diff --git a/scripts/makefile.clang b/scripts/makefile.clang
index fe0544a..2e15423 100644
--- a/scripts/makefile.clang
+++ b/scripts/makefile.clang
@@ -19,10 +19,14 @@
 CP = cp
 RM_F = rm -f
 
+# Compiler and linker flags
+NOHWOPT = -DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
+	-DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
 WARNMORE = -Wwrite-strings -Wpointer-arith -Wshadow \
 	-Wmissing-declarations -Wtraditional -Wcast-align \
 	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
-CPPFLAGS = -I$(ZLIBINC) # -DPNG_DEBUG=5
+DEFS = $(NOHWOPT)
+CPPFLAGS = -I$(ZLIBINC) $(DEFS) # -DPNG_DEBUG=5
 CFLAGS = -O2 -Wall -Wextra -Wundef # $(WARNMORE) -g
 LDFLAGS = -L$(ZLIBLIB) # -g
 LIBS = -lz -lm
diff --git a/scripts/makefile.darwin b/scripts/makefile.darwin
index 9cc0381..e41a3e6 100644
--- a/scripts/makefile.darwin
+++ b/scripts/makefile.darwin
@@ -12,6 +12,7 @@
 
 # where "make install" puts libpng.a, libpng16.dylib, png.h, pngconf.h,
 # and pnglibconf.h
+
 prefix=/usr/local
 exec_prefix=$(prefix)
 
@@ -39,7 +40,10 @@
 CP=cp
 RM_F=rm -f
 
-CPPFLAGS=-I$(ZLIBINC)
+NOHWOPT=-DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
+        -DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
+DEFS=$(NOHWOPT)
+CPPFLAGS=-I$(ZLIBINC) $(DEFS)
 CFLAGS=-O3 -funroll-loops -Wall -Wextra -Wundef
 LDFLAGS=-L. -L$(ZLIBLIB) -lpng16 -lz
 
diff --git a/scripts/makefile.gcc b/scripts/makefile.gcc
index e2ea897..b215a70 100644
--- a/scripts/makefile.gcc
+++ b/scripts/makefile.gcc
@@ -19,10 +19,14 @@
 CP = cp
 RM_F = rm -f
 
+# Compiler and linker flags
+NOHWOPT = -DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
+	-DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
 WARNMORE = -Wwrite-strings -Wpointer-arith -Wshadow \
 	-Wmissing-declarations -Wtraditional -Wcast-align \
 	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
-CPPFLAGS = -I$(ZLIBINC) # -DPNG_DEBUG=5
+DEFS = $(NOHWOPT)
+CPPFLAGS = -I$(ZLIBINC) $(DEFS) # -DPNG_DEBUG=5
 CFLAGS = -O2 -Wall -Wextra -Wundef # $(WARNMORE) -g
 LDFLAGS = -L$(ZLIBLIB) # -g
 LIBS = -lz -lm
diff --git a/scripts/makefile.linux b/scripts/makefile.linux
index 7b1b9b0..beffbbb 100644
--- a/scripts/makefile.linux
+++ b/scripts/makefile.linux
@@ -40,11 +40,14 @@
 ZLIBLIB=../zlib
 ZLIBINC=../zlib
 
