

docs/DXIL.rst

@@ -3261,7 +3261,9 @@ SM.TRIOUTPUTPRIMITIVEMISMATCH             Hull Shader declared with Tri Domain m
 SM.UNDEFINEDOUTPUT                        Not all elements of output %0 were written.
 SM.VALIDDOMAIN                            Invalid Tessellator Domain specified. Must be isoline, tri or quad.
 SM.VIEWIDNEEDSSLOT                        ViewID requires compatible space in pixel shader input signature
+SM.WAVESIZEMINGEQMAX                      Declared Minimum WaveSize %0 greater or equal to declared Maximum Wavesize %1
 SM.WAVESIZENEEDSDXIL16PLUS                WaveSize is valid only for DXIL version 1.6 and higher.
+SM.WAVESIZEPREFERREDOUTOFRANGE            Preferred WaveSize %0 outside valid range [%1..%2]
 SM.WAVESIZEVALUE                          Declared WaveSize %0 outside valid range [%1..%2], or not a power of 2.
 SM.ZEROHSINPUTCONTROLPOINTWITHINPUT       When HS input control point count is 0, no input signature should exist.
 TYPES.DEFINED                             Type must be defined based on DXIL primitives

include/dxc/DXIL/DxilConstants.h

@@ -448,10 +448,23 @@ inline bool IsFeedbackTexture(DXIL::ResourceKind ResourceKind) {
          ResourceKind == DXIL::ResourceKind::FeedbackTexture2DArray;
 }
 
-inline bool IsValidWaveSizeValue(unsigned size) {
+inline bool isPowerOf2(unsigned x) { return (x & (x - 1)) == 0; }
+
+inline bool IsValidWaveSizeValue(unsigned min_wave, unsigned max_wave,
+                                 unsigned pref_wave) {
   // must be power of 2 between 4 and 128
-  return size >= kMinWaveSize && size <= kMaxWaveSize &&
-         (size & (size - 1)) == 0;
+  bool minIsValid = min_wave >= kMinWaveSize && min_wave <= kMaxWaveSize &&
+                    isPowerOf2(min_wave);
+  if (max_wave == 0)
+    return true;
+  bool maxIsValid = max_wave >= kMinWaveSize && max_wave <= kMaxWaveSize &&
+                    isPowerOf2(max_wave);
+  // 0 is a valid value for the preferred wave size
+  bool prefIsValid =
+      pref_wave == 0 || (pref_wave >= kMinWaveSize &&
+                         pref_wave <= kMaxWaveSize && isPowerOf2(pref_wave));
+
+  return minIsValid && maxIsValid && prefIsValid;
 }
 
 // TODO: change opcodes.

include/dxc/DXIL/DxilFunctionProps.h

@@ -34,7 +34,9 @@ struct DxilFunctionProps {
     memset(&Node, 0, sizeof(Node));
     Node.LaunchType = DXIL::NodeLaunchType::Invalid;
     Node.LocalRootArgumentsTableIndex = -1;
-    waveSize = 0;
+    waveMinSize = 0;
+    waveMaxSize = 0;
+    wavePreferredSize = 0;
   }
   union {
     // Geometry shader.
@@ -107,9 +109,11 @@ struct DxilFunctionProps {
   std::vector<NodeIOProperties> InputNodes;
   std::vector<NodeIOProperties> OutputNodes;
 
-  // WaveSize is currently allowed only on compute shaders, but could be
-  // supported on other shader types in the future
-  unsigned waveSize;
+  // SM 6.6 allows WaveSize specification for only a single required size. SM
+  // 6.8+ allows specification of WaveSize as a min, max and preferred value.
+  unsigned waveMinSize;
+  unsigned waveMaxSize;
+  unsigned wavePreferredSize;
   // Save root signature for lib profile entry.
   std::vector<uint8_t> serializedRootSignature;
   void SetSerializedRootSignature(const uint8_t *pData, unsigned size) {

include/dxc/DXIL/DxilMetadataHelper.h

@@ -318,6 +318,7 @@ class DxilMDHelper {
   static const unsigned kDxilNodeInputsTag = 20;
   static const unsigned kDxilNodeOutputsTag = 21;
   static const unsigned kDxilNodeMaxDispatchGridTag = 22;
+  static const unsigned kDxilRangedWaveSizeTag = 23;
 
