any way to overcome saturation in PSUBUSB?

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john_25

Joined: 05 Jun 2014
Posts: 5

john_25 08 Jun 2014, 07:07

according to:
http://www.jaist.ac.jp/iscenter-new/mpc/altix/altixdata/opt/intel/vtune/doc/users_guide/mergedProjects/analyzer_ec/mergedProjects/reference_olh/mergedProjects/instructions/instruct32_hh/vc263.htm

it states:

Quote:

The PSUBUSB instruction subtracts packed unsigned byte integers. When an individual byte result is less than zero (a negative value), the saturated value of 00H is written to the destination operand.

anyway to over come this and keep the negative values?

08 Jun 2014, 07:07

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20344
Location: In your JS exploiting you and your system

revolution 08 Jun 2014, 07:14

Use an unsaturating instruction like PSUBB.

BTW: Both Intel and AMD have freely downloadable PDFs of the official instruction sets.

08 Jun 2014, 07:14

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