Function InvCbrt

The InvCbrt function computes an inverse cube root.

Performance:

  Default processor Intel® Pentium® III processor Intel® Pentium® 4 processor Intel® Pentium® 4 processor with Streaming SIMD Extensions 3 (SSE3) Intel® Itanium® 2 processor
vsInvCbrt (HA version) 31.55 31.04 23.82 24.63 7.19
vdInvCbrt (HA version) 42.03 42.03 41.57 46.67 9.22
Notes:
1) Units - CPE (Clocks per Element)
2) Performance was measured on "working" interval (double precision: [-1,1]; single precision: [-1,1] )
3) Data - vectors of 1000 elements with random generated numbers
4) "Default" means X87 code for all IA-32 processors
5) Performance of "default" version was measured on Intel® Pentium® III processor

 
Notes:
1) *           X87 code for all processors
2) **         Intel® Pentium® III processor
3) ***       Intel® Pentium® 4 processor
4) ****     Intel® Pentium® 4 processor with Streaming SIMD Extensions 3 (SSE3)
5) *****   Intel® Itanium® 2 processor
6) Logarithmic scale is used for "Vectors Size" axis

Maximal observed error for the whole function domain:

  Default processor Pentium III processor Pentium 4 processor Pentium 4 processor with SSE3 Itanium 2 processor
vsInvCbrt (HA version) 0.7930 0.7830 0.8550 0.8550 0.5010
vdInvCbrt (HA version) 0.5700 0.5700 0.5110 0.5110 0.5000
Notes:
1) Units - ULP (Units in The Last Place)

Special values:

Function Input Argument Result Default processor Pentium III processor Pentium 4 processor Pentium 4 processor with SSE3 Itanium 2 processor
vsInvCbrt/vdInvCbrt
(HA version)
+/- 0 +/- Inf (Raise DZ Exeption) + + + + +
NaN (Both QnaN and SNaN) NaN (Raise Invalid Exeption for SnaN) + + + + +
+/- Inf +/- 0 + + + + +

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