search for: seldagtodag

...flag I tried several things, but I got stuck in some way in all of them. For example, an approach that I tried is to have a ‘dummy_cmp’ instruction, that I generate instead of the regular ‘cmp’ when the comparison is redundant. The ‘dummy_cmp’ must be removed at a latter stage, ideally during the selDAGToDAG phase, but I failed to do so. - So my first question is. How do I remove the ‘dummy_cmp’ node in the MyTargetISelDAGtoDAG::Select() function? Another approach that I tried, which I regard as preferable, is to directly avoid the creation of a ‘cmp’ instruction during ISelLowering. Instead of ‘cmp...

...> I tried several things, but I got stuck in some way in all of them. For example, an approach that I tried is to have a ‘dummy_cmp’ instruction, that I generate instead of the regular ‘cmp’ when the comparison is redundant. The ‘dummy_cmp’ must be removed at a latter stage, ideally during the selDAGToDAG phase, but I failed to do so. > > - So my first question is. How do I remove the ‘dummy_cmp’ node in the MyTargetISelDAGtoDAG::Select() function? > > Another approach that I tried, which I regard as preferable, is to directly avoid the creation of a ‘cmp’ instruction during ISelLower...

...nstruction : let Uses = [SR] in { def BRCC : T2ccbr< "br", "br"> ; } def : Pat<(CPU74brcc_g bb:$a, imm:$cc), (BRCC jmptarget:$a, imm:$cc, 0)>; def : Pat<(CPU74brcc_i bb:$a, imm:$cc, GR16:$ins), (BRCC jmptarget:$a, imm:$cc, GR16:$ins)>; Then, in MyTargetISelDAGToDAG I create ‘CPU74brcc_g' instructions if they are glued to a ‘compare’ instruction, or ‘CPU74brcc_i' instructions if they link to the result of an arithmetic instruction. During instruction selection these are replaced by actual, physical, BRCC instructions. This solution has proved to work...