VanitySearch is a bitcoin address prefix finder. If you want to generate safe private keys, use the -s option to enter your passphrase which will be used for generating a base key as for BIP38 standard (VanitySeacrh.exe -s "My PassPhrase" 1MyPrefix).
VanitySearch may not compute a good grid size for your GPU, so try different values using -g option in order to get the best performances. If you want to use GPUs and CPUs together, you may have best performances by keeping one CPU core for handling GPU(s)/CPU exchanges (use -t option to set the number of CPU threads).

• Fixed size arithmetic
• Fast Modular Inversion (Delayed Right Shift 62 bits)
• SecpK1 Fast modular multiplication (2 steps folding 512bits to 256bits using 64 bits digits)
• Use some properties of elliptic curve to generate more keys
• SSE Secure Hash Algorithm SHA256 and RIPEMD160 (CPU)
• Multi-GPU support
• CUDA optimisation via inline PTX assembly
• Seed protected by pbkdf2_hmac_sha512 (BIP38)

You can downlad latest release from https://github.com/JeanLucPons/VanitySearch/releases

VanitySeacrh [-check] [-v] [-u] [-gpu] [-stop] [-o outputfile] [-gpuId gpuId] [-g gridSize] [-s seed] [-t threadNumber] prefix
prefix: prefix to search
-v: Print version
-check: Check CPU and GPU kernel vs CPU
-u: Search uncompressed addresses
-o outputfile: Output results to the specified file
-gpu: Enable gpu calculation
-gpu gpuId1,gpuId2,...: List of GPU(s) to use, default is 0
-g gridSize1,gridSize2,...: Specify GPU(s) kernel gridsize, default is 16*(MP number)
-s seed: Specify a seed for the base key, default is random
-t threadNumber: Specify number of CPU thread, default is number of core
-nosse : Disable SSE hash function
-l : List cuda enabled devices
-stop: Stop when prefix is found

Exemple (Windows, Intel Core i7-4770 3.4GHz 8 multithreaded cores, GeForce GTX 645):

C:\C++\VanitySearch\x64\Release>VanitySearch.exe -stop -gpu 1Happy
Start Wed Mar  6 15:29:00 2019
Search: 1Happy
Difficulty: 264104224
Base Key:FED6C568C2E57730BF38D07FD4489C2BE095D2861C00A653492621D2434306B9
Number of CPU thread: 7
GPU: GPU #0 GeForce GTX 645 (3x192 cores) Grid(24x128)
41.641 MK/s (GPU 30.670 MK/s) (2^27.76) [P 57.71%][60.00% in 00:00:00]
Pub Addr: 1HappydNsxC6mueAXMHG6AzBQJWyBaF7QN
Prv Addr: 5KkX6nAeQr8efUWoom3AeSLBGj3wJC6bceeuxiSJM7psXjwbJFh
Prv Key : 0xFED6C568C2E57730BF38D07FD4489C2BE115D286237FA653492621D24343D7CA
Check   : 13QQPP6PaRnDLpQPhAy2YwfWMy8MZ473q9
Check   : 1HappydNsxC6mueAXMHG6AzBQJWyBaF7QN (comp)

Intall CUDA SDK and open VanitySearch.sln in Visual C++ 2017.
You may need to reset your Windows SDK version in project properties.
In Build->Configuration Manager, select the Release configuration.
Build and enjoy.

Note: The current relase has been compiled with CUDA SDK 10.0, if you have a different release of the CUDA SDK, you may need to update CUDA SDK paths in VanitySearch.vcxproj using a text editor. The current nvcc option are set up to architecture starting at 3.0 capability, for older hardware, add the desired compute capabilities to the list in GPUEngine.cu properties, CUDA C/C++, Device, Code Generation.

Intall CUDA SDK.
Depenging on the CUDA SDK version and on your Linux distribution you may need to install an older gcc (just for the CUDA SDK).
Add a link to the good gcc in /usr/local/cuda, nvcc will use this path first.

lrwxrwxrwx 1 root root      16 mars   1 10:54 /usr/local/cuda/bin/g++ -> /usr/bin/g++-4.8*
lrwxrwxrwx 1 root root      16 mars   1 10:53 /usr/local/cuda/bin/gcc -> /usr/bin/gcc-4.8*

Edit the makefile and set up the good compute capabilites for your hardware and CUDA SDK path. You can enter a list of architectrure (refer to nvcc documentation). Here it is set up for compute capability 2.0 (Fermi) which is deprecated for recent CUDA SDK.

-gencode=arch=compute_20,code=sm_20

VanitySearch need to be compiled and linked with a recent gcc. The current release has been compiled with gcc 7.3.0.
Go to the VanitySearch directory.

$ g++ -v
gcc version 7.3.0 (Ubuntu 7.3.0-27ubuntu1~18.04)
$ make all (for build without CUDA support)
or
$ make gpu=1 all

Runnig VanitySearch (Intel(R) Xeon(R) CPU, 8 cores, @ 2.93GHz, Quadro 600 (x2))

$export LD_LIBRARY_PATH=/usr/local/cuda-8.0/lib64
pons@linpons:~/VanitySearch$ ./VanitySearch -stop -t 7 -gpu -gpuId 0,1 1Happy
Start Wed Mar  6 15:26:23 2019
Search: 1Happy
Difficulty: 264104224
Base Key:3840A1BDE4792771D67CBFBCB75F2EF08644CDCB93A20A2F953EA289D5785F42
Number of CPU thread: 7
GPU: GPU #1 Quadro 600 (2x48 cores) Grid(16x128)
GPU: GPU #0 Quadro 600 (2x48 cores) Grid(16x128)
24.621 MK/s (GPU 15.726 MK/s) (2^26.99) [P 39.60%][50.00% in 00:00:02]
Pub Addr: 1HappyE4YFXy9NKv47wLSNNxhQ8pHmmnS4
Prv Addr: 5JF4UXBP9PF68hZGHidd39sWBpVfvvGuUaMJXq5b68JAh97FXiS
Prv Key : 0x3840A1BDE4792771D67CBFBCB75F2EF08644CDCB93A20A33953EA289D6109E5C
Check   : 1CP8uGjwfmHfNuXRbSCfw74445CizNjXcA
Check   : 1HappyE4YFXy9NKv47wLSNNxhQ8pHmmnS4 (comp)

VanitySearch is licensed under GPLv3.