diff options
Diffstat (limited to 'crypto/openssl/doc/crypto/OPENSSL_ia32cap.pod')
| -rw-r--r-- | crypto/openssl/doc/crypto/OPENSSL_ia32cap.pod | 35 |
1 files changed, 0 insertions, 35 deletions
diff --git a/crypto/openssl/doc/crypto/OPENSSL_ia32cap.pod b/crypto/openssl/doc/crypto/OPENSSL_ia32cap.pod deleted file mode 100644 index 121a8ddee5e1..000000000000 --- a/crypto/openssl/doc/crypto/OPENSSL_ia32cap.pod +++ /dev/null @@ -1,35 +0,0 @@ -=pod - -=head1 NAME - -OPENSSL_ia32cap - finding the IA-32 processor capabilities - -=head1 SYNOPSIS - - unsigned long *OPENSSL_ia32cap_loc(void); - #define OPENSSL_ia32cap (*(OPENSSL_ia32cap_loc())) - -=head1 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 three bits are -significant, namely bit #28 denoting Hyperthreading, which is used to -distinguish Intel P4 core, bit #26 denoting SSE2 support, and bit #4 -denoting presence of Time-Stamp Counter. Clearing bit #26 at run-time -for example 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. 'env OPENSSL_ia32cap=0x10 apps/openssl', to achieve -same effect without modifying the application source code. -Alternatively you can reconfigure the toolkit with no-sse2 option and -recompile. - -=cut |