Hi Timm, On Tue, 2021-02-02 at 11:23 +0100, Timm Bäder via Elfutils-devel wrote: > advance_pc() uses show_op_index to save whether the current op_index > is > > 0 OR the new op_index is > 0. > > The new op index is calculated via > > new_op_index = (op_index + op_advance) % max_ops_per_instr; > > since all of the variables involved are unsigned, > new_op_index >= op_index is always true. > > So... > > if op_index > 0, then new_op_index > 0 > if op_index == 0, then new_op_index >= 0 > > and if the new_op_index is > 0, then the old one was as well. > > In any case, we only need to check the new_op_index, since show_op_index > used to OR the two comparisons. > > In other words: > > op_index > 0 | new_op_index > 0 || show_op_index > ------------------------------------------------ > true true true > false true true > true false true xx > false false false > > ... but since the third line (marked with xx) is not possible, > the table becomes: > > op_index > 0 | new_op_index > 0 || show_op_index > ------------------------------------------------ > true true true > false true true > false false false > > ... and show_op_index is equal to (new_op_index > 0). > So, remove the show_op_index variable and simply replace it by comparing > the new op_index > 0.
Very nice simplification. Thanks for the extensive commit message. In most cases max_ops_per_instr is actually 1. In which case op_index will always be zero. Pushed to trunk. Thanks, Mark
