1 files changed, 9 insertions, 0 deletions
diff --git a/lib/Target/X86/Disassembler/X86Disassembler.cpp b/lib/Target/X86/Disassembler/X86Disassembler.cpp
index ca71c4f..f03068e 100644
--- a/lib/Target/X86/Disassembler/X86Disassembler.cpp
+++ b/lib/Target/X86/Disassembler/X86Disassembler.cpp
@@ -683,6 +683,15 @@ static bool translateInstruction(MCInst &mcInst,
   }
   
   mcInst.setOpcode(insn.instructionID);
+  // If when reading the prefix bytes we determined the overlapping 0xf2 or 0xf3
+  // prefix bytes should be disassembled as xrelease and xacquire then set the
+  // opcode to those instead of the rep and repne opcodes.
+  if (insn.xAcquireRelease) {
+    if(mcInst.getOpcode() == X86::REP_PREFIX)
+      mcInst.setOpcode(X86::XRELEASE_PREFIX);
+    else if(mcInst.getOpcode() == X86::REPNE_PREFIX)
+      mcInst.setOpcode(X86::XACQUIRE_PREFIX);
+  }
   
   int index;