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???
05/30/12 12:29
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 		 #187581 - provided the case ...
Responding to: ???'s previous message
Christoph Franck said:

Save This Code
x = (x >= 0) ? (x >> 10) : (-((-x) >> 10));
 
is so much faster and results in smaller code? (provided the case (x == NEGATIVE_MAX) never occurs or is handled separately)

If I now IAR this is exactly why they will call the division routine for signed 64-bit integers. They will never sacrifice correctness under any circumstance for code size or speed.

What does it generate for unsigned 64-bit integers? And why did you not use unsigned as recommended in the article?

List of 33 messages in thread
TopicAuthorDate
Where can one learn Intermediate C techniques for 8051            01/01/70 00:00      
   on the right track            01/01/70 00:00      
      one more thing            01/01/70 00:00      
         Not uncommon bid bad coding standards to comply with            01/01/70 00:00      
         Not afraid of globals, but...            01/01/70 00:00      
   More keil optimizer interesting tidbits            01/01/70 00:00      
      optimization            01/01/70 00:00      
      nothing gained, nothing lost            01/01/70 00:00      
         I don't            01/01/70 00:00      
            you can do both            01/01/70 00:00      
               That is not helping the compiler            01/01/70 00:00      
                  exact same            01/01/70 00:00      
                     Technically, they are not the same            01/01/70 00:00      
                        Hmmm...            01/01/70 00:00      
                        C don't do full evaluation of logical expressions            01/01/70 00:00      
                           In discrete mathematics proving one is not a proof            01/01/70 00:00      
                              Lazy evaluation demanded            01/01/70 00:00      
                                 I have learned something new because of this            01/01/70 00:00      
                                    me too            01/01/70 00:00      
                                       Very Important            01/01/70 00:00      
                              Breaks.            01/01/70 00:00      
                                 Compile the code            01/01/70 00:00      
                                    To be more exact            01/01/70 00:00      
                                       Stop It!!            01/01/70 00:00      
                                          That is exactly what I intended            01/01/70 00:00      
                                             Switch Break.            01/01/70 00:00      
               obfusciating code to help the compiler is a VERY bad idea            01/01/70 00:00      
                  the source of this            01/01/70 00:00      
   Where can one learn Intermediate C techniques for 8051            01/01/70 00:00      
   Getting the least out of your compiler            01/01/70 00:00      
      Maybe IAR should follow their own advice?            01/01/70 00:00      
         provided the case ...            01/01/70 00:00      
            Compilers not knowing the target chip.            01/01/70 00:00      

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