Andrew Haley aph at
Fri Sep 8 14:38:11 UTC 2017

I notice that Math.multiplyHigh(long, long) doesn't use a C2 intrinsic,
even on machines with appropriate C2 patterns.  So it's rather slow.

JDK-5100935, No way to access the 64-bit integer multiplication of
64-bit CPUs efficiently, is closed, even though there is still no
efficient way to do this.  Is writing an intrinsic for multiplyHigh on
someone's to-do list?  I see no bug for it.

Andrew Haley
Java Platform Lead Engineer
Red Hat UK Ltd. <>
EAC8 43EB D3EF DB98 CC77 2FAD A5CD 6035 332F A671

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