1
|
1
|
|
2
|
|
3 // written by Walter Bright
|
|
4 // www.digitalmars.com
|
|
5 // Placed into the public domain
|
|
6
|
|
7 /* NOTE: This file has been patched from the original DMD distribution to
|
|
8 work with the GDC compiler.
|
|
9 NOTE: This file has been patched from the original GDC distribution to
|
|
10 work with the LLVMDC compiler.
|
|
11
|
|
12 Modified by David Friedman, May 2006
|
|
13 Modified by Tomas Lindquist Olsen, August 2007
|
|
14 */
|
|
15
|
|
16 /** These functions are built-in intrinsics to the compiler.
|
|
17 *
|
|
18 Intrinsic functions are functions built in to the compiler,
|
|
19 usually to take advantage of specific CPU features that
|
|
20 are inefficient to handle via external functions.
|
|
21 The compiler's optimizer and code generator are fully
|
|
22 integrated in with intrinsic functions, bringing to bear
|
|
23 their full power on them.
|
|
24 This can result in some surprising speedups.
|
|
25 * Macros:
|
|
26 * WIKI=Phobos/StdIntrinsic
|
|
27 */
|
|
28
|
|
29 module std.intrinsic;
|
|
30
|
|
31 /**
|
|
32 * Scans the bits in v starting with bit 0, looking
|
|
33 * for the first set bit.
|
|
34 * Returns:
|
|
35 * The bit number of the first bit set.
|
|
36 * The return value is undefined if v is zero.
|
|
37 */
|
|
38 version (LLVM)
|
|
39 int bsf(uint v)
|
|
40 {
|
|
41 uint m = 1;
|
|
42 uint i;
|
|
43 for (i = 0; i < 32; i++,m<<=1) {
|
|
44 if (v&m)
|
|
45 return i;
|
|
46 }
|
|
47 return i; // supposed to be undefined
|
|
48 }
|
|
49 else
|
|
50 int bsf(uint v);
|
|
51
|
|
52 /**
|
|
53 * Scans the bits in v from the most significant bit
|
|
54 * to the least significant bit, looking
|
|
55 * for the first set bit.
|
|
56 * Returns:
|
|
57 * The bit number of the first bit set.
|
|
58 * The return value is undefined if v is zero.
|
|
59 * Example:
|
|
60 * ---
|
|
61 * import std.intrinsic;
|
|
62 *
|
|
63 * int main()
|
|
64 * {
|
|
65 * uint v;
|
|
66 * int x;
|
|
67 *
|
|
68 * v = 0x21;
|
|
69 * x = bsf(v);
|
|
70 * printf("bsf(x%x) = %d\n", v, x);
|
|
71 * x = bsr(v);
|
|
72 * printf("bsr(x%x) = %d\n", v, x);
|
|
73 * return 0;
|
|
74 * }
|
|
75 * ---
|
|
76 * Output:
|
|
77 * bsf(x21) = 0<br>
|
|
78 * bsr(x21) = 5
|
|
79 */
|
|
80 version (LLVM)
|
|
81 int bsr(uint v)
|
|
82 {
|
|
83 uint m = 0x80000000;
|
|
84 uint i;
|
|
85 for (i = 32; i ; i--,m>>>=1) {
|
|
86 if (v&m)
|
|
87 return i-1;
|
|
88 }
|
|
89 return i; // supposed to be undefined
|
|
90 }
|
|
91 else
|
|
92 int bsr(uint v);
|
|
93
|
|
94 /**
|
|
95 * Tests the bit.
|
|
96 */
|
|
97 version (LLVM)
|
|
98 int bt(uint *p, uint bitnum)
|
|
99 {
|
|
100 return (p[bitnum / (uint.sizeof*8)] & (1<<(bitnum & ((uint.sizeof*8)-1)))) ? -1 : 0 ;
|
|
101 }
|
|
102 else
|
|
103 int bt(uint *p, uint bitnum);
|
|
104
|
|
105 /**
|
|
106 * Tests and complements the bit.
|
|
107 */
|
|
108 version (LLVM)
|
|
109 int btc(uint *p, uint bitnum)
|
|
110 {
|
|
111 uint * q = p + (bitnum / (uint.sizeof*8));
|
|
112 uint mask = 1 << (bitnum & ((uint.sizeof*8) - 1));
|
|
113 int result = *q & mask;
|
|
114 *q ^= mask;
|
|
115 return result ? -1 : 0;
|
|
116 }
|
|
117 else
|
|
118 int btc(uint *p, uint bitnum);
|
|
119
|
|
120 /**
|
|
121 * Tests and resets (sets to 0) the bit.
|
|
122 */
|
|
123 version (LLVM)
|
|
124 int btr(uint *p, uint bitnum)
|
|
125 {
|
|
126 uint * q = p + (bitnum / (uint.sizeof*8));
|
|
127 uint mask = 1 << (bitnum & ((uint.sizeof*8) - 1));
|
|
128 int result = *q & mask;
|
|
129 *q &= ~mask;
|
|
130 return result ? -1 : 0;
|
|
131 }
|
|
132 else
|
|
133 int btr(uint *p, uint bitnum);
|
|
134
|
|
135 /**
|
|
136 * Tests and sets the bit.
