Index: llvm/include/llvm/Analysis/TargetTransformInfo.h
===================================================================
--- llvm/include/llvm/Analysis/TargetTransformInfo.h
+++ llvm/include/llvm/Analysis/TargetTransformInfo.h
@@ -396,14 +396,6 @@
   /// incurs significant execution cost.
   bool isLoweredToCall(const Function *F) const;
 
-  ///
-  /// \brief isExpensiveForFolding check if instruction can be replaced
-  /// with conditional instruction (csel/cset etc), if not - then instruction is
-  /// considered as expensive
-  /// \param I - instructions for checking
-  /// \return true if it cannot be replaced with one conditional instruction
-  bool isExpensiveForFolding(const Instruction& I) const;
-
   struct LSRCost {
     /// TODO: Some of these could be merged. Also, a lexical ordering
     /// isn't always optimal.
Index: llvm/lib/Analysis/TargetTransformInfo.cpp
===================================================================
--- llvm/lib/Analysis/TargetTransformInfo.cpp
+++ llvm/lib/Analysis/TargetTransformInfo.cpp
@@ -247,10 +247,6 @@
   return TTIImpl->isHardwareLoopProfitable(L, SE, AC, LibInfo, HWLoopInfo);
 }
 
-bool TargetTransformInfo::isExpensiveForFolding(const Instruction& I) const {
-  return TTIImpl->isExpensiveForFolding(I);
-}
-
 void TargetTransformInfo::getUnrollingPreferences(
     Loop *L, ScalarEvolution &SE, UnrollingPreferences &UP) const {
   return TTIImpl->getUnrollingPreferences(L, SE, UP);
Index: llvm/lib/Transforms/Utils/SimplifyCFG.cpp
===================================================================
--- llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -127,11 +127,6 @@
     cl::desc("Limit maximum recursion depth when calculating costs of "
              "speculatively executed instructions"));
 
-static cl::opt<bool> CheckSpeculationCost(
-    "check-speculation-cost", cl::Hidden, cl::init(true),
-    cl::desc("When merging conditional stores, add additional cost to instructions "
-             "which cannot be represented by one conditional instruction"));
-
 STATISTIC(NumBitMaps, "Number of switch instructions turned into bitmaps");
 STATISTIC(NumLinearMaps,
           "Number of switch instructions turned into linear mapping");
@@ -2410,6 +2405,23 @@
                     << "  T: " << IfTrue->getName()
                     << "  F: " << IfFalse->getName() << "\n");
 
+  // We need to be sure, that DomBlock has
+  // enough room for new instructions
+  // First add cost of Select instruction, that will be added to this block
+  // (this cost is equal to number of phi nodes in BB)
+  unsigned Cost = NumPhis;
+
+  for (const auto& Instr : *DomBlock)
+  {
+    if (!isa<BranchInst>(&Instr))
+      Cost += TTI.getUserCost(&Instr);
+  }
+
+  if (Cost > PHINodeFoldingThreshold * TargetTransformInfo::TCC_Basic) {
+    // DomBlock already too large
+    return false;
+  }
+
   // If we can still promote the PHI nodes after this gauntlet of tests,
   // do all of the PHI's now.
   Instruction *InsertPt = DomBlock->getTerminator();
@@ -2971,10 +2983,6 @@
       if (isa<BinaryOperator>(I) || isa<GetElementPtrInst>(I) ||
           isa<StoreInst>(I)) {
         ++N;
-
-        if (CheckSpeculationCost && TTI.isExpensiveForFolding(I)) {
-          ++N;
-        }
       }
 
       // Free instructions.
Index: llvm/test/Transforms/SimplifyCFG/AArch64/check-instr-cost-for-folding.ll
===================================================================
--- llvm/test/Transforms/SimplifyCFG/AArch64/check-instr-cost-for-folding.ll
+++ llvm/test/Transforms/SimplifyCFG/AArch64/check-instr-cost-for-folding.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -mtriple=aarch64-linux-gnu -simplifycfg -check-speculation-cost=true -S >%t
+; RUN: opt < %s -mtriple=aarch64-linux-gnu -simplifycfg -S >%t
 ; RUN: FileCheck %s < %t
 ; ModuleID = 'do_select.c'
 
@@ -32,7 +32,7 @@
 ; CHECK-LABEL: if.then:
 ; CHECK-NEXT:   %or = or i64 %res_in.020, %bit.addr.017
 ; CHECK-NEXT:   %inc = add nsw i32 %retval1.019, 1
-; CHECK-NEXT:   store i8* null, i8** %proc, align 8
+; CHECK-NEXT:   br label %if.end
   %or = or i64 %res_in.020, %bit.addr.017
   %inc = add nsw i32 %retval1.019, 1
   store i8* null, i8** %proc, align 8