mirror of
https://github.com/nim-lang/Nim.git
synced 2025-12-29 01:14:41 +00:00
47 lines
1.3 KiB
Nim
47 lines
1.3 KiB
Nim
discard """
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targets: "js c cpp"
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output: '''ok'''
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"""
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import math
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const manualTest = false
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when manualTest:
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import strformat
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proc frexp_test(lo, hi, step: float64) =
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var exp: int
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var frac: float64
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var eps = 1e-15.float64
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var x:float64 = lo
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while x <= hi:
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frac = frexp(x.float, exp)
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let rslt = pow(2.0, float(exp)) * frac
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doAssert(abs(rslt - x) < eps)
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when manualTest:
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echo fmt("x: {x:10.3f} exp: {exp:4d} frac: {frac:24.20f} check: {$(abs(rslt - x) < eps):-5s} {rslt: 9.3f}")
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x += step
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when manualTest:
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var exp: int
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var frac: float64
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for flval in [1.7976931348623157e+308, -1.7976931348623157e+308, # max, min float64
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3.4028234663852886e+38, -3.4028234663852886e+38, # max, min float32
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4.9406564584124654e-324, -4.9406564584124654e-324, # smallest/largest positive/negative float64
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1.4012984643248171e-45, -1.4012984643248171e-45, # smallest/largest positive/negative float32
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2.2250738585072014e-308, 1.1754943508222875e-38]: # smallest normal float64/float32
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frac = frexp(flval, exp)
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echo fmt("{flval:25.16e}, {exp: 6d}, {frac: .20f} {frac * pow(2.0, float(exp)): .20e}")
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frexp_test(-1000.0, 1000.0, 0.0125)
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else:
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frexp_test(-200000.0, 200000.0, 0.125)
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echo "ok"
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