Make vertex buffers optional in the TraditionalRaster pipeline and add VerticesFromVertexID.test

include/Support/Pipeline.h

@@ -383,11 +383,11 @@ struct VertexAttribute {
 
 struct IOBindings {
   std::string VertexBuffer;
-  CPUBuffer *VertexBufferPtr;
+  CPUBuffer *VertexBufferPtr = nullptr;
   llvm::SmallVector<VertexAttribute> VertexAttributes;
 
   std::string RenderTarget;
-  CPUBuffer *RTargetBufferPtr;
+  CPUBuffer *RTargetBufferPtr = nullptr;
 
   uint32_t getVertexStride() const {
     uint32_t Stride = 0;

lib/API/DX/Device.cpp

@@ -1638,6 +1638,16 @@ class DXDevice : public offloadtest::Device {
       if (auto Err = CreateBuffer(Resource, IS.RootResources))
         return Err;
     }
+
+    if (P.isTraditionalRaster() && P.Bindings.VertexBufferPtr) {
+      auto VBOrErr = offloadtest::createVertexBufferFromCPUBuffer(
+          *this, *P.Bindings.VertexBufferPtr);
+      if (!VBOrErr)
+        return VBOrErr.takeError();
+      IS.VB = std::move(*VBOrErr);
+      llvm::outs() << "Vertex buffer created.\n";
+    }
+
     return llvm::Error::success();
   }
 
@@ -1911,39 +1921,11 @@ class DXDevice : public offloadtest::Device {
     return llvm::Error::success();
   }
 
-  llvm::Error createVertexBuffer(Pipeline &P, InvocationState &IS) {
-    if (!P.Bindings.VertexBufferPtr)
-      return llvm::createStringError(
-          std::errc::invalid_argument,
-          "No vertex buffer bound for graphics pipeline.");
-
-    auto VBOrErr = offloadtest::createVertexBufferFromCPUBuffer(
-        *this, *P.Bindings.VertexBufferPtr);
-    if (!VBOrErr)
-      return VBOrErr.takeError();
-    IS.VB = std::move(*VBOrErr);
-
-    auto &VBBuf = llvm::cast<DXBuffer>(*IS.VB);
-    D3D12_VERTEX_BUFFER_VIEW VBView = {};
-    VBView.BufferLocation = VBBuf.Buffer->GetGPUVirtualAddress();
-    VBView.SizeInBytes = static_cast<UINT>(IS.VB->getSizeInBytes());
-    VBView.StrideInBytes = P.Bindings.getVertexStride();
-
-    IS.CB->CmdList->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
-    IS.CB->CmdList->IASetVertexBuffers(0, 1, &VBView);
-
-    return llvm::Error::success();
-  }
-
   llvm::Error createGraphicsCommands(Pipeline &P, InvocationState &IS) {
     auto &RT = llvm::cast<DXTexture>(*IS.RT);
     auto &DS = llvm::cast<DXTexture>(*IS.DS);
     auto &RTReadback = llvm::cast<DXBuffer>(*IS.RTReadback);
 
-    if (!IS.VB)
-      return llvm::createStringError(std::errc::invalid_argument,
-                                     "Vertex buffer not initialized.");
-
     const DXPipelineState &DXPipeline =
         llvm::cast<DXPipelineState>(*IS.Pipeline.get());
     IS.CB->CmdList->SetGraphicsRootSignature(DXPipeline.RootSig.Get());
@@ -1981,6 +1963,17 @@ class DXDevice : public offloadtest::Device {
                                 static_cast<LONG>(VP.Height)};
     IS.CB->CmdList->RSSetScissorRects(1, &Scissor);
 
