From ffc5c11555d506d6ad70c95eda1862f388b03062 Mon Sep 17 00:00:00 2001 From: Jeffrey Walton Date: Tue, 28 Jul 2015 20:36:22 -0400 Subject: [PATCH] Improved comment on xorbuff and GCC's selection of vmovdqa --- misc.cpp | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/misc.cpp b/misc.cpp index ca6f465f..e3bbfd93 100644 --- a/misc.cpp +++ b/misc.cpp @@ -16,8 +16,9 @@ NAMESPACE_BEGIN(CryptoPP) -// Vectorization at -O3 requires IsStrictAligned for GCC 4.8 and above with xorbuf and VerifyBufsEqual. -// Problems have not been experienced for the word32 variant, but it may aoccur in the future. +// Vectorization at -O3 requires IsStrictAligned for GCC 4.8 and above with xorbuf +// and VerifyBufsEqual. With vectorization, GCC generates a `vmovdqa` instruction. The +// instruction is sensitive to unaligned data due to XMM register use. void xorbuf(byte *buf, const byte *mask, size_t count) {