1 /* This file is part of the program psim.
3 Copyright (C) 1994-1996, Andrew Cagney <cagney@highland.com.au>
4 Copyright (C) 1997, Free Software Foundation, Inc.
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 2 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program; if not, write to the Free Software
18 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
28 /* 32bit target expressions:
30 Each calculation is performed three times using each of the
31 signed64, unsigned64 and long integer types. The macro ALU_END
32 (in _ALU_RESULT_VAL) then selects which of the three alternative
33 results will be used in the final assignment of the target
34 register. As this selection is determined at compile time by
35 fields in the instruction (OE, EA, Rc) the compiler has sufficient
36 information to firstly simplify the selection code into a single
37 case and then back anotate the equations and hence eliminate any
38 resulting dead code. That dead code being the calculations that,
39 as it turned out were not in the end needed.
41 64bit arrithemetic is used firstly because it allows the use of
42 gcc's efficient long long operators (typically efficiently output
43 inline) and secondly because the resultant answer will contain in
44 the low 32bits the answer while in the high 32bits is either carry
45 or status information. */
49 /* 16bit target expressions:
51 These are a simplified version of the 32bit target expressions */
55 /* 64bit target expressions:
57 Unfortunatly 128bit arrithemetic isn't that common. Consequently
58 the 32/64 bit trick can not be used. Instead all calculations are
59 required to retain carry/overflow information in separate
60 variables. Even with this restriction it is still possible for the
61 trick of letting the compiler discard the calculation of unneeded
65 /* Macro's to type cast 32bit constants to 64bits */
66 #define SIGNED64(val) ((signed64)(signed32)(val))
67 #define UNSIGNED64(val) ((unsigned64)(unsigned32)(val))
70 /* Start a section of ALU code */
72 #define ALU16_BEGIN(VAL) \
74 signed_word alu_carry_val; \
75 unsigned_word alu_overflow_val; \
78 #define ALU32_BEGIN(VAL) \
80 natural_word alu_val; \
81 unsigned64 alu_carry_val; \
82 signed64 alu_overflow_val; \
85 #define ALU_BEGIN(VAL) XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_BEGIN)(VAL)
87 /* More basic alu operations */
91 #define ALU16_SET(VAL) \
93 alu_carry_val = (unsigned16)(VAL); \
94 alu_overflow_val = (signed16)(VAL); \
97 #define ALU32_SET(VAL) \
99 alu_val = (unsigned32)(VAL); \
100 alu_carry_val = (unsigned32)(alu_val); \
101 alu_overflow_val = (signed32)(alu_val); \
104 #define ALU64_SET(VAL) \
107 alu_carry_val = ((unsigned64)alu_val) >> 32; \
108 alu_overflow_val = ((signed64)alu_val) >> 32; \
111 #define ALU_SET(VAL) XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_SET)(VAL)
116 #define ALU16_ADD(VAL) \
118 alu_carry_val += (unsigned16)(VAL); \
119 alu_overflow_val += (signed16)(VAL); \
122 #define ALU32_ADD(VAL) \
125 alu_carry_val += (unsigned32)(VAL); \
126 alu_overflow_val += (signed32)(VAL); \
129 #define ALU64_ADD(VAL) \
131 unsigned64 alu_lo = (UNSIGNED64(alu_val) \
132 + UNSIGNED64(VAL)); \
133 signed alu_carry = ((alu_lo & BIT(31)) != 0); \
134 alu_carry_val = (alu_carry_val \
135 + UNSIGNED64(EXTRACTED(val, 0, 31)) \
137 alu_overflow_val = (alu_overflow_val \
138 + SIGNED64(EXTRACTED(val, 0, 31)) \
140 alu_val = alu_val + val; \
143 #define ALU_ADD(VAL) XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_ADD)(VAL)
148 #define ALU16_ADD_CA \
150 signed carry = ALU_CARRY; \
154 #define ALU32_ADD_CA \
156 signed carry = ALU_CARRY; \
160 #define ALU64_ADD_CA \
162 signed carry = ALU_CARRY; \
166 #define ALU_ADD_CA XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_ADD_CA)
171 #define ALU16_SUB(VAL) \
173 alu_carry_val -= (unsigned16)(VAL); \
174 alu_overflow_val -= (signed16)(VAL); \
177 #define ALU32_SUB(VAL) \
180 alu_carry_val -= (unsigned32)(VAL); \
181 alu_overflow_val -= (signed32)(VAL); \
184 #define ALU64_SUB(VAL) \
186 error("ALU_SUB64"); \
189 #define ALU_SUB(VAL) XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_SUB)(VAL)
194 #define ALU16_SUB_CA \
196 signed carry = ALU_CARRY; \
200 #define ALU32_SUB_CA \
202 signed carry = ALU_CARRY; \
206 #define ALU64_SUB_CA \
208 signed carry = ALU_CARRY; \
212 #define ALU_SUB_CA XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_SUB_CA)
217 #define ALU16_OR(VAL) \
222 #define ALU32_OR(VAL) \
225 alu_carry_val = (unsigned32)(alu_val); \
226 alu_overflow_val = (signed32)(alu_val); \
229 #define ALU64_OR(VAL) \
234 #define ALU_OR(VAL) XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_OR)(VAL)
239 #define ALU16_XOR(VAL) \
241 error("ALU16_XOR"); \
244 #define ALU32_XOR(VAL) \
247 alu_carry_val = (unsigned32)(alu_val); \
248 alu_overflow_val = (signed32)(alu_val); \
251 #define ALU64_XOR(VAL) \
253 error("ALU_XOR64"); \
256 #define ALU_XOR(VAL) XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_XOR)(VAL)
261 #define ALU16_NEGATE \
263 error("ALU_NEGATE16"); \
266 #define ALU32_NEGATE \
268 alu_val = -alu_val; \
269 alu_carry_val = -alu_carry_val; \
270 alu_overflow_val = -alu_overflow_val; \
273 #define ALU64_NEGATE \
275 error("ALU_NEGATE64"); \
278 #define ALU_NEGATE XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_NEGATE)
283 #define ALU16_AND(VAL) \
285 error("ALU_AND16"); \
288 #define ALU32_AND(VAL) \
291 alu_carry_val = (unsigned32)(alu_val); \
292 alu_overflow_val = (signed32)(alu_val); \
295 #define ALU64_AND(VAL) \
297 error("ALU_AND64"); \
300 #define ALU_AND(VAL) XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_AND)(VAL)
305 #define ALU16_NOT(VAL) \
307 error("ALU_NOT16"); \
312 signed64 new_alu_val = ~alu_val; \
313 ALU_SET(new_alu_val); \
318 error("ALU_NOT64"); \
321 #define ALU_NOT XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_NOT)
325 /* Make available various results */
328 /* overflow occures if the sign bit differs from the carry bit */
330 #define ALU16_HAD_OVERFLOW \
331 (!(alu_overflow_val & MSBIT32 (0)) != !(alu_overflow_val & MSBIT32 (16)))
333 #define ALU32_HAD_OVERFLOW \
334 ((((unsigned64)(alu_overflow_val & BIT64(0))) >> 32) \
335 != (alu_overflow_val & MSBIT64(32)))
337 #define ALU_HAD_OVERFLOW XCONCAT3(ALU,WITH_TARGET_WORD_BITSIZE,_HAD_OVERFLOW)
339 /* carry found in bit before sign */
341 #define ALU16_HAD_CARRY \
342 (alu_carry_val & MSBIT32(16))
344 #define ALU32_HAD_CARRY \
345 (alu_carry_val & MSBIT64(31))