Nicolas Cellier uploaded a new version of KernelTests to project The Trunk: http://source.squeak.org/trunk/KernelTests-nice.313.mcz
==================== Summary ====================
Name: KernelTests-nice.313 Author: nice Time: 2 October 2016, 3:19:37.781599 pm UUID: e6139cfd-b985-42d5-9f24-ffeb0ce8cf6c Ancestors: KernelTests-mt.311
Test edge cases of Integer>>nthRoot:
=============== Diff against KernelTests-mt.311 ===============
Item was added: + ----- Method: IntegerTest>>testNthRootExactnessForHugeValue (in category 'tests - mathematical functions') ----- + testNthRootExactnessForHugeValue + self assert: ((10 raisedTo: 600) nthRoot: 300) classAndValueEquals: 100. + self assert: ((10 raisedTo: 600) + 1 nthRoot: 300) classAndValueEquals: 100.0!
Item was added: + ----- Method: IntegerTest>>testNthRootImmuneToDoubleRounding (in category 'tests - mathematical functions') ----- + testNthRootImmuneToDoubleRounding + "Use a specially crafted number for causing double rounding. + Solution is 10...01.1 - verySmallQuantity. + Where verySmallQuantity is approximately 1/53/(1<<53). + If the verySmallQuantity is not taken into account, then solution is rounded to 10....010" + | exponent crafted root highPrecisionRoot | + exponent := 4. + crafted := (1 << Float precision + 3 raisedTo: exponent) - 1. + root := crafted nthRoot: exponent. + highPrecisionRoot := (crafted << (exponent squared * Float precision * 4) nthRootRounded: exponent) / (1 << (exponent * Float precision * 4)). + self assert: (root asFraction - highPrecisionRoot) abs < (root predecessor asFraction - highPrecisionRoot) abs. + + "Same with the other sign. + Solution is 10...00.1 + verySmallQuantity." + crafted := (1 << Float precision + 1 raisedTo: exponent) + 1. + root := crafted nthRoot: exponent. + highPrecisionRoot := (crafted << (exponent squared * Float precision * 4) nthRootRounded: exponent) / (1 << (exponent * Float precision * 4)). + self assert: (root asFraction - highPrecisionRoot) abs < (root successor asFraction - highPrecisionRoot) abs.!