HP Ski Simulator, IA-64 manual 2 IA-32 Instruction Display

Ski IA-64 Simulator Reference Manual 1.0L

Figure 3-10. xski’s Program Window Showing IA-64 Predication and Breakpoints

3.5.2IA-32 Instruction Display

IA-32 instructions are displayed as shown in Figure 3-11,according to the conventions for Intel assembly code. As with IA-64 instruction display, Ski uses the first column of each assembly language instruction line to show breakpoint loca- tions, numbering them “ 0” through “ 9.” Except for the use of iabs rather than bs, IA-32 breakpoint commands are the same as IA-64 breakpoint commands and include iabs, bD, bd, and bl,as described in Section 8.3, “Program Break- points”. In the second column, Ski puts a greater-than symbol (“ >”) to point to the next instruction to be executed, i.e., the location pointed to by the ip register.

Because IA-32 instructions are variable in length, it is possible to set the ip to point into the middle of an instruction. This can happen, for example, when an instruction with prefix bytes is needed at the top of the first pass through a loop, and the same instruction without the prefix bytes is needed at the top of subsequent passes. When this happens, Ski uses a plus- sign (“ +”) in column two, rather than a greater-than symbol, to warn you that ip points somewhere in the middle of the line of code displayed on the screen. To update the display, use the command “ pj ip”. This will cause Ski to reinterpret the instruction stream and to display the variable length instructions with the new interpretation.

3-8 Screen Presentation Copyright © 2000 Hewlett-Packard Co.