[llvm-commits] [PATCH] Compress Repeated Byte Output

[Chris Lattner]

On Aug 31, 2011, at 9:19 AM, David A. Greene wrote:

> Chris Lattner <clattner at apple.com> writes:
> 
>> +    for (int i = 1, e = CA->getNumOperands(); i != e; ++i) {
>> 
>> Please declare 'i' as 'unsigned' instead of 'int'.
> 
> I'm not objecting to this, but rather am curious.
> 
> Typing loop counters as unsigned can do all sorts of horrible things to
> analysis and optimization due to wraparound requirements.  

This isn't the case for loops that start at a constant and stride by 1.

> I've got into
> the habit of always typing loop counters as signed to avoid these
> issues.  Is there a specific reason to prefer unsigned?

The value is unsigned, it conveys intentions more clearly.  This is quite consistent in the codebase.

-Chris