search for: div4_xform

...he load word instruction LDW takes an offset which is multiplied by 4 and added to the base pointer. This is dealt with in the patterns defined in XCoreInstrInfo.td. The following pattern is used for LDW: def : Pat<(load (add GRRegs:$addr, immUs4:$offset)), (LDW_2rus GRRegs:$addr, (div4_xform immUs4:$offset))>; immUs4 is true when offset is a multiple of 4 and the offset divided by 4 fits in an immediate. The div4_xform xform divides a constant by 4. These are both defined in XCoreInstrInfo.td. It sounds like your target may be able to use a similar approach. -- Richard Osborne...

Hi, my target architecture has a kind of "16bit addressing mode", i.e. one address does not address 8 bit but a 16bit chunk. Consequently, every constant used to calculate effective addresses must be divided by two. So far this is not such a problem for stack objects since FrameIndexes, function arguments etc. have a lot of custom lowering code where this can be done. But when it comes

...DW takes an > offset which is multiplied by 4 and added to the base pointer. This is > dealt with in the patterns defined in XCoreInstrInfo.td. The following > pattern is used for LDW: > > def : Pat<(load (add GRRegs:$addr, immUs4:$offset)), > (LDW_2rus GRRegs:$addr, (div4_xform immUs4:$offset))>; > Richard, thanks for your suggestion. However, I think what you describe is what I meant by 'only catch the targeted addresses of loads/stores', i.e. the address the instruction is reading from/writing to. However, if I have e.g. a chunk of code which stores the...