+# Compiler and linker flags
+NOHWOPT=-DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
+	-DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
 WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
 	-Wmissing-declarations -Wtraditional -Wcast-align \
 	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
-
-CPPFLAGS=-I$(ZLIBINC) # -DPNG_DEBUG=5
+DEFS=$(NOHWOPT)
+CPPFLAGS=-I$(ZLIBINC) $(DEFS) # -DPNG_DEBUG=5
 CFLAGS=-O3 -funroll-loops -Wall -Wextra -Wundef # $(WARNMORE) -g
 LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng16 -lz -lm # -g
 LDFLAGS_A=-L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) libpng.a -lz -lm # -g
diff --git a/scripts/makefile.linux-opt b/scripts/makefile.linux-opt
deleted file mode 100644
index 52874c9..0000000
--- a/scripts/makefile.linux-opt
+++ /dev/null
@@ -1,256 +0,0 @@
-# makefile for libpng.a and libpng16.so on Linux ELF with gcc
-# Copyright (C) 2020-2022 Cosmin Truta
-# Copyright (C) 1998, 1999, 2002, 2006, 2008, 2010-2014, 2017 Greg Roelofs and
-# Glenn Randers-Pehrson
-# Copyright (C) 1996, 1997 Andreas Dilger
-#
-# This code is released under the libpng license.
-# For conditions of distribution and use, see the disclaimer
-# and license in png.h
-
-# Library name:
-LIBNAME = libpng16
-PNGMAJ = 16
-RELEASE = 37
-
-# Shared library names:
-LIBSO=$(LIBNAME).so
-LIBSOMAJ=$(LIBNAME).so.$(PNGMAJ)
-LIBSOREL=$(LIBSOMAJ).$(RELEASE)
-OLDSO=libpng.so
-
-# Utilities:
-CC=gcc
-AR_RC=ar rc
-RANLIB=ranlib
-MKDIR_P=mkdir -p
-LN_SF=ln -sf
-CP=cp
-RM_F=rm -f
-
-# where "make install" puts libpng16.a, libpng16.so*,
-# libpng16/png.h, libpng16/pngconf.h, and libpng16/pnglibconf.h
-# Prefix must be a full pathname.
-prefix=/usr/local
-exec_prefix=$(prefix)
-
-# Where the zlib library and include files are located.
-#ZLIBLIB=/usr/local/lib
-#ZLIBINC=/usr/local/include
-ZLIBLIB=../zlib
-ZLIBINC=../zlib
-
-WARNMORE=-Wwrite-strings -Wpointer-arith -Wshadow \
-	-Wmissing-declarations -Wtraditional -Wcast-align \
-	-Wstrict-prototypes -Wmissing-prototypes # -Wconversion
-
-CPPFLAGS=-I$(ZLIBINC)
-CPPFLAGS += -DPNG_ARM_NEON
-CPPFLAGS += -DPNG_MIPS_MSA
-CPPFLAGS += -DPNG_INTEL_SSE
-CPPFLAGS += -DPNG_POWERPC_VSX
-
-CFLAGS=-O3 -funroll-loops -Wall -Wextra -Wundef # $(WARNMORE) -g
-LDFLAGS=-L. -Wl,-rpath,. -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) -lpng16 -lz -lm # -g
-LDFLAGS_A=-L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) libpng.a -lz -lm # -g
-
-INCPATH=$(prefix)/include
-LIBPATH=$(exec_prefix)/lib
-MANPATH=$(prefix)/man
-BINPATH=$(exec_prefix)/bin
-
-# override DESTDIR= on the make install command line to easily support
-# installing into a temporary location.  Example:
-#
-#    make install DESTDIR=/tmp/build/libpng
-#
-# If you're going to install into a temporary location
-# via DESTDIR, $(DESTDIR)$(prefix) must already exist before
-# you execute make install.
-DESTDIR=
-
-DB=$(DESTDIR)$(BINPATH)
-DI=$(DESTDIR)$(INCPATH)
-DL=$(DESTDIR)$(LIBPATH)
-DM=$(DESTDIR)$(MANPATH)
-
-# Pre-built configuration
-# See scripts/pnglibconf.mak for more options
-PNGLIBCONF_H_PREBUILT = scripts/pnglibconf.h.prebuilt
-
-# File lists
-OBJS = png.o pngerror.o pngget.o pngmem.o pngpread.o \
-       pngread.o pngrio.o pngrtran.o pngrutil.o pngset.o \
-       pngtrans.o pngwio.o pngwrite.o pngwtran.o pngwutil.o \
-       arm/arm_init.o arm/filter_neon_intrinsics.o \
-       intel/intel_init.o intel/filter_sse2_intrinsics.o \
-       mips/mips_init.o mips/filter_msa_intrinsics.o \
-       powerpc/powerpc_init.o powerpc/filter_vsx_intrinsics.o
