Does the Intel IA-32 processor with Intel®64 have more registers than IA-32 processors without Intel®64?
Yes, Intel’s IA-32 processors with Intel®64 have 16 General Purpose Registers (GPRs) and 16 XMM registers. The GPRs and XMM registers are 64 bits and 128 bits in width, respectively, in processors with Intel®64. The additional registers are only used by applications running in 64-bit mode. IA-32 processors without Intel®64 have 8 GPRs and 8 XMM registers. The GPRs and XMM registers are 32 bits and 128 bits in width, respectively, in processors without Intel®64. More details can be found in the Intel 64 and IA-32 Architectures Software Developer’s Manuals.
