diff --git a/CMakeLists.txt b/CMakeLists.txt
index ca593f2bb0..775ad9f891 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -333,32 +333,32 @@ endif()
 # single architecture work on macOS at least.
 #
 # Don't set CMAKE_OSX_ARCHITECTURES to more than a single value for now.
-if(APPLE)
+if(APPLE AND (NOT CMAKE_OSX_ARCHITECTURES STREQUAL ""))
 	set(CMAKE_SYSTEM_PROCESSOR "${CMAKE_OSX_ARCHITECTURES}")
 endif()
 
-if("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "(aarch64|arm64)")
+if("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "(aarch64|arm64|ARM64)")
 	set(HOST_AARCH64 true)
 elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "arm")
 	set(HOST_ARM true)
 elseif("${CMAKE_SYSTEM_NAME}" STREQUAL "SunOS" AND "${CMAKE_SYSTEM_PROCESSOR}" STREQUAL "i386")
 	set(HOST_X86_64 true)
-elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "(x86_64|amd64)")
+elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "(x86_64|amd64|AMD64)")
 	set(HOST_X86_64 true)
-elseif("${CMAKE_SYSTEM_NAME}" MATCHES "[i?86|x86]")
+elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "(i[3-6]?86|[xX]86)")
 	set(ENABLE_ASM false)
 	set(HOST_I386 true)
-elseif("${CMAKE_SYSTEM_NAME}" MATCHES "mips64")
+elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "mips64")
 	set(HOST_MIPS64 true)
-elseif("${CMAKE_SYSTEM_NAME}" MATCHES "mips")
+elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "mips")
 	set(HOST_MIPS true)
-elseif("${CMAKE_SYSTEM_NAME}" MATCHES "powerpc")
+elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "powerpc")
 	set(HOST_POWERPC true)
-elseif("${CMAKE_SYSTEM_NAME}" MATCHES "ppc64")
+elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "ppc64")
 	set(HOST_PPC64 true)
-elseif("${CMAKE_SYSTEM_NAME}" MATCHES "riscv64")
+elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "riscv64")
 	set(HOST_RISCV64 true)
-elseif("${CMAKE_SYSTEM_NAME}" MATCHES "sparc64")
+elseif("${CMAKE_SYSTEM_PROCESSOR}" MATCHES "sparc64")
 	set(HOST_SPARC64 true)
 else()
 	set(ENABLE_ASM false)