On Sunday 13 March 2011 12:15:07 Jason wrote: > On Friday 11 March 2011 11:46:09 Cactus wrote: > > On Mar 9, 12:35 am, Fredrik Johansson <fredrik.johans...@gmail.com> > > > > wrote: > > > Hi, > > > > > > On my system, valgrind detects an invalid read in mpn_mul when the > > > operands have certain sizes. For example, it happens when both operand > > > lengths are 2601 limbs. I'm attaching a test .c program and valgrind > > > output. > > > > > > I just re-ran "make check" to be sure no MPIR tests were failing. > > > System is an Intel Pentium T4400, 64 bit Ubuntu, and MPIR compile > > > flags included "-O2 -m64 -march=core2 -mtune=core2" > > > > > > Fredrik > > > > > > vlog.txt > > > > > > 5KViewDownload > > > > > > mpnbug.c > > > > > > < 1KViewDownload > > > > Valgrind doesn't run on Windows so I cannot look into these issues. > > > > But I have tried to use nedmalloc - a respected third party memoory > > allocator - with MPIR on Windows and it too reports bad allocations > > somewhere in large multiplies. > > > > Is anyone who works on Linux going to look into this? > > > > Brian > > I'll give it a go , and see what I can come up with > > Jason
The clue is in the "Invalid read of size 8" it's not a bug , it's by design. The core2 code uses SSE for the copyi.asm and if the copy is on an =8 mod 16 byte boundary then it is safe to read 8 bytes before (SSE requires 16 byte alignment) , there is no way to get a segfault as the extra 8 bytes must always be in the same page.To check it just delete the copyi.asm file and the errors go away. I dont really know valgrind , is there a way to set the byte granularity to 16 bytes? Jason -- You received this message because you are subscribed to the Google Groups "mpir-devel" group. To post to this group, send email to mpir-devel@googlegroups.com. To unsubscribe from this group, send email to mpir-devel+unsubscr...@googlegroups.com. For more options, visit this group at http://groups.google.com/group/mpir-devel?hl=en.
