> The final index into (ira_)memory_move_cost is 1 for loads and > 0 for stores. Thus the combination: > > entry_freq * memory_cost[1] + exit_freq * memory_cost[0] > > is the cost of loading a register on entry to a loop and > storing it back on exit from the loop. This is the cost to > use if the register is successfully allocated within the > loop but is spilled in the parent loop. Similarly: > > entry_freq * memory_cost[0] + exit_freq * memory_cost[1] > > is the cost of storing a register on entry to the loop and > restoring it on exit from the loop. This is the cost to > use if the register is spilled within the loop but is > successfully allocated in the parent loop. > > The patch adds a helper class for calculating these values and > mechanically replaces the existing instances. There is no attempt to > editorialise the choice between using “spill inside” and “spill outside” > costs. (I think one of them is the wrong way round, but a later patch > deals with that.) > > No functional change intended. > > gcc/ > PR rtl-optimization/98782 > * ira-int.h (ira_loop_border_costs): New class. > * ira-color.c (ira_loop_border_costs::ira_loop_border_costs): > New constructor. > (calculate_allocno_spill_cost): Use ira_loop_border_costs. > (color_pass): Likewise. > (move_spill_restore): Likewise.
Thanks for working on this. For profile bits, the patch looks good to me. In general I am trying to move away from the integer frequencies. It would be more precise to calculate the m_entry_freq and m_exit_freq as profile_count m_entry_count, m_exit_count and do conversion only later. count->to_frequency method basically scales it to the range 0...BB_FREQ_MAX. Honza
