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.
GPUOpen-Drivers · Dec 3, 2023 · c6f5fd8 · c6f5fd8
1 parent 7eb4d8a
commit c6f5fd8
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Showing 3 changed files with 1 addition and 13 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:
@@ -459,7 +457,6 @@ static const ShaderInputDesc VsAsVsSgprInputs[] = {
 // SGPRs: TES as hardware ES
 static const ShaderInputDesc TesAsEsSgprInputs[] = {
     {ShaderInput::OffChipLdsBase, offsetof(InterfaceData, entryArgIdxs.tes.offChipLdsBase)},
-    {ShaderInput::IsOffChip, 0},
     {ShaderInput::EsGsOffset, offsetof(InterfaceData, entryArgIdxs.tes.esGsOffset), true},
 };
 
@@ -618,8 +615,6 @@ uint64_t ShaderInputs::getShaderArgTys(PipelineState *pipelineState, ShaderStage
     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