| /* |
| * Copyright (c) 2007 The Hewlett-Packard Development Company |
| * All rights reserved. |
| * |
| * Redistribution and use of this software in source and binary forms, |
| * with or without modification, are permitted provided that the |
| * following conditions are met: |
| * |
| * The software must be used only for Non-Commercial Use which means any |
| * use which is NOT directed to receiving any direct monetary |
| * compensation for, or commercial advantage from such use. Illustrative |
| * examples of non-commercial use are academic research, personal study, |
| * teaching, education and corporate research & development. |
| * Illustrative examples of commercial use are distributing products for |
| * commercial advantage and providing services using the software for |
| * commercial advantage. |
| * |
| * If you wish to use this software or functionality therein that may be |
| * covered by patents for commercial use, please contact: |
| * Director of Intellectual Property Licensing |
| * Office of Strategy and Technology |
| * Hewlett-Packard Company |
| * 1501 Page Mill Road |
| * Palo Alto, California 94304 |
| * |
| * Redistributions of source code must retain the above copyright notice, |
| * this list of conditions and the following disclaimer. Redistributions |
| * in binary form must reproduce the above copyright notice, this list of |
| * conditions and the following disclaimer in the documentation and/or |
| * other materials provided with the distribution. Neither the name of |
| * the COPYRIGHT HOLDER(s), HEWLETT-PACKARD COMPANY, nor the names of its |
| * contributors may be used to endorse or promote products derived from |
| * this software without specific prior written permission. No right of |
| * sublicense is granted herewith. Derivatives of the software and |
| * output created using the software may be prepared, but only for |
| * Non-Commercial Uses. Derivatives of the software may be shared with |
| * others provided: (i) the others agree to abide by the list of |
| * conditions herein which includes the Non-Commercial Use restrictions; |
| * and (ii) such Derivatives of the software include the above copyright |
| * notice to acknowledge the contribution from this software where |
| * applicable, this list of conditions and the disclaimer below. |
| * |
| * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS |
| * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| * OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| * |
| * Authors: Gabe Black |
| */ |
| |
| #include <cassert> |
| |
| #include "arch/x86/emulenv.hh" |
| #include "base/misc.hh" |
| |
| using namespace X86ISA; |
| |
| void EmulEnv::doModRM(const ExtMachInst & machInst) |
| { |
| assert(machInst.modRM.mod != 3); |
| //Use the SIB byte for addressing if the modrm byte calls for it. |
| if (machInst.modRM.rm == 4 && machInst.addrSize != 2) { |
| scale = 1 << machInst.sib.scale; |
| index = machInst.sib.index | (machInst.rex.x << 3); |
| base = machInst.sib.base | (machInst.rex.b << 3); |
| //In this special case, we don't use a base. The displacement also |
| //changes, but that's managed by the predecoder. |
| if (machInst.sib.base == INTREG_RBP && machInst.modRM.mod == 0) |
| base = NUM_INTREGS; |
| //In -this- special case, we don't use an index. |
| if (index == INTREG_RSP) |
| index = NUM_INTREGS; |
| } else { |
| if (machInst.addrSize == 2) { |
| unsigned rm = machInst.modRM.rm; |
| if (rm <= 3) { |
| scale = 1; |
| if (rm < 2) { |
| base = INTREG_RBX; |
| } else { |
| base = INTREG_RBP; |
| } |
| index = (rm % 2) ? INTREG_RDI : INTREG_RSI; |
| } else { |
| scale = 0; |
| switch (rm) { |
| case 4: |
| base = INTREG_RSI; |
| break; |
| case 5: |
| base = INTREG_RDI; |
| break; |
| case 6: |
| base = INTREG_RBP; |
| break; |
| case 7: |
| base = INTREG_RBX; |
| break; |
| } |
| } |
| } else { |
| scale = 0; |
| base = machInst.modRM.rm | (machInst.rex.b << 3); |
| if (machInst.modRM.mod == 0 && machInst.modRM.rm == 5) { |
| //Since we need to use a different encoding of this |
| //instruction anyway, just ignore the base in those cases |
| base = NUM_INTREGS; |
| } |
| } |
| } |
| //Figure out what segment to use. This won't be entirely accurate since |
| //the presence of a displacement is supposed to make the instruction |
| //default to the data segment. |
| if ((base != INTREG_RBP && base != INTREG_RSP) || machInst.dispSize) { |
| seg = SEGMENT_REG_DS; |
| //Handle any segment override that might have been in the instruction |
| int segFromInst = machInst.legacy.seg; |
| if (segFromInst) |
| seg = (SegmentRegIndex)(segFromInst - 1); |
| } else { |
| seg = SEGMENT_REG_SS; |
| } |
| } |
| |
| void EmulEnv::setSeg(const ExtMachInst & machInst) |
| { |
| seg = SEGMENT_REG_DS; |
| //Handle any segment override that might have been in the instruction |
| int segFromInst = machInst.legacy.seg; |
| if (segFromInst) |
| seg = (SegmentRegIndex)(segFromInst - 1); |
| } |