Revert "[AMDGPU] Modify adjustInliningThreshold to also consider the cost of passing function arguments through the stack"

This reverts commit 142c28f.

Author: JanekvO

llvm/lib/Target/AMDGPU/AMDGPUTargetTransformInfo.cpp

@@ -17,10 +17,8 @@
 #include "AMDGPUTargetTransformInfo.h"
 #include "AMDGPUTargetMachine.h"
 #include "MCTargetDesc/AMDGPUMCTargetDesc.h"
-#include "llvm/Analysis/InlineCost.h"
 #include "llvm/Analysis/LoopInfo.h"
 #include "llvm/Analysis/ValueTracking.h"
-#include "llvm/CodeGen/Analysis.h"
 #include "llvm/IR/IRBuilder.h"
 #include "llvm/IR/IntrinsicsAMDGPU.h"
 #include "llvm/IR/PatternMatch.h"
@@ -1169,57 +1167,10 @@ bool GCNTTIImpl::areInlineCompatible(const Function *Caller,
   return true;
 }
 
-static unsigned adjustInliningThresholdUsingCallee(const Function *Callee,
-                                                   const SITargetLowering *TLI,
-                                                   const GCNTTIImpl *TTIImpl) {
-  const int NrOfSGPRUntilSpill = 26;
-  const int NrOfVGPRUntilSpill = 32;
-
-  const DataLayout &DL = TTIImpl->getDataLayout();
-
-  unsigned adjustThreshold = 0;
-  int SGPRsInUse = 0;
-  int VGPRsInUse = 0;
-  for (const Argument &A : Callee->args()) {
-    SmallVector<EVT, 4> ValueVTs;
-    ComputeValueVTs(*TLI, DL, A.getType(), ValueVTs);
-    for (auto ArgVT : ValueVTs) {
-      unsigned CCRegNum = TLI->getNumRegistersForCallingConv(
-          A.getContext(), Callee->getCallingConv(), ArgVT);
-      if (AMDGPU::isArgPassedInSGPR(&A))
-        SGPRsInUse += CCRegNum;
-      else
-        VGPRsInUse += CCRegNum;
-    }
-  }
-
-  // The cost of passing function arguments through the stack:
-  //  1 instruction to put a function argument on the stack in the caller.
-  //  1 instruction to take a function argument from the stack in callee.
-  //  1 instruction is explicitly take care of data dependencies in callee
-  //  function.
-  InstructionCost ArgStackCost(1);
-  ArgStackCost += const_cast<GCNTTIImpl *>(TTIImpl)->getMemoryOpCost(
-      Instruction::Store, Type::getInt32Ty(Callee->getContext()), Align(4),
-      AMDGPUAS::PRIVATE_ADDRESS, TTI::TCK_SizeAndLatency);
-  ArgStackCost += const_cast<GCNTTIImpl *>(TTIImpl)->getMemoryOpCost(
-      Instruction::Load, Type::getInt32Ty(Callee->getContext()), Align(4),
-      AMDGPUAS::PRIVATE_ADDRESS, TTI::TCK_SizeAndLatency);
-
-  // The penalty cost is computed relative to the cost of instructions and does
-  // not model any storage costs.
-  adjustThreshold += std::max(0, SGPRsInUse - NrOfSGPRUntilSpill) *
-                     *ArgStackCost.getValue() * InlineConstants::getInstrCost();
-  adjustThreshold += std::max(0, VGPRsInUse - NrOfVGPRUntilSpill) *
-                     *ArgStackCost.getValue() * InlineConstants::getInstrCost();
-  return adjustThreshold;
-}
-
 unsigned GCNTTIImpl::adjustInliningThreshold(const CallBase *CB) const {
   // If we have a pointer to private array passed into a function
   // it will not be optimized out, leaving scratch usage.
   // Increase the inline threshold to allow inlining in this case.
-  unsigned adjustThreshold = 0;
   uint64_t AllocaSize = 0;
   SmallPtrSet<const AllocaInst *, 8> AIVisited;
   for (Value *PtrArg : CB->args()) {
@@ -1241,10 +1192,9 @@ unsigned GCNTTIImpl::adjustInliningThreshold(const CallBase *CB) const {
       }
     }
   }
-  adjustThreshold +=
-      adjustInliningThresholdUsingCallee(CB->getCalledFunction(), TLI, this);
-  adjustThreshold += AllocaSize ? ArgAllocaCost : AllocaSize;
-  return adjustThreshold;
+  if (AllocaSize)
+    return ArgAllocaCost;
+  return 0;
 }
 
 void GCNTTIImpl::getUnrollingPreferences(Loop *L, ScalarEvolution &SE,