A89: Rotate with carry in TIGCC

To: "Assembly-89@Lists. Ticalc. Org" <assembly-89@lists.ticalc.org>
Subject: A89: Rotate with carry in TIGCC
From: "Alex Astashyn" <simba@inyc.com>
Date: Sat, 6 Jan 2001 02:40:18 -0500
Importance: Normal
Reply-To: assembly-89@lists.ticalc.org


I am trying to perform the following task:
In the array of words data[], shift elements the right by one bit, and copy
the lowest bit of the next element into the highest bit of the current
element. I use the following code for that:

	WORD data[]; //filled with values later
	for(i = starting_index; i < ending_index; i++)
		data[i] = (data[i] >> 1) | (data[i + 1] << 15);

However, the performance of this piece of code is unsatisfactory. If I were
writing in C for Intel processor, I would rewrite the code in inline asm
using RCR instruction (Rotate Carry Right), so I wouldn't have to deal with
all that shifting and ORing. Unfortunately, I know no M-68K assembly, so the
question is: Is there a way to do similar thing in TIGCC?

Thank you very much.

Alex Astashyn

Follow-Ups:

Re: A89: Rotate with carry in TIGCC

From: Olle Hedman <oh@hem.passagen.se>