[DirectX] Updating DXContainer logic to read version 1.2 of static samplers (#160184)

joaosaffran · web-flow · commit 4ff986af637f · 2025-09-26T17:07:45.000Z
This PR is updating `Object/DXContainer.h` so that we can read data from
root signature version 1.2, which adds flags into static samplers.
diff --git a/llvm/include/llvm/Object/DXContainer.h b/llvm/include/llvm/Object/DXContainer.h
@@ -228,11 +228,11 @@ class RootSignature {
   uint32_t Flags;
   ViewArray<dxbc::RTS0::v1::RootParameterHeader> ParametersHeaders;
   StringRef PartData;
-  ViewArray<dxbc::RTS0::v1::StaticSampler> StaticSamplers;
+  ViewArray<dxbc::RTS0::v3::StaticSampler> StaticSamplers;
 
   using param_header_iterator =
       ViewArray<dxbc::RTS0::v1::RootParameterHeader>::iterator;
-  using samplers_iterator = ViewArray<dxbc::RTS0::v1::StaticSampler>::iterator;
+  using samplers_iterator = ViewArray<dxbc::RTS0::v3::StaticSampler>::iterator;
 
 public:
   RootSignature(StringRef PD) : PartData(PD) {}
diff --git a/llvm/lib/Object/DXContainer.cpp b/llvm/lib/Object/DXContainer.cpp
@@ -276,10 +276,13 @@ Error DirectX::RootSignature::parse() {
       RootParametersOffset,
       NumParameters * sizeof(dxbc::RTS0::v1::RootParameterHeader));
 
-  StaticSamplers.Stride = sizeof(dxbc::RTS0::v1::StaticSampler);
-  StaticSamplers.Data = PartData.substr(
-      StaticSamplersOffset,
-      NumStaticSamplers * sizeof(dxbc::RTS0::v1::StaticSampler));
+  StaticSamplers.Stride = (Version <= 2)
+                              ? sizeof(dxbc::RTS0::v1::StaticSampler)
+                              : sizeof(dxbc::RTS0::v3::StaticSampler);
+
+  StaticSamplers.Data = PartData.substr(StaticSamplersOffset,
+                                        static_cast<size_t>(NumStaticSamplers) *
+                                            StaticSamplers.Stride);
 
   return Error::success();
 }
diff --git a/llvm/lib/ObjectYAML/DXContainerYAML.cpp b/llvm/lib/ObjectYAML/DXContainerYAML.cpp
@@ -209,6 +209,11 @@ DXContainerYAML::RootSignatureYamlDesc::create(
     NewS.RegisterSpace = S.RegisterSpace;
     NewS.ShaderVisibility = dxbc::ShaderVisibility(S.ShaderVisibility);
 
+    if (Version > 2) {
+#define STATIC_SAMPLER_FLAG(Num, Enum, Flag)                                   \
+  NewS.Enum = (S.Flags & llvm::to_underlying(dxbc::StaticSamplerFlags::Enum));
+#include "llvm/BinaryFormat/DXContainerConstants.def"
+    }
     RootSigDesc.StaticSamplers.push_back(NewS);
   }
 
