/* { dg-do compile } */ /* { dg-options "-O2 -fdump-tree-forwprop2-details" } */ int ctz1 (unsigned x) { static const char table[32] = "\x00\x01\x1c\x02\x1d\x0e\x18\x03\x1e\x16\x14" "\x0f\x19\x11\x04\b\x1f\x1b\r\x17\x15\x13\x10\x07\x1a\f\x12\x06\v\x05\n\t"; return table[((unsigned)((x & -x) * 0x077CB531U)) >> 27]; } int ctz2 (unsigned x) { #define u 0 static short table[64] = { 32, 0, 1,12, 2, 6, u,13, 3, u, 7, u, u, u, u,14, 10, 4, u, u, 8, u, u,25, u, u, u, u, u,21,27,15, 31,11, 5, u, u, u, u, u, 9, u, u,24, u, u,20,26, 30, u, u, u, u,23, u,19,29, u,22,18,28,17,16, u }; x = (x & -x) * 0x0450FBAF; return table[x >> 26]; } int ctz3 (unsigned x) { static int table[32] = { 0, 1, 2,24, 3,19, 6,25, 22, 4,20,10,16, 7,12,26, 31,23,18, 5,21, 9,15,11,30,17, 8,14,29,13,28,27 }; if (x == 0) return 32; x = (x & -x) * 0x04D7651F; return table[x >> 27]; } static const unsigned long long magic = 0x03f08c5392f756cdULL; static const char table[64] = { 0, 1, 12, 2, 13, 22, 17, 3, 14, 33, 23, 36, 18, 58, 28, 4, 62, 15, 34, 26, 24, 48, 50, 37, 19, 55, 59, 52, 29, 44, 39, 5, 63, 11, 21, 16, 32, 35, 57, 27, 61, 25, 47, 49, 54, 51, 43, 38, 10, 20, 31, 56, 60, 46, 53, 42, 9, 30, 45, 41, 8, 40, 7, 6, }; int ctz4 (unsigned long x) { unsigned long lsb = x & -x; return table[(lsb * magic) >> 58]; } /* { dg-final { scan-tree-dump-times {= \.CTZ} 4 "forwprop2" { target aarch64*-*-* } } } */