operands.isa revision 8303
16019Shines@cs.fsu.edu// -*- mode:c++ -*-
27091Sgblack@eecs.umich.edu// Copyright (c) 2010 ARM Limited
37091Sgblack@eecs.umich.edu// All rights reserved
47091Sgblack@eecs.umich.edu//
57091Sgblack@eecs.umich.edu// The license below extends only to copyright in the software and shall
67091Sgblack@eecs.umich.edu// not be construed as granting a license to any other intellectual
77091Sgblack@eecs.umich.edu// property including but not limited to intellectual property relating
87091Sgblack@eecs.umich.edu// to a hardware implementation of the functionality of the software
97091Sgblack@eecs.umich.edu// licensed hereunder.  You may use the software subject to the license
107091Sgblack@eecs.umich.edu// terms below provided that you ensure that this notice is replicated
117091Sgblack@eecs.umich.edu// unmodified and in its entirety in all distributions of the software,
127091Sgblack@eecs.umich.edu// modified or unmodified, in source code or in binary form.
137091Sgblack@eecs.umich.edu//
146019Shines@cs.fsu.edu// Copyright (c) 2007-2008 The Florida State University
156019Shines@cs.fsu.edu// All rights reserved.
166019Shines@cs.fsu.edu//
176019Shines@cs.fsu.edu// Redistribution and use in source and binary forms, with or without
186019Shines@cs.fsu.edu// modification, are permitted provided that the following conditions are
196019Shines@cs.fsu.edu// met: redistributions of source code must retain the above copyright
206019Shines@cs.fsu.edu// notice, this list of conditions and the following disclaimer;
216019Shines@cs.fsu.edu// redistributions in binary form must reproduce the above copyright
226019Shines@cs.fsu.edu// notice, this list of conditions and the following disclaimer in the
236019Shines@cs.fsu.edu// documentation and/or other materials provided with the distribution;
246019Shines@cs.fsu.edu// neither the name of the copyright holders nor the names of its
256019Shines@cs.fsu.edu// contributors may be used to endorse or promote products derived from
266019Shines@cs.fsu.edu// this software without specific prior written permission.
276019Shines@cs.fsu.edu//
286019Shines@cs.fsu.edu// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
296019Shines@cs.fsu.edu// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
306019Shines@cs.fsu.edu// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
316019Shines@cs.fsu.edu// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
326019Shines@cs.fsu.edu// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
336019Shines@cs.fsu.edu// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
346019Shines@cs.fsu.edu// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
356019Shines@cs.fsu.edu// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
366019Shines@cs.fsu.edu// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
376019Shines@cs.fsu.edu// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
386019Shines@cs.fsu.edu// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
396019Shines@cs.fsu.edu//
406019Shines@cs.fsu.edu// Authors: Stephen Hines
416019Shines@cs.fsu.edu
426019Shines@cs.fsu.edudef operand_types {{
436019Shines@cs.fsu.edu    'sb' : ('signed int', 8),
446019Shines@cs.fsu.edu    'ub' : ('unsigned int', 8),
456019Shines@cs.fsu.edu    'sh' : ('signed int', 16),
466019Shines@cs.fsu.edu    'uh' : ('unsigned int', 16),
476019Shines@cs.fsu.edu    'sw' : ('signed int', 32),
486019Shines@cs.fsu.edu    'uw' : ('unsigned int', 32),
496019Shines@cs.fsu.edu    'ud' : ('unsigned int', 64),
