infernap12/jdk
1
0
Fork 0
mirror of https://github.com/openjdk/jdk.git synced 2026-02-18 22:35:12 +00:00
Code Issues Packages Projects Releases Wiki Activity

8238289: Use _byteswap_ functions to implenent Bytes::swap_uX on Windows

Browse Source 
Reviewed-by: minqi, dholmes
This commit is contained in:
Ralf Schmelter 2020-04-07 09:06:01 +02:00
parent edc4ffe54b
commit f5a728af03
1 changed files with 4 additions and 47 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
src/hotspot/os_cpu/windows_x86/bytes_windows_x86.inline.hpp
View File

@ -25,63 +25,20 @@
#ifndef OS_CPU_WINDOWS_X86_BYTES_WINDOWS_X86_INLINE_HPP
#define OS_CPU_WINDOWS_X86_BYTES_WINDOWS_X86_INLINE_HPP
#pragma warning(disable: 4035) // Disable warning 4035: no return value
#include <stdlib.h>
// Efficient swapping of data bytes from Java byte
// ordering to native byte ordering and vice versa.
inline u2 Bytes::swap_u2(u2 x) {
#ifdef AMD64
address p = (address) &x;
return ( (u2(p[0]) << 8 ) | ( u2(p[1])) );
#else
__asm {
mov ax, x
xchg al, ah
}
// no return statement needed, result is already in ax
// compiler warning C4035 disabled via warning pragma
#endif // AMD64
return (u2) _byteswap_ushort((unsigned short) x);
}
inline u4 Bytes::swap_u4(u4 x) {
#ifdef AMD64
address p = (address) &x;
return ( (u4(p[0]) << 24) | (u4(p[1]) << 16) | (u4(p[2]) << 8) | u4(p[3])) ;
#else
__asm {
mov eax, x
bswap eax
}
// no return statement needed, result is already in eax
// compiler warning C4035 disabled via warning pragma
#endif // AMD64
}
#ifdef AMD64
inline u8 Bytes::swap_u8(u8 x) {
address p = (address) &x;
return ( (u8(p[0]) << 56) | (u8(p[1]) << 48) | (u8(p[2]) << 40) | (u8(p[3]) << 32) |
(u8(p[4]) << 24) | (u8(p[5]) << 16) | (u8(p[6]) << 8) | u8(p[7])) ;
}
#else
// Helper function for swap_u8
inline u8 Bytes::swap_u8_base(u4 x, u4 y) {
__asm {
mov eax, y
mov edx, x
bswap eax
bswap edx
}
// no return statement needed, result is already in edx:eax
// compiler warning C4035 disabled via warning pragma
return (u4) _byteswap_ulong((unsigned long) x);
}
inline u8 Bytes::swap_u8(u8 x) {
return swap_u8_base(*(u4*)&x, *(((u4*)&x)+1));
return (u8) _byteswap_uint64((unsigned __int64) x);
}
#endif // AMD64
#pragma warning(default: 4035) // Enable warning 4035: no return value
#endif // OS_CPU_WINDOWS_X86_BYTES_WINDOWS_X86_INLINE_HPP