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| author | Yawning Angel <yawning@schwanenlied.me> | 2015-08-17 18:41:41 +0000 |
|---|---|---|
| committer | Yawning Angel <yawning@schwanenlied.me> | 2015-08-17 18:41:41 +0000 |
| commit | a77616f6056a9dbb5722600ff2465d8ec5b3d063 (patch) | |
| tree | 91e92bb47374ed3a07848cb7a32b8e2332693e31 | |
| parent | 5fe18bcf5459d8801fdeaf01e74571cd36ba47da (diff) | |
| download | tor-a77616f6056a9dbb5722600ff2465d8ec5b3d063.tar.gz tor-a77616f6056a9dbb5722600ff2465d8ec5b3d063.zip | |
Enable ed25519-donna's SSE2 code when possible for 32 bit x86.
This probably requires the user to manually set CFLAGS, but should
result in a net gain on 32 bit x86. Enabling SSE2 support would be
possible on x86_64, but will result in slower performance.
Implements feature #16535.
| -rw-r--r-- | changes/feature16535 | 4 | ||||
| -rw-r--r-- | src/ext/ed25519/donna/README.tor | 4 | ||||
| -rw-r--r-- | src/ext/ed25519/donna/ed25519-donna-portable.h | 10 |
3 files changed, 18 insertions, 0 deletions
diff --git a/changes/feature16535 b/changes/feature16535 new file mode 100644 index 0000000000..3df46b658a --- /dev/null +++ b/changes/feature16535 @@ -0,0 +1,4 @@ + o Minor features (performance) + - Improve the runtime speed of Ed25519 operations and Curve25519 keypair + generation when built targeting 32 bit x86 platforms with SSE2 + available. Implements ticket 16535. diff --git a/src/ext/ed25519/donna/README.tor b/src/ext/ed25519/donna/README.tor index 2bb0efc012..026d180c24 100644 --- a/src/ext/ed25519/donna/README.tor +++ b/src/ext/ed25519/donna/README.tor @@ -40,3 +40,7 @@ as of 8757bd4cd209cb032853ece0ce413f122eef212c. * On non-x86 targets, GCC's Stack Protector dislikes variables that have alignment constraints greater than that of other primitive types. The `ALIGN` macro is thus no-oped for all non-SSE2 builds. + + * On 32 bit x86 targets that the compiler thinks supports SSE2, always + enable SSE2 support by force defining ED25519_SSE2 (x86_64 would also + always support this, but that code path is slower). diff --git a/src/ext/ed25519/donna/ed25519-donna-portable.h b/src/ext/ed25519/donna/ed25519-donna-portable.h index 9ec83b87e3..1cd644c003 100644 --- a/src/ext/ed25519/donna/ed25519-donna-portable.h +++ b/src/ext/ed25519/donna/ed25519-donna-portable.h @@ -158,6 +158,16 @@ static inline void U64TO8_LE(unsigned char *p, const uint64_t v) { #define ALIGN(x) #endif +/* Tor: Force enable SSE2 on 32 bit x86 systems if the compile target + * architecture supports it. This is not done on x86-64 as the non-SSE2 + * code benchmarks better, at least on Haswell. + */ +#if defined(__SSE2__) && !defined(CPU_X86_64) + /* undef in case it's manually specified... */ + #undef ED25519_SSE2 + #define ED25519_SSE2 +#endif + #include <stdlib.h> #include <string.h> |