Port __ARM_NEON changes also to MadtRex makefiles

Author: Qubitol

epochX/cudacpp/CODEGEN/PLUGIN/CUDACPP_SA_OUTPUT/MadtRex/makefiles/cudacpp_driver.mk

@@ -415,6 +415,7 @@ CXXFLAGS += $(OMPFLAGS)
 
 # Set the build flags appropriate to each BACKEND choice (example: "make BACKEND=cppnone")
 # [NB MGONGPU_PVW512 is needed because "-mprefer-vector-width=256" is not exposed in a macro]
+# [Use 'g++ <buildflags> -E -dM - < /dev/null' to check which #define's are enabled]
 # [See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96476]
 ifeq ($(UNAME_P),ppc64le)
   ifeq ($(BACKEND),cppsse4)
@@ -426,21 +427,23 @@ ifeq ($(UNAME_P),ppc64le)
   else ifeq ($(BACKEND),cpp512z)
     $(error Invalid SIMD BACKEND='$(BACKEND)': only 'cppnone' and 'cppsse4' are supported on PowerPC for the moment)
   endif
-else ifeq ($(UNAME_P),arm)
-  ifeq ($(BACKEND),cppsse4)
-    override AVXFLAGS = -D__ARM_NEON__ # ARM NEON with 128 width (Q/quadword registers)
+else ifeq ($(UNAME_P),arm) # ARM on Apple silicon
+  ifeq ($(BACKEND),cppnone) # this internally undefines __ARM_NEON
+    override AVXFLAGS = -DMGONGPU_NOARMNEON
+  else ifeq ($(BACKEND),cppsse4) # __ARM_NEON is always defined on Apple silicon
+    override AVXFLAGS =
   else ifeq ($(BACKEND),cppavx2)
     $(error Invalid SIMD BACKEND='$(BACKEND)': only 'cppnone' and 'cppsse4' are supported on ARM for the moment)
   else ifeq ($(BACKEND),cpp512y)
     $(error Invalid SIMD BACKEND='$(BACKEND)': only 'cppnone' and 'cppsse4' are supported on ARM for the moment)
   else ifeq ($(BACKEND),cpp512z)
     $(error Invalid SIMD BACKEND='$(BACKEND)': only 'cppnone' and 'cppsse4' are supported on ARM for the moment)
   endif
-else ifeq ($(UNAME_P),aarch64)
-  ifeq ($(BACKEND),cppnone)
+else ifeq ($(UNAME_P),aarch64) # ARM on Linux
+  ifeq ($(BACKEND),cppnone) # +nosimd ensures __ARM_NEON is absent
     override AVXFLAGS = -march=armv8-a+nosimd
-  else ifeq ($(BACKEND),cppsse4)
-    override AVXFLAGS = -march=armv8-a+simd -D__ARM_NEON__
+  else ifeq ($(BACKEND),cppsse4) # +simd ensures __ARM_NEON is present (128 width Q/quadword registers)
+    override AVXFLAGS = -march=armv8-a+simd
   else ifeq ($(BACKEND),cppavx2)
     $(error Invalid SIMD BACKEND='$(BACKEND)': only 'cppnone' and 'cppsse4' are supported on aarch64 for the moment)
   else ifeq ($(BACKEND),cpp512y)

epochX/cudacpp/CODEGEN/PLUGIN/CUDACPP_SA_OUTPUT/MadtRex/makefiles/cudacpp_runner.mk

@@ -259,6 +259,7 @@ CXXFLAGS += $(OMPFLAGS)
 
 # Set the build flags appropriate to each BACKEND choice (example: "make BACKEND=cppnone")
 # [NB MGONGPU_PVW512 is needed because "-mprefer-vector-width=256" is not exposed in a macro]
+# [Use 'g++ <buildflags> -E -dM - < /dev/null' to check which #define's are enabled]
 # [See https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96476]
 ifeq ($(UNAME_P),ppc64le)
   ifeq ($(BACKEND),cppsse4)
@@ -270,21 +271,23 @@ ifeq ($(UNAME_P),ppc64le)
   else ifeq ($(BACKEND),cpp512z)
     $(error Invalid SIMD BACKEND='$(BACKEND)': only 'cppnone' and 'cppsse4' are supported on PowerPC for the moment)
   endif
-else ifeq ($(UNAME_P),arm)
-  ifeq ($(BACKEND),cppsse4)
-    override AVXFLAGS = -D__ARM_NEON__ # ARM NEON with 128 width (Q/quadword registers)
+else ifeq ($(UNAME_P),arm) # ARM on Apple silicon
+  ifeq ($(BACKEND),cppnone) # this internally undefines __ARM_NEON
+    override AVXFLAGS = -DMGONGPU_NOARMNEON
+  else ifeq ($(BACKEND),cppsse4) # __ARM_NEON is always defined on Apple silicon
+    override AVXFLAGS =
   else ifeq ($(BACKEND),cppavx2)
     $(error Invalid SIMD BACKEND='$(BACKEND)': only 'cppnone' and 'cppsse4' are supported on ARM for the moment)
   else ifeq ($(BACKEND),cpp512y)
     $(error Invalid SIMD BACKEND='$(BACKEND)': only 'cppnone' and 'cppsse4' are supported on ARM for the moment)
   else ifeq ($(BACKEND),cpp512z)
     $(error Invalid SIMD BACKEND='$(BACKEND)': only 'cppnone' and 'cppsse4' are supported on ARM for the moment)
   endif
-else ifeq ($(UNAME_P),aarch64)
-  ifeq ($(BACKEND),cppnone)
+else ifeq ($(UNAME_P),aarch64) # ARM on Linux
+  ifeq ($(BACKEND),cppnone) # +nosimd ensures __ARM_NEON is absent
     override AVXFLAGS = -march=armv8-a+nosimd
-  else ifeq ($(BACKEND),cppsse4)
-    override AVXFLAGS = -march=armv8-a+simd -D__ARM_NEON__
+  else ifeq ($(BACKEND),cppsse4) # +simd ensures __ARM_NEON is present (128 width Q/quadword registers)
+    override AVXFLAGS = -march=armv8-a+simd
   else ifeq ($(BACKEND),cppavx2)
     $(error Invalid SIMD BACKEND='$(BACKEND)': only 'cppnone' and 'cppsse4' are supported on aarch64 for the moment)
   else ifeq ($(BACKEND),cpp512y)