43 lines
1002 B
C
43 lines
1002 B
C
#include <stdint.h>
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#include <string.h>
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static inline uint32_t swapc(uint32_t x, int c)
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{
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return c ? x>>24 | x>>8&0xff00 | x<<8&0xff0000 | x<<24 : x;
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}
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const char *__mo_lookup(const void *p, size_t size, const char *s)
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{
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const uint32_t *mo = p;
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int sw = *mo - 0x950412de;
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uint32_t b = 0, n = swapc(mo[2], sw);
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uint32_t o = swapc(mo[3], sw);
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uint32_t t = swapc(mo[4], sw);
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if (n>=size/4 || o>=size-4*n || t>=size-4*n || ((o|t)%4))
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return 0;
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o/=4;
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t/=4;
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for (;;) {
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uint32_t ol = swapc(mo[o+2*(b+n/2)], sw);
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uint32_t os = swapc(mo[o+2*(b+n/2)+1], sw);
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if (os >= size || ol >= size-os || ((char *)p)[os+ol])
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return 0;
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int sign = strcmp(s, (char *)p + os);
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if (!sign) {
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uint32_t tl = swapc(mo[t+2*(b+n/2)], sw);
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uint32_t ts = swapc(mo[t+2*(b+n/2)+1], sw);
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if (ts >= size || tl >= size-ts || ((char *)p)[ts+tl])
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return 0;
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return (char *)p + ts;
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}
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else if (n == 1) return 0;
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else if (sign < 0)
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n /= 2;
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else {
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b += n/2;
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n -= n/2;
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}
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}
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return 0;
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}
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