boringssl/include/openssl/cpu.h
Adam Langley 04c36b5062 Never set RC4_CHAR.
RC4_CHAR is a bit in the x86(-64) CPUID information that switches the
RC4 asm code from using an array of 256 uint32_t's to 256 uint8_t's. It
was originally written for the P4, where the uint8_t style was faster.

(On modern chips, setting RC4_CHAR took RC4-MD5 from 458 to 304 MB/s.
Although I wonder whether, on a server with many connections, using less
cache wouldn't be better.)

However, I'm not too worried about a slowdown of RC4 on P4 systems these
days (the last new P4 chip was released nine years ago) and I want the
code to be simplier.

Also, RC4_CHAR was set when the CPUID family was 15, but Intel actually
lists 15 as a special code meaning "also check the extended family
bits", which the asm didn't do.

The RC4_CHAR support remains in the RC4 asm code to avoid drift with
upstream.

Change-Id: If3febc925a83a76f453b9e9f8de5ee43759927c6
Reviewed-on: https://boringssl-review.googlesource.com/3550
Reviewed-by: David Benjamin <davidben@chromium.org>
Reviewed-by: Adam Langley <agl@google.com>
2015-02-20 23:59:59 +00:00

122 lines
5.4 KiB
C

/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*
* This product includes cryptographic software written by Eric Young
* (eay@cryptsoft.com). This product includes software written by Tim
* Hudson (tjh@cryptsoft.com). */
#ifndef OPENSSL_HEADER_CPU_H
#define OPENSSL_HEADER_CPU_H
#include <openssl/base.h>
#if defined(__cplusplus)
extern "C" {
#endif
/* Runtime CPU feature support */
#if defined(OPENSSL_X86) || defined(OPENSSL_X86_64)
/* OPENSSL_ia32cap_P contains the Intel CPUID bits when running on an x86 or
* x86-64 system.
*
* Index 0:
* EDX for CPUID where EAX = 1
* Bit 30 is used to indicate an Intel CPU
* Index 1:
* ECX for CPUID where EAX = 1
* Index 2:
* EBX for CPUID where EAX = 7
*
* Note: the CPUID bits are pre-adjusted for the OSXSAVE bit and the YMM and XMM
* bits in XCR0, so it is not necessary to check those. */
extern uint32_t OPENSSL_ia32cap_P[4];
#endif
#if defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64)
/* CRYPTO_is_NEON_capable returns true if the current CPU has a NEON unit. Note
* that |OPENSSL_armcap_P| also exists and contains the same information in a
* form that's easier for assembly to use. */
OPENSSL_EXPORT char CRYPTO_is_NEON_capable(void);
/* CRYPTO_set_NEON_capable sets the return value of |CRYPTO_is_NEON_capable|.
* By default, unless the code was compiled with |-mfpu=neon|, NEON is assumed
* not to be present. It is not autodetected. Calling this with a zero
* argument also causes |CRYPTO_is_NEON_functional| to return false. */
OPENSSL_EXPORT void CRYPTO_set_NEON_capable(char neon_capable);
/* CRYPTO_is_NEON_functional returns true if the current CPU has a /working/
* NEON unit. Some phones have a NEON unit, but the Poly1305 NEON code causes
* it to fail. See https://code.google.com/p/chromium/issues/detail?id=341598 */
OPENSSL_EXPORT char CRYPTO_is_NEON_functional(void);
/* CRYPTO_set_NEON_functional sets the "NEON functional" flag. For
* |CRYPTO_is_NEON_functional| to return true, both this flag and the NEON flag
* must be true. By default NEON is assumed to be functional if the code was
* compiled with |-mfpu=neon| or if |CRYPTO_set_NEON_capable| has been called
* with a non-zero argument. */
OPENSSL_EXPORT void CRYPTO_set_NEON_functional(char neon_functional);
#endif /* OPENSSL_ARM */
#if defined(__cplusplus)
} /* extern C */
#endif
#endif /* OPENSSL_HEADER_CPU_H */