507639Sgblack@eecs.umich.edu    'tud' : ('twin64 int', 64),
516019Shines@cs.fsu.edu    'sf' : ('float', 32),
526019Shines@cs.fsu.edu    'df' : ('float', 64)
536019Shines@cs.fsu.edu}};
546019Shines@cs.fsu.edu
556312Sgblack@eecs.umich.edulet {{
566312Sgblack@eecs.umich.edu    maybePCRead = '''
577720Sgblack@eecs.umich.edu        ((%(reg_idx)s == PCReg) ? readPC(xc) : xc->%(func)s(this, %(op_idx)s))
586312Sgblack@eecs.umich.edu    '''
597186Sgblack@eecs.umich.edu    maybeAlignedPCRead = '''
607720Sgblack@eecs.umich.edu        ((%(reg_idx)s == PCReg) ? (roundDown(readPC(xc), 4)) :
617186Sgblack@eecs.umich.edu         xc->%(func)s(this, %(op_idx)s))
627186Sgblack@eecs.umich.edu    '''
636312Sgblack@eecs.umich.edu    maybePCWrite = '''
647093Sgblack@eecs.umich.edu        ((%(reg_idx)s == PCReg) ? setNextPC(xc, %(final_val)s) :
656312Sgblack@eecs.umich.edu         xc->%(func)s(this, %(op_idx)s, %(final_val)s))
666312Sgblack@eecs.umich.edu    '''
677148Sgblack@eecs.umich.edu    maybeIWPCWrite = '''
687148Sgblack@eecs.umich.edu        ((%(reg_idx)s == PCReg) ? setIWNextPC(xc, %(final_val)s) :
697148Sgblack@eecs.umich.edu         xc->%(func)s(this, %(op_idx)s, %(final_val)s))
707148Sgblack@eecs.umich.edu    '''
717184Sgblack@eecs.umich.edu    maybeAIWPCWrite = '''
727184Sgblack@eecs.umich.edu        if (%(reg_idx)s == PCReg) {
737289Sgblack@eecs.umich.edu            bool thumb = THUMB;
747289Sgblack@eecs.umich.edu            if (thumb) {
757289Sgblack@eecs.umich.edu                setNextPC(xc, %(final_val)s);
767289Sgblack@eecs.umich.edu            } else {
777184Sgblack@eecs.umich.edu                setIWNextPC(xc, %(final_val)s);
787184Sgblack@eecs.umich.edu            }
797184Sgblack@eecs.umich.edu        } else {
807184Sgblack@eecs.umich.edu            xc->%(func)s(this, %(op_idx)s, %(final_val)s);
817184Sgblack@eecs.umich.edu        }
827184Sgblack@eecs.umich.edu    '''
837797Sgblack@eecs.umich.edu
847797Sgblack@eecs.umich.edu    #PCState operands need to have a sorting index (the number at the end)
857797Sgblack@eecs.umich.edu    #less than all the integer registers which might update the PC. That way
867797Sgblack@eecs.umich.edu    #if the flag bits of the pc state are updated and a branch happens through
877797Sgblack@eecs.umich.edu    #R15, the updates are layered properly and the R15 update isn't lost.
887797Sgblack@eecs.umich.edu    srtNormal = 5
897797Sgblack@eecs.umich.edu    srtCpsr = 4
907797Sgblack@eecs.umich.edu    srtBase = 3
917797Sgblack@eecs.umich.edu    srtPC = 2
927797Sgblack@eecs.umich.edu    srtMode = 1
937797Sgblack@eecs.umich.edu    srtEPC = 0
947797Sgblack@eecs.umich.edu
957797Sgblack@eecs.umich.edu    def floatReg(idx):
967797Sgblack@eecs.umich.edu        return ('FloatReg', 'sf', idx, 'IsFloating', srtNormal)
977797Sgblack@eecs.umich.edu
987797Sgblack@eecs.umich.edu    def intReg(idx):
997797Sgblack@eecs.umich.edu        return ('IntReg', 'uw', idx, 'IsInteger', srtNormal,
1007797Sgblack@eecs.umich.edu                maybePCRead, maybePCWrite)
1017797Sgblack@eecs.umich.edu
1027797Sgblack@eecs.umich.edu    def intRegNPC(idx):
1037797Sgblack@eecs.umich.edu        return ('IntReg', 'uw', idx, 'IsInteger', srtNormal)
1047797Sgblack@eecs.umich.edu
1057797Sgblack@eecs.umich.edu    def intRegAPC(idx, id = srtNormal):
1067797Sgblack@eecs.umich.edu        return ('IntReg', 'uw', idx, 'IsInteger', id,
1077797Sgblack@eecs.umich.edu                maybeAlignedPCRead, maybePCWrite)
1087797Sgblack@eecs.umich.edu
1097797Sgblack@eecs.umich.edu    def intRegIWPC(idx):
