2 * Copyright (c) 2003 The Regents of The University of Michigan
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29 #ifndef __BASE_BITFIELD_HH__
30 #define __BASE_BITFIELD_HH__
32 #include "sim/host.hh"
35 * Generate a 64-bit mask of 'nbits' 1s, right justified.
40 return (nbits == 64) ? (uint64_t)-1LL : (1ULL << nbits) - 1;
45 * Extract the bitfield from position 'first' to 'last' (inclusive)
46 * from 'val' and right justify it. MSB is numbered 63, LSB is 0.
51 bits(T val, int first, int last)
53 int nbits = first - last + 1;
54 return (val >> last) & mask(nbits);
58 * Sign-extend an N-bit value to 64 bits.
65 int sign_bit = bits(val, N-1, N-1);
66 return sign_bit ? (val | ~mask(N)) : val;
69 #endif // __BASE_BITFIELD_HH__