[Mesa-dev] [PATCH 0/6] glsl: Add support for switch statements

[Dan McCabe]

On 06/19/2011 02:21 PM, Eric Anholt wrote:
> On Sat, 18 Jun 2011 09:29:32 +0200, Keith Packard<keithp at keithp.com>  wrote:
>> On Fri, 17 Jun 2011 17:43:14 -0700, Dan McCabe<zen3d.linux at gmail.com>  wrote:
>>
>>>      		break; // implicit exit from loop at end of switch
>>>      	} while (true);
>> Seems like this could just be
>>
>>          } while (false);
>>
>> as I don't see any way the loop could go around more than once.
> "while (true)" is the instruction available in the hardware, this isn't
> a description of C code.
Correct. It is primarily intended to explain approximately an equivalent 
for the underlying code and is intended to interpreted with a grain of 
salt. It is really pseudo-code that looks a lot like C :).

I also wanted to use "while(true)" to explicitly indicate the actual 
effect of the implicit "break" at the end of the "loop". With 
"while(false)", you have to scratch  your head to figure out why that 
final "break" is there, because it ought not be needed in a 
"while(false)" loop.