+namespace {
+ // Handles the condition code status of instructions in IT blocks
+ class ITStatus
+ {
+ public:
+ // Returns the condition code for instruction in IT block
+ unsigned getITCC() {
+ unsigned CC = ARMCC::AL;
+ if (instrInITBlock())
+ CC = ITStates.back();
+ return CC;
+ }
+
+ // Advances the IT block state to the next T or E
+ void advanceITState() {
+ ITStates.pop_back();
+ }
+
+ // Returns true if the current instruction is in an IT block
+ bool instrInITBlock() {
+ return !ITStates.empty();
+ }
+
+ // Returns true if current instruction is the last instruction in an IT block
+ bool instrLastInITBlock() {
+ return ITStates.size() == 1;
+ }
+
+ // Called when decoding an IT instruction. Sets the IT state for the following
+ // instructions that for the IT block. Firstcond and Mask correspond to the
+ // fields in the IT instruction encoding.
+ void setITState(char Firstcond, char Mask) {
+ // (3 - the number of trailing zeros) is the number of then / else.
+ unsigned CondBit0 = Firstcond & 1;
+ unsigned NumTZ = CountTrailingZeros_32(Mask);
+ unsigned char CCBits = static_cast<unsigned char>(Firstcond & 0xf);
+ assert(NumTZ <= 3 && "Invalid IT mask!");
+ // push condition codes onto the stack the correct order for the pops
+ for (unsigned Pos = NumTZ+1; Pos <= 3; ++Pos) {
+ bool T = ((Mask >> Pos) & 1) == CondBit0;
+ if (T)
+ ITStates.push_back(CCBits);
+ else
+ ITStates.push_back(CCBits ^ 1);
+ }
+ ITStates.push_back(CCBits);
+ }
+
+ private:
+ std::vector<unsigned char> ITStates;
+ };
+}
+