|
|
137 * Params:
|
|
138 * p = a non-NULL pointer to an array of uints.
|
|
139 * index = a bit number, starting with bit 0 of p[0],
|
|
140 * and progressing. It addresses bits like the expression:
|
|
141 ---
|
|
142 p[index / (uint.sizeof*8)] & (1 << (index & ((uint.sizeof*8) - 1)))
|
|
143 ---
|
|
144 * Returns:
|
|
145 * A non-zero value if the bit was set, and a zero
|
|
146 * if it was clear.
|
|
147 *
|
|
148 * Example:
|
|
149 * ---
|
|
150 import std.intrinsic;
|
|
151
|
|
152 int main()
|
|
153 {
|
|
154 uint array[2];
|
|
155
|
|
156 array[0] = 2;
|
|
157 array[1] = 0x100;
|
|
158
|
|
159 printf("btc(array, 35) = %d\n", <b>btc</b>(array, 35));
|
|
160 printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);
|
|
161
|
|
162 printf("btc(array, 35) = %d\n", <b>btc</b>(array, 35));
|
|
163 printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);
|
|
164
|
|
165 printf("bts(array, 35) = %d\n", <b>bts</b>(array, 35));
|
|
166 printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);
|
|
167
|
|
168 printf("btr(array, 35) = %d\n", <b>btr</b>(array, 35));
|
|
169 printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);
|
|
170
|
|
171 printf("bt(array, 1) = %d\n", <b>bt</b>(array, 1));
|
|
172 printf("array = [0]:x%x, [1]:x%x\n", array[0], array[1]);
|
|
173
|
|
174 return 0;
|
|
175 }
|
|
176 * ---
|
|
177 * Output:
|
|
178 <pre>
|
|
179 btc(array, 35) = 0
|
|
180 array = [0]:x2, [1]:x108
|
|
181 btc(array, 35) = -1
|
|
182 array = [0]:x2, [1]:x100
|
|
183 bts(array, 35) = 0
|
|
184 array = [0]:x2, [1]:x108
|
|
185 btr(array, 35) = -1
|
|
186 array = [0]:x2, [1]:x100
|
|
187 bt(array, 1) = -1
|
|
188 array = [0]:x2, [1]:x100
|
|
189 </pre>
|
|
190 */
|
|
191 version (LLVM)
|
|
192 int bts(uint *p, uint bitnum)
|
|
193 {
|
|
194 uint * q = p + (bitnum / (uint.sizeof*8));
|
|
195 uint mask = 1 << (bitnum & ((uint.sizeof*8) - 1));
|
|
196 int result = *q & mask;
|
|
197 *q |= mask;
|
|
198 return result ? -1 : 0;
|
|
199 }
|
|
200 else
|
|
201 int bts(uint *p, uint bitnum);
|
|
202
|
|
203
|
|
204 /**
|
|
205 * Swaps bytes in a 4 byte uint end-to-end, i.e. byte 0 becomes
|
|
206 byte 3, byte 1 becomes byte 2, byte 2 becomes byte 1, byte 3
|
|
207 becomes byte 0.
|
|
208 */
|
|
209 version (LLVM)
|
|
210 pragma(LLVM_internal, "intrinsic", "llvm.bswap.i32.i32")
|
|
211 uint bswap(uint val);
|
|
212 else
|
|
213 uint bswap(uint v);
|
|
214
|
|
215
|
|
216 /**
|
|
217 * Reads I/O port at port_address.
|
|
218 */
|
|
219 version (LLVM)
|
|
220 ubyte inp(uint p) { return 0; }
|
|
221 else
|
|
222 ubyte inp(uint port_address);
|
|
223
|
|
224 /**
|
|
225 * ditto
|
|
226 */
|
|
227 version (LLVM)
|
|
228 ushort inpw(uint p) { return 0; }
|
|
229 else
|
|
230 ushort inpw(uint port_address);
|
|
231
|
|
232 /**
|
|
233 * ditto
|
|
234 */
|
|
235 version (LLVM)
|
|
236 uint inpl(uint p) { return 0; }
|
|
237 else
|
|
238 uint inpl(uint port_address);
|
|
239
|
|
240
|
|
241 /**
|
|
242 * Writes and returns value to I/O port at port_address.
|
|
243 */
|
|
244 version (LLVM)
|
|
245 ubyte outp(uint p, ubyte v) { return v; }
|
|
246 else
|
|
247 ubyte outp(uint port_address, ubyte value);
|
|
248
|
|
249 /**
|
|
250 * ditto
|
|
251 */
|
|
252 version (LLVM)
|
|
253 ushort outpw(uint p, ushort v) { return v; }
|
|
254 else
|
|
255 ushort outpw(uint port_address, ushort value);
|
|
256
|
|
257 /**
|
|
258 * ditto
|
|
259 */
|
|
260 version (LLVM)
|
|
261 uint outpl(uint p, uint v) { return v; }
|
|
262 else
|
|
263 uint outpl(uint port_address, uint value);
|
|
264
|
|
265
|