   // Node Input/Output State.
   static const unsigned kDxilNodeOutputIDTag = 0;

lib/DXIL/DxilMetadataHelper.cpp

@@ -1596,10 +1596,17 @@ MDTuple *DxilMDHelper::EmitDxilEntryProperties(uint64_t rawShaderFlag,
     NumThreadVals.emplace_back(Uint32ToConstMD(props.numThreads[2]));
     MDVals.emplace_back(MDNode::get(m_Ctx, NumThreadVals));
 
-    if (props.waveSize != 0) {
-      MDVals.emplace_back(Uint32ToConstMD(DxilMDHelper::kDxilWaveSizeTag));
-      vector<Metadata *> WaveSizeVal;
-      WaveSizeVal.emplace_back(Uint32ToConstMD(props.waveSize));
+    if (props.waveMinSize != 0) {
+      bool UseRange = props.waveMaxSize != 0;
+      MDVals.emplace_back(
+          Uint32ToConstMD(UseRange ? DxilMDHelper::kDxilRangedWaveSizeTag
+                                   : DxilMDHelper::kDxilWaveSizeTag));
+      SmallVector<Metadata *, 3> WaveSizeVal;
+      WaveSizeVal.emplace_back(Uint32ToConstMD(props.waveMinSize));
+      if (UseRange) {
+        WaveSizeVal.emplace_back(Uint32ToConstMD(props.waveMaxSize));
+        WaveSizeVal.emplace_back(Uint32ToConstMD(props.wavePreferredSize));
+      }
       MDVals.emplace_back(MDNode::get(m_Ctx, WaveSizeVal));
     }
   } break;
@@ -1823,7 +1830,14 @@ void DxilMDHelper::LoadDxilEntryProperties(const MDOperand &MDO,
     case DxilMDHelper::kDxilWaveSizeTag: {
       DXASSERT(props.IsCS() || props.IsNode(), "else invalid shader kind");
       MDNode *pNode = cast<MDNode>(MDO.get());
-      props.waveSize = ConstMDToUint32(pNode->getOperand(0));
+      props.waveMinSize = ConstMDToUint32(pNode->getOperand(0));
+    } break;
+    case DxilMDHelper::kDxilRangedWaveSizeTag: {
+      DXASSERT(props.IsCS() || props.IsNode(), "else invalid shader kind");
+      MDNode *pNode = cast<MDNode>(MDO.get());
+      props.waveMinSize = ConstMDToUint32(pNode->getOperand(0));
+      props.waveMaxSize = ConstMDToUint32(pNode->getOperand(1));
+      props.wavePreferredSize = ConstMDToUint32(pNode->getOperand(2));
     } break;
     case DxilMDHelper::kDxilEntryRootSigTag: {
       MDNode *pNode = cast<MDNode>(MDO.get());
@@ -2644,10 +2658,17 @@ void DxilMDHelper::EmitDxilNodeState(std::vector<llvm::Metadata *> &MDVals,
 
   // Optional Fields
 
-  if (props.waveSize != 0) {
-    MDVals.emplace_back(Uint32ToConstMD(DxilMDHelper::kDxilWaveSizeTag));
-    vector<Metadata *> WaveSizeVal;
-    WaveSizeVal.emplace_back(Uint32ToConstMD(props.waveSize));
+  if (props.waveMinSize != 0) {
+    bool UseRange = props.waveMaxSize != 0;
+    MDVals.emplace_back(
+        Uint32ToConstMD(UseRange ? DxilMDHelper::kDxilRangedWaveSizeTag
+                                 : DxilMDHelper::kDxilWaveSizeTag));
+    SmallVector<Metadata *, 3> WaveSizeVal;
+    WaveSizeVal.emplace_back(Uint32ToConstMD(props.waveMinSize));
+    if (UseRange) {
+      WaveSizeVal.emplace_back(Uint32ToConstMD(props.waveMaxSize));
+      WaveSizeVal.emplace_back(Uint32ToConstMD(props.wavePreferredSize));
+    }
     MDVals.emplace_back(MDNode::get(m_Ctx, WaveSizeVal));
   }
 

lib/DXIL/DxilModule.cpp

@@ -400,7 +400,7 @@ void DxilModule::SetWaveSize(unsigned size) {
            "only works for CS profile");
   DxilFunctionProps &props = m_DxilEntryPropsMap.begin()->second->props;
   DXASSERT_NOMSG(m_pSM->GetKind() == props.shaderKind);
-  props.waveSize = size;
+  props.waveMinSize = size;
 }
 
 unsigned DxilModule::GetWaveSize() const {
@@ -410,7 +410,7 @@ unsigned DxilModule::GetWaveSize() const {
     return 0;
   const DxilFunctionProps &props = m_DxilEntryPropsMap.begin()->second->props;
   DXASSERT_NOMSG(m_pSM->GetKind() == props.shaderKind);
-  return props.waveSize;
+  return props.waveMinSize;
 }
 
