[LLVM] Pass APInt by const reference. NFC. (#86278)

This patch adjusts argument passing for `APInt` to improve the
compile-time.
Compile-time improvement:
https://llvm-compile-time-tracker.com/compare.php?from=d1f182c895728d89c5c3d198b133e212a5d9d4a3&to=32d6611af69bf4e76373f9bc7d9649650f760e48&stat=instructions:u

Author: dtcxzyw

llvm/include/llvm/Analysis/MemoryBuiltins.h

@@ -217,7 +217,7 @@ struct SizeOffsetAPInt : public SizeOffsetType<APInt, SizeOffsetAPInt> {
   SizeOffsetAPInt() = default;
   SizeOffsetAPInt(APInt Size, APInt Offset) : SizeOffsetType(Size, Offset) {}
 
-  static bool known(APInt V) { return V.getBitWidth() > 1; }
+  static bool known(const APInt &V) { return V.getBitWidth() > 1; }
 };
 
 /// Evaluate the size and offset of an object pointed to by a Value*

llvm/include/llvm/CodeGen/SelectionDAG.h

@@ -883,7 +883,7 @@ class SelectionDAG {
 
   /// Returns a vector of type ResVT whose elements contain the linear sequence
   ///   <0, Step, Step * 2, Step * 3, ...>
-  SDValue getStepVector(const SDLoc &DL, EVT ResVT, APInt StepVal);
+  SDValue getStepVector(const SDLoc &DL, EVT ResVT, const APInt &StepVal);
 
   /// Returns a vector of type ResVT whose elements contain the linear sequence
   ///   <0, 1, 2, 3, ...>

llvm/include/llvm/MC/MCStreamer.h

@@ -740,7 +740,7 @@ class MCStreamer {
   /// Special case of EmitValue that avoids the client having
   /// to pass in a MCExpr for constant integers.
   virtual void emitIntValue(uint64_t Value, unsigned Size);
-  virtual void emitIntValue(APInt Value);
+  virtual void emitIntValue(const APInt &Value);
 
   /// Special case of EmitValue that avoids the client having to pass
   /// in a MCExpr for constant integers & prints in Hex format for certain

llvm/lib/CodeGen/GlobalISel/LegalizerHelper.cpp

@@ -7855,7 +7855,7 @@ LegalizerHelper::LegalizeResult LegalizerHelper::lowerBswap(MachineInstr &MI) {
 
 //{ (Src & Mask) >> N } | { (Src << N) & Mask }
 static MachineInstrBuilder SwapN(unsigned N, DstOp Dst, MachineIRBuilder &B,
-                                 MachineInstrBuilder Src, APInt Mask) {
+                                 MachineInstrBuilder Src, const APInt &Mask) {
   const LLT Ty = Dst.getLLTTy(*B.getMRI());
   MachineInstrBuilder C_N = B.buildConstant(Ty, N);
   MachineInstrBuilder MaskLoNTo0 = B.buildConstant(Ty, Mask);

llvm/lib/CodeGen/SelectionDAG/SelectionDAG.cpp

@@ -2031,7 +2031,8 @@ SDValue SelectionDAG::getStepVector(const SDLoc &DL, EVT ResVT) {
   return getStepVector(DL, ResVT, One);
 }
 
-SDValue SelectionDAG::getStepVector(const SDLoc &DL, EVT ResVT, APInt StepVal) {
+SDValue SelectionDAG::getStepVector(const SDLoc &DL, EVT ResVT,
+                                    const APInt &StepVal) {
   assert(ResVT.getScalarSizeInBits() == StepVal.getBitWidth());
   if (ResVT.isScalableVector())
     return getNode(

llvm/lib/MC/MCStreamer.cpp

@@ -141,7 +141,7 @@ void MCStreamer::emitIntValue(uint64_t Value, unsigned Size) {
   unsigned Index = IsLittleEndian ? 0 : 8 - Size;
   emitBytes(StringRef(reinterpret_cast<char *>(&Swapped) + Index, Size));
 }
-void MCStreamer::emitIntValue(APInt Value) {
+void MCStreamer::emitIntValue(const APInt &Value) {
   if (Value.getNumWords() == 1) {
     emitIntValue(Value.getLimitedValue(), Value.getBitWidth() / 8);
     return;