Patrick.Schluter at bbox.fr
Tue Jan 8 09:30:14 UTC 2019
On Monday, 7 January 2019 at 21:46:21 UTC, H. S. Teoh wrote:
> On Mon, Jan 07, 2019 at 08:41:32PM +0000, Patrick Schluter via
> Digitalmars-d-learn wrote:
>> On Monday, 7 January 2019 at 20:28:21 UTC, H. S. Teoh wrote:
>> > On Mon, Jan 07, 2019 at 08:06:17PM +0000, Patrick Schluter
>> > via Digitalmars-d-learn wrote:
>> > > Up to 32 bit processors, shifting was more expensive than
>> > > branching.
>> > Really? Haha, never knew that, even though I date all the
>> > way back to writing assembly on 8-bit processors. :-D
>> Most of my career was programming for 80186. Shifting by one
>> was 2 cycles in register and 15 in memory. Shifting by 4, 9
>> cycles for regs/21 for mem. And 80186 was a fast shifter
>> compared to 8088/86 or 68000 (8+2n cycles).
> I used to hack 6502 assembly code.
Yeah, that's also what I started with, on the Apple II in the
early 80s. I was quite surprized that my 6502 knowledge came in
very handy when we worked on dial-in modems in the late 90s as
the Rockwell modems all used 6502 derived micro-controllers for
> During the PC revolution I wrote an entire application in 8088
> assembly. Used to know many of the opcodes and cycle counts by
> heart like you do, but it's all but a faint memory now.
I had to lookup the exact cycle counts ;-) . I remember the
relative costs, more or less, but not the details anymore.
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