Enhancements to expt
#651
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Enhancements to expt
#651
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* Don't use Scheme arithmentic where not needed in exponentiation by squaring (the exponent is known to be a fixnum). * Fast path for exponent=2 (much much faster). * Change name `exact_exponent_expt` -> `fixnum_exponent_expt` * Move the bignum check to `my_expt`, so the exponent is always a fixnum when calling `fixnum_exponent_expt`. * Since the exponent is always a fixnum in `fixnum_exponent_expt`, compare with `MAKE_INT(0)` instead of using `zerop`. Results: * for some integer exponents, `expt` is faster * specifically, for exponent = 2, it is more than twice as fast
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exact_exponent_expt->fixnum_exponent_exptmy_expt, so the exponent is always a fixnum when callingfixnum_exponent_expt.fixnum_exponent_expt, compare withMAKE_INT(0)instead of usingzerop.Results:
exptis faster