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remove unsafe

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This commit is contained in:
Shaojin Wen 2025-12-04 19:11:52 +08:00
parent c58aa70718
commit cebefd7b89
1 changed files with 4 additions and 37 deletions
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41
src/java.base/share/classes/jdk/internal/util/DecimalDigits.java
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@ -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;
}
/**