[Autobackout][FunctionalRegression]Revert of change: 09dd7ec: llvm-16: Implement lost functionality from instcombine

Add two additional peephole in GenXSimplify:
     %1 = bitcast <32 x i1> %in1 to i32
     %2 = bitcast <32 x i1> %in2 to i32
     %binop = binop i32 %1, %2
     %3 = bitcast i32 %binop to <32 x i1>
    And
     %1 = trunc <32 x i16> %in1 to <32 x i1>
     %2 = trunc <32 x i16> %in2 to <32 x i1>
     %binop = binop <32 x i1> %1, %2
     %3 = zext <32 x i1> %binop to <32 x i16>
    To:
     %binop = binop <32 x i16> %in1, %in2

Author: sys-igc

IGC/VectorCompiler/lib/GenXOpts/CMAnalysis/InstructionSimplifyGenX.cpp

@@ -1,6 +1,6 @@
 /*========================== begin_copyright_notice ============================
 
-Copyright (C) 2017-2025 Intel Corporation
+Copyright (C) 2017-2024 Intel Corporation
 
 SPDX-License-Identifier: MIT
 
@@ -183,70 +183,13 @@ static Value *simplifyMulDDQ(BinaryOperator &Mul) {
   return Result;
 }
 
-static inline bool isBitcastFits(BitCastInst *BC) {
-  return BC->getSrcTy()->isVectorTy() && BC->getDestTy()->isIntegerTy();
-}
-
-static inline bool isTrunkFits(TruncInst *TC) {
-  return TC->getSrcTy()->isVectorTy() &&
-         TC->getDestTy()->isVectorTy() &&
-         TC->getDestTy()->getScalarType()->isIntegerTy(1);
-}
-
-static inline bool simplifyBinOp(BinaryOperator *BinOp) {
-  bool Changed = false;
-
-  auto *Bitcast1 = dyn_cast<BitCastInst>(BinOp->getOperand(0));
-  auto *Bitcast2 = dyn_cast<BitCastInst>(BinOp->getOperand(1));
-  if (Bitcast1 && Bitcast2 && (Bitcast1->getSrcTy() == Bitcast2->getSrcTy())) {
-    if (isBitcastFits(Bitcast1) && isBitcastFits(Bitcast2)) {
-      for (auto *User : BinOp->users()) {
-        if (auto *BitcastBack = dyn_cast<BitCastInst>(User)) {
-          if (BitcastBack->getDestTy()->isVectorTy()) {
-            IRBuilder<> Builder(BinOp);
-            auto *NewOp =
-                Builder.CreateBinOp(BinOp->getOpcode(), Bitcast1->getOperand(0),
-                                    Bitcast2->getOperand(0));
-            BitcastBack->replaceAllUsesWith(NewOp);
-            Changed = true;
-            BinOp = cast<BinaryOperator>(NewOp);
-            break;
-          }
-        }
-      }
-    }
-  }
-  auto *Trunc1 = dyn_cast<TruncInst>(BinOp->getOperand(0));
-  auto *Trunc2 = dyn_cast<TruncInst>(BinOp->getOperand(1));
-  if (Trunc1 && Trunc2 && (Trunc1->getSrcTy() == Trunc2->getSrcTy())) {
-    if (isTrunkFits(Trunc1) && isTrunkFits(Trunc2)) {
-      for (auto *User : BinOp->users()) {
-        if (auto *ZextInst = dyn_cast<ZExtInst>(User)) {
-          if (auto *DestVecType = dyn_cast<VectorType>(ZextInst->getDestTy())) {
-            if (DestVecType->getElementType()->isIntegerTy()) {
-              IRBuilder<> Builder(BinOp);
-              auto *NewOp =
-                  Builder.CreateBinOp(BinOp->getOpcode(), Trunc1->getOperand(0),
-                                      Trunc2->getOperand(0));
-              ZextInst->replaceAllUsesWith(NewOp);
-              Changed = true;
-              break;
-            }
-          }
-        }
-      }
-    }
-  }
-  return Changed;
-}
-
 static Value *GenXSimplifyInstruction(llvm::Instruction *Inst) {
   IGC_ASSERT(Inst);
   if (!GenXEnablePeepholes)
     return nullptr;
-  if (Inst->getOpcode() == Instruction::Mul)
+  if (Inst->getOpcode() == Instruction::Mul) {
     return simplifyMulDDQ(*cast<BinaryOperator>(Inst));
-
+  }
   return nullptr;
 }
 
@@ -563,8 +506,6 @@ bool GenXSimplify::runOnFunction(Function &F) {
         Changed |= replaceWithNewValue(*Inst, *V);
         continue;
       }
-      if (auto *BO = dyn_cast<BinaryOperator>(Inst))
-        Changed |= simplifyBinOp(BO);
     }
   }