 DXIL::InputPrimitive DxilModule::GetInputPrimitive() const {

lib/DxilContainer/DxilContainerAssembler.cpp

@@ -1812,11 +1812,10 @@ class DxilRDATWriter : public DxilPartWriter {
           shaderKind = (uint32_t)props.shaderKind;
           if (pInfo2 && DM.HasDxilEntryProps(&function)) {
             const auto &entryProps = DM.GetDxilEntryProps(&function);
-            unsigned waveSize = entryProps.props.waveSize;
-            if (waveSize) {
-              pInfo2->MinimumExpectedWaveLaneCount = waveSize;
-              pInfo2->MaximumExpectedWaveLaneCount = waveSize;
-            }
+            pInfo2->MinimumExpectedWaveLaneCount = entryProps.props.waveMinSize;
+            pInfo2->MaximumExpectedWaveLaneCount =
+                entryProps.props.waveMaxSize > 0 ? entryProps.props.waveMaxSize
+                                                 : entryProps.props.waveMinSize;
             pInfo2->ShaderFlags = 0;
             if (entryProps.props.IsNode()) {
               shaderInfo = AddShaderNodeInfo(DM, function, entryProps, *pInfo2,

lib/HLSL/DxilValidation.cpp

@@ -5251,18 +5251,36 @@ static void ValidateEntryProps(ValidationContext &ValCtx,
 
   // validate wave size (currently allowed only on CS but might be supported on
   // other shader types in the future)
-  if (props.waveSize != 0) {
+  if (props.waveMinSize != 0) {
     if (DXIL::CompareVersions(ValCtx.m_DxilMajor, ValCtx.m_DxilMinor, 1, 6) <
         0) {
       ValCtx.EmitFnFormatError(F, ValidationRule::SmWaveSizeNeedsDxil16Plus,
                                {});
     }
-    if (!DXIL::IsValidWaveSizeValue(props.waveSize)) {
+    if (!DXIL::IsValidWaveSizeValue(props.waveMinSize, props.waveMaxSize,
+                                    props.wavePreferredSize)) {
       ValCtx.EmitFnFormatError(F, ValidationRule::SmWaveSizeValue,
-                               {std::to_string(props.waveSize),
+                               {std::to_string(props.waveMinSize),
                                 std::to_string(DXIL::kMinWaveSize),
                                 std::to_string(DXIL::kMaxWaveSize)});
     }
+
+    bool prefInRange = props.wavePreferredSize == 0
+                           ? true
+                           : props.wavePreferredSize >= props.waveMinSize &&
+                                 props.wavePreferredSize <= props.waveMaxSize;
+    if (!prefInRange) {
+      ValCtx.EmitFnFormatError(F, ValidationRule::SmWaveSizePreferredOutOfRange,
+                               {std::to_string(props.wavePreferredSize),
+                                std::to_string(props.waveMinSize),
+                                std::to_string(props.waveMaxSize)});
+    }
+
+    if (props.waveMaxSize != 0 && props.waveMinSize >= props.waveMaxSize) {
+      ValCtx.EmitFnFormatError(F, ValidationRule::SmWaveSizeMinGEQMax,
+                               {std::to_string(props.waveMinSize),
+                                std::to_string(props.waveMaxSize)});
+    }
   }
 
   if (ShaderType == DXIL::ShaderKind::Compute || props.IsNode()) {

tools/clang/include/clang/Basic/Attr.td

@@ -908,7 +908,7 @@ def HLSLWaveSensitive : InheritableAttr {
 
 def HLSLWaveSize : InheritableAttr {
   let Spellings = [CXX11<"", "wavesize", 2017>];
-  let Args = [IntArgument<"Size">];
+  let Args = [IntArgument<"Min">, DefaultIntArgument<"Max", 0>, DefaultIntArgument<"Preferred", 0>];
   let Documentation = [Undocumented];
 }
 

tools/clang/lib/CodeGen/CGHLSLMS.cpp

@@ -1809,8 +1809,11 @@ void CGMSHLSLRuntime::AddHLSLFunctionInfo(Function *F, const FunctionDecl *FD) {
     funcProps->ShaderProps.PS.EarlyDepthStencil = true;
   }
 
