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Altera_Forum's avatar
Altera_Forum
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15 years ago

NIOS II GCC -funroll-all-loops

I have try a bench for see if the unrool loop flag work fine, When the inital idx value is a constant know at compilation -> the unrool work fine. But if the inital idx value is not know at com...
Altera_Forum's avatar
Altera_Forum
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14 years ago

If the compiler doesn't know how many times the loop is going to iterate then I wouldn't expect it to unroll the loop for you. So by not specifying an initial value for 'idx' the compiler has no clue if it should unroll the loop 2, 3, 4, 5, ...100, etc.... times. Loop unrolling is a static optimization so all the unknowns need to be.... known for the optimization to occur.