Unformatted text preview: nt IDENT and combining operation OPER, we can measure the routine for different operations.
#define IDENT 0 #define OPER + we sum the elements of the vector. Using the declarations:
#define IDENT 1 #define OPER * we compute the product of the vector elements. As a starting point, here are the CPE measurements for combine1 running on an Intel Pentium III, trying all combinations of data type and combining operation. In our measurements, we found that the timings were generally equal for single and double-precision ﬂoating point data. We therefore show only the measurements for single precision. Function combine1 combine1 Page 211 211 Method Abstract unoptimized Abstract -O2 Integer + * 42.06 41.86 31.25 33.25 Floating Point + * 41.44 160.00 31.25 143.00 By default, the compiler generates code suitable for stepping with a symbolic debugger. Very little optimization is performed since the intention is to make the object code closely match the computations indicated in the source code. By simply setting the command line switch to ‘ -O2’ we enable optimizati...
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