diff options
Diffstat (limited to 'doc/man3/OPENSSL_ia32cap.pod')
| -rw-r--r-- | doc/man3/OPENSSL_ia32cap.pod | 50 |
1 files changed, 11 insertions, 39 deletions
diff --git a/doc/man3/OPENSSL_ia32cap.pod b/doc/man3/OPENSSL_ia32cap.pod index 73c96d70e698..c6c1c0185ad8 100644 --- a/doc/man3/OPENSSL_ia32cap.pod +++ b/doc/man3/OPENSSL_ia32cap.pod @@ -69,10 +69,10 @@ executed on SSE2 capable CPU, but under control of OS that does not enable XMM registers. Historically address of the capability vector copy was exposed to application through OPENSSL_ia32cap_loc(), but not anymore. Now the only way to affect the capability detection is to set -OPENSSL_ia32cap environment variable prior target application start. To -give a specific example, on Intel P4 processor 'env -OPENSSL_ia32cap=0x16980010 apps/openssl', or better yet 'env -OPENSSL_ia32cap=~0x1000000 apps/openssl' would achieve the desired +B<OPENSSL_ia32cap> environment variable prior target application start. To +give a specific example, on Intel P4 processor +C<env OPENSSL_ia32cap=0x16980010 apps/openssl>, or better yet +C<env OPENSSL_ia32cap=~0x1000000 apps/openssl> would achieve the desired effect. Alternatively you can reconfigure the toolkit with no-sse2 option and recompile. @@ -97,6 +97,8 @@ and RORX; =item bit #64+16 denoting availability of AVX512F extension; +=item bit #64+17 denoting availability of AVX512DQ extension; + =item bit #64+18 denoting availability of RDSEED instruction; =item bit #64+19 denoting availability of ADCX and ADOX instructions; @@ -116,50 +118,20 @@ aka AVX512IFMA extension; =back -To control this extended capability word use ':' as delimiter when -setting up OPENSSL_ia32cap environment variable. For example assigning -':~0x20' would disable AVX2 code paths, and ':0' - all post-AVX +To control this extended capability word use C<:> as delimiter when +setting up B<OPENSSL_ia32cap> environment variable. For example assigning +C<:~0x20> would disable AVX2 code paths, and C<:0> - all post-AVX extensions. -It should be noted that whether or not some of the most "fancy" -extension code paths are actually assembled depends on current assembler -version. Base minimum of AES-NI/PCLMULQDQ, SSSE3 and SHA extension code -paths are always assembled. Apart from that, minimum assembler version -requirements are summarized in below table: - - Extension | GNU as | nasm | llvm - ------------+--------+--------+-------- - AVX | 2.19 | 2.09 | 3.0 - AVX2 | 2.22 | 2.10 | 3.1 - ADCX/ADOX | 2.23 | 2.10 | 3.3 - AVX512 | 2.25 | 2.11.8 | see NOTES - AVX512IFMA | 2.26 | 2.11.8 | see NOTES - VAES | 2.30 | 2.13.3 | - -=head1 NOTES - -Even though AVX512 support was implemented in llvm 3.6, compilation of -assembly modules apparently requires explicit -march flag. But then -compiler generates processor-specific code, which in turn contradicts -the mere idea of run-time switch execution facilitated by the variable -in question. Till the limitation is lifted, it's possible to work around -the problem by making build procedure use following script: - - #!/bin/sh - exec clang -no-integrated-as "$@" - -instead of real clang. In which case it doesn't matter which clang -version is used, as it is GNU assembler version that will be checked. - =head1 RETURN VALUES Not available. =head1 COPYRIGHT -Copyright 2004-2020 The OpenSSL Project Authors. All Rights Reserved. +Copyright 2004-2021 The OpenSSL Project Authors. All Rights Reserved. -Licensed under the OpenSSL license (the "License"). You may not use +Licensed under the Apache License 2.0 (the "License"). You may not use this file except in compliance with the License. You can obtain a copy in the file LICENSE in the source distribution or at L<https://www.openssl.org/source/license.html>. |