[MERGE #5301 @sigatrev] OS#17676093: (ARM) ensure indir hoisting legalization is postRegAlloc aware

Merge pull request #5301 from sigatrev:armlower

using InsertAdd in the lowerer calls Legalize with the default value postRegAlloc (false). For HoistIndirOffsetAsAdd and HoistIndirIndexOpndAsAdd, this was causing newly inserted LDIMMs to not be legalized when inserted after regAlloc.

Author: sigatrev

lib/Backend/Lower.cpp

@@ -14877,7 +14877,7 @@ IR::RegOpnd *Lowerer::GenerateArrayTest(
 
 ///----------------------------------------------------------------------------
 ///
-/// Instr::HoistIndirOffset
+/// Lowerer::HoistIndirOffset
 ///
 ///     Replace the offset of the given indir with a new symbol, which becomes the indir index.
 ///     Assign the new symbol by creating an assignment from the constant offset.
@@ -14927,7 +14927,10 @@ IR::Instr *Lowerer::HoistIndirOffsetAsAdd(IR::Instr* instr, IR::IndirOpnd *orgOp
         IR::RegOpnd *newBaseOpnd = IR::RegOpnd::New(StackSym::New(TyMachPtr, instr->m_func), regNum, TyMachPtr, instr->m_func);
 
         IR::IntConstOpnd *src2 = IR::IntConstOpnd::New(offset, TyInt32, instr->m_func);
-        IR::Instr * instrAdd = Lowerer::InsertAdd(false, newBaseOpnd, baseOpnd, src2, instr);
+
+        IR::Instr * instrAdd = IR::Instr::New(Js::OpCode::Add_A, newBaseOpnd, baseOpnd, src2, instr->m_func);
+        LowererMD::ChangeToAdd(instrAdd, false);
+        instr->InsertBefore(instrAdd);
 
         orgOpnd->ReplaceBaseOpnd(newBaseOpnd);
         orgOpnd->SetOffset(0);
@@ -14939,7 +14942,9 @@ IR::Instr *Lowerer::HoistIndirIndexOpndAsAdd(IR::Instr* instr, IR::IndirOpnd *or
 {
         IR::RegOpnd *newBaseOpnd = IR::RegOpnd::New(StackSym::New(TyMachPtr, instr->m_func), regNum, TyMachPtr, instr->m_func);
 
-        IR::Instr * instrAdd = Lowerer::InsertAdd(false, newBaseOpnd, baseOpnd, indexOpnd->UseWithNewType(TyMachPtr, instr->m_func), instr);
+        IR::Instr * instrAdd = IR::Instr::New(Js::OpCode::Add_A, newBaseOpnd, baseOpnd, indexOpnd->UseWithNewType(TyMachPtr, instr->m_func), instr->m_func);
+        LowererMD::ChangeToAdd(instrAdd, false);
+        instr->InsertBefore(instrAdd);
 
         orgOpnd->ReplaceBaseOpnd(newBaseOpnd);
         orgOpnd->SetIndexOpnd(nullptr);
@@ -14949,7 +14954,7 @@ IR::Instr *Lowerer::HoistIndirIndexOpndAsAdd(IR::Instr* instr, IR::IndirOpnd *or
 
 ///----------------------------------------------------------------------------
 ///
-/// Instr::HoistSymOffset
+/// Lowerer::HoistSymOffset
 ///
 ///     Replace the given sym with an indir using the given base and offset.
 ///     (This is used, for instance, to hoist a sym offset that is too large to encode.)

lib/Backend/arm/LegalizeMD.cpp

@@ -621,7 +621,8 @@ void LegalizeMD::LegalizeIndirOpndForVFP(IR::Instr* insertInstr, IR::IndirOpnd *
             indexOpnd = newIndexOpnd;
         }
 
-        Lowerer::HoistIndirIndexOpndAsAdd(insertInstr, indirOpnd, baseOpnd, indexOpnd, fPostRegAlloc? SCRATCH_REG : RegNOREG);
+        IR::Instr * instrAdd = Lowerer::HoistIndirIndexOpndAsAdd(insertInstr, indirOpnd, baseOpnd, indexOpnd, fPostRegAlloc? SCRATCH_REG : RegNOREG);
+        LegalizeMD::LegalizeInstr(instrAdd, fPostRegAlloc);
     }
 
     if (IS_CONST_UINT10((offset < 0? -offset: offset)))

lib/Backend/arm64/LegalizeMD.cpp

@@ -373,7 +373,8 @@ void LegalizeMD::LegalizeIndirOffset(IR::Instr * instr, IR::IndirOpnd * indirOpn
                 indexOpnd = newIndexOpnd;
             }
 
-            Lowerer::HoistIndirIndexOpndAsAdd(instr, indirOpnd, baseOpnd, indexOpnd, fPostRegAlloc ? SCRATCH_REG : RegNOREG);
+            IR::Instr * instrAdd = Lowerer::HoistIndirIndexOpndAsAdd(instr, indirOpnd, baseOpnd, indexOpnd, fPostRegAlloc ? SCRATCH_REG : RegNOREG);
+            LegalizeMD::LegalizeInstr(instrAdd, fPostRegAlloc);
         }
     }
     else if (indirOpnd->GetIndexOpnd() != nullptr && offset != 0)