Merge pull request #7426 from gita-omr/ool_in_warm_pr

Move out-of-line instructions to warm cache
eclipse-omr · Aug 20, 2024 · f2a5b8c · f2a5b8c
2 parents e0dde22 + f93c09f
commit f2a5b8c
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Showing 4 changed files with 70 additions and 1 deletion.
diff --git a/compiler/control/OMROptions.cpp b/compiler/control/OMROptions.cpp
@@ -1003,6 +1003,7 @@ TR::OptionTable OMR::Options::_jitOptions[] = {
         TR::Options::setStaticNumeric, (intptr_t)&OMR::Options::_minProfiledCheckcastFrequency, 0, "F%d", NOT_IN_SUBSET},
    {"minSleepTimeMsForCompThrottling=", "M<nnn>\tLower bound for sleep time during compilation throttling (ms)",
                                          TR::Options::setStaticNumeric, (intptr_t)&OMR::Options::_minSleepTimeMsForCompThrottling, 0, "F%d", NOT_IN_SUBSET },
+   {"moveOOLInstructionsToWarmCode", "M\tmove out-of-line instructions to after last warm instruction", SET_OPTION_BIT(TR_MoveOOLInstructionsToWarmCode), "F"},
    {"noAotSecondRunDetection", "M\tdo not do second run detection for AOT", SET_OPTION_BIT(TR_NoAotSecondRunDetection), "F", NOT_IN_SUBSET },
 #ifdef DEBUG
    {"noExceptions",       "C\tfail compilation for methods with exceptions",

diff --git a/compiler/control/OMROptions.hpp b/compiler/control/OMROptions.hpp
@@ -381,7 +381,7 @@ enum TR_CompilationOptions
    TR_BreakOnNew                          = 0x08000000 + 9,
    TR_DisableInliningUnrecognizedIntrinsics = 0x10000000 + 9,
    TR_EnableVectorAPIExpansion            = 0x20000000 + 9,
-   // Available                           = 0x40000000 + 9,
+   TR_MoveOOLInstructionsToWarmCode       = 0x40000000 + 9,
    // Available                           = 0x80000000 + 9,
 
    // Option word 10

diff --git a/compiler/x/codegen/OMRCodeGenerator.cpp b/compiler/x/codegen/OMRCodeGenerator.cpp
@@ -1867,6 +1867,9 @@ void OMR::X86::CodeGenerator::doRegisterAssignment(TR_RegisterKinds kindsToAssig
 
       self()->doBackwardsRegisterAssignment(kindsToAssign, self()->getAppendInstruction());
       }
+
+   if (TR::Options::getCmdLineOptions()->getOption(TR_MoveOOLInstructionsToWarmCode))
+      moveOutOfLineInstructionsToWarmCode();
    }
 
 bool OMR::X86::CodeGenerator::isReturnInstruction(TR::Instruction *instr)
@@ -3500,3 +3503,62 @@ OMR::X86::CodeGenerator::getOutOfLineCodeSize()
 
    return totalSize;
    }
+
+void
+OMR::X86::CodeGenerator::moveOutOfLineInstructionsToWarmCode()
+   {
+   // OOL instructions are already attached at the end of the IL (after cold instructions)
+   // and register allocated.
+   // Move them to immediately after the last warm instruction, unless they already happened to be
+   // there (e.g. there are no cold instructions)
+   //
+   if (!self()->getLastWarmInstruction())
+      return;
+
+   if (self()->comp()->getOption(TR_TraceCG))
+      traceMsg(self()->comp(), "Moving OutOfLine instructions to after %p\n", self()->getLastWarmInstruction());
+
+   auto oiIterator = self()->getOutlinedInstructionsList().begin();
+
+   while (oiIterator != self()->getOutlinedInstructionsList().end())
+      {
+      TR::Instruction *firstOLInstruction = (*oiIterator)->getFirstInstruction();
+      TR::Instruction *lastOLInstruction  = (*oiIterator)->getAppendInstruction();
+
+      TR_ASSERT_FATAL(firstOLInstruction, "VFPRestore instruction should preceeed any OOL section\n");
+      TR_ASSERT_FATAL(self()->getLastWarmInstruction() != self()->getAppendInstruction(),
+                      "Last warm instruction can't be append instruction since OOL code was attached already\n");
+
+      if (self()->getLastWarmInstruction() != firstOLInstruction->getPrev())
+         {
+         // remove from previous location
+         if (firstOLInstruction->getPrev())
+            firstOLInstruction->getPrev()->setNext(lastOLInstruction->getNext());
+
+         if (lastOLInstruction->getNext())
+            lastOLInstruction->getNext()->setPrev(firstOLInstruction->getPrev());
+
+         // update codegen append instruction
+         if (lastOLInstruction == self()->getAppendInstruction())
+            self()->setAppendInstruction(firstOLInstruction->getPrev());
+
+         // insert after last warm instruction
+         TR::Instruction *mainlineAppendInstruction = self()->getLastWarmInstruction();
+         mainlineAppendInstruction->setLastWarmInstruction(false);
+         lastOLInstruction->setLastWarmInstruction(true);
+         self()->setLastWarmInstruction(lastOLInstruction);
+
+         TR::Instruction *mainlineFollowInstruction = mainlineAppendInstruction->getNext();
+
+         mainlineAppendInstruction->setNext(firstOLInstruction);
+         firstOLInstruction->setPrev(mainlineAppendInstruction);
+
+         lastOLInstruction->setNext(mainlineFollowInstruction);
+
+         if (mainlineFollowInstruction)
+            mainlineFollowInstruction->setPrev(lastOLInstruction);
+         }
+
+      ++oiIterator;
+      }
+   }
diff --git a/compiler/x/codegen/OMRCodeGenerator.hpp b/compiler/x/codegen/OMRCodeGenerator.hpp
@@ -654,6 +654,12 @@ class OMR_EXTENSIBLE CodeGenerator : public OMR::CodeGenerator
    bool considerTypeForGRA(TR::DataType dt);
    bool considerTypeForGRA(TR::SymbolReference *symRef);
 
+   /*
+    * \brief move out-of-line instructions from cold code to warm
+    *
+    */
+   void moveOutOfLineInstructionsToWarmCode();
+
    uint32_t getOutOfLineCodeSize();
 
    /*