As I understand it, -march=native will detect the ISA and extensions to use from cpuid (which include model, family and stepping information). -march=xxx will use a baseline set of extensions and a baseline ISA. There are a lot of possible combinations of extensions, so only the most relevant were chosen (e.g. skylake-avx512 was added to reflect an important extension of some skylakes). -march ...
The generated flags.make in the cmake build directory DOES add my -march=armv8-a+sve switch to the C_FLAGS variable. I believe that cmake is compiling my file correctly, but I was misled by the incorrectly generated compile_commands.json which is done by CMAKE_EXPORT_COMPILE_COMMANDS.
-march: generate instructions for a specific machine type. Defaults to x86-64-v3 on AMD64 and armv8-a on AArch64. Use -march=compatibility for best compatibility, or -march=native for best performance if a native executable is deployed on the same machine or on a machine with the same CPU features. To list all available machine types, use ...
How to set RISC-V -march for zig build Asked 1 year, 1 month ago Modified 1 year, 1 month ago Viewed 290 times
What are the differences and tradeoffs between -march=haswell, -march=core-avx2, and -mavx2 for compiling avx2 intrinsics? I know that -mavx2 is a flag and -march=haswell/core-avx2 are architectures which just translate to a bunch of flags. So -mavx2 is a subset of the other two. But beyond that, how do I choose the right one for my application?
"I want change it to -march=x86-64 in cmake, How to do it? - Find out how exactly PCL adds -march=native flag. If it does that via variable CMAKE_CXX_FLAGS, then you may try to modify that variable (but note about variables scoping rules). If PCL adds the flag to some property, then you may try modify that property. CMake doesn't give you a control over combined compiler flags. You need to ...
-march=foo implies -mtune=foo unless you also specify a different -mtune. This is one reason why using -march is better than just enabling options like -mavx without doing anything about tuning. Caveat: -march=native on a CPU that GCC doesn't specifically recognize will still enable new instruction sets that GCC can detect, but will leave -mtune=generic. Use a new enough GCC that knows about ...