1 files changed, 28 insertions, 14 deletions

diff --git a/lib/Target/X86/Disassembler/X86Disassembler.cpp b/lib/Target/X86/Disassembler/X86Disassembler.cpp
index c58254ae38c1..62312777318e 100644
--- a/lib/Target/X86/Disassembler/X86Disassembler.cpp
+++ b/lib/Target/X86/Disassembler/X86Disassembler.cpp
@@ -103,7 +103,7 @@ StringRef llvm::X86Disassembler::GetInstrName(unsigned Opcode,
   return MII->getName(Opcode);
 }
 
-#define debug(s) DEBUG(Debug(__FILE__, __LINE__, s));
+#define debug(s) LLVM_DEBUG(Debug(__FILE__, __LINE__, s));
 
 namespace llvm {
 
@@ -247,6 +247,8 @@ MCDisassembler::DecodeStatus X86GenericDisassembler::getInstruction(
                  // It should not be 'pause' f3 90
                  InternalInstr.opcode != 0x90)
           Flags |= X86::IP_HAS_REPEAT;
+        if (InternalInstr.hasLockPrefix)
+          Flags |= X86::IP_HAS_LOCK;
       }
       Instr.setFlags(Flags);
     }
@@ -265,13 +267,10 @@ MCDisassembler::DecodeStatus X86GenericDisassembler::getInstruction(
 /// @param reg        - The Reg to append.
 static void translateRegister(MCInst &mcInst, Reg reg) {
 #define ENTRY(x) X86::x,
-  uint8_t llvmRegnums[] = {
-    ALL_REGS
-    0
-  };
+  static constexpr MCPhysReg llvmRegnums[] = {ALL_REGS};
 #undef ENTRY
 
-  uint8_t llvmRegnum = llvmRegnums[reg];
+  MCPhysReg llvmRegnum = llvmRegnums[reg];
   mcInst.addOperand(MCOperand::createReg(llvmRegnum));
 }
 
@@ -664,8 +663,6 @@ static void translateImmediate(MCInst &mcInst, uint64_t immediate,
   case TYPE_ZMM:
     mcInst.addOperand(MCOperand::createReg(X86::ZMM0 + (immediate >> 4)));
     return;
-  case TYPE_BNDR:
-    mcInst.addOperand(MCOperand::createReg(X86::BND0 + (immediate >> 4)));
   default:
     // operand is 64 bits wide.  Do nothing.
     break;
@@ -761,7 +758,7 @@ static bool translateRMMemory(MCInst &mcInst, InternalInstruction &insn,
 #undef ENTRY
       }
     } else {
-      baseReg = MCOperand::createReg(0);
+      baseReg = MCOperand::createReg(X86::NoRegister);
     }
 
     if (insn.sibIndex != SIB_INDEX_NONE) {
@@ -780,7 +777,22 @@ static bool translateRMMemory(MCInst &mcInst, InternalInstruction &insn,
 #undef ENTRY
       }
     } else {
-      indexReg = MCOperand::createReg(0);
+      // Use EIZ/RIZ for a few ambiguous cases where the SIB byte is present,
+      // but no index is used and modrm alone should have been enough.
+      // -No base register in 32-bit mode. In 64-bit mode this is used to
+      //  avoid rip-relative addressing.
+      // -Any base register used other than ESP/RSP/R12D/R12. Using these as a
+      //  base always requires a SIB byte.
+      // -A scale other than 1 is used.
+      if (insn.sibScale != 1 ||
+          (insn.sibBase == SIB_BASE_NONE && insn.mode != MODE_64BIT) ||
+          (insn.sibBase != SIB_BASE_NONE &&
+           insn.sibBase != SIB_BASE_ESP && insn.sibBase != SIB_BASE_RSP &&
+           insn.sibBase != SIB_BASE_R12D && insn.sibBase != SIB_BASE_R12)) {
+        indexReg = MCOperand::createReg(insn.addressSize == 4 ? X86::EIZ :
+                                                                X86::RIZ);
+      } else
+        indexReg = MCOperand::createReg(X86::NoRegister);
     }
 
     scaleAmount = MCOperand::createImm(insn.sibScale);
@@ -797,12 +809,14 @@ static bool translateRMMemory(MCInst &mcInst, InternalInstruction &insn,
         tryAddingPcLoadReferenceComment(insn.startLocation +
                                         insn.displacementOffset,
                                         insn.displacement + pcrel, Dis);
-        baseReg = MCOperand::createReg(X86::RIP); // Section 2.2.1.6
+        // Section 2.2.1.6
+        baseReg = MCOperand::createReg(insn.addressSize == 4 ? X86::EIP :
+                                                               X86::RIP);
       }
       else
-        baseReg = MCOperand::createReg(0);
+        baseReg = MCOperand::createReg(X86::NoRegister);
 
-      indexReg = MCOperand::createReg(0);
+      indexReg = MCOperand::createReg(X86::NoRegister);
       break;
     case EA_BASE_BX_SI:
       baseReg = MCOperand::createReg(X86::BX);
@@ -821,7 +835,7 @@ static bool translateRMMemory(MCInst &mcInst, InternalInstruction &insn,
       indexReg = MCOperand::createReg(X86::DI);
       break;
     default:
-      indexReg = MCOperand::createReg(0);
+      indexReg = MCOperand::createReg(X86::NoRegister);
       switch (insn.eaBase) {
       default:
         debug("Unexpected eaBase");