Remove the shader input IsOffChip

This SGPR was originally for pre-GFX9 when tessellation on-chip mode is available. Now, this SGPR is necessary when merged shader doesn't provide it since tessellation is always in off-chip mode. Also, always make the SGPR corresponding to offChipLdsBase present because we are always on off-chip tessellation mode.
GPUOpen-Drivers · Dec 4, 2023 · 2e2ebcd · 2e2ebcd
1 parent 7eb4d8a
commit 2e2ebcd
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Showing 3 changed files with 6 additions and 30 deletions.
diff --git a/lgc/include/lgc/patch/ShaderInputs.h b/lgc/include/lgc/patch/ShaderInputs.h
@@ -86,7 +86,6 @@ enum class ShaderInput : unsigned {
   GsWaveId,   // GS wave ID
 
   // Unmerged hardware ES SGPRs
-  IsOffChip,  // is_off_chip
   EsGsOffset, // ES to GS offset
 
   // Unmerged hardware HS SGPRs

diff --git a/lgc/patch/NggPrimShader.cpp b/lgc/patch/NggPrimShader.cpp
@@ -3118,9 +3118,7 @@ void NggPrimShader::runEs(ArrayRef<Argument *> args) {
   if (m_hasTes) {
     // Set up system value SGPRs
     if (m_pipelineState->isTessOffChip()) {
-      Value *isOffChip = PoisonValue::get(m_builder.getInt32Ty()); // Unused
-      esArgs.push_back(m_hasGs ? offChipLdsBase : isOffChip);
-      esArgs.push_back(m_hasGs ? isOffChip : offChipLdsBase);
+      esArgs.push_back(offChipLdsBase);
     }
 
     if (m_hasGs)
@@ -3336,8 +3334,6 @@ Value *NggPrimShader::runPartEs(ArrayRef<Argument *> args, Value *position) {
   if (m_hasTes) {
     // Set up system value SGPRs
     if (m_pipelineState->isTessOffChip()) {
-      Value *isOffChip = PoisonValue::get(m_builder.getInt32Ty()); // Unused
-      partEsArgs.push_back(isOffChip);
       partEsArgs.push_back(offChipLdsBase);
     }
 
@@ -7511,8 +7507,6 @@ Value *NggPrimShader::fetchXfbOutput(Function *target, ArrayRef<Argument *> args
   if (m_hasTes) {
     // Set up system value SGPRs
     if (m_pipelineState->isTessOffChip()) {
-      Value *isOffChip = PoisonValue::get(m_builder.getInt32Ty()); // Unused
-      xfbFetcherArgs.push_back(isOffChip);
       xfbFetcherArgs.push_back(offChipLdsBase);
     }
 

diff --git a/lgc/patch/ShaderInputs.cpp b/lgc/patch/ShaderInputs.cpp
@@ -228,8 +228,6 @@ const char *ShaderInputs::getInputName(ShaderInput inputKind) {
     return "GsVsOffset";
   case ShaderInput::GsWaveId:
     return "GsWaveId";
-  case ShaderInput::IsOffChip:
-    return "IsOffChip";
   case ShaderInput::EsGsOffset:
     return "EsGsOffset";
   case ShaderInput::TfBufferBase:
@@ -458,8 +456,7 @@ static const ShaderInputDesc VsAsVsSgprInputs[] = {
 
 // SGPRs: TES as hardware ES
 static const ShaderInputDesc TesAsEsSgprInputs[] = {
-    {ShaderInput::OffChipLdsBase, offsetof(InterfaceData, entryArgIdxs.tes.offChipLdsBase)},
-    {ShaderInput::IsOffChip, 0},
+    {ShaderInput::OffChipLdsBase, offsetof(InterfaceData, entryArgIdxs.tes.offChipLdsBase), true},
     {ShaderInput::EsGsOffset, offsetof(InterfaceData, entryArgIdxs.tes.esGsOffset), true},
 };
 
@@ -471,12 +468,12 @@ static const ShaderInputDesc TesAsVsSgprInputs[] = {
     {ShaderInput::StreamOutOffset1, offsetof(InterfaceData, entryArgIdxs.tes.streamOutData.streamOffsets[1])},
     {ShaderInput::StreamOutOffset2, offsetof(InterfaceData, entryArgIdxs.tes.streamOutData.streamOffsets[2])},
     {ShaderInput::StreamOutOffset3, offsetof(InterfaceData, entryArgIdxs.tes.streamOutData.streamOffsets[3])},
-    {ShaderInput::OffChipLdsBase, offsetof(InterfaceData, entryArgIdxs.tes.offChipLdsBase)},
+    {ShaderInput::OffChipLdsBase, offsetof(InterfaceData, entryArgIdxs.tes.offChipLdsBase), true},
 };
 
 // SGPRs: TCS
 static const ShaderInputDesc TcsSgprInputs[] = {
-    {ShaderInput::OffChipLdsBase, offsetof(InterfaceData, entryArgIdxs.tcs.offChipLdsBase)},
+    {ShaderInput::OffChipLdsBase, offsetof(InterfaceData, entryArgIdxs.tcs.offChipLdsBase), true},
     {ShaderInput::TfBufferBase, offsetof(InterfaceData, entryArgIdxs.tcs.tfBufferBase), true},
 };
 
@@ -608,25 +605,11 @@ uint64_t ShaderInputs::getShaderArgTys(PipelineState *pipelineState, ShaderStage
       getShaderInputUsage(shaderStage, ShaderInput::InstanceId)->enable();
     }
     break;
-  case ShaderStageTessControl:
-    if (pipelineState->isTessOffChip()) {
-      // LDS buffer base for off-chip
-      getShaderInputUsage(shaderStage, ShaderInput::OffChipLdsBase)->enable();
-    }
-    break;
   case ShaderStageTessEval:
-    if (pipelineState->isTessOffChip()) {
-      // LDS buffer base for off-chip
-      getShaderInputUsage(shaderStage, ShaderInput::OffChipLdsBase)->enable();
-      // is_off_chip register. Enabling it here only has an effect when TES is hardware ES.
-      getShaderInputUsage(shaderStage, ShaderInput::IsOffChip)->enable();
-    }
     if (!hasGs) {
-      // TES as hardware VS: handle HW stream-out. StreamOutInfo is required for off-chip even if there is no
-      // stream-out.
-      if (pipelineState->isTessOffChip() || enableHwXfb)
-        getShaderInputUsage(shaderStage, ShaderInput::StreamOutInfo)->enable();
+      // TES as hardware VS: handle HW stream-out.
       if (enableHwXfb) {
+        getShaderInputUsage(shaderStage, ShaderInput::StreamOutInfo)->enable();
         getShaderInputUsage(shaderStage, ShaderInput::StreamOutWriteIndex)->enable();
         for (unsigned i = 0; i < MaxTransformFeedbackBuffers; ++i) {
           if (xfbStrides[i] > 0)