[DirectX] Updating Root Signature Metadata to contain Static Sampler flags (llvm#160210)

Root Signature 1.2 adds flags to static samplers. This requires us to
change the metadata representation to account for it when being
generated. This patch focus on the metadata changes required in the
backend, frontend changes will come in a future PR.

Author: joaosaffran

clang/test/CodeGenHLSL/RootSignature.hlsl

@@ -82,8 +82,8 @@ void RootDescriptorsEntry() {}
 // checking minLOD, maxLOD
 // CHECK-SAME: float -1.280000e+02, float 1.280000e+02,
 
-// checking register, space and visibility
-// CHECK-SAME: i32 42, i32 0, i32 0}
+// checking register, space, visibility and flags
+// CHECK-SAME: i32 42, i32 0, i32 0, i32 0}
 
 #define SampleStaticSampler \
   "StaticSampler(s42, " \

llvm/include/llvm/Frontend/HLSL/HLSLRootSignature.h

@@ -131,6 +131,7 @@ struct StaticSampler {
   float MaxLOD = std::numeric_limits<float>::max();
   uint32_t Space = 0;
   dxbc::ShaderVisibility Visibility = dxbc::ShaderVisibility::All;
+  dxbc::StaticSamplerFlags Flags = dxbc::StaticSamplerFlags::None;
 };
 
 /// Models RootElement : RootFlags | RootConstants | RootParam

llvm/lib/Frontend/HLSL/RootSignatureMetadata.cpp

@@ -218,6 +218,7 @@ MDNode *MetadataBuilder::BuildStaticSampler(const StaticSampler &Sampler) {
       ConstantAsMetadata::get(Builder.getInt32(Sampler.Space)),
       ConstantAsMetadata::get(
           Builder.getInt32(to_underlying(Sampler.Visibility))),
+      ConstantAsMetadata::get(Builder.getInt32(to_underlying(Sampler.Flags))),
   };
   return MDNode::get(Ctx, Operands);
 }
@@ -417,7 +418,7 @@ Error MetadataParser::parseDescriptorTable(mcdxbc::RootSignatureDesc &RSD,
 
 Error MetadataParser::parseStaticSampler(mcdxbc::RootSignatureDesc &RSD,
                                          MDNode *StaticSamplerNode) {
-  if (StaticSamplerNode->getNumOperands() != 14)
+  if (StaticSamplerNode->getNumOperands() != 15)
     return make_error<InvalidRSMetadataFormat>("Static Sampler");
 
   mcdxbc::StaticSampler Sampler;
@@ -501,6 +502,17 @@ Error MetadataParser::parseStaticSampler(mcdxbc::RootSignatureDesc &RSD,
     return Error(std::move(E));
   Sampler.ShaderVisibility = *Visibility;
 
+  if (RSD.Version < 3) {
+    RSD.StaticSamplers.push_back(Sampler);
+    return Error::success();
+  }
+  assert(RSD.Version >= 3);
+
+  if (std::optional<uint32_t> Val = extractMdIntValue(StaticSamplerNode, 14))
+    Sampler.Flags = *Val;
+  else
+    return make_error<InvalidRSMetadataValue>("Static Sampler Flags");
+
   RSD.StaticSamplers.push_back(Sampler);
   return Error::success();
 }

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-StaticSamplers-Invalid-AddressU.ll

@@ -16,4 +16,4 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
 !dx.rootsignatures = !{!2} ; list of function/root signature pairs
 !2 = !{ ptr @main, !3, i32 2 } ; function, root signature
 !3 = !{ !5 } ; list of root signature elements
-!5 = !{ !"StaticSampler", i32 4, i32 666, i32 3, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0 }
+!5 = !{ !"StaticSampler", i32 4, i32 666, i32 3, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0, i32 0 }

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-StaticSamplers-Invalid-AddressV.ll

@@ -16,4 +16,4 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
 !dx.rootsignatures = !{!2} ; list of function/root signature pairs
 !2 = !{ ptr @main, !3, i32 2 } ; function, root signature
 !3 = !{ !5 } ; list of root signature elements
-!5 = !{ !"StaticSampler", i32 4, i32 2, i32 666, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0 }
+!5 = !{ !"StaticSampler", i32 4, i32 2, i32 666, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0, i32 0 }

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-StaticSamplers-Invalid-AddressW.ll

@@ -16,4 +16,4 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
 !dx.rootsignatures = !{!2} ; list of function/root signature pairs
 !2 = !{ ptr @main, !3, i32 2 } ; function, root signature
 !3 = !{ !5 } ; list of root signature elements
-!5 = !{ !"StaticSampler", i32 4, i32 2, i32 3, i32 666, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0 }
+!5 = !{ !"StaticSampler", i32 4, i32 2, i32 3, i32 666, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0, i32 0 }

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-StaticSamplers-Invalid-BorderColor.ll

@@ -16,4 +16,4 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
 !dx.rootsignatures = !{!2} ; list of function/root signature pairs
 !2 = !{ ptr @main, !3, i32 2 } ; function, root signature
 !3 = !{ !5 } ; list of root signature elements
-!5 = !{ !"StaticSampler", i32 4, i32 2, i32 3, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 666, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0 }
+!5 = !{ !"StaticSampler", i32 4, i32 2, i32 3, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 666, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0, i32 0 }

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-StaticSamplers-Invalid-ComparisonFunc.ll

@@ -16,4 +16,4 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
 !dx.rootsignatures = !{!2} ; list of function/root signature pairs
 !2 = !{ ptr @main, !3, i32 2 } ; function, root signature
 !3 = !{ !5 } ; list of root signature elements
-!5 = !{ !"StaticSampler", i32 4, i32 2, i32 3, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 666, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0 }
+!5 = !{ !"StaticSampler", i32 4, i32 2, i32 3, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 666, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0, i32 0 }

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-StaticSamplers-Invalid-Filter.ll

@@ -16,4 +16,4 @@ attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
 !dx.rootsignatures = !{!2} ; list of function/root signature pairs
 !2 = !{ ptr @main, !3, i32 2 } ; function, root signature
 !3 = !{ !5 } ; list of root signature elements
-!5 = !{ !"StaticSampler", i32 45, i32 2, i32 3, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0 }
+!5 = !{ !"StaticSampler", i32 45, i32 2, i32 3, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0, i32 0 }

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-StaticSamplers-Invalid-Flag.ll

@@ -0,0 +1,19 @@
+; RUN: not opt -passes='print<dxil-root-signature>' %s -S -o - 2>&1 | FileCheck %s
+
+
+target triple = "dxil-unknown-shadermodel6.0-compute"
+
+; CHECK: error: Invalid value for Static Sampler Flag: 4 
+; CHECK-NOT: Root Signature Definitions
+
+define void @main() #0 {
+entry:
+  ret void
+}
+attributes #0 = { "hlsl.numthreads"="1,1,1" "hlsl.shader"="compute" }
+
+
+!dx.rootsignatures = !{!2} ; list of function/root signature pairs
+!2 = !{ ptr @main, !3, i32 3 } ; function, root signature
+!3 = !{ !5 } ; list of root signature elements
+!5 = !{ !"StaticSampler", i32 4, i32 2, i32 3, i32 5, float 0x3FF6CCCCC0000000, i32 9, i32 3, i32 2, float -1.280000e+02, float 1.280000e+02, i32 42, i32 0, i32 0, i32 4 }