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8.8.4 Register Naming

Register operands are always prefixes with `%'. The 80386 registers consist of

• the 8 32-bit registers `%eax' (the accumulator), `%ebx', `%ecx', `%edx', `%edi', `%esi', `%ebp' (the frame pointer), and `%esp' (the stack pointer).

• the 8 16-bit low-ends of these: `%ax', `%bx', `%cx', `%dx', `%di', `%si', `%bp', and `%sp'.

• the 8 8-bit registers: `%ah', `%al', `%bh', `%bl', `%ch', `%cl', `%dh', and `%dl' (These are the high-bytes and low-bytes of `%ax', `%bx', `%cx', and `%dx')

• the 6 section registers `%cs' (code section), `%ds' (data section), `%ss' (stack section), `%es', `%fs', and `%gs'.

• the 3 processor control registers `%cr0', `%cr2', and `%cr3'.

• the 6 debug registers `%db0', `%db1', `%db2', `%db3', `%db6', and `%db7'.

• the 2 test registers `%tr6' and `%tr7'.

• the 8 floating point register stack `%st' or equivalently `%st(0)', `%st(1)', `%st(2)', `%st(3)', `%st(4)', `%st(5)', `%st(6)', and `%st(7)'.