[PATCH] D143471: [X86][MC][NFC] Refine code in X86MCCodeEmitter.cpp about opcode prefix

[Phoebe Wang via Phabricator via llvm-commits]

pengfei added inline comments.


================
Comment at: llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp:774-776
+PrefixKind X86MCCodeEmitter::emitPrefixImpl(unsigned &CurOp, const MCInst &MI,
                                       const MCSubtargetInfo &STI,
                                       raw_ostream &OS) const {
----------------
Format.


================
Comment at: llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp:855
 
-  uint64_t Encoding = TSFlags & X86II::EncodingMask;
+  X86OpcodePrefix Prefix(*Ctx.getRegisterInfo());
+  switch (TSFlags & X86II::EncodingMask) {
----------------
Should be better to move below logic into `X86OpcodePrefix `? Then we can simplify the function to:

```
  X86OpcodePrefix Prefix(*Ctx.getRegisterInfo(), TSFlags);
  Prefix.emit(OS);
  return Prefix.getKind();
```


================
Comment at: llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp:860
+  case X86II::XOP:
+    Prefix.setLowerBound(XOP);
+    break;
----------------
Should be better to use `setEncoding`?


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D143471/new/

https://reviews.llvm.org/D143471