[llvm] [LFI][AArch64] Add rewrites for memory accesses (PR #195167)

[Peter Smith via llvm-commits]

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@@ -111,6 +204,75 @@ void AArch64MCLFIRewriter::emitMov(MCRegister Dest, MCRegister Src,
   emitInst(Inst, Out, STI);
 }
 
+void AArch64MCLFIRewriter::emitAddImm(MCRegister Dest, MCRegister Src,
+                                      int64_t Imm, MCStreamer &Out,
+                                      const MCSubtargetInfo &STI) {
+  assert(std::abs(Imm) <= 4095);
+  MCInst Inst;
+  if (Imm >= 0) {
+    Inst.setOpcode(AArch64::ADDXri);
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smithp35 wrote:

For consistency with emitAddReg could be worth adding a comment
// add Dest, Src1, Imm
and
// sub Dest, Src1, Imm
below.

https://github.com/llvm/llvm-project/pull/195167