1107797Sgblack@eecs.umich.edu        return ('IntReg', 'uw', idx, 'IsInteger', srtNormal,
1117797Sgblack@eecs.umich.edu                maybePCRead, maybeIWPCWrite)
1127797Sgblack@eecs.umich.edu
1137797Sgblack@eecs.umich.edu    def intRegAIWPC(idx):
1147797Sgblack@eecs.umich.edu        return ('IntReg', 'uw', idx, 'IsInteger', srtNormal,
1157797Sgblack@eecs.umich.edu                maybePCRead, maybeAIWPCWrite)
1167797Sgblack@eecs.umich.edu
1177797Sgblack@eecs.umich.edu    def intRegCC(idx):
1187797Sgblack@eecs.umich.edu        return ('IntReg', 'uw', idx, None, srtNormal)
1197797Sgblack@eecs.umich.edu
1207797Sgblack@eecs.umich.edu    def cntrlReg(idx, id = srtNormal, type = 'uw'):
1217797Sgblack@eecs.umich.edu        return ('ControlReg', type, idx, (None, None, 'IsControl'), id)
1227797Sgblack@eecs.umich.edu
1237797Sgblack@eecs.umich.edu    def cntrlRegNC(idx, id = srtNormal, type = 'uw'):
1247797Sgblack@eecs.umich.edu        return ('ControlReg', type, idx, None, id)
1257797Sgblack@eecs.umich.edu
1267797Sgblack@eecs.umich.edu    def pcStateReg(idx, id):
1277797Sgblack@eecs.umich.edu        return ('PCState', 'uw', idx, (None, None, 'IsControl'), id)
1286312Sgblack@eecs.umich.edu}};
1296312Sgblack@eecs.umich.edu
1306019Shines@cs.fsu.edudef operands {{
1317119Sgblack@eecs.umich.edu    #Abstracted integer reg operands
1327797Sgblack@eecs.umich.edu    'Dest': intReg('dest'),
1337797Sgblack@eecs.umich.edu    'IWDest': intRegIWPC('dest'),
1347797Sgblack@eecs.umich.edu    'AIWDest': intRegAIWPC('dest'),
1357797Sgblack@eecs.umich.edu    'Dest2': intReg('dest2'),
1367797Sgblack@eecs.umich.edu    'Result': intReg('result'),
1377797Sgblack@eecs.umich.edu    'Base': intRegAPC('base', id = srtBase),
1387797Sgblack@eecs.umich.edu    'Index': intReg('index'),
1397797Sgblack@eecs.umich.edu    'Shift': intReg('shift'),
1407797Sgblack@eecs.umich.edu    'Op1': intReg('op1'),
1417797Sgblack@eecs.umich.edu    'Op2': intReg('op2'),
1427797Sgblack@eecs.umich.edu    'Op3': intReg('op3'),
1437797Sgblack@eecs.umich.edu    'Reg0': intReg('reg0'),
1447797Sgblack@eecs.umich.edu    'Reg1': intReg('reg1'),
1457797Sgblack@eecs.umich.edu    'Reg2': intReg('reg2'),
1467797Sgblack@eecs.umich.edu    'Reg3': intReg('reg3'),
1476019Shines@cs.fsu.edu
1487797Sgblack@eecs.umich.edu    #Fixed index integer reg operands
1497797Sgblack@eecs.umich.edu    'SpMode': intRegNPC('intRegInMode((OperatingMode)regMode, INTREG_SP)'),
1507797Sgblack@eecs.umich.edu    'LR': intRegNPC('INTREG_LR'),
1517797Sgblack@eecs.umich.edu    'R7': intRegNPC('7'),
1528204SAli.Saidi@ARM.com    # First four arguments are passed in registers
1537797Sgblack@eecs.umich.edu    'R0': intRegNPC('0'),
1548204SAli.Saidi@ARM.com    'R1': intRegNPC('1'),
1558204SAli.Saidi@ARM.com    'R2': intRegNPC('2'),
1568204SAli.Saidi@ARM.com    'R3': intRegNPC('3'),
1577797Sgblack@eecs.umich.edu
1587797Sgblack@eecs.umich.edu    #Pseudo integer condition code registers
1598303SAli.Saidi@ARM.com    'CondCodesNZ': intRegCC('INTREG_CONDCODES_NZ'),
1608303SAli.Saidi@ARM.com    'CondCodesC': intRegCC('INTREG_CONDCODES_C'),
1618303SAli.Saidi@ARM.com    'CondCodesV': intRegCC('INTREG_CONDCODES_V'),
1628301SAli.Saidi@ARM.com    'CondCodesGE': intRegCC('INTREG_CONDCODES_GE'),
1638303SAli.Saidi@ARM.com    'OptCondCodesNZ': intRegCC(
1648303SAli.Saidi@ARM.com            '''(condCode == COND_AL || condCode == COND_UC ||
1658303SAli.Saidi@ARM.com                condCode == COND_CC || condCode == COND_CS ||
1668303SAli.Saidi@ARM.com                condCode == COND_VS || condCode == COND_VC) ?
