Add GRF selection based on spill allowed option

Author: jfuentes

IGC/Compiler/CISACodeGen/EmitVISAPass.cpp

@@ -700,7 +700,7 @@ bool EmitPass::runOnFunction(llvm::Function& F)
         CShader * simd16Program = Iter->second->GetShader(SIMDMode::SIMD16);
         if (simd16Program &&
             simd16Program->ProgramOutput()->m_programBin != 0 &&
-            simd16Program->ProgramOutput()->m_scratchSpaceUsedBySpills == 0)
+            !m_pCtx->hasSpills(simd16Program->ProgramOutput()->m_scratchSpaceUsedBySpills))
             return false;
     }
     if (IGC_IS_FLAG_ENABLED(EnableKernelCostInfo)) {
@@ -813,7 +813,7 @@ bool EmitPass::runOnFunction(llvm::Function& F)
             m_encoder->GetSimdSize() == prevShader->GetEncoder().GetSimdSize() &&
             prevShader->GetEncoder().IsCodePatchCandidate() &&
             prevShader->ProgramOutput()->m_programBin &&
-            prevShader->ProgramOutput()->m_scratchSpaceUsedBySpills == 0)
+            !m_pCtx->hasSpills(prevShader->ProgramOutput()->m_scratchSpaceUsedBySpills))
         {
             prevKernel = prevShader->GetEncoder().GetVISAKernel();
             m_encoder->SetPayloadEnd(prevShader->GetEncoder().GetPayloadEnd());
@@ -1324,7 +1324,7 @@ bool EmitPass::runOnFunction(llvm::Function& F)
 
         if (m_encoder->IsCodePatchCandidate())
         {
-            if (m_currShader->ProgramOutput()->m_scratchSpaceUsedBySpills)
+            if (m_pCtx->hasSpills(m_currShader->ProgramOutput()->m_scratchSpaceUsedBySpills))
             {
                 if (IGC_GET_FLAG_VALUE(CodePatchExperiments))
                 {
@@ -1434,7 +1434,7 @@ bool EmitPass::runOnFunction(llvm::Function& F)
         if (!m_encoder->IsCodePatchCandidate() ||
             m_encoder->HasPrevKernel() ||
             !m_currShader->ProgramOutput()->m_programBin ||
-            m_currShader->ProgramOutput()->m_scratchSpaceUsedBySpills)
+            m_pCtx->hasSpills(m_currShader->ProgramOutput()->m_scratchSpaceUsedBySpills))
         {
             m_pCtx->m_prevShader = nullptr;
             // Postpone destroying VISA builder to

IGC/Compiler/CISACodeGen/OpenCLKernelCodeGen.cpp

@@ -220,7 +220,7 @@ namespace IGC
                 auto& annotatnions = funcMD.UserAnnotations;
                 auto output = shader->ProgramOutput();
 
-                if (output->m_scratchSpaceUsedBySpills > 0 &&
+                if (hasSpills(output->m_scratchSpaceUsedBySpills) &&
                     std::find(annotatnions.begin(), annotatnions.end(), "igc-do-not-spill") != annotatnions.end())
                 {
                     std::string msg =
@@ -3252,7 +3252,7 @@ namespace IGC
             return RetryType::NO_Retry_Pick_Prv;
         }
         else if (
-            pOutput->m_scratchSpaceUsedBySpills == 0 ||
+            !ctx->hasSpills(pOutput->m_scratchSpaceUsedBySpills) ||
             ctx->getModuleMetaData()->compOpt.OptDisable ||
             ctx->m_retryManager.IsLastTry() ||
             (!ctx->m_retryManager.kernelSkip.empty() &&

IGC/Compiler/CodeGenPublic.h

@@ -1029,6 +1029,7 @@ namespace IGC
         // Map to store global offsets in original global buffer
         std::map<std::string, uint64_t> inlineProgramScopeGlobalOffsets;
         std::vector<std::string> entry_names;
+        uint m_spillAllowed = 0;
     private:
         //For storing error message
         std::stringstream oclErrorMessage;
@@ -1279,6 +1280,11 @@ namespace IGC
 
             return false;
         }
+
+        bool hasSpills(uint mscratchSpaceUsedBySpills)
+        {
+            return (mscratchSpaceUsedBySpills > m_spillAllowed);
+        }
     };
 
     struct SComputeShaderSecondCompileInput

visa/G4_Kernel.cpp

@@ -2150,6 +2150,7 @@ GRFMode::GRFMode(const TARGET_PLATFORM platform, Options *op) : options(op) {
 unsigned GRFMode::setModeByRegPressure(unsigned maxRP,
                                        unsigned largestInputReg) {
   unsigned size = configs.size(), i = 0;
+  bool spillAllowed = 0;
   // find appropiate GRF based on reg pressure
   for (; i < size; i++) {
     if (configs[i].VRTEnable && configs[i].numGRF >= lowerBoundGRF &&
@@ -2159,8 +2160,12 @@ unsigned GRFMode::setModeByRegPressure(unsigned maxRP,
           // Check that we've at least 8 GRFs over and above
           // those blocked for kernel input. This helps cases
           // where an 8 GRF variable shows up in entry BB.
-          (largestInputReg + 8) <= configs[i].numGRF)
-        return configs[currentMode].numGRF;
+          (largestInputReg + 8) <= configs[i].numGRF) {
+        if (spillAllowed && currentMode > 0)
+          return configs[--currentMode].numGRF;
+        else
+          return configs[currentMode].numGRF;
+      }
     }
   }
   // RP is greater than the maximum GRF available, so set the largest GRF