diff options
Diffstat (limited to 'gcc/cfgloopanal.c')
| -rw-r--r-- | gcc/cfgloopanal.c | 25 |
1 files changed, 20 insertions, 5 deletions
diff --git a/gcc/cfgloopanal.c b/gcc/cfgloopanal.c index c00d1c501be..db5bd2a62b9 100644 --- a/gcc/cfgloopanal.c +++ b/gcc/cfgloopanal.c @@ -29,6 +29,7 @@ along with GCC; see the file COPYING3. If not see #include "expr.h" #include "output.h" #include "graphds.h" +#include "params.h" /* Checks whether BB is executed exactly once in each LOOP iteration. */ @@ -372,6 +373,7 @@ init_set_costs (void) unsigned estimate_reg_pressure_cost (unsigned n_new, unsigned n_old) { + unsigned cost; unsigned regs_needed = n_new + n_old; /* If we have enough registers, we should use them and not restrict @@ -379,12 +381,25 @@ estimate_reg_pressure_cost (unsigned n_new, unsigned n_old) if (regs_needed + target_res_regs <= target_avail_regs) return 0; - /* If we are close to running out of registers, try to preserve them. */ if (regs_needed <= target_avail_regs) - return target_reg_cost * n_new; - - /* If we run out of registers, it is very expensive to add another one. */ - return target_spill_cost * n_new; + /* If we are close to running out of registers, try to preserve + them. */ + cost = target_reg_cost * n_new; + else + /* If we run out of registers, it is very expensive to add another + one. */ + cost = target_spill_cost * n_new; + + if (optimize && flag_ira && (flag_ira_algorithm == IRA_ALGORITHM_REGIONAL + || flag_ira_algorithm == IRA_ALGORITHM_MIXED) + && number_of_loops () <= (unsigned) IRA_MAX_LOOPS_NUM) + /* IRA regional allocation deals with high register pressure + better. So decrease the cost (to do more accurate the cost + calculation for IRA, we need to know how many registers lives + through the loop transparently). */ + cost /= 2; + + return cost; } /* Sets EDGE_LOOP_EXIT flag for all loop exits. */ |