[llvm] 6b9fe9e - [HLSL] Emit a version in the dx.rootsignatures metadata (#145113)

[via llvm-commits]

Author: Justin Bogner
Date: 2025-06-20T16:21:47-07:00
New Revision: 6b9fe9e0bc7421d89f38ade857c91f0ae153ad9c

URL: https://github.com/llvm/llvm-project/commit/6b9fe9e0bc7421d89f38ade857c91f0ae153ad9c
DIFF: https://github.com/llvm/llvm-project/commit/6b9fe9e0bc7421d89f38ade857c91f0ae153ad9c.diff

LOG: [HLSL] Emit a version in the dx.rootsignatures metadata (#145113)

In #144957 the backend was updated to expect a version in the metadata,
but since the frontend wasn't updated this breaks compilation. This is a
somewhat temporary fix to that until #144813 lands.

Added: 
    

Modified: 
    clang/lib/CodeGen/CGHLSLRuntime.cpp
    clang/test/CodeGenHLSL/RootSignature.hlsl
    llvm/lib/Target/DirectX/DXILRootSignature.cpp
    llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Error.ll

Removed: 
    


################################################################################
diff  --git a/clang/lib/CodeGen/CGHLSLRuntime.cpp b/clang/lib/CodeGen/CGHLSLRuntime.cpp
index 34960c34e109f..3103f1798e14e 100644
--- a/clang/lib/CodeGen/CGHLSLRuntime.cpp
+++ b/clang/lib/CodeGen/CGHLSLRuntime.cpp
@@ -72,12 +72,17 @@ void addRootSignature(ArrayRef<llvm::hlsl::rootsig::RootElement> Elements,
 
   llvm::hlsl::rootsig::MetadataBuilder Builder(Ctx, Elements);
   MDNode *RootSignature = Builder.BuildRootSignature();
-  MDNode *FnPairing =
-      MDNode::get(Ctx, {ValueAsMetadata::get(Fn), RootSignature});
+
+  // TODO: We need to wire the root signature version up through the frontend
+  // rather than hardcoding it.
+  ConstantAsMetadata *Version =
+      ConstantAsMetadata::get(ConstantInt::get(llvm::Type::getInt32Ty(Ctx), 2));
+  MDNode *MDVals =
+      MDNode::get(Ctx, {ValueAsMetadata::get(Fn), RootSignature, Version});
 
   StringRef RootSignatureValKey = "dx.rootsignatures";
   auto *RootSignatureValMD = M.getOrInsertNamedMetadata(RootSignatureValKey);
-  RootSignatureValMD->addOperand(FnPairing);
+  RootSignatureValMD->addOperand(MDVals);
 }
 
 } // namespace

diff  --git a/clang/test/CodeGenHLSL/RootSignature.hlsl b/clang/test/CodeGenHLSL/RootSignature.hlsl
index ca843ffbb1ced..6618ca741aa9d 100644
--- a/clang/test/CodeGenHLSL/RootSignature.hlsl
+++ b/clang/test/CodeGenHLSL/RootSignature.hlsl
@@ -3,14 +3,14 @@
 // CHECK: !dx.rootsignatures = !{![[#EMPTY_ENTRY:]], ![[#DT_ENTRY:]],
 // CHECK-SAME: ![[#RF_ENTRY:]], ![[#RC_ENTRY:]], ![[#RD_ENTRY:]], ![[#SS_ENTRY:]]}
 
-// CHECK: ![[#EMPTY_ENTRY]] = !{ptr @EmptyEntry, ![[#EMPTY:]]}
+// CHECK: ![[#EMPTY_ENTRY]] = !{ptr @EmptyEntry, ![[#EMPTY:]], i32 2}
 // CHECK: ![[#EMPTY]] = !{}
 
 [shader("compute"), RootSignature("")]
 [numthreads(1,1,1)]
 void EmptyEntry() {}
 
-// CHECK: ![[#DT_ENTRY]] = !{ptr @DescriptorTableEntry, ![[#DT_RS:]]}
+// CHECK: ![[#DT_ENTRY]] = !{ptr @DescriptorTableEntry, ![[#DT_RS:]], i32 2}
 // CHECK: ![[#DT_RS]] = !{![[#TABLE:]]}
 // CHECK: ![[#TABLE]] = !{!"DescriptorTable", i32 0, ![[#CBV:]], ![[#SRV:]]}
 // CHECK: ![[#CBV]] = !{!"CBV", i32 1, i32 0, i32 0, i32 -1, i32 4}
@@ -25,7 +25,7 @@ void EmptyEntry() {}
 [numthreads(1,1,1)]
 void DescriptorTableEntry() {}
 
