[llvm] [X86][GlobalISel] Enable G_BUILD_VECTOR and G_CONSTANT_POOL (PR #92844)

[Matt Arsenault via llvm-commits]

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@@ -576,11 +576,32 @@ bool X86InstructionSelector::selectLoadStoreOp(MachineInstr &I,
   if (NewOpc == Opc)
     return false;
 
-  X86AddressMode AM;
-  X86SelectAddress(*MRI.getVRegDef(I.getOperand(1).getReg()), MRI, AM);
-
   I.setDesc(TII.get(NewOpc));
   MachineInstrBuilder MIB(MF, I);
+  const MachineInstr *Ptr = MRI.getVRegDef(I.getOperand(1).getReg());
+
+  if (Ptr->getOpcode() == TargetOpcode::G_CONSTANT_POOL) {
+    assert(Opc == TargetOpcode::G_LOAD &&
+           "Only G_LOAD from constant pool is expected");
+    // TODO: Need a separate move for Large model
+    if (TM.getCodeModel() == CodeModel::Large)
+      return false;
+
+    unsigned char OpFlag = STI.classifyLocalReference(nullptr);
+    unsigned PICBase = 0;
+    if (OpFlag == X86II::MO_GOTOFF)
+      PICBase = STI.getInstrInfo()->getGlobalBaseReg(&MF);
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arsenm wrote:

TII is already a member 

https://github.com/llvm/llvm-project/pull/92844