20091029, 23:09  #1 
Apr 2003
772_{10} Posts 
runtime error when using redc
I have a problem when I use ecm under windows (both win32 and win64 Bit version).
I have started ecm with the following commandline: ecm.exe v pp1 5000 <test.txt >>out.txt test.txt contains only the following line: 168451*2^6730668+1 The output at the time of the crash is: GMPECM 6.2.3 [powered by GMP 4.2.1_MPIR_1.1.1] [P+1] Input number is 168451*2^6730668+1 (2026139 digits) Using REDC Using B1=5000, B2=287928, polynomial x^1, x0=982738599 P = 525, l = 512, s_1 = 240, k = s_2 = 1, m_1 = 3 When I run ecm with the following line everything runs without a problem: >ecm.exe v pp1 mpzmod 5000 <test.txt Is there a known problem with the "redc" code or what did I do wrong? 
20091030, 05:27  #2 
Apr 2003
2^{2}×193 Posts 
Correction: mpzmod did not work also. Output here is:
GMPECM 6.2.2 [configured with GMP 4.2.1 and enableasmredc] [P+1] Input number is 79817*2^1191+1 (364 digits) Using B1=5000, B2=287928, polynomial x^1, x0=158395725 Step 1 took 46ms Step 2 took 78ms Input number is 168451*2^6730668+1 (2026139 digits) Using B1=5000, B2=287928, polynomial x^1, x0=1798276254 Step 1 took 5574695ms Could not initialise ntt_context, presumably out of memory Please report internal errors at <ecmdiscuss@lists.gforge.inria.fr>. 
20091030, 10:00  #3 
Just call me Henry
"David"
Sep 2007
Liverpool (GMT/BST)
3·5·397 Posts 
the problem is your number:)
it is way too large 
20091030, 11:18  #4 
Apr 2003
1404_{8} Posts 
This is a little bit unexpected as ecm and p1 also crash and they work with prime95 without any problems.

20091030, 12:01  #5  
Just call me Henry
"David"
Sep 2007
Liverpool (GMT/BST)
3×5×397 Posts 
Quote:
gmpecm isnt designed for more than a few hundred(it will do several thousand digits slowly) 

20091030, 13:09  #6 
Apr 2003
2^{2}×193 Posts 
Thanks for the info. I knew that ecm uses its own implementation but I thought till now that both implementations would be able to handle numbers of the same size.

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