1678303SAli.Saidi@ARM.com               INTREG_ZERO : INTREG_CONDCODES_NZ'''),
1688303SAli.Saidi@ARM.com    'OptCondCodesC': intRegCC(
1698303SAli.Saidi@ARM.com            '''(condCode == COND_HI || condCode == COND_LS ||
1708303SAli.Saidi@ARM.com                condCode == COND_CS || condCode == COND_CC) ?
1718303SAli.Saidi@ARM.com               INTREG_CONDCODES_C : INTREG_ZERO'''),
1728303SAli.Saidi@ARM.com    'OptCondCodesV': intRegCC(
1738303SAli.Saidi@ARM.com            '''(condCode == COND_VS || condCode == COND_VC ||
1748303SAli.Saidi@ARM.com                condCode == COND_GE || condCode == COND_LT ||
1758303SAli.Saidi@ARM.com                condCode == COND_GT || condCode == COND_LE) ?
1768303SAli.Saidi@ARM.com               INTREG_CONDCODES_V : INTREG_ZERO'''),
1777797Sgblack@eecs.umich.edu    'FpCondCodes': intRegCC('INTREG_FPCONDCODES'),
1787797Sgblack@eecs.umich.edu
1797797Sgblack@eecs.umich.edu    #Abstracted floating point reg operands
1807797Sgblack@eecs.umich.edu    'FpDest': floatReg('(dest + 0)'),
1817797Sgblack@eecs.umich.edu    'FpDestP0': floatReg('(dest + 0)'),
1827797Sgblack@eecs.umich.edu    'FpDestP1': floatReg('(dest + 1)'),
1837797Sgblack@eecs.umich.edu    'FpDestP2': floatReg('(dest + 2)'),
1847797Sgblack@eecs.umich.edu    'FpDestP3': floatReg('(dest + 3)'),
1857797Sgblack@eecs.umich.edu    'FpDestP4': floatReg('(dest + 4)'),
1867797Sgblack@eecs.umich.edu    'FpDestP5': floatReg('(dest + 5)'),
1877797Sgblack@eecs.umich.edu    'FpDestP6': floatReg('(dest + 6)'),
1887797Sgblack@eecs.umich.edu    'FpDestP7': floatReg('(dest + 7)'),
1897797Sgblack@eecs.umich.edu    'FpDestS0P0': floatReg('(dest + step * 0 + 0)'),
1907797Sgblack@eecs.umich.edu    'FpDestS0P1': floatReg('(dest + step * 0 + 1)'),
1917797Sgblack@eecs.umich.edu    'FpDestS1P0': floatReg('(dest + step * 1 + 0)'),
1927797Sgblack@eecs.umich.edu    'FpDestS1P1': floatReg('(dest + step * 1 + 1)'),
1937797Sgblack@eecs.umich.edu    'FpDestS2P0': floatReg('(dest + step * 2 + 0)'),
1947797Sgblack@eecs.umich.edu    'FpDestS2P1': floatReg('(dest + step * 2 + 1)'),
1957797Sgblack@eecs.umich.edu    'FpDestS3P0': floatReg('(dest + step * 3 + 0)'),
1967797Sgblack@eecs.umich.edu    'FpDestS3P1': floatReg('(dest + step * 3 + 1)'),
1977797Sgblack@eecs.umich.edu
1987797Sgblack@eecs.umich.edu    'FpDest2': floatReg('(dest2 + 0)'),
1997797Sgblack@eecs.umich.edu    'FpDest2P0': floatReg('(dest2 + 0)'),
2007797Sgblack@eecs.umich.edu    'FpDest2P1': floatReg('(dest2 + 1)'),
