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 $Id: md.c 7540 2007-03-20 00:02:41Z michi $
36 #include "vm/jit/arm/md-abi.h"
38 #include "vm/exceptions.h"
39 #include "vm/global.h"
41 #include "vm/jit/asmpart.h"
42 #include "vm/jit/md.h"
44 #include "vm/jit/codegen-common.h" /* REMOVE ME: for codegendata */
47 /* md_init *********************************************************************
49 Do some machine dependent initialization.
51 *******************************************************************************/
59 /* md_codegen_patch_branch *****************************************************
61 Back-patches a branch instruction.
63 *******************************************************************************/
65 void md_codegen_patch_branch(codegendata *cd, s4 branchmpc, s4 targetmpc)
68 s4 disp; /* branch displacement */
70 /* calculate the patch position */
72 mcodeptr = (s4 *) (cd->mcodebase + branchmpc);
74 /* Calculate the branch displacement. */
76 disp = (targetmpc - branchmpc - 4) >> 2;
78 if ((disp < (s4) 0xff000000) || (disp > (s4) 0x00ffffff))
79 vm_abort("md_codegen_patch_branch: branch displacement out of range: %d > +/-%d", disp, 0x00ffffff);
81 /* sanity check: are we really patching a branch instruction */
83 assert((mcodeptr[-1] & 0x0e000000) == 0x0a000000);
85 /* patch the branch instruction before the mcodeptr */
87 mcodeptr[-1] |= (disp & 0x00ffffff);
91 /* md_stacktrace_get_returnaddress *********************************************
93 Returns the return address of the current stackframe, specified by
94 the passed stack pointer and the stack frame size.
96 *******************************************************************************/
98 u1 *md_stacktrace_get_returnaddress(u1 *sp, u4 framesize)
102 /*printf("md_stacktrace_get_returnaddress(): called (sp=%x, framesize=%d)\n", sp, framesize);*/
104 /* on ARM the return address is located on the top of the stackframe */
105 /* ATTENTION: this is only true for non-leaf methods !!! */
106 ra = *((u1 **) (sp + framesize - SIZEOF_VOID_P));
108 /*printf("md_stacktrace_get_returnaddress(): result (ra=%x)\n", ra);*/
114 /* md_assembler_get_patch_address **********************************************
116 Gets the patch address of the currently compiled method. The offset
117 is extracted from the load instruction(s) before the jump and added
118 to the right base address (PV or REG_METHODPTR).
122 e51cc040 ldr ip, [ip, #-64]
128 e590b000 ldr fp, [r0]
129 e59bc000 ldr ip, [fp]
133 How we find out the patching address to store new method pointer:
134 - loaded IP with LDR IP,[METHODPTR]?
135 yes=INVOKEVIRTUAL or INVOKEINTERFACE (things are easy!)
136 - loaded IP from data segment
137 yes=INVOKESTATIC or INVOKESPECIAL (things are complicated)
138 recompute pointer to data segment, maybe larger offset
140 *******************************************************************************/
142 u1 *md_get_method_patch_address(u1 *ra, stackframeinfo *sfi, u1 *mptr)
146 u1 *pa; /* patch address */
148 /* sanity check: are we inside jit code? */
150 assert(*((u4 *) (ra - 2*4)) == 0xe1a0e00f /*MOV LR,PC*/);
151 assert(*((u4 *) (ra - 1*4)) == 0xe1a0f00c /*MOV PC,IP*/);
153 /* get the load instruction and offset */
155 mcode = *((u4 *) (ra - 12));
156 offset = (s4) (mcode & 0x0fff);
158 assert ((mcode & 0xff70f000) == 0xe510c000);
160 if ((mcode & 0x000f0000) == 0x000b0000) {
161 /* sanity check: offset was positive */
163 assert((mcode & 0x00800000) == 0x00800000);
165 /* we loaded from REG_METHODPTR */
170 /* sanity check: we loaded from REG_IP; offset was negative or zero */
172 assert((mcode & 0x008f0000) == 0x000c0000 ||
173 (mcode & 0x008f0fff) == 0x008c0000);
175 /* we loaded from data segment; offset can be larger */
177 mcode = *((u4 *) (ra - 4*4));
179 /* check for "SUB IP, IP, #??, ROTL 12" */
181 if ((mcode & 0xffffff00) == 0xe24cca00)
182 offset += (s4) ((mcode & 0x00ff) << 12);
184 /* and get the final data segment address */
186 pa = sfi->pv - offset;
193 /* md_codegen_get_pv_from_pc ***************************************************
197 *******************************************************************************/
199 u1 *md_codegen_get_pv_from_pc(u1 *ra)
202 u4 mcode1, mcode2, mcode3;
206 /* this can either be a RECOMPUTE_IP in JIT code or a fake in asm_calljavafunction */
207 mcode1 = *((u4*) ra);
208 if ((mcode1 & 0xffffff00) == 0xe24fcf00 /*sub ip,pc,#__*/)
209 pv -= (s4) ((mcode1 & 0x000000ff) << 2);
210 else if ((mcode1 & 0xffffff00) == 0xe24fc000 /*sub ip,pc,#__*/)
211 pv -= (s4) (mcode1 & 0x000000ff);
213 /* if this happens, we got an unexpected instruction at (*ra) */
214 vm_abort("Unable to find method: %p (instr=%x)", ra, mcode1);
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: