bugProgramming from the Ground Up Book - Bugs: bug #18506, Does mul have two syntaxes?


bug #18506: Does mul have two syntaxes?

Submitted by:  None
Submitted on:  Mon 11 Dec 2006 09:56:54 PM UTC  
Category:  None Severity:  3 - Normal
Item Group:  None Status:  None
Privacy:  Public Assigned to:  None
Open/Closed:  Open

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Thu 17 May 2007 10:21:24 AM UTC, comment #1: 

mul and imul are single Operand instructions.
They additionally take values in al, ax, eax and store in dx, dx:ax , edx:eax respectively, because of the possibility of an overflow.
The second version dx:ax already existed on 16-bit arch.

Mon 11 Dec 2006 09:56:54 PM UTC, original submission:  

When I assemble this using as:

mul %eax, %ecx

the following error occurs:
Error: suffix or operands invalid for `mul'

According to some folks on freenode #asm, this syntax for mul does not exist. Instead, mul takes one operand and stores the result into %edx:%eax.



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