Change BlockCipher::parallelism() to return the native parallelism of

the implementation rather than the preferred one. Update all
implementations.

Add a new function parallel_bytes() which returns
  parallelism() * BLOCK_SIZE * BUILD_TIME_CONSTANT

This is because i noticed all current calls of parallelism() just
multiplied the result by the block size already, so this simplified
that code.

The build time constant is set to 4, which was the previous default
return value of parallelism(). However the SIMD versions returned
2*native paralellism rather than 4*, so this increases the buffer
sizes used for those algorithms.

The constant multiple lives in buildh.in and build.h, and is named
BOTAN_BLOCK_CIPHER_PAR_MULT.

1 files changed, 1 insertions, 0 deletions

diff --git a/src/build-data/buildh.in b/src/build-data/buildh.in
index 90d274d58..2f5413113 100644
--- a/src/build-data/buildh.in
+++ b/src/build-data/buildh.in
@@ -15,6 +15,7 @@
 /* Chunk sizes */
 #define BOTAN_DEFAULT_BUFFER_SIZE 4096
 #define BOTAN_MEM_POOL_CHUNK_SIZE 64*1024
+#define BOTAN_BLOCK_CIPHER_PAR_MULT 4
 
 /* BigInt toggles */
 #define BOTAN_MP_WORD_BITS %{mp_bits}