OPENSSL_ia32cap(3) OpenSSL OPENSSL_ia32cap(3)NAME
OPENSSL_ia32cap - finding the IA-32 processor capabilities
LIBRARY
libcrypto, -lcrypto
SYNOPSIS
unsigned long *OPENSSL_ia32cap_loc(void);
#define OPENSSL_ia32cap (*(OPENSSL_ia32cap_loc()))
DESCRIPTION
Value returned by OPENSSL_ia32cap_loc() is address of a variable containing IA-32 processor capabilities bit vector as it appears in EDX
register after executing CPUID instruction with EAX=1 input value (see Intel Application Note #241618). Naturally it's meaningful on
IA-32[E] platforms only. The variable is normally set up automatically upon toolkit initialization, but can be manipulated afterwards to
modify crypto library behaviour. For the moment of this writing six bits are significant, namely:
1. bit #28 denoting Hyperthreading, which is used to distiguish
cores with shared cache; 2. bit #26 denoting SSE2 support; 3. bit #25 denoting SSE support; 4. bit #23 denoting MMX support; 5. bit #20,
reserved by Intel, is used to choose between RC4 code
pathes; 6. bit #4 denoting presence of Time-Stamp Counter.
For example, clearing bit #26 at run-time disables high-performance SSE2 code present in the crypto library. You might have to do this if
target OpenSSL application is executed on SSE2 capable CPU, but under control of OS which does not support SSE2 extentions. Even though you
can manipulate the value programmatically, you most likely will find it more appropriate to set up an environment variable with the same
name prior starting target application, e.g. on Intel P4 processor 'env OPENSSL_ia32cap=0x12900010 apps/openssl', to achieve same effect
without modifying the application source code. Alternatively you can reconfigure the toolkit with no-sse2 option and recompile.
1.0.1i 2011-06-05 OPENSSL_ia32cap(3)
Check Out this Related Man Page
cpu_capabilities(3alleg4) Allegro manual cpu_capabilities(3alleg4)NAME
cpu_capabilities - Contains the capability flags of the CPU. Allegro game programming library.
SYNOPSIS
#include <allegro.h>
extern int cpu_capabilities;
DESCRIPTION
Contains CPU flags indicating what features are available on the current CPU. The flags can be any combination of these:
CPU_ID - Indicates that the "cpuid" instruction is
available. If this is set, then all Allegro CPU
variables are 100% reliable, otherwise there
may be some mistakes.
CPU_FPU - An FPU is available.
CPU_IA64 - Running on Intel 64 bit CPU
CPU_AMD64 - Running on AMD 64 bit CPU
CPU_MMX - Intel MMX instruction set is available.
CPU_MMXPLUS - Intel MMX+ instruction set is available.
CPU_SSE - Intel SSE instruction set is available.
CPU_SSE2 - Intel SSE2 instruction set is available.
CPU_SSE3 - Intel SSE3 instruction set is available.
CPU_3DNOW - AMD 3DNow! instruction set is available.
CPU_ENH3DNOW - AMD Enhanced 3DNow! instruction set is
available.
CPU_CMOV - Pentium Pro "cmov" instruction is available.
You can check for multiple features by OR-ing the flags together. For example, to check if the CPU has an FPU and MMX instructions avail-
able, you'd do:
if ((cpu_capabilities & (CPU_FPU | CPU_MMX)) ==
(CPU_FPU | CPU_MMX)) {
printf("CPU has both an FPU and MMX instructions!
");
}
You can read this variable after you have called check_cpu() (which is automatically called by allegro_init()).
SEE ALSO check_cpu(3alleg4), cpu_vendor(3alleg4), cpu_family(3alleg4), cpu_model(3alleg4), cpu_capabilities(3alleg4), allegro_init(3alleg4)Allegro version 4.4.2 cpu_capabilities(3alleg4)
hi,
I have got a simple doubt,
How to find whether i am working on 32 bit hp-ux or 64 bit hp-ux? is their any system call by which i can print it in my 'c ' code.
Thanx in advance. (2 Replies)
Hello
I created an application in c language for HP-UX operative system,and it runs on a 32 bits PARISC processor. My problem is that I have to run this same application but now in a 64 bits Parisc processor. But I am not able to compile the application with the 64 bit server, and I only could use... (1 Reply)
I have a C application which is to be supported on AIX, Solaris and HPUX.
There are chunks of code which need to #ifdef'd for 64 bit OS's only, i.e., I need these code to be executed only for 64 bit OS's on all the three platforms.
Can someone guide me how to do this. I tried using #ifdef _LP64... (0 Replies)
i read that an application can remain as a 32-bit applicarion and still run on a 64-bit operating system without any code changes.
But some documents also suggest that during porting 32 bit applications need to have code changes especially pointers and int and long and that they should be... (2 Replies)