-  if (const HLSLWaveSizeAttr *Attr = FD->getAttr<HLSLWaveSizeAttr>())
-    funcProps->waveSize = Attr->getSize();
+  if (const HLSLWaveSizeAttr *Attr = FD->getAttr<HLSLWaveSizeAttr>()) {
+    funcProps->waveMinSize = Attr->getMin();
+    funcProps->waveMaxSize = Attr->getMax();
+    funcProps->wavePreferredSize = Attr->getPreferred();
+  }
 
   // Node shader
   if (isNode) {

tools/clang/lib/Sema/SemaHLSL.cpp

@@ -12620,21 +12620,39 @@ HLSLWaveSizeAttr *ValidateWaveSizeAttributes(Sema &S, Decl *D,
                                              const AttributeList &A) {
   // validate that the wavesize argument is a power of 2 between 4 and 128
   // inclusive
-  HLSLWaveSizeAttr *pAttr = ::new (S.Context)
-      HLSLWaveSizeAttr(A.getRange(), S.Context, ValidateAttributeIntArg(S, A),
-                       A.getAttributeSpellingListIndex());
+  HLSLWaveSizeAttr *pAttr = ::new (S.Context) HLSLWaveSizeAttr(
+      A.getRange(), S.Context, ValidateAttributeIntArg(S, A, 0),
+      ValidateAttributeIntArg(S, A, 1), ValidateAttributeIntArg(S, A, 2),
+      A.getAttributeSpellingListIndex());
+
+  int minWave = pAttr->getMin();
+  int maxWave = pAttr->getMax();
+  int prefWave = pAttr->getPreferred();
 
-  unsigned waveSize = pAttr->getSize();
-  if (!DXIL::IsValidWaveSizeValue(waveSize)) {
+  if (!DXIL::IsValidWaveSizeValue(minWave, maxWave, prefWave)) {
     S.Diag(A.getLoc(), diag::err_hlsl_wavesize_size)
         << DXIL::kMinWaveSize << DXIL::kMaxWaveSize;
   }
 
+  bool prefInRange =
+      prefWave == 0 ? true : prefWave >= minWave && prefWave <= maxWave;
+  if (!prefInRange) {
+    S.Diag(A.getLoc(), diag::err_hlsl_wavesize_pref_size_out_of_range)
+        << (unsigned)prefWave << (unsigned)minWave << (unsigned)maxWave;
+  }
+
+  if (maxWave != 0 && minWave >= maxWave) {
+    S.Diag(A.getLoc(), diag::err_hlsl_wavesize_min_geq_max)
+        << (unsigned)minWave << (unsigned)maxWave;
+  }
+
   // make sure there is not already an existing conflicting
   // wavesize attribute on the decl
   HLSLWaveSizeAttr *waveSizeAttr = D->getAttr<HLSLWaveSizeAttr>();
   if (waveSizeAttr) {
-    if (waveSizeAttr->getSize() != pAttr->getSize()) {
+    if (waveSizeAttr->getMin() != pAttr->getMin() ||
+        waveSizeAttr->getMax() != pAttr->getMax() ||
+        waveSizeAttr->getPreferred() != pAttr->getPreferred()) {
       S.Diag(A.getLoc(), diag::err_hlsl_conflicting_shader_attribute)
           << pAttr->getSpelling() << waveSizeAttr->getSpelling();
       S.Diag(waveSizeAttr->getLocation(), diag::note_conflicting_attribute);
@@ -14609,7 +14627,13 @@ void hlsl::CustomPrintHLSLAttr(const clang::Attr *A, llvm::raw_ostream &Out,
     Attr *noconst = const_cast<Attr *>(A);
     HLSLWaveSizeAttr *ACast = static_cast<HLSLWaveSizeAttr *>(noconst);
     Indent(Indentation, Out);
-    Out << "[wavesize(" << ACast->getSize() << ")]\n";
+    Out << "[wavesize(" << ACast->getMin();
+    if (ACast->getMax() > 0) {
+      Out << ", " << ACast->getMax();
+      if (ACast->getPreferred() > 0)
+        Out << ", " << ACast->getPreferred();
+    }
+    Out << ")]\n";
     break;
   }