■ A branch or any instruction that modifies the PC must either be outside an IT block or must be
the last instruction inside the IT block. These are:
– ADD PC, PC, Rm
– MOV PC, Rm
– B, BL, BX, BLX
– any LDM, LDR, or POP instruction that writes to the PC
这里提到的 IT block 是什么意思?把指令换成ADD PC,PC,R1;倒是可以编译通过。 |