From: Owen Anderson <resistor@mac.com>
Date: Thu, 6 Oct 2011 23:33:11 +0000 (+0000)
Subject: Fix the check for nested IT instructions in the disassembler.  We need to perform... 
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=7011eee9b509f3a0f95a75f68787384f31ea3e01;p=oota-llvm.git

Fix the check for nested IT instructions in the disassembler.  We need to perform the check before adding the Thumb predicate, which pops on entry off the ITBlock queue.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141339 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
index 36aa6b10ee4..5f6fc29b089 100644
--- a/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
+++ b/lib/Target/ARM/Disassembler/ARMDisassembler.cpp
@@ -724,15 +724,18 @@ DecodeStatus ThumbDisassembler::getInstruction(MCInst &MI, uint64_t &Size,
   result = decodeThumb2Instruction16(MI, insn16, Address, this, STI);
   if (result != MCDisassembler::Fail) {
     Size = 2;
+
+    // Nested IT blocks are UNPREDICTABLE.  Must be checked before we add
+    // the Thumb predicate.
+    if (MI.getOpcode() == ARM::t2IT && !ITBlock.empty())
+      result = MCDisassembler::SoftFail;
+
     Check(result, AddThumbPredicate(MI));
 
     // If we find an IT instruction, we need to parse its condition
     // code and mask operands so that we can apply them correctly
     // to the subsequent instructions.
     if (MI.getOpcode() == ARM::t2IT) {
-      // Nested IT blocks are UNPREDICTABLE.
-      if (!ITBlock.empty())
-        return MCDisassembler::SoftFail;
 
       // (3 - the number of trailing zeros) is the number of then / else.
       unsigned firstcond = MI.getOperand(0).getImm();