2017797Sgblack@eecs.umich.edu    'FpDest2P2': floatReg('(dest2 + 2)'),
2027797Sgblack@eecs.umich.edu    'FpDest2P3': floatReg('(dest2 + 3)'),
2037797Sgblack@eecs.umich.edu
2047797Sgblack@eecs.umich.edu    'FpOp1': floatReg('(op1 + 0)'),
2057797Sgblack@eecs.umich.edu    'FpOp1P0': floatReg('(op1 + 0)'),
2067797Sgblack@eecs.umich.edu    'FpOp1P1': floatReg('(op1 + 1)'),
2077797Sgblack@eecs.umich.edu    'FpOp1P2': floatReg('(op1 + 2)'),
2087797Sgblack@eecs.umich.edu    'FpOp1P3': floatReg('(op1 + 3)'),
2097797Sgblack@eecs.umich.edu    'FpOp1P4': floatReg('(op1 + 4)'),
2107797Sgblack@eecs.umich.edu    'FpOp1P5': floatReg('(op1 + 5)'),
2117797Sgblack@eecs.umich.edu    'FpOp1P6': floatReg('(op1 + 6)'),
2127797Sgblack@eecs.umich.edu    'FpOp1P7': floatReg('(op1 + 7)'),
2137797Sgblack@eecs.umich.edu    'FpOp1S0P0': floatReg('(op1 + step * 0 + 0)'),
2147797Sgblack@eecs.umich.edu    'FpOp1S0P1': floatReg('(op1 + step * 0 + 1)'),
2157797Sgblack@eecs.umich.edu    'FpOp1S1P0': floatReg('(op1 + step * 1 + 0)'),
2167797Sgblack@eecs.umich.edu    'FpOp1S1P1': floatReg('(op1 + step * 1 + 1)'),
2177797Sgblack@eecs.umich.edu    'FpOp1S2P0': floatReg('(op1 + step * 2 + 0)'),
2187797Sgblack@eecs.umich.edu    'FpOp1S2P1': floatReg('(op1 + step * 2 + 1)'),
2197797Sgblack@eecs.umich.edu    'FpOp1S3P0': floatReg('(op1 + step * 3 + 0)'),
2207797Sgblack@eecs.umich.edu    'FpOp1S3P1': floatReg('(op1 + step * 3 + 1)'),
2217797Sgblack@eecs.umich.edu
2227797Sgblack@eecs.umich.edu    'FpOp2': floatReg('(op2 + 0)'),
2237797Sgblack@eecs.umich.edu    'FpOp2P0': floatReg('(op2 + 0)'),
2247797Sgblack@eecs.umich.edu    'FpOp2P1': floatReg('(op2 + 1)'),
2257797Sgblack@eecs.umich.edu    'FpOp2P2': floatReg('(op2 + 2)'),
2267797Sgblack@eecs.umich.edu    'FpOp2P3': floatReg('(op2 + 3)'),
2277797Sgblack@eecs.umich.edu
2287797Sgblack@eecs.umich.edu    #Abstracted control reg operands
2297797Sgblack@eecs.umich.edu    'MiscDest': cntrlReg('dest'),
2307797Sgblack@eecs.umich.edu    'MiscOp1': cntrlReg('op1'),
2317797Sgblack@eecs.umich.edu
2327797Sgblack@eecs.umich.edu    #Fixed index control regs
2337797Sgblack@eecs.umich.edu    'Cpsr': cntrlReg('MISCREG_CPSR', srtCpsr),
2348302SAli.Saidi@ARM.com    'CpsrQ': cntrlReg('MISCREG_CPSR_Q', srtCpsr),
2357797Sgblack@eecs.umich.edu    'Spsr': cntrlRegNC('MISCREG_SPSR'),
2367797Sgblack@eecs.umich.edu    'Fpsr': cntrlRegNC('MISCREG_FPSR'),
2377797Sgblack@eecs.umich.edu    'Fpsid': cntrlRegNC('MISCREG_FPSID'),
