x86[_64]cpuid.pl: handle new extensions.

[openssl.git] / doc / crypto / OPENSSL_ia32cap.pod

diff --git a/doc/crypto/OPENSSL_ia32cap.pod b/doc/crypto/OPENSSL_ia32cap.pod
index dca2e20aced6af9b526b7eb1eefb7abd9af84251..af6b4f3a4d1d87fa4a16ef76c84c4cd8abb0b8e9 100644 (file)
--- a/doc/crypto/OPENSSL_ia32cap.pod
+++ b/doc/crypto/OPENSSL_ia32cap.pod
@@ -2,7 +2,7 @@
 
 =head1 NAME
 
-OPENSSL_ia32cap - finding the IA-32 processor capabilities
+OPENSSL_ia32cap - the IA-32 processor capabilities vector
 
 =head1 SYNOPSIS
 
@@ -18,30 +18,52 @@ input value (see Intel Application Note #241618). Naturally it's
 meaningful on x86 and x86_64 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 seven bits are significant, namely:
-
-1. bit #4 denoting presence of Time-Stamp Counter.
-2. bit #20, reserved by Intel, is used to choose among RC4 code
-   paths;
-3. bit #23 denoting MMX support;
-4. bit #25 denoting SSE support;
-5. bit #26 denoting SSE2 support;
-6. bit #28 denoting Hyperthreading, which is used to distiguish
-   cores with shared cache;
-7. bit #30, reserved by Intel, is used to choose among RC4 code
-   paths;
-8. bit #57 denoting Intel AES instruction set extension;
+moment of this writing following bits are significant:
+
+=item bit #4 denoting presence of Time-Stamp Counter.
+
+=item bit #19 denoting availability of CLFLUSH instruction;
+
+=item bit #20, reserved by Intel, is used to choose among RC4 code paths;
+
+=item bit #23 denoting MMX support;
+
+=item bit #24, FXSR bit, denoting availability of XMM registers;
+
+=item bit #25 denoting SSE support;
+
+=item bit #26 denoting SSE2 support;
+
+=item bit #28 denoting Hyperthreading, which is used to distiguish
+      cores with shared cache;
+
+=item bit #30, reserved by Intel, is used to choose among RC4 code
+      paths;
+
+=item bit #33 denoting availability of PCLMULQDQ instruction;
+
+=item bit #41 denoting SSSE3, Supplemental SSE3, support;
+
+=item bit #43 denoting AMD XOP support (forced to zero on Intel);
+
+=item bit #57 denoting AES-NI instruction set extension;
+
+=item bit #59, OSXSAVE bit, denoting availability of YMM registers;
+
+=item bit #60 denoting AVX extension;
 
 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.
+SSE2 code present in the crypto library, while clearing bit #24
+disables SSE2 code operating on 128-bit XMM register bank. You might
+have to do the latter if target OpenSSL application is executed on SSE2
+capable CPU, but under control of OS that does not enable XMM
+registers. 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=0x16980010 apps/openssl', to
+achieve same effect without modifying the application source code.
+Alternatively you can reconfigure the toolkit with no-sse2 option and
+recompile.
 
 Less intuituve is clearing bit #28. The truth is that it's not copied
 from CPUID output verbatim, but is adjusted to reflect whether or not
@@ -49,4 +71,3 @@ the data cache is actually shared between logical cores. This in turn
 affects the decision on whether or not expensive countermeasures
 against cache-timing attacks are applied, most notably in AES assembler
 module.
-=cut