1 /*
2 NetWinder Floating Point Emulator
3 (c) Rebel.COM, 1998,1999
4
5 Direct questions, comments to Scott Bambrough <scottb@netwinder.org>
6
7 This program is free software; you can redistribute it and/or modify
8 it under the terms of the GNU General Public License as published by
9 the Free Software Foundation; either version 2 of the License, or
10 (at your option) any later version.
11
12 This program is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
15 GNU General Public License for more details.
16
17 You should have received a copy of the GNU General Public License
18 along with this program; if not, write to the Free Software
19 Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
20 */
21
22 static inline unsigned long readRegister(const unsigned int nReg)
23 {
24 /* Note: The CPU thinks it has dealt with the current instruction.
25 As a result the program counter has been advanced to the next
26 instruction, and points 4 bytes beyond the actual instruction
27 that caused the invalid instruction trap to occur. We adjust
28 for this in this routine. LDF/STF instructions with Rn = PC
29 depend on the PC being correct, as they use PC+8 in their
30 address calculations. */
31 struct pt_regs *regs = GET_USERREG();
32 unsigned int val = regs->uregs[nReg];
33 if (REG_PC == nReg)
34 val -= 4;
35 return val;
36 }
37
38 static inline void
39 writeRegister(const unsigned int nReg, const unsigned long val)
40 {
41 struct pt_regs *regs = GET_USERREG();
42 regs->uregs[nReg] = val;
43 }
44
45 static inline unsigned long readCPSR(void)
46 {
47 return (readRegister(REG_CPSR));
48 }
49
50 static inline void writeCPSR(const unsigned long val)
51 {
52 writeRegister(REG_CPSR, val);
53 }
54
55 static inline unsigned long readConditionCodes(void)
56 {
57 #ifdef __FPEM_TEST__
58 return (0);
59 #else
60 return (readCPSR() & CC_MASK);
61 #endif
62 }
63
64 static inline void writeConditionCodes(const unsigned long val)
65 {
66 struct pt_regs *regs = GET_USERREG();
67 unsigned long rval;
68 /*
69 * Operate directly on userRegisters since
70 * the CPSR may be the PC register itself.
71 */
72 rval = regs->ARM_cpsr & ~CC_MASK;
73 regs->ARM_cpsr = rval | (val & CC_MASK);
74 }
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