Fix #892: use -msse4 rather than -msse4.1 in Makefiles (#991)

There was an inconsistency in the Makefiles versus `tests/BUILD` and
`tests/make.sh`, in that a couple of the Makewfiles used `-msse4.1`
while the BUILD file and `tests/make.sh` used `-msse4`. In addition, it
seems that `-msse4` subsumes `-msse4.1`, and so overall, it appears
better to use `-msse4`.

Fixes #892.

Author: mhucka

pybind_interface/Makefile

@@ -41,7 +41,7 @@ endif
 
 # The flags for the compilation of the simd-specific Pybind11 interfaces
 PYBINDFLAGS_BASIC = $(PYBINDFLAGS)
-PYBINDFLAGS_SSE = -msse4.1 $(PYBINDFLAGS)
+PYBINDFLAGS_SSE = -msse4 $(PYBINDFLAGS)
 PYBINDFLAGS_AVX2 = -mavx2 -mfma $(PYBINDFLAGS)
 PYBINDFLAGS_AVX512 = -mavx512f -mbmi2 $(PYBINDFLAGS)
 

pybind_interface/sse/CMakeLists.txt

@@ -21,7 +21,7 @@ if(WIN32)
     # This prevents a conflict with /RTC1 in DEBUG builds.
     add_compile_options($<$<NOT:$<CONFIG:Debug>>:/O2>)
 else()
-    add_compile_options(-msse4.1 -O3 -flto=auto)
+    add_compile_options(-msse4 -O3 -flto=auto)
 endif()
 
 if(APPLE)

tests/Makefile

@@ -25,7 +25,7 @@ SSE_FILES =
 AVX2_FILES =
 AVX512_FILES =
 ifneq (,$(HAVE_SSE))
-    SSE_FLAGS ?= -msse4.1
+    SSE_FLAGS ?= -msse4
     SSE_FILES := $(wildcard *_sse_test.cc)
 endif
 ifneq (,$(HAVE_AVX2))