| |
| /*---------------------------------------------------------------*/ |
| /*--- ---*/ |
| /*--- This file (guest-ppc32/ghelpers.c) is ---*/ |
| /*--- Copyright (c) 2004 OpenWorks LLP. All rights reserved. ---*/ |
| /*--- ---*/ |
| /*---------------------------------------------------------------*/ |
| |
| /* |
| This file is part of LibVEX, a library for dynamic binary |
| instrumentation and translation. |
| |
| Copyright (C) 2004 OpenWorks, LLP. |
| |
| 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; Version 2 dated June 1991 of the |
| license. |
| |
| 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, or liability |
| for damages. See the GNU General Public License for more details. |
| |
| Neither the names of the U.S. Department of Energy nor the |
| University of California nor the names of its contributors may be |
| used to endorse or promote products derived from this software |
| without prior written permission. |
| |
| 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 |
| USA. |
| */ |
| |
| #include "libvex_basictypes.h" |
| #include "libvex_emwarn.h" |
| #include "libvex_guest_ppc32.h" |
| #include "libvex_ir.h" |
| #include "libvex.h" |
| |
| #include "main/vex_util.h" |
| #include "guest-ppc32/gdefs.h" |
| |
| |
| /* This file contains helper functions for ppc32 guest code. |
| Calls to these functions are generated by the back end. |
| These calls are of course in the host machine code and |
| this file will be compiled to host machine code, so that |
| all makes sense. |
| |
| Only change the signatures of these helper functions very |
| carefully. If you change the signature here, you'll have to change |
| the parameters passed to it in the IR calls constructed by |
| guest-ppc32/toIR.c. |
| */ |
| |
| |
| #define INT32_MIN (-2147483647-1) |
| |
| |
| |
| /* CALLED FROM GENERATED CODE: CLEAN HELPER */ |
| /* Calculates CR7[LT,GT,EQ,SO] flags from the supplied |
| thunk parameters. |
| Returns values in high field (correct wrt actual CR) |
| */ |
| UInt ppc32g_calculate_cr7 ( UInt op, UInt val, UInt xer_so ) |
| { |
| if (op) { // val contains cr7 flags to be returned |
| return (val & 0xF0000000); |
| } else { // val contains result to be tested |
| Int sval = (Int)val; |
| xer_so = xer_so & 1; |
| return ( ((xer_so == 1) ? (1<<28) : 0) |
| | ((sval == 0) ? (1<<29) : 0) |
| | ((sval > 0) ? (1<<30) : 0) |
| | ((sval < 0) ? (1<<31) : 0) ); |
| } |
| } |
| |
| |
| // Calculate XER_OV |
| UInt ppc32g_calculate_xer_ov ( UInt op, UInt res, UInt argL, UInt argR ) |
| { |
| switch (op) { |
| case PPC32G_FLAG_OP_ADD: // addo, addc |
| case PPC32G_FLAG_OP_ADDE: // addeo, addmeo, addzeo |
| return ((argL^argR^-1) & (argL^res) & (1<<31)) ? 1:0; |
| // i.e. ((both_same_sign) & (sign_changed) & (sign_mask)) |
| |
| case PPC32G_FLAG_OP_DIVW: // divwo |
| return ((argL == INT32_MIN && argR == -1) || argR == 0) ? 1:0; |
| |
| case PPC32G_FLAG_OP_DIVWU: // divwuo |
| return (argR == 0) ? 1:0; |
| |
| case PPC32G_FLAG_OP_MULLW: { // mullwo |
| /* OV true if result can't be represented in 32 bits |
| i.e sHi != sign extension of sLo */ |
| Long l_res = (Long)((Int)argL) * (Long)((Int)argR); |
| Int sHi = (Int)(l_res >> 32); |
| Int sLo = (Int)l_res; |
| return (sHi != (sLo >> /*s*/ 31)) ? 1:0; |
| } |
| |
| case PPC32G_FLAG_OP_NEG: // nego |
| return (argL == 0x80000000) ? 1:0; |
| |
