/* src/vm/jit/i386/md.c - machine dependent i386 functions Copyright (C) 1996-2005, 2006 R. Grafl, A. Krall, C. Kruegel, C. Oates, R. Obermaisser, M. Platter, M. Probst, S. Ring, E. Steiner, C. Thalinger, D. Thuernbeck, P. Tomsich, C. Ullrich, J. Wenninger, Institut f. Computersprachen - TU Wien This file is part of CACAO. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA. Contact: cacao@cacaojvm.org Authors: Christian Thalinger Edwin Steiner $Id: md.c 5962 2006-11-12 13:39:50Z edwin $ */ #include "config.h" #include #include "vm/types.h" #include "vm/global.h" #include "vm/jit/asmpart.h" #include "vm/jit/codegen-common.h" #if !defined(NDEBUG) && defined(ENABLE_DISASSEMBLER) #include "vm/options.h" /* XXX debug */ #include "vm/jit/disass.h" /* XXX debug */ #endif /* md_init ********************************************************************* Do some machine dependent initialization. *******************************************************************************/ void md_init(void) { (void) asm_md_init(); } /* md_codegen_patch_branch ***************************************************** Back-patches a branch instruction. *******************************************************************************/ void md_codegen_patch_branch(codegendata *cd, s4 branchmpc, s4 targetmpc) { s4 *mcodeptr; s4 disp; /* branch displacement */ /* calculate the patch position */ mcodeptr = (s4 *) (cd->mcodebase + branchmpc); /* Calculate the branch displacement. */ disp = targetmpc - branchmpc; /* I don't think we have to check for branch-displacement overflow, +/-2GB should be enough. */ /* patch the branch instruction before the mcodeptr */ mcodeptr[-1] = disp; } /* md_stacktrace_get_returnaddress ********************************************* Returns the return address of the current stackframe, specified by the passed stack pointer and the stack frame size. *******************************************************************************/ u1 *md_stacktrace_get_returnaddress(u1 *sp, u4 framesize) { u1 *ra; /* on i386 the return address is above the current stack frame */ ra = *((u1 **) (sp + framesize)); return ra; } /* md_get_method_patch_address ************************************************* Gets the patch address of the currently compiled method. The offset is extracted from the load instruction(s) before the jump and added to the right base address (PV or REG_METHODPTR). INVOKESTATIC/SPECIAL: b9 30 00 49 b7 mov $0xb7490030,%ecx ff d1 call *%ecx INVOKEVIRTUAL: 8b 08 mov (%eax),%ecx 8b 91 00 00 00 00 mov 0x0(%ecx),%edx ff d2 call *%edx INVOKEINTERFACE: 8b 08 mov (%eax),%ecx 8b 89 00 00 00 00 mov 0x0(%ecx),%ecx 8b 91 00 00 00 00 mov 0x0(%ecx),%edx ff d2 call *%edx *******************************************************************************/ u1 *md_get_method_patch_address(u1 *ra, stackframeinfo *sfi, u1 *mptr) { u1 mcode; s4 offset; u1 *pa; /* patch address */ /* go back to the actual call instruction (2-bytes) */ ra = ra - 2; /* get the last byte of the call */ mcode = ra[1]; /* check for the different calls */ if (mcode == 0xd1) { /* INVOKESTATIC/SPECIAL */ /* patch address is 4-bytes before the call instruction */ pa = ra - 4; } else if (mcode == 0xd2) { /* INVOKEVIRTUAL/INTERFACE */ /* Get the offset from the instruction (the offset address is 4-bytes before the call instruction). */ offset = *((s4 *) (ra - 4)); /* add the offset to the method pointer */ pa = mptr + offset; } else { /* catch any problems */ pa = NULL; /* avoid warnings */ vm_abort("couldn't find a proper call instruction sequence"); } return pa; } /* md_codegen_get_pv_from_pc *************************************************** On this architecture just a wrapper function to codegen_get_pv_from_pc. *******************************************************************************/ u1 *md_codegen_get_pv_from_pc(u1 *ra) { u1 *pv; /* Get the start address of the function which contains this address from the method table. */ pv = codegen_get_pv_from_pc(ra); return pv; } /* md_cacheflush *************************************************************** Calls the system's function to flush the instruction and data cache. *******************************************************************************/ void md_cacheflush(u1 *addr, s4 nbytes) { /* do nothing */ } /* md_icacheflush ************************************************************** Calls the system's function to flush the instruction cache. *******************************************************************************/ void md_icacheflush(u1 *addr, s4 nbytes) { /* do nothing */ } /* md_dcacheflush ************************************************************** Calls the system's function to flush the data cache. *******************************************************************************/ void md_dcacheflush(u1 *addr, s4 nbytes) { /* do nothing */ } /* md_patch_replacement_point ************************************************** Patch the given replacement point. *******************************************************************************/ void md_patch_replacement_point(rplpoint *rp) { u8 mcode; /* XXX this is probably unsafe! */ /* save the current machine code */ mcode = *(u8*)rp->pc; /* write spinning instruction */ *(u2*)(rp->pc) = 0xebfe; /* write 5th byte */ rp->pc[4] = (rp->mcode >> 32); /* write first word */ *(u4*)(rp->pc) = (u4) rp->mcode; /* store saved mcode */ rp->mcode = mcode; #if !defined(NDEBUG) && defined(ENABLE_DISASSEMBLER) && 0 { u1* u1ptr = rp->pc; DISASSINSTR(u1ptr); fflush(stdout); } #endif /* XXX if required asm_cacheflush(rp->pc,8); */ } /* * These are local overrides for various environment variables in Emacs. * Please do not remove this and leave it at the end of the file, where * Emacs will automagically detect them. * --------------------------------------------------------------------- * Local variables: * mode: c * indent-tabs-mode: t * c-basic-offset: 4 * tab-width: 4 * End: * vim:noexpandtab:sw=4:ts=4: */