diff options
Diffstat (limited to 'contrib/gcc/sched-ebb.c')
| -rw-r--r-- | contrib/gcc/sched-ebb.c | 29 |
1 files changed, 19 insertions, 10 deletions
diff --git a/contrib/gcc/sched-ebb.c b/contrib/gcc/sched-ebb.c index e9d7482..47dd83f 100644 --- a/contrib/gcc/sched-ebb.c +++ b/contrib/gcc/sched-ebb.c @@ -52,7 +52,8 @@ static int schedule_more_p PARAMS ((void)); static const char *ebb_print_insn PARAMS ((rtx, int)); static int rank PARAMS ((rtx, rtx)); static int contributes_to_priority PARAMS ((rtx, rtx)); -static void compute_jump_reg_dependencies PARAMS ((rtx, regset)); +static void compute_jump_reg_dependencies PARAMS ((rtx, regset, regset, + regset)); static void schedule_ebb PARAMS ((rtx, rtx)); /* Return nonzero if there are more insns that should be scheduled. */ @@ -160,22 +161,30 @@ contributes_to_priority (next, insn) return 1; } -/* INSN is a JUMP_INSN. Store the set of registers that must be considered - to be set by this jump in SET. */ +/* INSN is a JUMP_INSN, COND_SET is the set of registers that are + conditionally set before INSN. Store the set of registers that + must be considered as used by this jump in USED and that of + registers that must be considered as set in SET. */ static void -compute_jump_reg_dependencies (insn, set) +compute_jump_reg_dependencies (insn, cond_set, used, set) rtx insn; - regset set; + regset cond_set, used, set; { basic_block b = BLOCK_FOR_INSN (insn); edge e; for (e = b->succ; e; e = e->succ_next) - if ((e->flags & EDGE_FALLTHRU) == 0) - { - bitmap_operation (set, set, e->dest->global_live_at_start, - BITMAP_IOR); - } + if (e->flags & EDGE_FALLTHRU) + /* The jump may be a by-product of a branch that has been merged + in the main codepath after being conditionalized. Therefore + it may guard the fallthrough block from using a value that has + conditionally overwritten that of the main codepath. So we + consider that it restores the value of the main codepath. */ + bitmap_operation (set, e->dest->global_live_at_start, cond_set, + BITMAP_AND); + else + bitmap_operation (used, used, e->dest->global_live_at_start, + BITMAP_IOR); } /* Used in schedule_insns to initialize current_sched_info for scheduling |
