75 lines
2.2 KiB
C++
75 lines
2.2 KiB
C++
/*
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NetWinder Floating Point Emulator
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(c) Rebel.COM, 1998,1999
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Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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*/
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static inline unsigned long readRegister(const unsigned int nReg)
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{
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/* Note: The CPU thinks it has dealt with the current instruction.
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As a result the program counter has been advanced to the next
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instruction, and points 4 bytes beyond the actual instruction
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that caused the invalid instruction trap to occur. We adjust
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for this in this routine. LDF/STF instructions with Rn = PC
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depend on the PC being correct, as they use PC+8 in their
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address calculations. */
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unsigned long *userRegisters = GET_USERREG();
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unsigned int val = userRegisters[nReg];
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if (REG_PC == nReg)
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val -= 4;
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return val;
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}
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static inline void
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writeRegister(const unsigned int nReg, const unsigned long val)
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{
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unsigned long *userRegisters = GET_USERREG();
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userRegisters[nReg] = val;
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}
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static inline unsigned long readCPSR(void)
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{
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return (readRegister(REG_CPSR));
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}
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static inline void writeCPSR(const unsigned long val)
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{
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writeRegister(REG_CPSR, val);
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}
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static inline unsigned long readConditionCodes(void)
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{
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#ifdef __FPEM_TEST__
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return (0);
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#else
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return (readCPSR() & CC_MASK);
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#endif
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}
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static inline void writeConditionCodes(const unsigned long val)
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{
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unsigned long *userRegisters = GET_USERREG();
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unsigned long rval;
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/*
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* Operate directly on userRegisters since
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* the CPSR may be the PC register itself.
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*/
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rval = userRegisters[REG_CPSR] & ~CC_MASK;
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userRegisters[REG_CPSR] = rval | (val & CC_MASK);
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}
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