Valgrind is the most commonly used collection of open source tools for analyzing and profiling everything from the cache and heap behavior of an application to memory leaks and potential multithreading issues. It works in tandem with the underlying operating system as, depending on the tool used, it has to intercept everything from memory allocations to instructions related to multithreading and related. This is the reason why it is only fully supported under Linux on 64-bit x86_64 architectures.
Using Valgrind on other supported platforms (Linux on x86, PowerPC, ARM, S390, MIPS, and ARM, also Solaris and macOS) is definitely also an option, but the primary development target of the Valgrind project is x86_64/Linux, making it the best platform to do profiling and debugging on, even if other platforms will be targeted later on.
On the Valgrind website...