+    if (IS.VB) {
+      auto &VBBuf = llvm::cast<DXBuffer>(*IS.VB);
+      D3D12_VERTEX_BUFFER_VIEW VBView = {};
+      VBView.BufferLocation = VBBuf.Buffer->GetGPUVirtualAddress();
+      VBView.SizeInBytes = static_cast<UINT>(IS.VB->getSizeInBytes());
+      VBView.StrideInBytes = P.Bindings.getVertexStride();
+      IS.CB->CmdList->IASetVertexBuffers(0, 1, &VBView);
+    }
+
+    IS.CB->CmdList->IASetPrimitiveTopology(D3D_PRIMITIVE_TOPOLOGY_TRIANGLELIST);
+
     IS.CB->CmdList->DrawInstanced(P.getVertexCount(), 1, 0, 0);
 
     // Transition the render target to copy source and copy to the readback
@@ -2108,9 +2101,6 @@ class DXDevice : public offloadtest::Device {
       if (auto Err = createDepthStencil(P, State))
         return Err;
       llvm::outs() << "Depth stencil created.\n";
-      if (auto Err = createVertexBuffer(P, State))
-        return Err;
-      llvm::outs() << "Vertex buffer created.\n";
 
       ShaderContainer VS = {};
       ShaderContainer PS = {};

lib/API/MTL/MTLDevice.cpp

@@ -955,17 +955,13 @@ class MTLDevice : public offloadtest::Device {
       }
     }
 
-    if (P.isTraditionalRaster()) {
-      if (!P.Bindings.VertexBufferPtr)
-        return llvm::createStringError(
-            std::errc::invalid_argument,
-            "No vertex buffer specified for graphics pipeline.");
-
+    if (P.isTraditionalRaster() && P.Bindings.VertexBufferPtr) {
       auto VBOrErr = offloadtest::createVertexBufferFromCPUBuffer(
           *this, *P.Bindings.VertexBufferPtr);
       if (!VBOrErr)
         return VBOrErr.takeError();
       IS.VB = std::move(*VBOrErr);
+      llvm::outs() << "Vertex buffer created.\n";
     }
     return llvm::Error::success();
   }
@@ -1146,9 +1142,10 @@ class MTLDevice : public offloadtest::Device {
     CmdEncoder->setCullMode(MTL::CullModeNone);
     CmdEncoder->setFrontFacingWinding(MTL::WindingCounterClockwise);
 
-    // Bind vertex buffer at slot 0 to match the vertex descriptor which
-    // references buffer index 0.
-    CmdEncoder->setVertexBuffer(llvm::cast<MTLBuffer>(*IS.VB).Buf, 0, 0);
+    if (IS.VB)
+      // Bind vertex buffer at slot 0 to match the vertex descriptor which
+      // references buffer index 0.
+      CmdEncoder->setVertexBuffer(llvm::cast<MTLBuffer>(*IS.VB).Buf, 0, 0);
 
     CmdEncoder->drawPrimitives(MTL::PrimitiveTypeTriangle, NS::UInteger(0),
                                P.getVertexCount());
@@ -1388,8 +1385,8 @@ class MTLDevice : public offloadtest::Device {
             "Mismatch between vertex shader attribute count and pipeline "
             "vertex input count.");
 
-      // Collect the attribute indices the shader expects so that we can map the
-      // specified attributes onto the correct indices.
+      // Collect the attribute indices the shader expects so that we can map
+      // the specified attributes onto the correct indices.
       llvm::StringMap<uint32_t> ShaderAttrIndices;
       for (uint32_t I = 0; I < FnAttrs->count(); ++I) {
         auto *A = static_cast<MTL::VertexAttribute *>(FnAttrs->object(I));

lib/API/VK/Device.cpp

@@ -1931,17 +1931,15 @@ class VulkanDevice : public offloadtest::Device {
       // conditional on the pipeline definition.
       if (auto Err = createDepthStencil(P, IS))
         return Err;
+    }
 
