Better error handling of invalid IT mask '0000', instead of just asserting.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@101827 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Johnny Chen
2010-04-19 23:02:58 +00:00
parent 35bb85b7ee
commit d0f3c46d16
3 changed files with 11 additions and 5 deletions

View File

@ -508,17 +508,23 @@ bool ThumbDisassembler::getInstruction(MCInst &MI,
}
// A8.6.50
// Valid return values are {1, 2, 3, 4}, with 0 signifying an error condition.
static unsigned short CountITSize(unsigned ITMask) {
// First count the trailing zeros of the IT mask.
unsigned TZ = CountTrailingZeros_32(ITMask);
assert(TZ <= 3 && "Encoding error");
if (TZ > 3) {
DEBUG(errs() << "Encoding error of IT mask");
return 0;
}
return (4 - TZ);
}
/// Init ITState.
void Session::InitIT(unsigned short bits7_0) {
/// Init ITState. Note that at least one bit is always 1 in mask.
bool Session::InitIT(unsigned short bits7_0) {
ITCounter = CountITSize(slice(bits7_0, 3, 0));
ITState = bits7_0;
// Only need to check for > 0.
return ITCounter > 0;
}
/// Update ITState if necessary.