| /* |
| * Copyright (C) 1995 Advanced RISC Machines Limited. All rights reserved. |
| * |
| * This software may be freely used, copied, modified, and distributed |
| * provided that the above copyright notice is preserved in all copies of the |
| * software. |
| */ |
| |
| /* |
| * angel_bytesex.c - Code to support byte-sex independence |
| * Copyright: (C) 1991, Advanced RISC Machines Ltd., Cambridge, England. |
| */ |
| |
| /* |
| * RCS $Revision$ |
| * Checkin $Date$ |
| */ |
| |
| #include "angel_bytesex.h" |
| |
| static int reversing_bytes = 0; |
| |
| void bytesex_reverse(yes_or_no) |
| int yes_or_no; |
| { reversing_bytes = yes_or_no; |
| } |
| |
| int bytesex_reversing() |
| { |
| return reversing_bytes; |
| } |
| |
| int32 bytesex_hostval(v) |
| int32 v; |
| { /* Return v with the same endian-ness as the host */ |
| /* This mess generates better ARM code than the more obvious mess */ |
| /* and may eventually peephole to optimal code... */ |
| if (reversing_bytes) |
| { unsigned32 t; |
| /* t = v ^ (v ror 16) */ |
| t = v ^ ((v << 16) | (((unsigned32)v) >> 16)); |
| t &= ~0xff0000; |
| /* v = v ror 8 */ |
| v = (v << 24) | (((unsigned32)v) >> 8); |
| v = v ^ (t >> 8); |
| } |
| return v; |
| } |
| |
| int32 bytesex_hostval_16(v) |
| int32 v; |
| { |
| if (reversing_bytes) { |
| v = ((v >> 8) & 0xff) | ((v << 8) & 0xff00); |
| } |
| return v; |
| } |