From cf118c014683069b5dbe91898acdc40f2f0a1f5d Mon Sep 17 00:00:00 2001 From: Lasse Collin Date: Mon, 31 Oct 2022 16:26:05 +0200 Subject: [PATCH] Build: Clarify comment in configure.ac about SSE2. --- configure.ac | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) diff --git a/configure.ac b/configure.ac index 11b25cd6..20da4a82 100644 --- a/configure.ac +++ b/configure.ac @@ -820,7 +820,10 @@ if test "x$enable_external_sha256$sha256_func_found" = xyesno; then AC_MSG_ERROR([--enable-external-sha256 was specified but no supported external SHA-256 implementation was found]) fi -# Check for SSE2 intrinsics. +# Check for SSE2 intrinsics. There is no run-time detection for SSE2 so if +# compiler options enable SSE2 then SSE2 support is required by the binaries. +# The compile-time check for SSE2 is done with #ifdefs because some compilers +# (ICC, MSVC) allow SSE2 intrinsics even when SSE2 isn't enabled. AC_CHECK_DECL([_mm_movemask_epi8], [AC_DEFINE([HAVE__MM_MOVEMASK_EPI8], [1], [Define to 1 if _mm_movemask_epi8 is available.])],