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 7504 2007-03-12 13:17:07Z twisti $
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 /* patch the branch instruction before the mcodeptr */
83 mcodeptr[-1] |= (disp & 0x00ffffff);
87 /* md_stacktrace_get_returnaddress *********************************************
89 Returns the return address of the current stackframe, specified by
90 the passed stack pointer and the stack frame size.
92 *******************************************************************************/
94 u1 *md_stacktrace_get_returnaddress(u1 *sp, u4 framesize)
98 /*printf("md_stacktrace_get_returnaddress(): called (sp=%x, framesize=%d)\n", sp, framesize);*/
100 /* on ARM the return address is located on the top of the stackframe */
101 /* ATTENTION: this is only true for non-leaf methods !!! */
102 ra = *((u1 **) (sp + framesize - SIZEOF_VOID_P));
104 /*printf("md_stacktrace_get_returnaddress(): result (ra=%x)\n", ra);*/
110 /* md_assembler_get_patch_address **********************************************
112 Gets the patch address of the currently compiled method. The offset
113 is extracted from the load instruction(s) before the jump and added
114 to the right base address (PV or REG_METHODPTR).
118 e51cc040 ldr ip, [ip, #-64]
124 e590b000 ldr fp, [r0]
125 e59bc000 ldr ip, [fp]
129 How we find out the patching address to store new method pointer:
130 - loaded IP with LDR IP,[METHODPTR]?
131 yes=INVOKEVIRTUAL or INVOKEINTERFACE (things are easy!)
132 - loaded IP from data segment
133 yes=INVOKESTATIC or INVOKESPECIAL (things are complicated)
134 recompute pointer to data segment, maybe larger offset
136 *******************************************************************************/
138 u1 *md_get_method_patch_address(u1 *ra, stackframeinfo *sfi, u1 *mptr)
142 u1 *pa; /* patch address */
144 /* sanity check: are we inside jit code? */
146 assert(*((u4 *) (ra - 2*4)) == 0xe1a0e00f /*MOV LR,PC*/);
147 assert(*((u4 *) (ra - 1*4)) == 0xe1a0f00c /*MOV PC,IP*/);
149 /* get the load instruction and offset */
151 mcode = *((u4 *) (ra - 12));
152 offset = (s4) (mcode & 0x0fff);
154 assert ((mcode & 0xff70f000) == 0xe510c000);
156 if ((mcode & 0x000f0000) == 0x000b0000) {
157 /* sanity check: offset was positive */
159 assert((mcode & 0x00800000) == 0x00800000);
161 /* we loaded from REG_METHODPTR */
166 /* sanity check: we loaded from REG_IP; offset was negative or zero */
168 assert((mcode & 0x008f0000) == 0x000c0000 ||
169 (mcode & 0x008f0fff) == 0x008c0000);
171 /* we loaded from data segment; offset can be larger */
173 mcode = *((u4 *) (ra - 4*4));
175 /* check for "SUB IP, IP, #??, ROTL 12" */
177 if ((mcode & 0xffffff00) == 0xe24cca00)
178 offset += (s4) ((mcode & 0x00ff) << 12);
180 /* and get the final data segment address */
182 pa = sfi->pv - offset;
189 /* md_codegen_get_pv_from_pc ***************************************************
193 *******************************************************************************/
195 u1 *md_codegen_get_pv_from_pc(u1 *ra)
198 u4 mcode1, mcode2, mcode3;
202 /* this can either be a RECOMPUTE_IP in JIT code or a fake in asm_calljavafunction */
203 mcode1 = *((u4*) ra);
204 if ((mcode1 & 0xffffff00) == 0xe24fcf00 /*sub ip,pc,#__*/)
205 pv -= (s4) ((mcode1 & 0x000000ff) << 2);
206 else if ((mcode1 & 0xffffff00) == 0xe24fc000 /*sub ip,pc,#__*/)
207 pv -= (s4) (mcode1 & 0x000000ff);
209 /* if this happens, we got an unexpected instruction at (*ra) */
210 vm_abort("Unable to find method: %p (instr=%x)", ra, mcode1);
213 /* if we have a RECOMPUTE_IP there can be more than one instruction */
214 mcode2 = *((u4*) (ra + 4));
215 mcode3 = *((u4*) (ra + 8));
216 if ((mcode2 & 0xffffff00) == 0xe24ccb00 /*sub ip,ip,#__*/)
217 pv -= (s4) ((mcode2 & 0x000000ff) << 10);
218 if ((mcode3 & 0xffffff00) == 0xe24cc700 /*sub ip,ip,#__*/)
219 pv -= (s4) ((mcode3 & 0x000000ff) << 18);
221 /* we used PC-relative adressing; but now it is LR-relative */
224 /* if we found our method the data segment has to be valid */
225 /* we check this by looking up the IsLeaf field, which has to be boolean */
226 assert( *((s4*)pv-4) == (s4)true || *((s4*)pv-4) == (s4)false );
232 /* md_cacheflush ***************************************************************
234 Calls the system's function to flush the instruction and data
237 *******************************************************************************/
239 void md_cacheflush(u1 *addr, s4 nbytes)
241 asm_cacheflush(addr, nbytes);
245 /* md_icacheflush **************************************************************
247 Calls the system's function to flush the instruction cache.
249 *******************************************************************************/
251 void md_icacheflush(u1 *addr, s4 nbytes)
253 asm_cacheflush(addr, nbytes);
257 /* md_dcacheflush **************************************************************
259 Calls the system's function to flush the data cache.
261 *******************************************************************************/
263 void md_dcacheflush(u1 *addr, s4 nbytes)
265 asm_cacheflush(addr, nbytes);
270 * These are local overrides for various environment variables in Emacs.
271 * Please do not remove this and leave it at the end of the file, where
272 * Emacs will automagically detect them.
273 * ---------------------------------------------------------------------
276 * indent-tabs-mode: t
280 * vim:noexpandtab:sw=4:ts=4: