Do you think it's possible to compile ssh using the Intel compiler? I don't really know where to start and there's not much info on google, so I thought I'd ask the community.
I really want to take advantage of the compression performance improvements. My idea is to set up an unencrypted ssh tunnel (but with maximum compression) as follows:
ssh -N -g -f -C -o CompressionLevel=9 -o Cipher=none eamorr#172.16.1.218 -L 6999:172.16.1.218:3129
Any advice greatly appreciated,
Build instructions for OpenSSH can be found here: http://unixwiz.net/techtips/openssh.html.
When you do the ./configure steps you'll want to do something like ./configure CC=icc CXX=icpc in order to use the ICC compiler rather than gcc.
If you've done it right then when you subsequently do a make you should see during the build that the compile lines will start with icc ... or icpc ... rather than gcc ... or g++ ....
Related
I searched a long time for a way of changing CMake's build directory without cding into it.
I eventually find the -H option and make my scripts with it.
Now I typed in cmake --help and I directly have seen following output:
$ cmake --help
Usage
cmake [options] <path-to-source>
cmake [options] <path-to-existing-build>
cmake [options] -S <path-to-source> -B <path-to-build>
I recently use:
$ cmake --version
cmake version 3.14.0
CMake suite maintained and supported by Kitware (kitware.com/cmake).
and I think in older version this was missing.
Nevertheless, I wonder if there is any difference between -H and -S option. Furthermore I wonder if they are safe to use at all. I found this questions in other posts, but it has not been answered (e.g. here: How to tell CMake where to put build files?)
-H option is not documented and exists long before -S option. It was somewhat considered a "trick" before -S option existed. The -H option purpouse was to make developers life easier, but they left it in release builds, so people started using it. Since cmake 3.13 (I think it's Novemeber 2018) the -S option is available, making -H obsolete (or not? I don't know what the intention of cmake developers is).
Seeing cmake sources the -H and -S option act exactly the same.
I am trying to run qemu with code that my teacher provided so that we are able to work on our assignment.
This is being run in Ubuntu 18.04
LIBPATH=/usr/lib/gcc/arm-none-eabi/6.3.1/
arm-none-eabi-as -mcpu=arm926ej-s -g ts.s -o ts.o
arm-none-eabi-gcc -c -mcpu=arm926ej-s -g t.c -o t.o
arm-none-eabi-ld -T t.ld ts.o t.o -o t.elf
arm-none-eabi-ld -T t.ld -L $LIBPATH ts.o t.o -o t.elf -lgcc #-lstr
arm-none-eabi-objcopy -O binary t.elf t.bin
rm *.o *.elf
echo ready to go?
read dummy
qemu-system-arm -M realview-pbx-a9 -m 128M -kernel t.bin \
-serial mon:stdio -serial /dev/pts/2 -serial /dev/pts/2 -serial /dev/pts/2
And the numbers in the last line `-serial /dev/pts/#' are from running ps in the terminal and grabbing the number. All of this is in an executable file, and when I run the file the qemu screen does display, but when I press enter again I recieve this error message
unknown keycodes `(unnamed)', please report to qemu-devel#nongnu.org
I cannot seem to find any clear answer on how to solve this problem. I have tried uninstalling and reinstalling qemu a couple of time.
QEMU's "unknown keycodes" message is about key handling in its graphics window, and means that the host keyboard mapping you're using has some odd setup that it doesn't entirely understand. Usually this means that a few keys won't work right in the graphics window, and you can ignore it unless you're actually having a problem with them. The whole keycode system was completely rewritten in a newer version of QEMU, and this message doesn't even exist any more.
If your test program isn't expecting to use the graphical screen, then you can definitely ignore the message (indeed you could turn off the graphics screen entirely with -display none).
The command line options to QEMU you're using for the serial port look really odd -- you seem to be trying to connect multiple serial ports to the same host tty, which I'm pretty sure won't work right. Unless you're actually using serial ports 1 through 3, just drop those and use the serial port 0 that is set up with "-serial mon:stdio".
When I compile things with gitbash and gcc, is there someway to shorten what I need to type?
