Hi, I am working on a new port. The machine is 16 bit and supports pre-dec and post-inc addressing modes. I need your help because I do not manage to have GCC generating proper pre dec or post inc assembler code. I modified GO_IF_LEGITIMATE_ADDRESS routines so that addresses with PRE_DEC or POST_INC as RTL code are accepted. Then I sometimes get valid code like: move r1,-(r0) move r1,-2(r0) move r2,r0 But only with optimization options. Moreover, the previous example would be better coded with: move r1,-(r0) move r1,-(r0) move r2,r0 because it does the same thing and pre dec is a cheaper operation than -2(r0) (indexed with displacement). I tried to implement the cost function so that pre dec is cheaper than indexed with displacement but it does not work. So I cannot control pre dec and post inc in move operations. Besides, it never generates this addressing mode with other operations like add, and, ior ... which should be available. I took inspiration from MSP430 and defined patterns to directly consider the pre dec and post inc, but nothing changed. Please, I need advice. Regards. Florent
