6 integer arithmetic operations the load effective

Info iconThis preview shows page 1. Sign up to view the full content.

View Full Document Right Arrow Icon
This is the end of the preview. Sign up to access the rest of the document.

Unformatted text preview: a single-character suffix denoting the size of the operand. For example, the mov (move data) instruction has 3 variants: movb (move byte), movw (move word), and movl (move double word). The suffix ‘l’ is used for double words, since on many machines 32-bit quantities are referred to as “long words,” a holdover from an era when 16-bit word sizes were standard. Note that GAS uses the suffix ‘l’ to denote both a 4-byte integer as well as an 8-byte double-precision floating-point number. This causes no ambiguity, since floating point involves an entirely different set of instructions and registers. 3.4 Accessing Information An IA32 central processing unit (CPU) contains a set of eight registers storing 32-bit values. These registers are used to store integer data as well as pointers. Figure 3.2 diagrams the eight registers. Their names all begin with %e, but otherwise they have peculiar names. With the original 8086, the registers were 16-bits and each had a specific purpose. The n...
View Full Document

Ask a homework question - tutors are online