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2. Overflow and Timeout Exceptions: 64-bit

We have to emphasize here once more, that CDD does not detect overflows. However, since POLYBENCH compares the resulting constraint systems of the two implementations, we can deduce the numbers of exceptions raised: if CDD64's output is correct, compared to C3DD64's output, then CDD64 has no overflow, as shown in 6_tab:SPEC95_dual_conversion_exception_100. The numbers of exceptions come from C3DD64 and CDD64's executions on SPEC95 convex hull sampled database.

We notice that this example reveals a difference between the two implementations: an overflow exception from C3DD64. However, the convex hull sampled databases only contain fewer than $500$ tests (PerfectClub's $393$ tests do not show any difference in numbers of exceptions), thus we can conclude that the difference is not significant.


Table 20: SPEC95: Numbers of exceptions in sampled database
  SPEC95
timeout = 2 minutes #overflows #timeouts #operations
C3DD64-bit 1 0 485
CDD64-bit 0* 0 485



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Previous: 1. Dual Conversion versus Up: 6. Results for Dual Next: 3. Arithmetic Precision: 64-bit
Nguyen Que Duong
2006-09-16