even more perf, update benchmark numbers

Signed-off-by: martinvuyk <[email protected]>

stdlib/benchmarks/collections/bench_string.mojo

@@ -10,7 +10,7 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 # ===----------------------------------------------------------------------=== #
-# RUN: %mojo-no-debug %s -t
+# RUN: %mojo-no-debug %s
 # NOTE: to test changes on the current branch using run-benchmarks.sh, remove
 # the -t flag. Remember to replace it again before pushing any code.
 
@@ -23,6 +23,7 @@ from random import random_si64, seed
 from benchmark import Bench, BenchConfig, Bencher, BenchId, Unit, keep, run
 
 from utils._utf8_validation import _is_valid_utf8
+from utils import StringSlice
 
 
 # ===-----------------------------------------------------------------------===#
@@ -111,7 +112,7 @@ fn bench_string_split[
     @always_inline
     @parameter
     fn call_fn() raises:
-        var res: List[String]
+        var res: List[StringSlice[__origin_of(items)]]
 
         @parameter
         if sequence:
@@ -237,7 +238,7 @@ def main():
     )
     alias old_chars = ("a", "ó", "ل", "и", "一")
     alias new_chars = ("A", "Ó", "ل", "И", "一")
-    alias lengths = (10, 30, 50, 100, 1000, 10_000, 100_000, 1_000_000)
+    alias lengths = (1_000_000,)
     """At an average 5 letters per word and 300 words per page
     (in the English language):
 

stdlib/src/utils/string_slice.mojo

@@ -1358,11 +1358,11 @@ fn _split[
         # FIXME(#3526): use str_span and sep_span
         rhs = src_str.find(sep, lhs)
         # if not found go to the end
-        rhs += int(rhs == -1) * (str_byte_len + 1)
+        rhs += -int(rhs == -1) & (str_byte_len + 1)
 
         @parameter
         if has_maxsplit:
-            rhs += int(items == maxsplit) * (str_byte_len - rhs)
+            rhs += -int(items == maxsplit) & (str_byte_len - rhs)
             items += 1
 
         output.append(S(ptr=ptr + lhs, length=rhs - lhs))
@@ -1415,7 +1415,7 @@ fn _split[
 
         @parameter
         if has_maxsplit:
-            rhs += int(items == maxsplit) * (str_byte_len - rhs)
+            rhs += -int(items == maxsplit) & (str_byte_len - rhs)
             items += 1
 
         output.append(S(ptr=ptr + lhs, length=rhs - lhs))