1994-08-11 - Re: IDEA vs DES

Header Data

From: Hal <hfinney@shell.portal.com>
To: cypherpunks@toad.com
Message Hash: 4dd5559cba994a8c8708f55174136c20659e02a91d261d672215d12e8a34c2b1
Message ID: <199408111648.JAA25239@jobe.shell.portal.com>
Reply To: <199408110744.AAA20783@servo.qualcomm.com>
UTC Datetime: 1994-08-11 16:49:21 UTC
Raw Date: Thu, 11 Aug 94 09:49:21 PDT

Raw message

From: Hal <hfinney@shell.portal.com>
Date: Thu, 11 Aug 94 09:49:21 PDT
To: cypherpunks@toad.com
Subject: Re: IDEA vs DES
In-Reply-To: <199408110744.AAA20783@servo.qualcomm.com>
Message-ID: <199408111648.JAA25239@jobe.shell.portal.com>
MIME-Version: 1.0
Content-Type: text/plain


According to my references, the PowerPC 601 does an integer multiply
in 9 cycles (5 if the 2nd operand is 16 bits or less).  An integer
divide takes 36 cycles.  Adds, etc. take 1 cycle.

Floating-point multiplies take 1 cycle for single precision, 2 for double.
However, they are pipelined, so if you need to use the results of the
multiply on the next instruction, they will take 3 cycles.  Floating-point
adds take 1 cycle, again with the results available in 3.

There is a floating-point (but no integer) multiply-and-add instruction.
It has the same timing as the multiply.

Hal





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