/* src/vm/jit/alpha/md.c - machine dependent Alpha functions Copyright (C) 1996-2005, 2006, 2007, 2008 CACAOVM - Verein zur Foerderung der freien virtuellen Maschine CACAO Copyright (C) 2009 Theobroma Systems Ltd. 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. */ #include "config.h" #include #include #if defined(__LINUX__) # include extern unsigned long ieee_get_fp_control(); extern void ieee_set_fp_control(unsigned long fp_control); #endif #include "vm/jit/alpha/codegen.h" #include "vm/jit/alpha/md.h" #include "vm/jit/asmpart.h" #include "vm/jit/jit.hpp" #include "vm/jit/trap.hpp" /* global variables ***********************************************************/ bool has_ext_instr_set = false; /* has instruction set extensions */ /* md_init ********************************************************************* Do some machine dependent initialization. *******************************************************************************/ void md_init(void) { #if defined(__LINUX__) unsigned long int fpcw; #endif /* check for extended instruction set */ has_ext_instr_set = !asm_md_init(); #if defined(__LINUX__) /* Linux on Digital Alpha needs an initialisation of the ieee floating point control for IEEE compliant arithmetic (option -mieee of GCC). Under Digital Unix this is done automatically. */ /* initialize floating point control */ fpcw = ieee_get_fp_control(); fpcw = fpcw & ~IEEE_TRAP_ENABLE_INV & ~IEEE_TRAP_ENABLE_DZE /* We dont want underflow. */ /* & ~IEEE_TRAP_ENABLE_UNF */ & ~IEEE_TRAP_ENABLE_OVF; /* fpcw = fpcw */ /* | IEEE_TRAP_ENABLE_INV */ /* | IEEE_TRAP_ENABLE_DZE */ /* | IEEE_TRAP_ENABLE_OVF */ /* | IEEE_TRAP_ENABLE_UNF */ /* | IEEE_TRAP_ENABLE_INE */ /* | IEEE_TRAP_ENABLE_DNO; */ ieee_set_fp_control(fpcw); #endif } /* md_jit_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: a77bffb8 ldq pv,-72(pv) 6b5b4000 jsr (pv) INVOKEVIRTUAL: a7900000 ldq at,0(a0) a77c0000 ldq pv,0(at) 6b5b4000 jsr (pv) INVOKEINTERFACE: a7900000 ldq at,0(a0) a79cff98 ldq at,-104(at) a77c0018 ldq pv,24(at) 6b5b4000 jsr (pv) *******************************************************************************/ void *md_jit_method_patch_address(void *pv, void *ra, void *mptr) { uint32_t *pc; uint32_t mcode; int opcode; int base; int32_t disp; void *pa; /* patch address */ /* Go back to the load instruction (2 instructions). */ pc = ((uint32_t *) ra) - 2; /* Get first instruction word. */ mcode = pc[0]; /* Get opcode, base register and displacement. */ opcode = M_MEM_GET_Opcode(mcode); base = M_MEM_GET_Rb(mcode); disp = M_MEM_GET_Memory_disp(mcode); /* Check for short or long load (2 instructions). */ switch (opcode) { case 0x29: /* LDQ: TODO use define */ switch (base) { case REG_PV: /* Calculate the data segment address. */ pa = ((uint8_t *) pv) + disp; break; case REG_METHODPTR: /* Return NULL if no mptr was specified (used for replacement). */ if (mptr == NULL) return NULL; /* Calculate the address in the vftbl. */ pa = ((uint8_t *) mptr) + disp; break; default: vm_abort_disassemble(pc, 2, "md_jit_method_patch_address: unknown instruction %x", mcode); return NULL; } break; case 0x09: /* LDAH: TODO use define */ /* XXX write a regression for this */ vm_abort("md_jit_method_patch_address: IMPLEMENT ME!"); pa = NULL; break; default: vm_abort_disassemble(pc, 2, "md_jit_method_patch_address: unknown instruction %x", mcode); return NULL; } return pa; } /** * Decode the trap instruction at the given PC. * * @param trp information about trap to be filled * @param sig signal number * @param xpc exception PC * @param es execution state of the machine * @return true if trap was decoded successfully, false otherwise. */ bool md_trap_decode(trapinfo_t* trp, int sig, void* xpc, executionstate_t* es) { // Get the exception-throwing instruction. uint32_t mcode = *((uint32_t*) xpc); switch (sig) { case TRAP_SIGILL: // Check for valid trap instruction. // TODO Check the whole instruction. if (M_OP3_GET_Opcode(mcode) == 0x4) { trp->type = TRAP_PATCHER; trp->value = 0; return true; } return false; case TRAP_SIGSEGV: { // Retrieve base address of instruction. int32_t s1 = M_MEM_GET_Rb(mcode); uintptr_t addr = es->intregs[s1]; // Check for special-load. if (s1 == REG_ZERO) { int32_t d = M_MEM_GET_Ra(mcode); int32_t disp = M_MEM_GET_Memory_disp(mcode); // We use the exception type as load displacement. trp->type = disp; trp->value = es->intregs[d]; return true; } // Check for implicit NullPointerException. if (addr == 0) { trp->type = TRAP_NullPointerException; trp->value = 0; return true; } return false; } default: return false; } } /* md_patch_replacement_point ************************************************** Patch the given replacement point. *******************************************************************************/ #if defined(ENABLE_REPLACEMENT) void md_patch_replacement_point(u1 *pc, u1 *savedmcode, bool revert) { u4 mcode; if (revert) { /* restore the patched-over instruction */ *(u4*)(pc) = *(u4*)(savedmcode); } else { /* save the current machine code */ *(u4*)(savedmcode) = *(u4*)(pc); /* build the machine code for the patch */ mcode = (0xa41f0000 | (TRAP_PATCHER)); /* write the new machine code */ *(u4*)(pc) = mcode; } /* flush instruction cache */ md_icacheflush(pc,4); } #endif /* defined(ENABLE_REPLACEMENT) */ /* * 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: */