1 /* 2 * Copyright (c) 2002, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, 20 * CA 94065 USA or visit www.oracle.com if you need additional information or 21 * have any questions. 22 * 23 */ 24 25 package sun.jvm.hotspot.asm.sparc; 26 27 import sun.jvm.hotspot.asm.*; 28 29 class V9ReadDecoder extends InstructionDecoder 30 implements V9InstructionDecoder { 31 Instruction decode(int instruction, SPARCInstructionFactory factory) { 32 SPARCV9InstructionFactory v9factory = (SPARCV9InstructionFactory) factory; 33 Instruction instr = null; 34 int specialRegNum = getSourceRegister1(instruction); 35 36 // rs1 values 1, 7-14 are reserved - see page 214, A.44 Read State Register. 37 if (specialRegNum == 1 || (specialRegNum > 6 && specialRegNum < 15)) { 38 instr = v9factory.newIllegalInstruction(instruction); 39 } else { 40 int rdNum = getDestinationRegister(instruction); 41 if (specialRegNum == 15) { 42 // may be stbar, member or illegal 43 if (rdNum == 0) { 44 boolean iBit = isIBitSet(instruction); 45 if (iBit) { 46 instr = v9factory.newV9MembarInstruction((instruction & MMASK_MASK) >>> MMASK_START_BIT, 47 (instruction & CMASK_MASK) >>> CMASK_START_BIT); 48 } else { 49 instr = v9factory.newStbarInstruction(); 50 } 51 } else { // rd != 0 && rs1 == 15 52 instr = v9factory.newIllegalInstruction(instruction); 53 } 54 } else { 55 int asrRegNum = -1; 56 if (specialRegNum > 15){ 57 asrRegNum = specialRegNum; 58 specialRegNum = SPARCV9SpecialRegisters.ASR; 59 } 60 SPARCRegister rd = SPARCRegisters.getRegister(rdNum); 61 instr = v9factory.newV9ReadInstruction(specialRegNum, asrRegNum, rd); 62 } 63 } 64 return instr; 65 } 66 }