diff --git a/src/java.base/share/classes/jdk/internal/util/DecimalDigits.java b/src/java.base/share/classes/jdk/internal/util/DecimalDigits.java
index d3cf0a88da3..84c8372c2af 100644
--- a/src/java.base/share/classes/jdk/internal/util/DecimalDigits.java
+++ b/src/java.base/share/classes/jdk/internal/util/DecimalDigits.java
@@ -143,44 +143,11 @@ public final class DecimalDigits {
      * @return If both characters are digits, return (str[offset] - '0') * 10 + (str[offset + 1] - '0'), otherwise return -1
      */
     public static int digit2(byte[] str, int offset) {
-        // Used by trusted callers.  Assumes all necessary bounds checks have been done by the caller.
-        /*
-            Here we are doing a 2-Byte Vector operation on the short type.
-
-            x & 0xF0 != 0x30
-            ---------------
-            0 0b0011_0000 & 0b1111_0000 = 0b0011_0000
-            1 0b0011_0001 & 0b1111_0000 = 0b0011_0000
-            2 0b0011_0010 & 0b1111_0000 = 0b0011_0000
-            3 0b0011_0011 & 0b1111_0000 = 0b0011_0000
-            4 0b0011_0100 & 0b1111_0000 = 0b0011_0000
-            5 0b0011_0101 & 0b1111_0000 = 0b0011_0000
-            6 0b0011_0110 & 0b1111_0000 = 0b0011_0000
-            7 0b0011_0111 & 0b1111_0000 = 0b0011_0000
-            8 0b0011_1000 & 0b1111_0000 = 0b0011_0000
-            9 0b0011_1001 & 0b1111_0000 = 0b0011_0000
-
-            (((d = x & 0x0F) + 0x06) & 0xF0) != 0
-            ---------------
-            0 ((0b0011_0000) & 0b0000_1111 + 0b0110_0000) & 0b1111_0000 = 0b0110_0000
-            1 ((0b0011_0001) & 0b0000_1111 + 0b0110_0000) & 0b1111_0000 = 0b0110_0000
-            2 ((0b0011_0010) & 0b0000_1111 + 0b0110_0000) & 0b1111_0000 = 0b0110_0000
-            3 ((0b0011_0011) & 0b0000_1111 + 0b0110_0000) & 0b1111_0000 = 0b0110_0000
-            4 ((0b0011_0100) & 0b0000_1111 + 0b0110_0000) & 0b1111_0000 = 0b0110_0000
-            5 ((0b0011_0101) & 0b0000_1111 + 0b0110_0000) & 0b1111_0000 = 0b0110_0000
-            6 ((0b0011_0110) & 0b0000_1111 + 0b0110_0000) & 0b1111_0000 = 0b0110_0000
-            7 ((0b0011_0111) & 0b0000_1111 + 0b0110_0000) & 0b1111_0000 = 0b0110_0000
-            8 ((0b0011_1000) & 0b0000_1111 + 0b0110_0000) & 0b1111_0000 = 0b0110_0000
-            9 ((0b0011_1001) & 0b0000_1111 + 0b0110_0000) & 0b1111_0000 = 0b0110_0000
-         */
-        int d;
-        short x = UNSAFE.getShortUnaligned(str, Unsafe.ARRAY_BYTE_BASE_OFFSET + offset, false);
-        if ((((x & 0xF0F0) - 0x3030)
-                | (((d = x & 0x0F0F) + 0x0606) & 0xF0F0)) != 0
-        ) {
-            return -1;
+        byte c0 = str[offset], c1 = str[offset + 1];
+        if (c0 >= '0' && c0 <= '9' && c1 >= '0' && c1 <= '9') {
+            return c0 * 10 + c1 - ('0' * 10 + '0');
         }
-        return (d & 0xF) * 10 + (d >> 8);
+        return -1;
     }
 
     /**