Unformatted text preview: al Arithmetic Operations. These operations provide full 64bit multiplication and division, for both signed and unsigned numbers. The pair of registers %edx and %eax are viewed as forming a single 64bit quad word.
xorl %edx,%edx Explain why this instruction would be there, even though there are no EXCLUSIVE  OR operators in our C code. What operation in the C program does this instruction implement? 3.5.5 Special Arithmetic Operations
Figure 3.8 describes instructions that support generating the full 64bit product of two 32bit numbers, as well as integer division. The imull instruction listed in Figure 3.6 is known as the “twooperand” multiply instruction. It generates a 32bit product from two 32bit operands, implementing the operations *u and *t¿¾ described in ¿¾ Sections 2.3.4 and 2.3.5 (pages 61 and 62). Recall that when truncating the product to 32 bits, both unsigned multiply and two’s complement multiply have the same bitlevel behavior. IA32 also provides two diffe...
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This note was uploaded on 09/02/2010 for the course ELECTRICAL 360 taught by Professor Schultz during the Spring '10 term at BYU.
 Spring '10
 Schultz
 The American, Gulliver's Travels, 2.2.5 2.2.6 2.2.7 2.3 2.3.1 2.3.2 2.3.3 2.3.4 2.3.5

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