On Fri, May 9, 2008 at 12:03 AM, Ian Lance Taylor <[EMAIL PROTECTED]> wrote: > "Mohamed Shafi" <[EMAIL PROTECTED]> writes: > > > For the 16-bit target that i porting now to gcc 4.1.2 doesn't have any > > branch instructions. It only has jump instructions. For comparison > > operation it has this instruction: > > > > if cond Rx Ry > > execute this insn > > > > So compare and branch is implemented as > > > > if cond Rx Ry > > jmp Label > > For gcc's purposes this is no different from having a usual > conditional branch instruction. It's just a jump with a condition. > > > > This instructions has also another form. To check whether a particular > > bit in a register is set or not. > > > > if bs Rx, bitNo > > execute this insn > > > > My questions is how will i be able to implement this instruction in > > the back-end? > > Sure, this is just a conditional instruction where the condition is a > ZERO_EXTRACT. > > Look at the ARM backend for examples of how to work with conditional > instructions.
thanks for the pointer. In fact many back-ends have this, now that you have showed me where to look But it would of great help if you could tell the C statment that actually invoked this type of pattern .. Maybe wrt some back-end? Regards, Shafi
