/*
* Copyright 1997-2005 Sun Microsystems, Inc. All Rights Reserved.
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* This code is free software; you can redistribute it and/or modify it
* under the terms of the GNU General Public License version 2 only, as
* published by the Free Software Foundation.
*
* This code is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
* version 2 for more details (a copy is included in the LICENSE file that
* accompanied this code).
*
* You should have received a copy of the GNU General Public License version
* 2 along with this work; if not, write to the Free Software Foundation,
* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
*
* Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
* CA 95054 USA or visit www.sun.com if you need additional information or
* have any questions.
*
*/
inline void MacroAssembler::pd_patch_instruction(address branch, address target) {
unsigned char op = branch[0];
assert(op == 0xE8 /* call */ ||
op == 0xE9 /* jmp */ ||
op == 0xEB /* short jmp */ ||
(op & 0xF0) == 0x70 /* short jcc */ ||
op == 0x0F && (branch[1] & 0xF0) == 0x80 /* jcc */,
"Invalid opcode at patch point");
if (op == 0xEB || (op & 0xF0) == 0x70) {
// short offset operators (jmp and jcc)
char* disp = (char*) &branch[1];
int imm8 = target - (address) &disp[1];
guarantee(this->is8bit(imm8), "Short forward jump exceeds 8-bit offset");
*disp = imm8;
} else {
int* disp = (int*) &branch[(op == 0x0F)? 2: 1];
int imm32 = target - (address) &disp[1];
*disp = imm32;
}
}
#ifndef PRODUCT
inline void MacroAssembler::pd_print_patched_instruction(address branch) {
const char* s;
unsigned char op = branch[0];
if (op == 0xE8) {
s = "call";
} else if (op == 0xE9 || op == 0xEB) {
s = "jmp";
} else if ((op & 0xF0) == 0x70) {
s = "jcc";
} else if (op == 0x0F) {
s = "jcc";
} else {
s = "????";
}
tty->print("%s (unresolved)", s);
}
#endif // ndef PRODUCT