add root constant support

Author: joaosaffran

llvm/lib/Target/DirectX/DXILRootSignature.cpp

@@ -43,7 +43,7 @@ static bool reportError(LLVMContext *Ctx, Twine Message,
 static bool parseRootConstants(LLVMContext *Ctx, mcdxbc::RootSignatureDesc &RSD,
                                MDNode *RootConstNode) {
   if (RootConstNode->getNumOperands() != 5)
-    return reportError(Ctx, "Invalid format for RootFlag Element");
+    return reportError(Ctx, "Invalid format for Root constants element");
 
   dxbc::RootParameter NewParam;
   NewParam.ParameterType = dxbc::RootParameterType::Constants32Bit;
@@ -69,6 +69,8 @@ static bool parseRootConstants(LLVMContext *Ctx, mcdxbc::RootSignatureDesc &RSD,
       mdconst::extract<ConstantInt>(RootConstNode->getOperand(4));
   NewParam.Constants.Num32BitValues = Num32BitValues->getZExtValue();
 
+  RSD.Parameters.push_back(NewParam);
+
   return false;
 }
 
@@ -94,10 +96,12 @@ static bool parseRootSignatureElement(LLVMContext *Ctx,
   RootSignatureElementKind ElementKind =
       StringSwitch<RootSignatureElementKind>(ElementText->getString())
           .Case("RootFlags", RootSignatureElementKind::RootFlags)
+          .Case("RootConstants", RootSignatureElementKind::RootConstants)
           .Default(RootSignatureElementKind::Error);
 
   switch (ElementKind) {
-
+  case RootSignatureElementKind::RootConstants:
+    return parseRootConstants(Ctx, RSD, Element);
   case RootSignatureElementKind::RootFlags:
     return parseRootFlags(Ctx, RSD, Element);
   case RootSignatureElementKind::Error:
@@ -241,6 +245,34 @@ PreservedAnalyses RootSignatureAnalysisPrinter::run(Module &M,
     OS << indent(Space) << "NumStaticSamplers: " << 0 << ":\n";
     OS << indent(Space) << "StaticSamplersOffset: "
        << sizeof(RS.Header) + RS.Parameters.size_in_bytes() << ":\n";
+
+    OS << indent(Space) << "- Parameters: \n";
+    Space++;
+    for (const auto &Param : RS.Parameters) {
+      OS << indent(Space) << "Type: " << &Param.ParameterType << " \n";
+      OS << indent(Space) << "ShaderVisibility: " << &Param.ShaderVisibility
+         << " \n";
+      Space++;
+
+      switch (Param.ParameterType) {
+
+      case dxbc::RootParameterType::Constants32Bit: {
+        OS << indent(Space) << "- Constants: \n";
+        Space++;
+        OS << indent(Space)
+           << "RegisterSpace: " << &Param.Constants.RegisterSpace << " \n";
+        OS << indent(Space)
+           << "ShaderRegister: " << &Param.Constants.ShaderRegister << " \n";
+        OS << indent(Space)
+           << "Num32BitValues: " << &Param.Constants.Num32BitValues << " \n";
+        Space--;
+      } break;
+      case dxbc::RootParameterType::Empty:
+        break;
+      }
+      Space--;
+    }
+    Space--;
     Space--;
     // end root signature header
   }

llvm/lib/Target/DirectX/DXILRootSignature.h

@@ -13,6 +13,7 @@
 
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/Analysis/DXILMetadataAnalysis.h"
+#include "llvm/BinaryFormat/DXContainer.h"
 #include "llvm/IR/DiagnosticInfo.h"
 #include "llvm/IR/Metadata.h"
 #include "llvm/IR/Module.h"
@@ -24,7 +25,11 @@
 namespace llvm {
 namespace dxil {
 
-enum class RootSignatureElementKind { Error = 0, RootFlags = 1 };
+enum class RootSignatureElementKind {
+  Error = 0,
+  RootFlags = 1,
+  RootConstants = 2
+};
 class RootSignatureAnalysis : public AnalysisInfoMixin<RootSignatureAnalysis> {
   friend AnalysisInfoMixin<RootSignatureAnalysis>;
   static AnalysisKey Key;

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Constants-Error-invalid-metadata.ll

@@ -0,0 +1,17 @@
+; RUN: not opt -passes='print<dxil-root-signature>' %s -S -o - 2>&1 | FileCheck %s
+
+; CHECK: error: Invalid format for Root constants element
+; CHECK-NOT: Root Signature Definitions
+target triple = "dxil-unknown-shadermodel6.0-compute"
+
+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 } ; function, root signature
+!3 = !{ !4 } ; list of root signature elements
+!4 = !{ !"RootConstants", i32 0, i32 1, i32 2 }

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Constants-Error-invalid-shader-visibility.ll

@@ -0,0 +1,17 @@
+; RUN: not opt -passes='print<dxil-root-signature>' %s -S -o - 2>&1 | FileCheck %s
+
+; CHECK: error: Invalid shader visibility flag value in root constant.
+; CHECK-NOT: Root Signature Definitions
+target triple = "dxil-unknown-shadermodel6.0-compute"
+
+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 } ; function, root signature
+!3 = !{ !4 } ; list of root signature elements
+!4 = !{ !"RootConstants", i32 666, i32 1, i32 2, i32 3 }

llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Constants.ll

@@ -0,0 +1,33 @@
+; RUN: opt %s -dxil-embed -dxil-globals -S -o - | FileCheck %s
+; RUN: llc %s --filetype=obj -o - | obj2yaml | FileCheck %s --check-prefix=DXC
+
+target triple = "dxil-unknown-shadermodel6.0-compute"
+
+; CHECK: @dx.rts0 = private constant [48 x i8]  c"{{.*}}", section "RTS0", align 4
+
+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 } ; function, root signature
+!3 = !{ !4 } ; list of root signature elements
+!4 = !{ !"RootConstants", i32 0, i32 1, i32 2, i32 3 }
+
+
+; DXC: - Name:            RTS0
+; DXC-NEXT:    Size:            48
+; DXC-NEXT:    RootSignature:
+; DXC-NEXT:      Version:         2
+; DXC-NEXT:      NumStaticSamplers: 0
+; DXC-NEXT:      StaticSamplersOffset: 44
+; DXC-NEXT:      Parameters:
+; DXC-NEXT:        - ParameterType:   Constants32Bit
+; DXC-NEXT:          ShaderVisibility: All
+; DXC-NEXT:          Constants:
+; DXC-NEXT:            Num32BitValues:  3
+; DXC-NEXT:            RegisterSpace:   2
+; DXC-NEXT:            ShaderRegister:  1