1 /* src/vm/jit/arm/md.c - machine dependent Arm 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
25 Contact: cacao@cacaojvm.org
27 Authors: Michael Starzinger
30 $Id: md.c 6591 2007-01-02 19:14:25Z twisti $
39 #include "vm/global.h"
42 #include "vm/jit/arm/md-abi.h"
44 #include "vm/exceptions.h"
45 #include "vm/stringlocal.h"
46 #include "vm/jit/asmpart.h"
49 /* md_init *********************************************************************
51 Do some machine dependent initialization.
53 *******************************************************************************/
61 /* md_codegen_patch_branch *****************************************************
63 Back-patches a branch instruction.
65 *******************************************************************************/
67 void md_codegen_patch_branch(codegendata *cd, s4 branchmpc, s4 targetmpc)
70 s4 disp; /* branch displacement */
72 /* calculate the patch position */
74 mcodeptr = (s4 *) (cd->mcodebase + branchmpc);
76 /* Calculate the branch displacement. */
78 disp = (targetmpc - branchmpc - 4) >> 2;
80 if ((disp < (s4) 0xff000000) || (disp > (s4) 0x00ffffff))
81 vm_abort("md_codegen_patch_branch: branch displacement out of range: %d > +/-%d", disp, 0x00ffffff);
83 /* patch the branch instruction before the mcodeptr */
85 mcodeptr[-1] |= (disp & 0x00ffffff);
89 /* md_stacktrace_get_returnaddress *********************************************
91 Returns the return address of the current stackframe, specified by
92 the passed stack pointer and the stack frame size.
94 *******************************************************************************/
96 u1 *md_stacktrace_get_returnaddress(u1 *sp, u4 framesize)
100 /*printf("md_stacktrace_get_returnaddress(): called (sp=%x, framesize=%d)\n", sp, framesize);*/
102 /* on ARM the return address is located on the top of the stackframe */
103 /* ATTENTION: this is only true for non-leaf methods !!! */
104 ra = *((u1 **) (sp + framesize - SIZEOF_VOID_P));
106 /*printf("md_stacktrace_get_returnaddress(): result (ra=%x)\n", ra);*/
112 /* md_assembler_get_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).
120 e51cc040 ldr ip, [ip, #-64]
126 e590b000 ldr fp, [r0]
127 e59bc000 ldr ip, [fp]
131 How we find out the patching address to store new method pointer:
132 - loaded IP with LDR IP,[METHODPTR]?
133 yes=INVOKEVIRTUAL or INVOKEINTERFACE (things are easy!)
134 - loaded IP from data segment
135 yes=INVOKESTATIC or INVOKESPECIAL (things are complicated)
136 recompute pointer to data segment, maybe larger offset
138 *******************************************************************************/
140 u1 *md_get_method_patch_address(u1 *ra, stackframeinfo *sfi, u1 *mptr)
144 u1 *pa; /* patch address */
146 /* sanity check: are we inside jit code? */
148 assert(*((u4 *) (ra - 2*4)) == 0xe1a0e00f /*MOV LR,PC*/);
149 assert(*((u4 *) (ra - 1*4)) == 0xe1a0f00c /*MOV PC,IP*/);
151 /* get the load instruction and offset */
153 mcode = *((u4 *) (ra - 12));
154 offset = (s4) (mcode & 0x0fff);
156 assert ((mcode & 0xff70f000) == 0xe510c000);
158 if ((mcode & 0x000f0000) == 0x000b0000) {
159 /* sanity check: offset was positive */
161 assert((mcode & 0x00800000) == 0x00800000);
163 /* we loaded from REG_METHODPTR */
168 /* sanity check: we loaded from REG_IP; offset was negative or zero */
170 assert((mcode & 0x008f0000) == 0x000c0000 ||
171 (mcode & 0x008f0fff) == 0x008c0000);
173 /* we loaded from data segment; offset can be larger */
175 mcode = *((u4 *) (ra - 4*4));
177 /* check for "SUB IP, IP, #??, ROTL 12" */
179 if ((mcode & 0xffffff00) == 0xe24cca00)
180 offset += (s4) ((mcode & 0x00ff) << 12);
182 /* and get the final data segment address */
184 pa = sfi->pv - offset;
191 /* md_codegen_get_pv_from_pc ***************************************************
195 *******************************************************************************/
197 u1 *md_codegen_get_pv_from_pc(u1 *ra)
200 u4 mcode1, mcode2, mcode3;
204 /* this can either be a RECOMPUTE_IP in JIT code or a fake in asm_calljavafunction */
205 mcode1 = *((u4*) ra);
206 if ((mcode1 & 0xffffff00) == 0xe24fcf00 /*sub ip,pc,#__*/)
207 pv -= (s4) ((mcode1 & 0x000000ff) << 2);
208 else if ((mcode1 & 0xffffff00) == 0xe24fc000 /*sub ip,pc,#__*/)
209 pv -= (s4) (mcode1 & 0x000000ff);
211 /* if this happens, we got an unexpected instruction at (*ra) */
212 throw_cacao_exception_exit(string_java_lang_InternalError,
213 "Unable to find method: %p (instr=%x)\n",
217 /* if we have a RECOMPUTE_IP there can be more than one instruction */
218 mcode2 = *((u4*) (ra + 4));
219 mcode3 = *((u4*) (ra + 8));
220 if ((mcode2 & 0xffffff00) == 0xe24ccb00 /*sub ip,ip,#__*/)
221 pv -= (s4) ((mcode2 & 0x000000ff) << 10);
222 if ((mcode3 & 0xffffff00) == 0xe24cc700 /*sub ip,ip,#__*/)
223 pv -= (s4) ((mcode3 & 0x000000ff) << 18);
225 /* we used PC-relative adressing; but now it is LR-relative */
228 /* if we found our method the data segment has to be valid */
229 /* we check this by looking up the IsLeaf field, which has to be boolean */
230 assert( *((s4*)pv-4) == (s4)true || *((s4*)pv-4) == (s4)false );
236 /* md_cacheflush ***************************************************************
238 Calls the system's function to flush the instruction and data
241 *******************************************************************************/
243 void md_cacheflush(u1 *addr, s4 nbytes)
245 asm_cacheflush(addr, nbytes);
249 /* md_icacheflush **************************************************************
251 Calls the system's function to flush the instruction cache.
253 *******************************************************************************/
255 void md_icacheflush(u1 *addr, s4 nbytes)
257 asm_cacheflush(addr, nbytes);
261 /* md_dcacheflush **************************************************************
263 Calls the system's function to flush the data cache.
265 *******************************************************************************/
267 void md_dcacheflush(u1 *addr, s4 nbytes)
269 asm_cacheflush(addr, nbytes);
274 * These are local overrides for various environment variables in Emacs.
275 * Please do not remove this and leave it at the end of the file, where
276 * Emacs will automagically detect them.
277 * ---------------------------------------------------------------------
280 * indent-tabs-mode: t
284 * vim:noexpandtab:sw=4:ts=4: