We have (mt_slot_count() - 1 == mt_pivot_count()), except for maple_dense node. Since mas_mab_cp() doesn't apply to maple_dense node, it is fine to use mt_pivot_count() here. By doing so we can save instruction to decrease 1 from mt_slot_count(). Below is the comparison of generated code. Current: .L1595: lib/maple_tree.c:3165: mas_mab_cp(mas, split + skip, mt_slot_count(mas->node) - 1, movl %ebx, (%esp) # prephitmp_234, movzbl mt_slots(%edx), %ecx # mt_slots[_90], mt_slots[_90] movl %esi, 4(%esp) # _26, movzbl -23(%ebp), %eax # %sfp, movzbl -21(%ebp), %edx # %sfp, split decb %cl # tmp258 movzbl %cl, %ecx # tmp258, tmp260 addb %al, %dl #, split movl -16(%ebp), %eax # %sfp, movzbl %dl, %edx # tmp261, tmp262 call mas_mab_cp # After applying this patch: .L1595: lib/maple_tree.c:3165: mas_mab_cp(mas, split + skip, mt_pivot_count(mas->node), movl %ebx, (%esp) # prephitmp_231, movzbl mt_pivots(%edx), %ecx # mt_pivots[_87], mt_pivots[_87] movl %esi, 4(%esp) # _26, movzbl -23(%ebp), %eax # %sfp, movzbl -21(%ebp), %edx # %sfp, split addb %al, %dl #, split movl -16(%ebp), %eax # %sfp, movzbl %dl, %edx # tmp256, tmp257 call mas_mab_cp # Signed-off-by: Wei Yang <richard.weiyang@xxxxxxxxx> --- lib/maple_tree.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/lib/maple_tree.c b/lib/maple_tree.c index 51f49b29b8b0..8ff075645f21 100644 --- a/lib/maple_tree.c +++ b/lib/maple_tree.c @@ -3167,7 +3167,7 @@ static inline void mast_fill_bnode(struct maple_subtree_state *mast, cp = false; if (cp) - mas_mab_cp(mas, split + skip, mt_slot_count(mas->node) - 1, + mas_mab_cp(mas, split + skip, mt_pivot_count(mas->node), mast->bn, mast->bn->b_end); mast->bn->b_end--; -- 2.34.1
