1 /* src/vm/jit/x86_64/md.c - machine dependent x86_64 functions
3 Copyright (C) 1996-2005, 2006, 2007 R. Grafl, A. Krall, C. Kruegel,
4 C. Oates, R. Obermaisser, M. Platter, M. Probst, S. Ring,
5 E. Steiner, C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich,
6 J. Wenninger, Institut f. Computersprachen - TU Wien
8 This file is part of CACAO.
10 This program is free software; you can redistribute it and/or
11 modify it under the terms of the GNU General Public License as
12 published by the Free Software Foundation; either version 2, or (at
13 your option) any later version.
15 This program is distributed in the hope that it will be useful, but
16 WITHOUT ANY WARRANTY; without even the implied warranty of
17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 General Public License for more details.
20 You should have received a copy of the GNU General Public License
21 along with this program; if not, write to the Free Software
22 Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
34 #include "vm/jit/x86_64/md-abi.h"
38 #include "vm/jit/codegen-common.h"
39 #include "vm/jit/jit.h"
42 /* md_init *********************************************************************
44 Do some machine dependent initialization.
46 *******************************************************************************/
54 /* md_jit_method_patch_address *************************************************
56 Gets the patch address of the currently compiled method. The offset
57 is extracted from the load instruction(s) before the jump and added
58 to the right base address (PV or REG_METHODPTR).
62 4d 8b 15 e2 fe ff ff mov -286(%rip),%r10
63 49 ff d2 rex64Z callq *%r10
67 4c 8b 17 mov (%rdi),%r10
68 49 8b 82 00 00 00 00 mov 0x0(%r10),%rax
69 48 ff d3 rex64 callq *%rax
73 4c 8b 17 mov (%rdi),%r10
74 4d 8b 92 00 00 00 00 mov 0x0(%r10),%r10
75 49 8b 82 00 00 00 00 mov 0x0(%r10),%rax
76 48 ff d3 rex64 callq *%r11
78 *******************************************************************************/
80 void *md_jit_method_patch_address(void *pv, void *ra, void *mptr)
85 void *pa; /* patch address */
87 /* go back to the actual call instruction (3-bytes) */
89 pc = ((uint8_t *) ra) - 3;
91 /* get the last byte of the call */
95 /* check for the different calls */
98 /* INVOKESTATIC/SPECIAL */
100 /* Get the offset from the instruction (the offset address is
101 4-bytes before the call instruction). */
103 offset = *((int32_t *) (pc - 4));
105 /* add the offset to the return address (IP-relative addressing) */
109 else if (mcode == 0xd3) {
110 /* INVOKEVIRTUAL/INTERFACE */
112 /* return NULL if no mptr was specified (used for replacement) */
117 /* Get the offset from the instruction (the offset address is
118 4-bytes before the call instruction). */
120 offset = *((int32_t *) (pc - 4));
122 /* add the offset to the method pointer */
124 pa = ((uint8_t *) mptr) + offset;
127 /* catch any problems */
129 vm_abort("md_jit_method_patch_address: unknown instruction %x", mcode);
131 /* keep compiler happy */
140 /* md_patch_replacement_point **************************************************
142 Patch the given replacement point.
144 *******************************************************************************/
146 #if defined(ENABLE_REPLACEMENT)
147 void md_patch_replacement_point(u1 *pc, u1 *savedmcode, bool revert)
152 /* write saved machine code */
153 *(u2*)(pc) = *(u2*)(savedmcode);
156 /* save the current machine code */
157 *(u2*)(savedmcode) = *(u2*)(pc);
159 /* build the machine code for the patch */
162 /* write new machine code */
163 *(u2*)(pc) = (u2) mcode;
166 /* XXX if required asm_cacheflush(pc,8); */
168 #endif /* defined(ENABLE_REPLACEMENT) */
172 * These are local overrides for various environment variables in Emacs.
173 * Please do not remove this and leave it at the end of the file, where
174 * Emacs will automagically detect them.
175 * ---------------------------------------------------------------------
178 * indent-tabs-mode: t
182 * vim:noexpandtab:sw=4:ts=4: