Description

1. On a machine with 16-bit ints, the C expression (30000 + 30000) yields a negative result.
Why the negative result? How can you make it produce the correct result?
2. Assume that the following hexadecimal values are 16-bit twos-complement. Convert each to the corresponding decimal value. i. 0x0013 ii. 0x0444 iii. 0x1234 iv. 0xffff v. 0x8000
3. Give a representation for each of the following decimal values in 16-bit twos-complement bit-strings. Show the value in binary, octal and hexadecimal.
i. 1
ii. 100
iii. 1000 iv. 10000
v. 100000
vi. -5
vii. -100
4. What decimal numbers do the following single-precision IEEE 754-encoded bit-strings represent? a. 0 00000000 00000000000000000000000
b. 1 00000000 00000000000000000000000
c. 0 01111111 10000000000000000000000
d. 0 01111110 00000000000000000000000
e. 0 01111110 11111111111111111111111
f. 0 10000000 01100000000000000000000
g. 0 10010100 10000000000000000000000
h. 0 01101110 10100000101000001010000
Each of the above is a single 32-bit bit-string, but partitioned to show the sign, exponent and fraction parts.
5. Convert the following decimal numbers into IEEE 754-encoded bit-strings: a. 2.5
b. 0.375
c. 27.0
d. 100.0
6. Write a C function, six_middle_bits, which, given a uint32_t, extracts and returns the middle six bits.
7. Draw diagrams to show the difference between the following two data structures:

If x1 was located at &x1 == 0x1000 and x2 was located at &x2 == 0x2000, what would be the values of &x1.a, &x1.b, &x2.a, and &x2.b?
8. How large (#bytes) is each of the following C unions?

9. Consider the following C union

If we define a variable union _all var; and assign the following value var.uval = 0x00313233;, then what will each of the following printf(3)s produce:
a. printf(“%x “, var.uval);
b. printf(“%d “, var.ival);
c. printf(“%c “, var.cval);
d. printf(“%s “, var.sval);
e. printf(“%f “, var.fval);
f. printf(“%e “, var.fval);
You can assume that bytes are arranged from right-to-left in increasing address order.
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