Remove special cases for [LM]FENCE, MONITOR and MWAIT from

encoder and decoder by using new MRM_ forms.

llvm-svn: 96048

1 files changed, 2 insertions, 21 deletions

diff --git a/llvm/lib/Target/X86/X86CodeEmitter.cpp b/llvm/lib/Target/X86/X86CodeEmitter.cpp
index 6a42240736e..5cecd706ebf 100644
--- a/llvm/lib/Target/X86/X86CodeEmitter.cpp
+++ b/llvm/lib/Target/X86/X86CodeEmitter.cpp
@@ -762,27 +762,8 @@ void Emitter<CodeEmitter>::emitInstruction(const MachineInstr &MI,
   case X86II::MRM4r: case X86II::MRM5r:
   case X86II::MRM6r: case X86II::MRM7r: {
     MCE.emitByte(BaseOpcode);
-
-    // Special handling of lfence, mfence, monitor, and mwait.
-    if (Desc->getOpcode() == X86::LFENCE ||
-        Desc->getOpcode() == X86::MFENCE ||
-        Desc->getOpcode() == X86::MONITOR ||
-        Desc->getOpcode() == X86::MWAIT) {
-      emitRegModRMByte((Desc->TSFlags & X86II::FormMask)-X86II::MRM0r);
-
-      switch (Desc->getOpcode()) {
-      default: break;
-      case X86::MONITOR:
-        MCE.emitByte(0xC8);
-        break;
-      case X86::MWAIT:
-        MCE.emitByte(0xC9);
-        break;
-      }
-    } else {
-      emitRegModRMByte(MI.getOperand(CurOp++).getReg(),
-                       (Desc->TSFlags & X86II::FormMask)-X86II::MRM0r);
-    }
+    emitRegModRMByte(MI.getOperand(CurOp++).getReg(),
+                     (Desc->TSFlags & X86II::FormMask)-X86II::MRM0r);
 
     if (CurOp == NumOps)
       break;