diff --git a/llvm/test/ObjectYAML/DXContainer/RootSignature-StaticSamplers1.3.yaml b/llvm/test/ObjectYAML/DXContainer/RootSignature-StaticSamplers1.3.yaml
@@ -0,0 +1,65 @@
+# RUN: yaml2obj %s | obj2yaml | FileCheck %s
+
+--- !dxcontainer
+Header:
+  Hash:            [ 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 
+                     0x0, 0x0, 0x0, 0x0, 0x0, 0x0 ]
+  Version:
+    Major:           1
+    Minor:           0
+  PartCount:       1
+  PartOffsets:     [ 60 ]
+Parts:
+  - Name:            RTS0
+    Size:            80
+    RootSignature:
+      Version: 3
+      NumRootParameters: 0
+      RootParametersOffset: 24
+      NumStaticSamplers: 1
+      StaticSamplersOffset: 24
+      Parameters: []
+      Samplers: 
+        - Filter: MinLinearMagMipPoint 
+          AddressU: Wrap
+          AddressV: Mirror
+          AddressW: MirrorOnce
+          MipLODBias: 1.23
+          MaxAnisotropy: 20
+          ComparisonFunc: LessEqual
+          BorderColor: TransparentBlack
+          MinLOD: 4.56
+          MaxLOD: 8.90
+          ShaderRegister: 31 
+          RegisterSpace: 32
+          ShaderVisibility:  Mesh
+          SAMPLER_FLAG_UINT_BORDER_COLOR: true
+      AllowInputAssemblerInputLayout: true
+      DenyGeometryShaderRootAccess: true
+
+#CHECK:  - Name:            RTS0
+#CHECK-NEXT:    Size:            80
+#CHECK-NEXT:    RootSignature:
+#CHECK-NEXT:      Version:         3
+#CHECK-NEXT:      NumRootParameters: 0
+#CHECK-NEXT:      RootParametersOffset: 24
+#CHECK-NEXT:      NumStaticSamplers: 1
+#CHECK-NEXT:      StaticSamplersOffset: 24
+#CHECK-NEXT:      Parameters:      []
+#CHECK-NEXT:      Samplers:
+#CHECK-NEXT:        - Filter:          MinLinearMagMipPoint
+#CHECK-NEXT:          AddressU:        Wrap
+#CHECK-NEXT:          AddressV:        Mirror
+#CHECK-NEXT:          AddressW:        MirrorOnce
+#CHECK-NEXT:          MipLODBias:      1.23
+#CHECK-NEXT:          MaxAnisotropy:   20
+#CHECK-NEXT:          ComparisonFunc:  LessEqual
+#CHECK-NEXT:          BorderColor:     TransparentBlack
+#CHECK-NEXT:          MinLOD:          4.56
+#CHECK-NEXT:          MaxLOD:          8.9
+#CHECK-NEXT:          ShaderRegister:  31
+#CHECK-NEXT:          RegisterSpace:   32
+#CHECK-NEXT:          ShaderVisibility: Mesh
+#CHECK-NEXT:          SAMPLER_FLAG_UINT_BORDER_COLOR: true
+#CHECK-NEXT:      AllowInputAssemblerInputLayout: true
+#CHECK-NEXT:      DenyGeometryShaderRootAccess: true
diff --git a/llvm/unittests/Object/DXContainerTest.cpp b/llvm/unittests/Object/DXContainerTest.cpp
@@ -1200,4 +1200,52 @@ TEST(RootSignature, ParseStaticSamplers) {
     ASSERT_EQ(Sampler.RegisterSpace, 32u);
     ASSERT_EQ(Sampler.ShaderVisibility, 7u);
   }
+  {
+    // this is testing static sampler parsing for root signature version 1.2,
+    // it changes: the version number, the size of root signature being emitted
+    // and the values for flag fields.
+    uint8_t Buffer[] = {
+        0x44, 0x58, 0x42, 0x43, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+        0x90, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00, 0x3c, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x52, 0x54, 0x53, 0x30, 0x4c, 0x00, 0x00, 0x00, 0x03, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01, 0x00, 0x00, 0x00,
+        0x18, 0x00, 0x00, 0x00, 0x11, 0x00, 0x00, 0x00, 0x0a, 0x00, 0x00, 0x00,
+        0x01, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x00,
+        0xa4, 0x70, 0x9d, 0x3f, 0x14, 0x00, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00,
+        0x00, 0x00, 0x00, 0x00, 0x85, 0xeb, 0x91, 0x40, 0x66, 0x66, 0x0e, 0x41,
+        0x1f, 0x00, 0x00, 0x00, 0x20, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00,
+        0x01, 0x00, 0x00, 0x00};
+    DXContainer C =
+        llvm::cantFail(DXContainer::create(getMemoryBuffer<148>(Buffer)));
+
+    auto MaybeRS = C.getRootSignature();
+    ASSERT_TRUE(MaybeRS.has_value());
+    const auto &RS = MaybeRS.value();
+    ASSERT_EQ(RS.getVersion(), 3U);
+    ASSERT_EQ(RS.getNumParameters(), 0U);
+    ASSERT_EQ(RS.getRootParametersOffset(), 0U);
+    ASSERT_EQ(RS.getNumStaticSamplers(), 1U);
+    ASSERT_EQ(RS.getStaticSamplersOffset(), 24U);
+    ASSERT_EQ(RS.getFlags(), 17U);
+
+    auto Sampler = *RS.samplers().begin();
+
+    ASSERT_EQ(Sampler.Filter, 10U);
+    ASSERT_EQ(Sampler.AddressU, 1U);
+    ASSERT_EQ(Sampler.AddressV, 2U);
+    ASSERT_EQ(Sampler.AddressW, 5U);
+    ASSERT_FLOAT_EQ(Sampler.MipLODBias, 1.23F);
+    ASSERT_EQ(Sampler.MaxAnisotropy, 20U);
+    ASSERT_EQ(Sampler.ComparisonFunc, 4U);
+    ASSERT_EQ(Sampler.BorderColor, 0U);
+    ASSERT_FLOAT_EQ(Sampler.MinLOD, 4.56F);
+    ASSERT_FLOAT_EQ(Sampler.MaxLOD, 8.9F);
+    ASSERT_EQ(Sampler.ShaderRegister, 31U);
+    ASSERT_EQ(Sampler.RegisterSpace, 32U);
+    ASSERT_EQ(Sampler.ShaderVisibility, 7U);
+    ASSERT_EQ(Sampler.Flags, 1U);
+  }
 }