-
-OBJSDLL = $(OBJS:.o=.pic.o)
-
-.SUFFIXES:      .c .o .pic.o
-
-.c.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -o $@ $<
-
-.c.pic.o:
-	$(CC) -c $(CPPFLAGS) $(CFLAGS) -fPIC -o $@ $*.c
-
-all: libpng.a $(LIBSO) pngtest pngtest-static libpng.pc libpng-config
-
-pnglibconf.h: $(PNGLIBCONF_H_PREBUILT)
-	$(CP) $(PNGLIBCONF_H_PREBUILT) $@
-
-libpng.a: $(OBJS)
-	$(AR_RC) $@ $(OBJS)
-	$(RANLIB) $@
-
-libpng.pc:
-	cat scripts/libpng.pc.in | sed -e s!@prefix@!$(prefix)! \
-	-e s!@exec_prefix@!$(exec_prefix)! \
-	-e s!@libdir@!$(LIBPATH)! \
-	-e s!@includedir@!$(INCPATH)! \
-	-e s!-lpng16!-lpng16\ -lz\ -lm! > libpng.pc
-
-libpng-config:
-	( cat scripts/libpng-config-head.in; \
-	echo prefix=\"$(prefix)\"; \
-	echo I_opts=\"-I$(INCPATH)/$(LIBNAME)\"; \
-	echo L_opts=\"-L$(LIBPATH)\"; \
-	echo R_opts=\"-Wl,-rpath,$(LIBPATH)\"; \
-	echo libs=\"-lpng16 -lz -lm\"; \
-	cat scripts/libpng-config-body.in ) > libpng-config
-	chmod +x libpng-config
-
-$(LIBSO): $(LIBSOMAJ)
-	$(LN_SF) $(LIBSOMAJ) $(LIBSO)
-
-$(LIBSOMAJ): $(OBJSDLL)
-	$(CC) -shared -Wl,-soname,$(LIBSOMAJ) -o $(LIBSOMAJ) $(OBJSDLL)
-
-pngtest: pngtest.o $(LIBSO)
-	$(CC) -o pngtest $(CFLAGS) pngtest.o $(LDFLAGS)
-
-pngtest-static: pngtest.o libpng.a
-	$(CC) -o pngtest-static $(CFLAGS) pngtest.o $(LDFLAGS_A)
-
-test: pngtest pngtest-static
-	@echo ""
-	@echo "   Running pngtest dynamically linked with $(LIBSO):"
-	@echo ""
-	./pngtest
-	@echo ""
-	@echo "   Running pngtest statically linked with libpng.a:"
-	@echo ""
-	./pngtest-static
-
-install-headers: png.h pngconf.h pnglibconf.h
-	-@if [ ! -d $(DI) ]; then $(MKDIR_P) $(DI); fi
-	-@if [ ! -d $(DI)/$(LIBNAME) ]; then $(MKDIR_P) $(DI)/$(LIBNAME); fi
-	cp png.h pngconf.h pnglibconf.h $(DI)/$(LIBNAME)
-	chmod 644 $(DI)/$(LIBNAME)/png.h $(DI)/$(LIBNAME)/pngconf.h $(DI)/$(LIBNAME)/pnglibconf.h
-	-@$(RM_F) $(DI)/png.h $(DI)/pngconf.h $(DI)/pnglibconf.h
-	-@$(RM_F) $(DI)/libpng
-	(cd $(DI); $(LN_SF) $(LIBNAME) libpng; $(LN_SF) $(LIBNAME)/* .)
-
-install-static: install-headers libpng.a
-	-@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
-	cp libpng.a $(DL)/$(LIBNAME).a
-	chmod 644 $(DL)/$(LIBNAME).a
-	-@$(RM_F) $(DL)/libpng.a
-	(cd $(DL); $(LN_SF) $(LIBNAME).a libpng.a)
-
-install-shared: install-headers $(LIBSOMAJ) libpng.pc
-	-@if [ ! -d $(DL) ]; then $(MKDIR_P) $(DL); fi
-	-@$(RM_F) $(DL)/$(LIBSO)
-	-@$(RM_F) $(DL)/$(LIBSOREL)
-	-@$(RM_F) $(DL)/$(OLDSO)
-	cp $(LIBSOMAJ) $(DL)/$(LIBSOREL)
-	chmod 755 $(DL)/$(LIBSOREL)
-	(cd $(DL); \
-	$(LN_SF) $(LIBSOREL) $(LIBSO); \
-	$(LN_SF) $(LIBSO) $(OLDSO))
-	-@if [ ! -d $(DL)/pkgconfig ]; then $(MKDIR_P) $(DL)/pkgconfig; fi
-	-@$(RM_F) $(DL)/pkgconfig/$(LIBNAME).pc
-	-@$(RM_F) $(DL)/pkgconfig/libpng.pc
-	cp libpng.pc $(DL)/pkgconfig/$(LIBNAME).pc
-	chmod 644 $(DL)/pkgconfig/$(LIBNAME).pc
-	(cd $(DL)/pkgconfig; $(LN_SF) $(LIBNAME).pc libpng.pc)
-
-install-man: libpng.3 libpngpf.3 png.5
-	-@if [ ! -d $(DM) ]; then $(MKDIR_P) $(DM); fi
-	-@if [ ! -d $(DM)/man3 ]; then $(MKDIR_P) $(DM)/man3; fi
-	-@$(RM_F) $(DM)/man3/libpng.3
-	-@$(RM_F) $(DM)/man3/libpngpf.3
-	cp libpng.3 $(DM)/man3
-	cp libpngpf.3 $(DM)/man3
-	-@if [ ! -d $(DM)/man5 ]; then $(MKDIR_P) $(DM)/man5; fi
-	-@$(RM_F) $(DM)/man5/png.5
-	cp png.5 $(DM)/man5
-
-install-config: libpng-config
-	-@if [ ! -d $(DB) ]; then $(MKDIR_P) $(DB); fi
-	-@$(RM_F) $(DB)/libpng-config
-	-@$(RM_F) $(DB)/$(LIBNAME)-config
-	cp libpng-config $(DB)/$(LIBNAME)-config
-	chmod 755 $(DB)/$(LIBNAME)-config
-	(cd $(DB); $(LN_SF) $(LIBNAME)-config libpng-config)
