configure: Remove architecture-specific checks for hardware optimization

This mirrors the CMakeLists.txt improvements in configure.ac and
Makefile.am.

The complex compiler check is removed from Loongarch so that it is done
the same way as everything else along with the curious use of a library
in Makefile.am (never done in CMakeLists.txt)

The hard-disable of the Intel SSE optimizations done in libpng1.6 to
ensure that the configure options did not change mid-version is now
removed so the SSE optimizations are on by default (change already made
in 1.6 CMakeLists.txt but not configure.)

Signed-off-by: John Bowler <jbowler@acm.org>

CMakeLists.txt

@@ -156,23 +156,16 @@ set(libpng_mips_sources
 set(libpng_loongarch_sources
     loongarch/loongarch_lsx_init.c
     loongarch/filter_lsx_intrinsics.c)
-include(CheckCCompilerFlag)
-check_c_compiler_flag("-mlsx" COMPILER_SUPPORTS_LSX)
-if(COMPILER_SUPPORTS_LSX)
-  set_source_files_properties(${libpng_loongarch_sources}
-                              PROPERTIES
-                              COMPILE_FLAGS "-mlsx")
-endif()
 
 else(PNG_HARDWARE_OPTIMIZATIONS)
 
 # Disable opt for all arches
 add_definitions(
-  -DPNG_ARM_NEON_OPT=0
   -DPNG_ARM_NEON_OPT=0
   -DPNG_POWERPC_VSX_OPT=0
   -DPNG_INTEL_SSE_OPT=0
   -DPNG_MIPS_MSA_OPT=0
+  -DPNG_MIPS_MMI_OPT=0
   -DPNG_LOONGARCH_LSX_OPT=0
 )
 

Makefile.am

@@ -104,44 +104,14 @@ lib_LTLIBRARIES=libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@.la
 libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = png.c pngerror.c\
 	pngget.c pngmem.c pngpread.c pngread.c pngrio.c pngrtran.c pngrutil.c\
 	pngset.c pngtrans.c pngwio.c pngwrite.c pngwtran.c pngwutil.c\
-	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa
-
-if PNG_ARM_NEON
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += arm/arm_init.c\
-	arm/filter_neon_intrinsics.c \
-	arm/palette_neon_intrinsics.c
-endif
-
-if PNG_MIPS_MSA
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/mips_init.c\
-	mips/filter_msa_intrinsics.c
-endif
-
-if PNG_MIPS_MMI
-if !PNG_MIPS_MSA
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/mips_init.c
-endif
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += mips/filter_mmi_inline_assembly.c
-endif
-
-if PNG_INTEL_SSE
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += intel/intel_init.c\
-	intel/filter_sse2_intrinsics.c
-endif
-
-if PNG_POWERPC_VSX
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES += powerpc/powerpc_init.c\
-        powerpc/filter_vsx_intrinsics.c
-endif
-
-if PNG_LOONGARCH_LSX
-noinst_LTLIBRARIES= libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_SOURCES = loongarch/loongarch_lsx_init.c\
-	loongarch/filter_lsx_intrinsics.c
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx_la_CFLAGS = -mlsx
-libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_LIBADD = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
-# libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
-endif
+	png.h pngconf.h pngdebug.h pnginfo.h pngpriv.h pngstruct.h pngusr.dfa\
+	arm/arm_init.c arm/filter_neon_intrinsics.c\
+	arm/palette_neon_intrinsics.c\
+	intel/intel_init.c intel/filter_sse2_intrinsics.c\
+	loongarch/loongarch_lsx_init.c loongarch/filter_lsx_intrinsics.c\
+	mips/mips_init.c mips/filter_msa_intrinsics.c\
+	mips/filter_mmi_inline_assembly.c\
+	powerpc/powerpc_init.c powerpc/filter_vsx_intrinsics.c
 
 nodist_libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_SOURCES = pnglibconf.h
 
@@ -163,10 +133,6 @@ else
   libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES = libpng.sym
 endif
 
-if PNG_LOONGARCH_LSX
-  libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@_la_DEPENDENCIES += libpng@PNGLIB_MAJOR@@PNGLIB_MINOR@lsx.la
-endif
-
 #distribute headers in /usr/include/libpng/*
 pkgincludedir= $(includedir)/$(PNGLIB_BASENAME)
 pkginclude_HEADERS= png.h pngconf.h