Sanity check the option operand for DMB/DSB.

PR9648
rdar://problem/9257634

llvm-svn: 129146

2 files changed, 29 insertions, 8 deletions

diff --git a/llvm/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp b/llvm/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
index ca67e5e2e6e..7900f9960ad 100644
--- a/llvm/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
+++ b/llvm/lib/Target/ARM/Disassembler/ARMDisassemblerCore.cpp
@@ -3286,13 +3286,19 @@ static bool DisassembleMiscFrm(MCInst &MI, unsigned Opcode, uint32_t insn,
     unsigned short NumOps, unsigned &NumOpsAdded, BO B) {
 
   if (MemBarrierInstr(insn)) {
-    // DMBsy, DSBsy, and ISBsy instructions have zero operand and are taken care
-    // of within the generic ARMBasicMCBuilder::BuildIt() method.
-    //
     // Inst{3-0} encodes the memory barrier option for the variants.
-    MI.addOperand(MCOperand::CreateImm(slice(insn, 3, 0)));
-    NumOpsAdded = 1;
-    return true;
+    unsigned opt = slice(insn, 3, 0);
+    switch (opt) {
+    case ARM_MB::SY:  case ARM_MB::ST:
+    case ARM_MB::ISH: case ARM_MB::ISHST:
+    case ARM_MB::NSH: case ARM_MB::NSHST:
+    case ARM_MB::OSH: case ARM_MB::OSHST:
+      MI.addOperand(MCOperand::CreateImm(opt));
+      NumOpsAdded = 1;
+      return true;
+    default:
+      return false;
+    }
   }
 
   switch (Opcode) {
diff --git a/llvm/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h b/llvm/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
index 066a8e3178e..618526816f7 100644
--- a/llvm/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
+++ b/llvm/lib/Target/ARM/Disassembler/ThumbDisassemblerCore.h
@@ -1616,8 +1616,7 @@ static inline bool t2MiscCtrlInstr(uint32_t insn) {
 // A8.6.26
 // t2BXJ -> Rn
 //
-// Miscellaneous control: t2DMBsy (and its t2DMB variants),
-// t2DSBsy (and its t2DSB varianst), t2ISBsy, t2CLREX
+// Miscellaneous control:
 //   -> no operand (except pred-imm pred-ccr for CLREX, memory barrier variants)
 //
 // Hint: t2NOP, t2YIELD, t2WFE, t2WFI, t2SEV
@@ -1634,6 +1633,22 @@ static bool DisassembleThumb2BrMiscCtrl(MCInst &MI, unsigned Opcode,
   if (NumOps == 0)
     return true;
 
+  if (Opcode == ARM::t2DMB || Opcode == ARM::t2DSB) {
+    // Inst{3-0} encodes the memory barrier option for the variants.
+    unsigned opt = slice(insn, 3, 0);
+    switch (opt) {
+    case ARM_MB::SY:  case ARM_MB::ST:
+    case ARM_MB::ISH: case ARM_MB::ISHST:
+    case ARM_MB::NSH: case ARM_MB::NSHST:
+    case ARM_MB::OSH: case ARM_MB::OSHST:
+      MI.addOperand(MCOperand::CreateImm(opt));
+      NumOpsAdded = 1;
+      return true;
+    default:
+      return false;
+    }
+  }
+
   if (t2MiscCtrlInstr(insn))
     return true;