From: SourceForge.net <no...@so...> - 2009-05-30 15:01:17
|
Bugs item #2798543, was opened at 2009-05-29 14:53 Message generated for change (Comment added) made by dgp You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=110894&aid=2798543&group_id=10894 Please note that this message will contain a full copy of the comment thread, including the initial issue submission, for this request, not just the latest update. Category: 47. Bytecode Compiler Group: current: 8.5.7 Status: Open Resolution: None Priority: 5 Private: No Submitted By: Don Porter (dgp) Assigned to: Don Porter (dgp) Summary: bogus bignum exponent calculations Initial Comment: % string length [expr {10**2**15}] 32769 % string length [expr {10**2**16}] 17 % expr {10**2**16} 21936950640377856 ---------------------------------------------------------------------- >Comment By: Don Porter (dgp) Date: 2009-05-30 11:01 Message: Neither. All appearances say it's in TEBC's own "optimized table lookup" implementation. ---------------------------------------------------------------------- Comment By: Andreas Kupries (andreas_kupries) Date: 2009-05-29 17:54 Message: Curiosity: Is that ugliness all in Tcl's use of libtommath, or in libtommath itself ? ---------------------------------------------------------------------- Comment By: Don Porter (dgp) Date: 2009-05-29 17:36 Message: More ugliness: % expr {10**65553 == 10**17} 1 ---------------------------------------------------------------------- Comment By: Don Porter (dgp) Date: 2009-05-29 15:35 Message: Something wrong computing the value of "base" at line 5963? Computation is done in a short int, but what happens when l2 is so big that we're overflowing that? ---------------------------------------------------------------------- Comment By: Don Porter (dgp) Date: 2009-05-29 15:25 Message: Simpler demo: % expr {10**65536} 21936950640377856 Something in the logic that chooses among the many (!!) implementations of exponent computation is borked. ---------------------------------------------------------------------- You can respond by visiting: https://sourceforge.net/tracker/?func=detail&atid=110894&aid=2798543&group_id=10894 |