-
-install: install-static install-shared install-man install-config
-
-# If you installed in $(DESTDIR), test-installed won't work until you
-# move the library to its final location.  Use test-dd to test it
-# before then.
-
-test-dd:
-	echo
-	echo Testing installed dynamic shared library in $(DL).
-	$(CC) -I$(DI) $(CPPFLAGS) \
-	   `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
-	   -L$(DL) -L$(ZLIBLIB) -Wl, -rpath,$(DL) -Wl,-rpath,$(ZLIBLIB) \
-	   -o pngtestd `$(BINPATH)/$(LIBNAME)-config --ldflags`
-	./pngtestd pngtest.png
-
-test-installed:
-	echo
-	echo Testing installed dynamic shared library.
-	$(CC) $(CPPFLAGS) \
-	   `$(BINPATH)/$(LIBNAME)-config --cflags` pngtest.c \
-	   -L$(ZLIBLIB) -Wl,-rpath,$(ZLIBLIB) \
-	   -o pngtesti `$(BINPATH)/$(LIBNAME)-config --ldflags`
-	./pngtesti pngtest.png
-
-clean:
-	$(RM_F) $(OBJS) $(OBJSDLL) libpng.a
-	$(RM_F) pngtest*.o pngtest pngtesti pngtest-static pngout.png
-	$(RM_F) $(LIBSO) $(LIBSOMAJ)*
-	$(RM_F) libpng.pc pnglibconf.h libpng-config
-
-# DO NOT DELETE THIS LINE -- make depend depends on it.
-
-png.o      png.pic.o:      png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngerror.o pngerror.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngget.o   pngget.pic.o:   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngmem.o   pngmem.pic.o:   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngpread.o pngpread.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngread.o  pngread.pic.o:  png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngrio.o   pngrio.pic.o:   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngrtran.o pngrtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngrutil.o pngrutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngset.o   pngset.pic.o:   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngtrans.o pngtrans.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngwio.o   pngwio.pic.o:   png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngwrite.o pngwrite.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngwtran.o pngwtran.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-pngwutil.o pngwutil.pic.o: png.h pngconf.h pnglibconf.h pngpriv.h pngstruct.h pnginfo.h pngdebug.h
-arm/arm_init.o                  arm/arm_init.o:                      pngpriv.h
-arm/filter_neon_intrinsics.o    arm/filter_neon_intrinsics.pic.o:    pngpriv.h
-intel/intel_init.o              intel/intel_init.pic.o:              pngpriv.h
-intel/filter_sse2_intrinsics.o  intel/filter_sse2_intrinsics.pic.o:  pngpriv.h
-mips/mips_init.o                mips/mips_init.pic.o:                pngpriv.h
-mips/filter_msa_intrinsics.o    mips/filter_msa_intrinsics.pic.o:    pngpriv.h
-powerpc/powerpc_init.o          powerpc/powerpc_init.pic.o:          pngpriv.h
-powerpc/filter_vsx_intrinsics.o powerpc/filter_vsx_intrinsics.pic.o: pngpriv.h
-
-pngtest.o: png.h pngconf.h pnglibconf.h
diff --git a/scripts/makefile.std b/scripts/makefile.std
index a3bb944..ed1105f 100644
--- a/scripts/makefile.std
+++ b/scripts/makefile.std
@@ -40,9 +40,11 @@
 RM_F = rm -f
 AWK = awk
 
+NOHWOPT = -DPNG_ARM_NEON_OPT=0 -DPNG_MIPS_MSA_OPT=0 \
+	-DPNG_POWERPC_VSX_OPT=0 -DPNG_INTEL_SSE_OPT=0
 DFNFLAGS = # DFNFLAGS contains -D options to use in the libpng build
 DFA_EXTRA = # extra files that can be used to control configuration
-CPPFLAGS = -I$(ZLIBINC) # -DPNG_DEBUG=5
+CPPFLAGS = -I$(ZLIBINC) $(NOHWOPT) # -DPNG_DEBUG=5
 CFLAGS = -O # -g
 LDFLAGS = -L$(ZLIBLIB) # -g
 LIBS = -lz -lm