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 ```1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 ``` ``````scale=0 define gcd(a,b) { auto t; while (b) { t = b; b = a % b; a = t; } return a; } /* Division by reciprocal multiplication. */ define fmul(b,n,d) { return (2^b*n+d-1)/d; } /* Adjustment factor when a ceiling value is used. Use as: (imul * n) + (fmulxx * n + fadjxx) >> xx) */ define fadj(b,n,d) { auto v; d = d/gcd(n,d); v = 2^b*(d-1)/d; return v; } /* Compute the appropriate mul/adj values as well as a shift count, which brings the mul value into the range 2^b-1 <= x < 2^b. Such a shift value will be correct in the signed integer range and off by at most one in the upper half of the unsigned range. */ define fmuls(b,n,d) { auto s, m; for (s = 0; 1; s++) { m = fmul(s,n,d); if (m >= 2^(b-1)) return s; } return 0; } define timeconst(hz) { print "/* Automatically generated by kernel/timeconst.bc */\n" print "/* Time conversion constants for HZ == ", hz, " */\n" print "\n" print "#ifndef KERNEL_TIMECONST_H\n" print "#define KERNEL_TIMECONST_H\n\n" print "#include \n" print "#include \n\n" print "#if HZ != ", hz, "\n" print "#error \qkernel/timeconst.h has the wrong HZ value!\q\n" print "#endif\n\n" if (hz < 2) { print "#error Totally bogus HZ value!\n" } else { s=fmuls(32,1000,hz) obase=16 print "#define HZ_TO_MSEC_MUL32\tU64_C(0x", fmul(s,1000,hz), ")\n" print "#define HZ_TO_MSEC_ADJ32\tU64_C(0x", fadj(s,1000,hz), ")\n" obase=10 print "#define HZ_TO_MSEC_SHR32\t", s, "\n" s=fmuls(32,hz,1000) obase=16 print "#define MSEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000), ")\n" print "#define MSEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000), ")\n" obase=10 print "#define MSEC_TO_HZ_SHR32\t", s, "\n" obase=10 cd=gcd(hz,1000) print "#define HZ_TO_MSEC_NUM\t\t", 1000/cd, "\n" print "#define HZ_TO_MSEC_DEN\t\t", hz/cd, "\n" print "#define MSEC_TO_HZ_NUM\t\t", hz/cd, "\n" print "#define MSEC_TO_HZ_DEN\t\t", 1000/cd, "\n" print "\n" s=fmuls(32,1000000,hz) obase=16 print "#define HZ_TO_USEC_MUL32\tU64_C(0x", fmul(s,1000000,hz), ")\n" print "#define HZ_TO_USEC_ADJ32\tU64_C(0x", fadj(s,1000000,hz), ")\n" obase=10 print "#define HZ_TO_USEC_SHR32\t", s, "\n" s=fmuls(32,hz,1000000) obase=16 print "#define USEC_TO_HZ_MUL32\tU64_C(0x", fmul(s,hz,1000000), ")\n" print "#define USEC_TO_HZ_ADJ32\tU64_C(0x", fadj(s,hz,1000000), ")\n" obase=10 print "#define USEC_TO_HZ_SHR32\t", s, "\n" obase=10 cd=gcd(hz,1000000) print "#define HZ_TO_USEC_NUM\t\t", 1000000/cd, "\n" print "#define HZ_TO_USEC_DEN\t\t", hz/cd, "\n" print "#define USEC_TO_HZ_NUM\t\t", hz/cd, "\n" print "#define USEC_TO_HZ_DEN\t\t", 1000000/cd, "\n" print "\n" print "#endif /* KERNEL_TIMECONST_H */\n" } halt } timeconst(hz) ``````