1 /* src/vm/jit/i386/md.c - machine dependent i386 functions
3 Copyright (C) 1996-2005, 2006 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
25 Contact: cacao@cacaojvm.org
27 Authors: Christian Thalinger
30 $Id: md.c 7255 2007-01-29 21:39:38Z twisti $
41 #include "vm/global.h"
43 #include "vm/jit/asmpart.h"
44 #include "vm/jit/codegen-common.h"
45 #include "vm/jit/md.h"
47 #if !defined(NDEBUG) && defined(ENABLE_DISASSEMBLER)
48 #include "vmcore/options.h" /* XXX debug */
49 #include "vm/jit/disass.h" /* XXX debug */
53 /* md_init *********************************************************************
55 Do some machine dependent initialization.
57 *******************************************************************************/
65 /* md_codegen_patch_branch *****************************************************
67 Back-patches a branch instruction.
69 *******************************************************************************/
71 void md_codegen_patch_branch(codegendata *cd, s4 branchmpc, s4 targetmpc)
74 s4 disp; /* branch displacement */
76 /* calculate the patch position */
78 mcodeptr = (s4 *) (cd->mcodebase + branchmpc);
80 /* Calculate the branch displacement. */
82 disp = targetmpc - branchmpc;
84 /* I don't think we have to check for branch-displacement
85 overflow, +/-2GB should be enough. */
87 /* patch the branch instruction before the mcodeptr */
93 /* md_stacktrace_get_returnaddress *********************************************
95 Returns the return address of the current stackframe, specified by
96 the passed stack pointer and the stack frame size.
98 *******************************************************************************/
100 u1 *md_stacktrace_get_returnaddress(u1 *sp, u4 framesize)
104 /* on i386 the return address is above the current stack frame */
106 ra = *((u1 **) (sp + framesize));
112 /* md_get_method_patch_address *************************************************
114 Gets the patch address of the currently compiled method. The offset
115 is extracted from the load instruction(s) before the jump and added
116 to the right base address (PV or REG_METHODPTR).
118 INVOKESTATIC/SPECIAL:
120 b9 30 00 49 b7 mov $0xb7490030,%ecx
125 8b 08 mov (%eax),%ecx
126 8b 91 00 00 00 00 mov 0x0(%ecx),%edx
131 8b 08 mov (%eax),%ecx
132 8b 89 00 00 00 00 mov 0x0(%ecx),%ecx
133 8b 91 00 00 00 00 mov 0x0(%ecx),%edx
136 *******************************************************************************/
138 u1 *md_get_method_patch_address(u1 *ra, stackframeinfo *sfi, u1 *mptr)
142 u1 *pa; /* patch address */
144 /* go back to the actual call instruction (2-bytes) */
148 /* get the last byte of the call */
152 /* check for the different calls */
155 /* INVOKESTATIC/SPECIAL */
157 /* patch address is 4-bytes before the call instruction */
161 else if (mcode == 0xd2) {
162 /* INVOKEVIRTUAL/INTERFACE */
164 /* return NULL if no mptr was specified (used for replacement) */
169 /* Get the offset from the instruction (the offset address is
170 4-bytes before the call instruction). */
172 offset = *((s4 *) (ra - 4));
174 /* add the offset to the method pointer */
179 /* catch any problems */
181 pa = NULL; /* avoid warnings */
183 vm_abort("couldn't find a proper call instruction sequence");
190 /* md_codegen_get_pv_from_pc ***************************************************
192 On this architecture just a wrapper function to
193 codegen_get_pv_from_pc.
195 *******************************************************************************/
197 u1 *md_codegen_get_pv_from_pc(u1 *ra)
201 /* Get the start address of the function which contains this
202 address from the method table. */
204 pv = codegen_get_pv_from_pc(ra);
210 /* md_cacheflush ***************************************************************
212 Calls the system's function to flush the instruction and data
215 *******************************************************************************/
217 void md_cacheflush(u1 *addr, s4 nbytes)
223 /* md_icacheflush **************************************************************
225 Calls the system's function to flush the instruction cache.
227 *******************************************************************************/
229 void md_icacheflush(u1 *addr, s4 nbytes)
235 /* md_dcacheflush **************************************************************
237 Calls the system's function to flush the data cache.
239 *******************************************************************************/
241 void md_dcacheflush(u1 *addr, s4 nbytes)
247 /* md_patch_replacement_point **************************************************
249 Patch the given replacement point.
251 *******************************************************************************/
253 #if defined(ENABLE_REPLACEMENT)
254 void md_patch_replacement_point(codeinfo *code, s4 index, rplpoint *rp, u1 *savedmcode)
259 /* XXX this is probably unsafe! */
262 /* write spinning instruction */
263 *(u2*)(rp->pc) = 0xebfe;
266 rp->pc[4] = savedmcode[4];
268 /* write first word */
269 *(u4*)(rp->pc) = *(u4*)(savedmcode);
272 /* save the current machine code */
273 *(u4*)(savedmcode) = *(u4*)(rp->pc);
274 savedmcode[4] = rp->pc[4];
276 /* build the machine code for the patch */
277 disp = (code->replacementstubs - rp->pc)
278 + index * REPLACEMENT_STUB_SIZE
281 mcode = 0xe9 | ((u8) disp << 8);
283 /* write spinning instruction */
284 *(u2*)(rp->pc) = 0xebfe;
287 rp->pc[4] = (mcode >> 32);
289 /* write first word */
290 *(u4*)(rp->pc) = (u4) mcode;
293 #if !defined(NDEBUG) && defined(ENABLE_DISASSEMBLER) && 0
301 /* XXX if required asm_cacheflush(rp->pc,8); */
303 #endif /* defined(ENABLE_REPLACEMENT) */
306 * These are local overrides for various environment variables in Emacs.
307 * Please do not remove this and leave it at the end of the file, where
308 * Emacs will automagically detect them.
309 * ---------------------------------------------------------------------
312 * indent-tabs-mode: t
316 * vim:noexpandtab:sw=4:ts=4: