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Unformatted text preview: inal 8086 and its extensions in the 80286 are obsolete. Instead, Linux uses what is referred to as ﬂat addressing, where the entire memory space is viewed by the programmer as a large array of bytes. As we can see in the list of developments, a number of formats and instructions have been added to IA32 for manipulating vectors of small integers and ﬂoating-point numbers. These features were added to allow improved performance on multimedia applications, such as image processing, audio and video encoding and decoding, and three-dimensional computer graphics. Unfortunately, current versions of GCC will not generate any code that uses these new features. In fact, in its default invocations GCC assumes it is generating code for an i386. The compiler makes no attempt to exploit the many extensions added to what is now considered a very old architecture. 3.2 Program Encodings
Suppose we write a C program as two ﬁles p1.c and p2.c. We would then compile this code using a Unix command line:
unix> gcc -O2 -o p p1.c p2.c The...
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- Spring '10
- The American