From: "Jon Perryman" <jperr...@pacbell.net>
Sent: Tuesday, February 06, 2018 5:54 AM
This is too funny. Profess the virtues of C and provide actual examples that look like they prove
the point but when scrutinized actually disprove it. When I provided these type of examples, it
was considered a gross exaggeration. C is a mindset that is common. Here's the proof I'm not
exagerating at all.
Kirk Wolf wrote:
If you compile this with full optimization and look at the generated
assembly, you will find a fancy unrolled loop.
Who knows if MVCIN is any faster? It certainly won't handle len>256 cases.
This statement would be funny if it weren't so sad. The "fancy" loop would be a simple loop to
move each byte where the second operand starts at the end. "optimization" never recognized this
as an MVCIN loop but it really optimized the code it produced. MVCIN is obviously many times
faster than a single byte loop to move each character (how can this even be a question). Can
anyone tell us how many times faster MVC 256 bytes is than 256 MVC 1 byte?
To really prove C is superior, MVCIN is limited to 256 byte moves.
That's of no consequence, as a number of such instructions
can be strung together to deal with strings longer than 256 characters.
But wasn't the instruction intended just for printing?
In which case, the length of the string will be of the order
of 100 or so.
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