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lenticularis39
BUG(?) with math code
Hello all,
I'm using the latest snapshot compiled under Mac OS X 10.13 and clang. I am using OpenVMS 8.4.2L1 Everything is ok. I noticed some weird output on the console when I am compiling some math code under C.
SUBL_V 0000000000000000x - 18446744071562067968x = 18446744071562067968x + TRAP
[repeated several times]
The build is ok. So I don't know if this is a real bug or not.
regards, Fausto
If it's possible, could you please post the code you're trying to compile and the steps you take to compile it?
Sorry for being vague, here is more context. I was trying to build the reflisp package (a lisp interpreter). The build seems ok, even if I got those messages on the axpbox console.
I compiled with the default options of CC command, i.e. CC/VERBOSE MATH.C
Just as an example... 9 seconds to calculate 2^300 and print it
$ run lisp
; reading init.lsp
It's nearly a quarter past six .
2241> (load "times.lsp")
t reading times.lsp
2479> (load "bignum.lsp")
t reading bignum.lsp
3037> (time:perf (b-power-of-2 300))
2 to the power 300 is: 2111184054019605320843855217622375819155724851118195321145199981676251345946484577202763776
9
3052>
it seems the math code is quite ok, anyway.
I think that they need AXE tools and QVET tools to diagnose CPU processor and test instructions. QVET tools are available in ftp.hp.com (/pub/alphaserver/... ) I have some same problems as well. When I tried to list BCK files on DKA disk images, I got some CRC errors, etc. but was able list them from same BCK file on CDROM emulation with out any errors. etc..
I suppose this is not a sort of fatal error, maybe there could be some problem with some particular floating-point operation, but I suppose it will be quite difficult to debug. I am not familiar with QVET tool, I am sorry, but this only happens during the building, not at run-time, so I suppose this is also trickier to analyse.
I don't think the CRC errors are related to the CPU behavior - based on the state of most peripherals' code I would rather suspect the bug being there. Also es40 was initially written single-threaded, only later it was rewritten to be multi-threaded, introducing both known bugs and potentially yet unknown bugs into the code.
