From e18135c4f76c84063ba17b5a0eb03511c2e575e4 Mon Sep 17 00:00:00 2001 From: Sadeep Madurange Date: Mon, 29 Nov 2021 22:10:34 +0800 Subject: 2.6 --- 2/6.c | 35 +++++++++++++++++++++++++++++++++++ 1 file changed, 35 insertions(+) create mode 100644 2/6.c (limited to '2') diff --git a/2/6.c b/2/6.c new file mode 100644 index 0000000..67d7c09 --- /dev/null +++ b/2/6.c @@ -0,0 +1,35 @@ +#include + +unsigned setbits(unsigned x, int p, int n, unsigned y); + +int main(int argc, char *argv[]) { + int p, n; + unsigned x, y; + + p = 5; + n = 3; + x = 0; + y = 7; + + printf("New bit field: %x\n", setbits(x, p, n, y)); + + return 0; +} + +unsigned setbits(unsigned x, int p, int n, unsigned y) { + unsigned yLO, yLOA, xUnset, xPrime; + + // extract LO n bits from y + yLO = y & ~(~0 << n); + + // align extracted LO bits of y to position p: + yLOA = yLO << (p + 1 - n); + + // create mask with n bits from position p unset: + xUnset = (~0 << p) | ~(~0 << (p - n)); + + // mask out n bits from x starting at position p: + xPrime = x & xUnset; + + return xPrime | yLOA; +} \ No newline at end of file -- cgit v1.2.3