2387797Sgblack@eecs.umich.edu    'Fpscr': cntrlRegNC('MISCREG_FPSCR'),
2397797Sgblack@eecs.umich.edu    'FpscrQc': cntrlRegNC('MISCREG_FPSCR_QC'),
2407797Sgblack@eecs.umich.edu    'FpscrExc': cntrlRegNC('MISCREG_FPSCR_EXC'),
2417797Sgblack@eecs.umich.edu    'Cpacr': cntrlReg('MISCREG_CPACR'),
2427797Sgblack@eecs.umich.edu    'Fpexc': cntrlRegNC('MISCREG_FPEXC'),
2437797Sgblack@eecs.umich.edu    'Sctlr': cntrlRegNC('MISCREG_SCTLR'),
2447797Sgblack@eecs.umich.edu    'SevMailbox': cntrlRegNC('MISCREG_SEV_MAILBOX'),
2458209SAli.Saidi@ARM.com    'LLSCLock': cntrlRegNC('MISCREG_LOCKFLAG'),
2466019Shines@cs.fsu.edu
2476308Sgblack@eecs.umich.edu    #Register fields for microops
2488139SMatt.Horsnell@arm.com    'URa' : intReg('ura'),
2497797Sgblack@eecs.umich.edu    'IWRa' : intRegIWPC('ura'),
2507797Sgblack@eecs.umich.edu    'Fa' : floatReg('ura'),
2518139SMatt.Horsnell@arm.com    'URb' : intReg('urb'),
2528139SMatt.Horsnell@arm.com    'URc' : intReg('urc'),
2536308Sgblack@eecs.umich.edu
2546019Shines@cs.fsu.edu    #Memory Operand
2557797Sgblack@eecs.umich.edu    'Mem': ('Mem', 'uw', None, ('IsMemRef', 'IsLoad', 'IsStore'), srtNormal),
2566019Shines@cs.fsu.edu
2577797Sgblack@eecs.umich.edu    #PCState fields
2587797Sgblack@eecs.umich.edu    'PC': pcStateReg('instPC', srtPC),
2597797Sgblack@eecs.umich.edu    'NPC': pcStateReg('instNPC', srtPC),
2607797Sgblack@eecs.umich.edu    'pNPC': pcStateReg('instNPC', srtEPC),
2617797Sgblack@eecs.umich.edu    'IWNPC': pcStateReg('instIWNPC', srtPC),
2627797Sgblack@eecs.umich.edu    'Thumb': pcStateReg('thumb', srtPC),
2637797Sgblack@eecs.umich.edu    'NextThumb': pcStateReg('nextThumb', srtMode),
2647797Sgblack@eecs.umich.edu    'NextJazelle': pcStateReg('nextJazelle', srtMode),
2658205SAli.Saidi@ARM.com    'NextItState': pcStateReg('nextItstate', srtMode),
2668205SAli.Saidi@ARM.com    'Itstate': pcStateReg('itstate', srtMode),
2677797Sgblack@eecs.umich.edu
2687797Sgblack@eecs.umich.edu    #Register operands depending on a field in the instruction encoding. These
2697797Sgblack@eecs.umich.edu    #should be avoided since they may not be portable across different
2707797Sgblack@eecs.umich.edu    #encodings of the same instruction.
2717797Sgblack@eecs.umich.edu    'Rd': intReg('RD'),
2727797Sgblack@eecs.umich.edu    'Rm': intReg('RM'),
2737797Sgblack@eecs.umich.edu    'Rs': intReg('RS'),
2747797Sgblack@eecs.umich.edu    'Rn': intReg('RN'),
2757797Sgblack@eecs.umich.edu    'Rt': intReg('RT')
2766019Shines@cs.fsu.edu}};
277