BITOP speedup when or/and output is 0/255, stop processing further keys (#8110)

when performing the and operation, if the output is 0, we can jump out of the loop.
when performing an or operation, if the output is 0xff, we can jump out of the loop.

1 files changed, 13 insertions, 2 deletions

diff --git a/src/bitops.c b/src/bitops.c
index 5550b60d1..5e996679b 100644
--- a/src/bitops.c
+++ b/src/bitops.c
@@ -735,12 +735,23 @@ void bitopCommand(client *c) {
             output = (len[0] <= j) ? 0 : src[0][j];
             if (op == BITOP_NOT) output = ~output;
             for (i = 1; i < numkeys; i++) {
+                int skip = 0;
                 byte = (len[i] <= j) ? 0 : src[i][j];
                 switch(op) {
-                case BITOP_AND: output &= byte; break;
-                case BITOP_OR:  output |= byte; break;
+                case BITOP_AND:
+                    output &= byte;
+                    skip = (output == 0);
+                    break;
+                case BITOP_OR:
+                    output |= byte;
+                    skip = (output == 0xff);
+                    break;
                 case BITOP_XOR: output ^= byte; break;
                 }
+
+                if (skip) {
+                    break;
+                }
             }
             res[j] = output;
         }