8311220: Optimization for StringLatin UpperLower

Reviewed-by: redestad, liach
openjdk · Sep 18, 2023 · f09b7af · f09b7af · openjdk-notifier · Sep 18, 2023
1 parent 2e2d49c
commit f09b7af
Showing 1 changed file with 7 additions and 13 deletions.
diff --git a/src/java.base/share/classes/java/lang/StringLatin1.java b/src/java.base/share/classes/java/lang/StringLatin1.java
@@ -531,10 +531,9 @@ public static String toLowerCase(String str, byte[] value, Locale locale) {
         }
         int first;
         final int len = value.length;
-        // Now check if there are any characters that need to be changed, or are surrogate
+        // Now check if there are any characters that need to be changed
         for (first = 0 ; first < len; first++) {
-            int cp = value[first] & 0xff;
-            if (cp != CharacterDataLatin1.instance.toLowerCase(cp)) {  // no need to check Character.ERROR
+            if (CharacterDataLatin1.instance.isUpperCase(value[first] & 0xff)) {
                 break;
             }
         }
@@ -548,12 +547,7 @@ public static String toLowerCase(String str, byte[] value, Locale locale) {
         System.arraycopy(value, 0, result, 0, first);  // Just copy the first few
                                                        // lowerCase characters.
         for (int i = first; i < len; i++) {
-            int cp = value[i] & 0xff;
-            cp = CharacterDataLatin1.instance.toLowerCase(cp);
-            if (!canEncode(cp)) {                      // not a latin1 character
-                return toLowerCaseEx(str, value, first, locale, false);
-            }
-            result[i] = (byte)cp;
+            result[i] = (byte)CharacterDataLatin1.instance.toLowerCase(value[i] & 0xff);
         }
         return new String(result, LATIN1);
     }
@@ -605,10 +599,11 @@ public static String toUpperCase(String str, byte[] value, Locale locale) {
         int first;
         final int len = value.length;
 
-        // Now check if there are any characters that need to be changed, or are surrogate
+        // Now check if there are any characters that need to be changed
         for (first = 0 ; first < len; first++ ) {
             int cp = value[first] & 0xff;
-            if (cp != CharacterDataLatin1.instance.toUpperCaseEx(cp)) {   // no need to check Character.ERROR
+            boolean notUpperCaseEx = cp >= 'a' && (cp <= 'z' || cp == 0xb5 || (cp >= 0xdf && cp != 0xf7));
+            if (notUpperCaseEx) {
                 break;
             }
         }
@@ -623,8 +618,7 @@ public static String toUpperCase(String str, byte[] value, Locale locale) {
         System.arraycopy(value, 0, result, 0, first);  // Just copy the first few
                                                        // upperCase characters.
         for (int i = first; i < len; i++) {
-            int cp = value[i] & 0xff;
-            cp = CharacterDataLatin1.instance.toUpperCaseEx(cp);
+            int cp = CharacterDataLatin1.instance.toUpperCaseEx(value[i] & 0xff);
             if (!canEncode(cp)) {                      // not a latin1 character
                 return toUpperCaseEx(str, value, first, locale, false);
             }