Assembler Instruction Reference
December 18th, 2005A nifty and not-so-obvious feature of the Shark tool that comes with Apple’s CHUD performance tools, is the “instruction set reference” that you can pull up for either PowerPC or Intel ISAs.
The feature is hidden away in Shark’s Help menu:
Selecting either reference item brings up a floating window giving you easy access to the entire instruction set reference. What’s nice about the floating window is it stays visible no matter what application you’re working in. So if it’s convenient for you to have the instruction reference at your fingertips from gdb in the Terminal, you can bring it there.
The Shark interface to these references is just a lightweight PDF reader. If you’d rather read or search the document with a more conventional application like Preview or Acrobat Reader, you can access the underlying documents directly:
"/Library/Application Support/Shark/Helpers/PowerPC Help.app/Contents/Resources/PPCISA.pdf" "/Library/Application Support/Shark/Helpers/IA32 Help.app/Contents/Resources/IA32ISA.pdf"
Transitioning from a PowerPC world to an Intel one is full of mystery and intrigue. Browsing the Intel reference I discovered an instruction “MASKMOVDQU.” Geez! That’s a long instruction mnemonic. Prior to Windows 95, you couldn’t even name files that long on most Intel-based machines!
December 18th, 2005 at 11:23 am
Not that file names and instruction mnemonics have anything to do with each other, but MASKMOVDQU is part of SSE2, so it wasn’t introduced until after Windows 95 was out. :)
Oh, and PUNPCKHQDQ and PUNPCKLQDQ are also ten letters.
December 18th, 2005 at 11:27 am
Thanks, Eric. I think these instructions have a bit of charm about them. I’m sensing an ultra-geeky T-Shirt series :)