#4968: switch Matrix_modn_dense from ints to CPU longs
----------------------------+-----------------------------------------------
Reporter: malb | Owner: was
Type: enhancement | Status: new
Priority: major | Milestone: sage-wishlist
Component: linear algebra | Resolution:
Keywords: |
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Comment (by was):
> How about "long long" across the board?
Won't that have negative implications. For example, on a 32-bit machine
all matrices will take twice as much memory to store, and all arithmetic
will be an order of magnitude slower. That certainly wouldn't make me
happy!
{{{
%cython
def foo(n):
cdef long long i = 10, j = 10093, k
cdef int z
for z in range(n):
k += i*j
return k
///
}}}
{{{
%cython
def bar(n):
cdef int i = 10, j = 10093, k
cdef int z
for z in range(n):
k += i*j
return k
///
}}}
{{{
time foo(10^8)
///
587410688573299048L
CPU time: 0.29 s, Wall time: 0.29 s
}}}
{{{
time bar(10^8)
///
-171048080
CPU time: 0.04 s, Wall time: 0.04 s
}}}
{{{
0.29/0.04
///
7.25000000000000
}}}
--
Ticket URL: <http://trac.sagemath.org/sage_trac/ticket/4968#comment:3>
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