From: Shengchen Kan <shengchen.kan@intel.com>
Date: Sat, 18 Feb 2023 06:11:52 +0000 (+0800)
Subject: [X86][NFC] Assert MRMr0 format from emitREXPrefix
X-Git-Tag: upstream/17.0.6~17079
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=d3745461dacbf2e158a9e5fb47c0a518d64a936b;p=platform%2Fupstream%2Fllvm.git

[X86][NFC] Assert MRMr0 format from emitREXPrefix

The only instruction of this format is VEX encoding
---

diff --git a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
index cbdcba1..5e9aaef 100644
--- a/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
+++ b/llvm/lib/Target/X86/MCTargetDesc/X86MCCodeEmitter.cpp
@@ -1247,8 +1247,7 @@ PrefixKind X86MCCodeEmitter::emitREXPrefix(int MemOperand, const MCInst &MI,
     Prefix.setB(MI, CurOp++);
     break;
   case X86II::MRMr0:
-    Prefix.setR(MI, CurOp++);
-    break;
+    llvm_unreachable("MRMr0 format never need REX prefix!");
   case X86II::MRMDestMemFSIB:
     llvm_unreachable("FSIB format never need REX prefix!");
   }