Enable AVX2

FFTW does runtime detection of CPU features on x86, so this change does
not require AVX2 support to use the libraries, but does allow FFTW to
use the AVX2 code when the CPU supports it.

Signed-off-by: Trent Piepho <tpiepho@gmail.com>

fftw.spec

@@ -13,7 +13,7 @@
 
 Name:           fftw
 Version:        3.3.10
-Release:        5%{?dist}
+Release:        6%{?dist}
 Summary:        A Fast Fourier Transform library
 License:        GPLv2+
 URL:            http://www.fftw.org
@@ -292,7 +292,7 @@ prec_flags[3]=--enable-quad-precision
 %ifarch x86_64
 # Enable SSE2 and AVX support for x86_64
 for ((i=0; i<2; i++)) ; do
-    prec_flags[i]+=" --enable-sse2 --enable-avx"
+    prec_flags[i]+=" --enable-sse2 --enable-avx --enable-avx2"
 done
 %endif
 
@@ -525,6 +525,9 @@ done
 %endif
 
 %changelog
+* Mon Mar 27 2023 Trent Piepho <tpiepho@gmail.com> - 3.3.10-6
+- Enable AVX2 on x86-86
+
 * Thu Mar 02 2023 Orion Poplawski <orion@nwra.com> - 3.3.10-5
 - Use make macros
 - Drop openmpi vader workaround