In order to compile my helloworld program, I have to type the following in:
gcc -o helloworld.exe helloworld.m -I C:/GNUstep/GNUstep/System/Library/Headers -L C:/GNUstep/GNUstep/System/Library/Libraries -std=c99 -lobjc -lgnustep-base -fconstant-string-class=NSConstantString
Most people use Makefiles (or something related, e.g. CMake) in order to ease development. Makefiles are similar to bash scripts (the syntax is similar as well). After you created a Makefile you can run make and it does exactly what you specified.
If you want to know how to run Automake on Windows, read this: How to run a makefile in Windows?
My problem is that ocamlc and ocamlopt apear to be refusing to find third party libraries installed through apt-get. I first started having this problem when I tried to incorporate third-party modules into my own OCaml programs, and quickly wrote it off as a personal failing in understanding OCaml compilation. Soon-- however-- I found myself running into the same problem when trying to compile other peoples projects under their own instructions.
Here is the most straight-forward example. The others all use ocamlbuild, which obfuscates things a little bit.
The program: http://groups.google.com/group/fa.caml/msg/5aee553df34548e2
The compilation:
$ocamlc -g -dtypes -pp camlp4oof -I +camlp4 dynlink.cma camlp4lib.cma -cc g++ llvm.cma llvm_bitwriter.cma minml.ml -o minml
File "minml.ml", line 43, characters 0-9:
Error:Unbound module Llvm
Even when I provide ocamlc with the obsolute paths to the llvm files, like so...
$ ocamlc -g -dtypes -pp camlp4oof -I +camlp4 dynlink.cma camlp4lib.cma -cc g++ /usr/lib/ocaml/llvm-2.7/llvm.cma /usr/lib/ocaml/llvm-2.7/llvm_bitwriter.cma minml.ml -o minml
... to no avail.
What am I doing wrong?
Your command is doing two things: it's compiling minml.ml (into minml.cmo), then linking the resulting object into minml.
Compiling a module requires the interfaces of the dependencies. The interfaces contain typing information that is necessary to both the type checker and the code generator; this information is not repeated in the implementation (.cma here). So for the compilation stage, llvm.cmi must be available. The compiler looks for it in the include path, so you need an additional -I +llvm-2.7 (which is short for -I /usr/lib/ocaml/llvm-2.7).
The linking stage requires llvm.cma, which contains the bytecode implementation of the module. Here, you can either use -I or give a full path to let ocamlc know where to find the file.
ocamlc -g -dtypes -I +camlp4 -I +llvm-2.7 -pp camlp4oof -c minml.ml
ocamlc -g -cc g++ -I +camlp4 -I +llvm-2.7 dynlink.cma camlp4lib.cma llvm.cma llvm_bitwriter.cma minml.cmo -o minml
or if you want to do both stages in a single command:
ocamlc -g -dtypes -cc g++ -I +camlp4 -I +llvm-2.7 dynlink.cma camlp4lib.cma llvm.cma llvm_bitwriter.cma -pp camlp4oof minml.ml -o minml
I seem to remember being able to print out (or locate) the specific switches that each -O<num> option turns on. Can you remind?
Thanks!
The list of new features on gcc 4.3 shows a way to do it, via an extension to the --help command line option:
gcc -c -Q -O3 --help=optimizers > /tmp/O3-opts
gcc -c -Q -O2 --help=optimizers > /tmp/O2-opts
diff /tmp/O2-opts /tmp/O3-opts | grep enabled
Note, however that I never tried that, only read about it. The documentation about this command line option is at http://gcc.gnu.org/onlinedocs/gcc/Overall-Options.html#Overall-Options
If you ever read the list of new features on gcc 4.3, perhaps this was what you were recalling.
You may also try the good ol' manual
$ man gcc
at the subsection "Options That Control Optimization".
On many machines, 'info gcc' will produce a wealth of information. Using 'gcc -v --help' produced a very long listing of options from sub-processes (actually, 1001 lines on stdout, and 14 on stderr) on my Mac (PPC G4 and MacOS X 10.4.11).