3.3. x32

+3.3. x32

+ x32 is a new processor-specific Application Binary Interface (psABI) for x86_64. + An ABI defines the calling conventions between functions in a processing environment. + The interface determines what registers are used and what the sizes are for various C data types. +

+ Some processing environments prefer using 32-bit applications even when running + on Intel 64-bit platforms. + Consider the i386 psABI, which is a very old 32-bit ABI for Intel 64-bit platforms. + The i386 psABI does not provide efficient use and access of the Intel 64-bit processor resources, + leaving the system underutilized. + Now consider the x86_64 psABI. + This ABI is newer and uses 64-bits for data sizes and program pointers. + The extra bits increase the footprint size of the programs, libraries, + and also increases the memory and file system size requirements. + Executing under the x32 psABI enables user programs to utilize CPU and system resources + more efficiently while keeping the memory footprint of the applications low. + Extra bits are used for registers but not for addressing mechanisms. +