💾 Archived View for gmi.noulin.net › gitRepositories › dynamicArray › file › libdarray.c.gmi captured on 2023-01-29 at 13:21:43. Gemini links have been rewritten to link to archived content
-=-=-=-=-=-=-
libdarray.c (910B)
1
2 #include "libdarray.h"
3
4 bool dArrayIsValidIndex(intmax_t index) {
5 if (index >= ((intmax_t)1)<<dArrayAddrSpace) {
6 return false;
7 }
8 return true;
9 }
10
11 dArrayIxt dArrayIndex(intmax_t index) {
12 dArrayIxt r;
13 if (index >= ((intmax_t)1)<<dArrayAddrSpace) {
14 r.error = true;
15 return r;
16 }
17 r.error = false;
18
19 intmax_t bufx = index >> dArrayBaseBits;
20 if (!bufx) {
21 r.ix = 0;
22 r.offset = index;
23 }
24 else {
25 //int pos = 0;
26 /* for (int i = (bufx >> 1); i != 0; pos++) { */
27 /* i >>= 1; */
28 /* } */
29 /* find position of MSB */
30 #if __LP64__
31 asm ("bsrq %1, %0" : "=r" (r.ix) : "r" (bufx));
32 #else
33 asm ("bsrl %1, %0" : "=r" (r.ix) : "r" (bufx));
34 #endif
35 intmax_t mask = ~(0xFFFFFFFFFFFFFFFF << (dArrayBaseBits+r.ix));
36 r.ix++;
37 r.offset = index & mask;
38 }
39 return r;
40 }