-// CHECK: ![[#RF_ENTRY]] = !{ptr @RootFlagsEntry, ![[#RF_RS:]]}
+// CHECK: ![[#RF_ENTRY]] = !{ptr @RootFlagsEntry, ![[#RF_RS:]], i32 2}
 // CHECK: ![[#RF_RS]] = !{![[#ROOT_FLAGS:]]}
 // CHECK: ![[#ROOT_FLAGS]] = !{!"RootFlags", i32 2114}
 
@@ -38,7 +38,7 @@ void DescriptorTableEntry() {}
 [numthreads(1,1,1)]
 void RootFlagsEntry() {}
 
-// CHECK: ![[#RC_ENTRY]] = !{ptr @RootConstantsEntry, ![[#RC_RS:]]}
+// CHECK: ![[#RC_ENTRY]] = !{ptr @RootConstantsEntry, ![[#RC_RS:]], i32 2}
 // CHECK: ![[#RC_RS]] = !{![[#ROOT_CONSTANTS:]]}
 // CHECK: ![[#ROOT_CONSTANTS]] = !{!"RootConstants", i32 5, i32 1, i32 2, i32 1}
 
@@ -52,7 +52,7 @@ void RootFlagsEntry() {}
 [numthreads(1,1,1)]
 void RootConstantsEntry() {}
 
-// CHECK: ![[#RD_ENTRY]] = !{ptr @RootDescriptorsEntry, ![[#RD_RS:]]}
+// CHECK: ![[#RD_ENTRY]] = !{ptr @RootDescriptorsEntry, ![[#RD_RS:]], i32 2}
 // CHECK: ![[#RD_RS]] = !{![[#ROOT_CBV:]], ![[#ROOT_UAV:]], ![[#ROOT_SRV:]]}
 // CHECK: ![[#ROOT_CBV]] = !{!"RootCBV", i32 0, i32 0, i32 0, i32 4}
 // CHECK: ![[#ROOT_UAV]] = !{!"RootUAV", i32 0, i32 42, i32 3, i32 2}
@@ -66,7 +66,7 @@ void RootConstantsEntry() {}
 [numthreads(1,1,1)]
 void RootDescriptorsEntry() {}
 
-// CHECK: ![[#SS_ENTRY]] = !{ptr @StaticSamplerEntry, ![[#SS_RS:]]}
+// CHECK: ![[#SS_ENTRY]] = !{ptr @StaticSamplerEntry, ![[#SS_RS:]], i32 2}
 // CHECK: ![[#SS_RS]] = !{![[#STATIC_SAMPLER:]]}
 
 // checking filter = 0x4

diff  --git a/llvm/lib/Target/DirectX/DXILRootSignature.cpp b/llvm/lib/Target/DirectX/DXILRootSignature.cpp
index 1f175fd4ecd99..29e78fcce5262 100644
--- a/llvm/lib/Target/DirectX/DXILRootSignature.cpp
+++ b/llvm/lib/Target/DirectX/DXILRootSignature.cpp
@@ -491,8 +491,8 @@ analyzeModule(Module &M) {
 
   for (const auto &RSDefNode : RootSignatureNode->operands()) {
     if (RSDefNode->getNumOperands() != 3) {
-      reportError(Ctx, "Invalid format for Root Signature Definition. Pairs "
-                       "of function, root signature expected.");
+      reportError(Ctx, "Invalid Root Signature metadata - expected function, "
+                       "signature, and version.");
       continue;
     }
 

diff  --git a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Error.ll b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Error.ll
index 2a2188b1a13bb..0392065842116 100644
--- a/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Error.ll
+++ b/llvm/test/CodeGen/DirectX/ContainerData/RootSignature-Error.ll
@@ -2,7 +2,7 @@
 
 target triple = "dxil-unknown-shadermodel6.0-compute"
 
-; CHECK: error: Invalid format for Root Signature Definition. Pairs of function, root signature expected.
+; CHECK: error: Invalid Root Signature metadata - expected function, signature, and version.
 ; CHECK-NOT: Root Signature Definitions