diff options
author | Andy Polyakov <appro@openssl.org> | 2016-11-25 17:50:37 +0100 |
---|---|---|
committer | Andy Polyakov <appro@openssl.org> | 2016-11-26 22:24:10 +0100 |
commit | c477f8e7165d30c5c8ca98f7409714f56dc2048c (patch) | |
tree | c4eed4fdf69f6bacafe8c099e94309247f701ec6 | |
parent | f47201b3279b3fd16f90ba512e5b203e4944b30c (diff) |
INSTALL: clarify 386 and no-sse2 options.
This is 1.0.2-specific reformat of 5ae5dc96610f0a598dac9d2f267b5c0ddd77b2e4.
Reviewed-by: Rich Salz <rsalz@openssl.org>
-rwxr-xr-x | Configure | 5 | ||||
-rw-r--r-- | INSTALL | 45 |
2 files changed, 29 insertions, 21 deletions
@@ -58,12 +58,13 @@ my $usage="Usage: Configure [no-<cipher> ...] [enable-<cipher> ...] [experimenta # zlib-dynamic Like "zlib", but the zlib library is expected to be a shared # library and will be loaded in run-time by the OpenSSL library. # sctp include SCTP support -# 386 generate 80386 code # enable-weak-ssl-ciphers # Enable EXPORT and LOW SSLv3 ciphers that are disabled by # default. Note, weak SSLv2 ciphers are unconditionally # disabled. -# no-sse2 disables IA-32 SSE2 code, above option implies no-sse2 +# 386 generate 80386 code in assembly modules +# no-sse2 disables IA-32 SSE2 code in assembly modules, the above +# mentioned '386' option implies this one # no-<cipher> build without specified algorithm (rsa, idea, rc5, ...) # -<xxx> +<xxx> compiler options are passed through # @@ -74,24 +74,26 @@ no-asm Do not use assembler code. - 386 Use the 80386 instruction set only (the default x86 code is - more efficient, but requires at least a 486). Note: Use - compiler flags for any other CPU specific configuration, - e.g. "-m32" to build x86 code on an x64 system. - - no-sse2 Exclude SSE2 code pathes. Normally SSE2 extention is - detected at run-time, but the decision whether or not the - machine code will be executed is taken solely on CPU - capability vector. This means that if you happen to run OS - kernel which does not support SSE2 extension on Intel P4 - processor, then your application might be exposed to - "illegal instruction" exception. There might be a way - to enable support in kernel, e.g. FreeBSD kernel can be - compiled with CPU_ENABLE_SSE, and there is a way to - disengage SSE2 code pathes upon application start-up, - but if you aim for wider "audience" running such kernel, - consider no-sse2. Both 386 and no-asm options above imply - no-sse2. + 386 In 32-bit x86 builds, when generating assembly modules, + use the 80386 instruction set only (the default x86 code + is more efficient, but requires at least a 486). Note: + This doesn't affect code generated by compiler, you're + likely to complement configuration command line with + suitable compiler-specific option. + + no-sse2 Exclude SSE2 code paths from 32-bit x86 assembly modules. + Normally SSE2 extension is detected at run-time, but the + decision whether or not the machine code will be executed + is taken solely on CPU capability vector. This means that + if you happen to run OS kernel which does not support SSE2 + extension on Intel P4 processor, then your application + might be exposed to "illegal instruction" exception. + There might be a way to enable support in kernel, e.g. + FreeBSD kernel can be compiled with CPU_ENABLE_SSE, and + there is a way to disengage SSE2 code paths upon application + start-up, but if you aim for wider "audience" running + such kernel, consider no-sse2. Both the 386 and + no-asm options imply no-sse2. no-<cipher> Build without the specified cipher (bf, cast, des, dh, dsa, hmac, md2, md5, mdc2, rc2, rc4, rc5, rsa, sha). @@ -101,7 +103,12 @@ -Dxxx, -lxxx, -Lxxx, -fxxx, -mXXX, -Kxxx These system specific options will be passed through to the compiler to allow you to define preprocessor symbols, specify additional libraries, - library directories or other compiler options. + library directories or other compiler options. It might be + worth noting that some compilers generate code specifically + for processor the compiler currently executes on. This is + not necessarily what you might have in mind, since it might + be unsuitable for execution on other, typically older, + processor. Consult your compiler documentation. -DHAVE_CRYPTODEV Enable the BSD cryptodev engine even if we are not using BSD. Useful if you are running ocf-linux or something |