| case PPC32G_FLAG_OP_SUBF: // subfo |
| case PPC32G_FLAG_OP_SUBFC: // subfco |
| case PPC32G_FLAG_OP_SUBFE: // subfeo, subfmeo, subfzeo |
| return (((~argL)^argR^(-1)) & ((~argL)^res) & (1<<31)) ? 1:0; |
| |
| default: |
| break; |
| } |
| |
| vpanic("ppc32g_calculate_xer_ov(ppc32)"); |
| return 0; // notreached |
| } |
| |
| // Calculate XER_CA |
| UInt ppc32g_calculate_xer_ca ( UInt op, UInt res, |
| UInt argL, UInt argR, UInt ca ) |
| { |
| switch (op) { |
| case PPC32G_FLAG_OP_ADD: // addc[o], addic |
| return (res < argL) ? 1:0; |
| |
| case PPC32G_FLAG_OP_ADDE: // adde[o], addze[o], addme[o] |
| return (res < argL || (ca==1 && res==argL)) ? 1:0; |
| |
| case PPC32G_FLAG_OP_SUBFC: // subfc[o] |
| case PPC32G_FLAG_OP_SUBFI: // subfic |
| return (res <= argR) ? 1:0; |
| |
| case PPC32G_FLAG_OP_SUBFE: // subfe[o], subfze[o], subfme[o] |
| return ((res < argR) || (ca == 1 && res == argR)) ? 1:0; |
| |
| case PPC32G_FLAG_OP_SRAW: // sraw |
| if ((argR & 0x20) == 0) { // shift <= 31 |
| // xer_ca = sign && (bits_shifted_out != 0) |
| return (((argL & 0x80000000) && |
| ((argL & (0xFFFFFFFF >> (32-argR))) != 0)) != 0) ? 1:0; |
| } |
| // shift > 31 |
| // xer_ca = sign && src != 0 |
| return (((argL & 0x80000000) && (argR != 0)) != 0) ? 1:0; |
| |
| case PPC32G_FLAG_OP_SRAWI: // srawi |
| // xer_ca = sign && (bits_shifted_out != 0) |
| return (((argL & 0x80000000) && |
| ((argL & (0xFFFFFFFF >> (32-argR))) != 0)) != 0) ? 1:0; |
| |
| default: |
| break; |
| } |
| vpanic("ppc32g_calculate_xer_ov(ppc32)"); |
| return 0; // notreached |
| } |
| |
| |
| |
| |
| |
| |
| |
| /* Used by the optimiser to try specialisations. Returns an |
| equivalent expression, or NULL if none. */ |
| |
| #if 0 |
| /* temporarily unused */ |
| static Bool isU32 ( IRExpr* e, UInt n ) |
| { |
| return (e->tag == Iex_Const |
| && e->Iex.Const.con->tag == Ico_U32 |
| && e->Iex.Const.con->Ico.U32 == n); |
| } |
| #endif |
| IRExpr* guest_ppc32_spechelper ( HChar* function_name, |
| IRExpr** args ) |
| { |
| return NULL; |
| } |
| |
| |
| /*----------------------------------------------*/ |
| /*--- The exported fns .. ---*/ |
| /*----------------------------------------------*/ |
| |
| /* VISIBLE TO LIBVEX CLIENT */ |
| #if 0 |
| void LibVEX_GuestPPC32_put_cr7 ( UInt flags_native, |
| /*OUT*/VexGuestPPC32State* vex_state ) |
| { |
| vassert(0); // FIXME |
| } |
| #endif |
| |
| /* VISIBLE TO LIBVEX CLIENT */ |
| UInt LibVEX_GuestPPC32_get_cr7 ( /*IN*/VexGuestPPC32State* vex_state ) |
| { |
| UInt flags = ppc32g_calculate_cr7( |
| vex_state->guest_CC_OP, |
| vex_state->guest_CC_DEP1, |
| vex_state->guest_CC_DEP2 |
| ); |
| return flags; |
| } |
| |
| /* VISIBLE TO LIBVEX CLIENT */ |
| void LibVEX_GuestPPC32_initialise ( /*OUT*/VexGuestPPC32State* vex_state ) |
| { |
| vex_state->guest_GPR0 = 0; |
| vex_state->guest_GPR1 = 0; |
| vex_state->guest_GPR2 = 0; |
| vex_state->guest_GPR3 = 0; |
| vex_state->guest_GPR4 = 0; |
| vex_state->guest_GPR5 = 0; |
| vex_state->guest_GPR6 = 0; |
| vex_state->guest_GPR7 = 0; |
| vex_state->guest_GPR8 = 0; |
| vex_state->guest_GPR9 = 0; |
| vex_state->guest_GPR10 = 0; |
| vex_state->guest_GPR11 = 0; |
| vex_state->guest_GPR12 = 0; |
| vex_state->guest_GPR13 = 0; |
| vex_state->guest_GPR14 = 0; |
| vex_state->guest_GPR15 = 0; |
| vex_state->guest_GPR16 = 0; |
| vex_state->guest_GPR17 = 0; |