-      if (P.Bindings.VertexBufferPtr == nullptr)
-        return llvm::createStringError(
-            std::errc::invalid_argument,
-            "No Vertex buffer specified for graphics pipeline.");
-
+    if (P.isTraditionalRaster() && P.Bindings.VertexBufferPtr) {
       auto VBOrErr = offloadtest::createVertexBufferFromCPUBuffer(
           *this, *P.Bindings.VertexBufferPtr);
       if (!VBOrErr)
         return VBOrErr.takeError();
       IS.VB = std::move(*VBOrErr);
+      llvm::outs() << "Vertex buffer created.\n";
     }
 
     return llvm::Error::success();
@@ -2737,9 +2735,10 @@ class VulkanDevice : public offloadtest::Device {
                    << P.DispatchParameters.DispatchGroupCount[2] << " }\n";
     } else {
       VkDeviceSize Offsets[1]{0};
-      assert(IS.VB);
-      VkBuffer VBHandle = llvm::cast<VulkanBuffer>(*IS.VB).Buffer;
-      vkCmdBindVertexBuffers(IS.CB->CmdBuffer, 0, 1, &VBHandle, Offsets);
+      if (IS.VB) {
+        VkBuffer VBHandle = llvm::cast<VulkanBuffer>(*IS.VB).Buffer;
+        vkCmdBindVertexBuffers(IS.CB->CmdBuffer, 0, 1, &VBHandle, Offsets);
+      }
       // instanceCount must be >=1 to draw; previously was 0 which draws nothing
       vkCmdDraw(IS.CB->CmdBuffer, P.getVertexCount(), 1, 0, 0);
       llvm::outs() << "Drew " << P.getVertexCount() << " vertices.\n";

test/Graphics/VerticesFromVertexID.test

@@ -0,0 +1,74 @@
+#--- vertex.hlsl
+struct PSInput
+{
+    float4 position : SV_POSITION;
+    float4 color : COLOR;
+};
+
+PSInput main(uint vertexID : SV_VertexID)
+{
+    PSInput result;
+
+    if (vertexID == 0) {
+        result.position = float4(0.0, 0.25, 0.0, 1.0);
+        result.color = float4(1.0, 0.0, 0.0, 1.0);
+    } else if (vertexID == 1) {
+        result.position = float4(0.25, -0.25, 0.0, 1.0);
+        result.color = float4(0.0, 1.0, 0.0, 1.0);
+    } else {
+        result.position = float4(-0.25, -0.25, 0.0, 1.0);
+        result.color = float4(0.0, 0.0, 1.0, 1.0);
+    }
+
+    return result;
+}
+
+
+#--- pixel.hlsl
+struct PSInput
+{
+    float4 position : SV_POSITION;
+    float4 color : COLOR;
+};
+
+float4 main(PSInput input) : SV_TARGET
+{
+    return input.color;
+}
+#--- pipeline.yaml
+---
+Shaders:
+  - Stage: Vertex
+    Entry: main
+  - Stage: Pixel
+    Entry: main
+Buffers:
+  - Name: Output
+    Format: Float32
+    Channels: 4
+    FillSize: 1048576 # 256x256 @ 16 bytes per pixel
+    OutputProps:
+      Height: 256
+      Width: 256
+      Depth: 1
+Bindings:
+  RenderTarget: Output
+DescriptorSets: []
+DispatchParameters:
+  VertexCount: 3
+...
+#--- rules.yaml
+---
+- Type: PixelPercent
+  Val: 0.2 # No more than 0.2% of pixels may be visibly different.
+...
+#--- end
+
+# XFAIL: Clang && !Vulkan
+# REQUIRES: goldenimage
+
+# RUN: split-file %s %t
+# RUN: %dxc_target -T vs_6_0 -Fo %t-vertex.o %t/vertex.hlsl
+# RUN: %dxc_target -T ps_6_0 -Fo %t-pixel.o %t/pixel.hlsl
+# RUN: %offloader %t/pipeline.yaml %t-vertex.o %t-pixel.o -r Output -o %t/Output.png
+# RUN: imgdiff %t/Output.png %goldenimage_dir/hlsl/Graphics/VerticesFromVertexID.png -rules %t/rules.yaml