Here is the article.
Optimization vs Cheating
It is rather technical but it seems that the main drift is this-
Optimiztion-definition
"Therefore, any code optimization performed on a function that does not change the resulting value of the function for any argument, is uncontroversially considered a valid optimization. Therefore, techniques such as instruction selection, instruction scheduling, dead code elimination, and load/store reordering are all acceptable. These techniques change the performance profile of the function, without affecting its extensional meaning. "
Meaning "optimization" is okay because it doesn't affect the extensional meaning but does provide a higher performance profile. (what ati is doing unless futuremark can validate the 1.9% as a cheat)
Cheating-definition
"Optimization techniques which change your function into a function that extensionally differs from what you specified are generally not considered valid optimizations. These sorts of optimizations have occasionally been exposed, for example, in C++ compilers as features that programmers can optionally enable when they want the extra performance and are willing to accept that the meaning of their function is being changed but hopefully to a reasonable numeric approximation. One example of this is Visual C++'s "improve float consistency" option. Such non-extensional optimizations, in all sane programming systems, default to off. "
This is a cheat and is what futuremark has verified nvidia as doing-NOT OKAY
These were my impressions, what are yours?
rogo
Optimization vs Cheating
It is rather technical but it seems that the main drift is this-
Optimiztion-definition
"Therefore, any code optimization performed on a function that does not change the resulting value of the function for any argument, is uncontroversially considered a valid optimization. Therefore, techniques such as instruction selection, instruction scheduling, dead code elimination, and load/store reordering are all acceptable. These techniques change the performance profile of the function, without affecting its extensional meaning. "
Meaning "optimization" is okay because it doesn't affect the extensional meaning but does provide a higher performance profile. (what ati is doing unless futuremark can validate the 1.9% as a cheat)
Cheating-definition
"Optimization techniques which change your function into a function that extensionally differs from what you specified are generally not considered valid optimizations. These sorts of optimizations have occasionally been exposed, for example, in C++ compilers as features that programmers can optionally enable when they want the extra performance and are willing to accept that the meaning of their function is being changed but hopefully to a reasonable numeric approximation. One example of this is Visual C++'s "improve float consistency" option. Such non-extensional optimizations, in all sane programming systems, default to off. "
This is a cheat and is what futuremark has verified nvidia as doing-NOT OKAY
These were my impressions, what are yours?
rogo
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