| vex_state->guest_GPR18 = 0; |
| vex_state->guest_GPR19 = 0; |
| vex_state->guest_GPR20 = 0; |
| vex_state->guest_GPR21 = 0; |
| vex_state->guest_GPR22 = 0; |
| vex_state->guest_GPR23 = 0; |
| vex_state->guest_GPR24 = 0; |
| vex_state->guest_GPR25 = 0; |
| vex_state->guest_GPR26 = 0; |
| vex_state->guest_GPR27 = 0; |
| vex_state->guest_GPR28 = 0; |
| vex_state->guest_GPR29 = 0; |
| vex_state->guest_GPR30 = 0; |
| vex_state->guest_GPR31 = 0; |
| |
| vex_state->guest_CIA = 0; |
| vex_state->guest_LR = 0; |
| vex_state->guest_CTR = 0; |
| |
| vex_state->guest_CC_OP = 0; |
| vex_state->guest_CC_DEP1 = 0; |
| vex_state->guest_CC_DEP2 = 0; |
| |
| vex_state->guest_CR0to6 = 0; |
| |
| vex_state->guest_FPROUND = (UInt)PPC32rm_NEAREST; |
| |
| vex_state->guest_XER = 0; |
| |
| vex_state->guest_EMWARN = EmWarn_NONE; |
| |
| vex_state->guest_TISTART = 0; |
| vex_state->guest_TILEN = 0; |
| } |
| |
| |
| /*-----------------------------------------------------------*/ |
| /*--- Describing the ppc32 guest state, for the benefit ---*/ |
| /*--- of iropt and instrumenters. ---*/ |
| /*-----------------------------------------------------------*/ |
| |
| /* Figure out if any part of the guest state contained in minoff |
| .. maxoff requires precise memory exceptions. If in doubt return |
| True (but this is generates significantly slower code). |
| |
| By default we enforce precise exns for guest R1 (stack pointer), |
| CIA (current insn address) and LR (link register). These are the |
| minimum needed to extract correct stack backtraces from ppc32 |
| code. [[NB: not sure if keeping LR up to date is actually |
| necessary.]] |
| */ |
| Bool guest_ppc32_state_requires_precise_mem_exns ( Int minoff, |
| Int maxoff ) |
| { |
| Int lr_min = offsetof(VexGuestPPC32State, guest_LR); |
| Int lr_max = lr_min + 4 - 1; |
| Int r1_min = offsetof(VexGuestPPC32State, guest_GPR1); |
| Int r1_max = r1_min + 4 - 1; |
| Int cia_min = offsetof(VexGuestPPC32State, guest_CIA); |
| Int cia_max = cia_min + 4 - 1; |
| |
| if (maxoff < lr_min || minoff > lr_max) { |
| /* no overlap with LR */ |
| } else { |
| return True; |
| } |
| |
| if (maxoff < r1_min || minoff > r1_max) { |
| /* no overlap with R1 */ |
| } else { |
| return True; |
| } |
| |
| if (maxoff < cia_min || minoff > cia_max) { |
| /* no overlap with CIA */ |
| } else { |
| return True; |
| } |
| |
| return False; |
| } |
| |
| |
| #define ALWAYSDEFD(field) \ |
| { offsetof(VexGuestPPC32State, field), \ |
| (sizeof ((VexGuestPPC32State*)0)->field) } |
| |
| VexGuestLayout |
| ppc32Guest_layout |
| = { |
| /* Total size of the guest state, in bytes. */ |
| .total_sizeB = sizeof(VexGuestPPC32State), |
| |
| /* Describe the stack pointer. */ |
| .offset_SP = offsetof(VexGuestPPC32State,guest_GPR1), |
| .sizeof_SP = 4, |
| |
| /* Describe the instruction pointer. */ |
| .offset_IP = offsetof(VexGuestPPC32State,guest_CIA), |
| .sizeof_IP = 4, |
| |
| /* Describe any sections to be regarded by Memcheck as |
| 'always-defined'. */ |
| .n_alwaysDefd = 1, |
| /* flags thunk: only using last_result, which is always defd. */ |
| |
| .alwaysDefd |
| = { /* 0 */ ALWAYSDEFD(guest_CC_OP) |
| |
| // FIXME |
| } |
| }; |
| |
| |
| /*---------------------------------------------------------------*/ |
| /*--- end guest-ppc32/ghelpers.c ---*/ |
| /*---------------------------------------------------------------*/ |