Enable strict aliasing for release builds

.github/workflows/linux.yml

@@ -101,7 +101,10 @@ jobs:
           CXX: ccache g++
           LD: gcc
           RANLIB: gcc-ranlib
-          FLAGS: -O3 -flto -ffunction-sections -fdata-sections -DNDEBUG -pipe
+          FLAGS: >-
+            -O3 -fstrict-aliasing -fno-signed-zeros -fno-trapping-math
+            -fassociative-math -mfpmath=sse -msse4.2 -flto -ffunction-sections
+            -fdata-sections -DNDEBUG -pipe
           LINKFLAGS: -Wl,--as-needed
         run: |
           set -x

.github/workflows/macos.yml

@@ -58,7 +58,7 @@ jobs:
     env:
       CC: ccache clang
       CXX: ccache clang++
-      FLAGS: -O3 -DNDEBUG -pipe -march=nehalem
+      FLAGS: -DNDEBUG -O3 -fno-math-errno -fstrict-aliasing -march=nehalem -flto=thin -pipe
     steps:
       - uses: actions/checkout@v1
       - name: Install C++ compiler and libraries