RFR(S): 8187964: [s390][ppc]: Intrinsify Math.multiplyHigh(long, long)
lutz.schmidt at sap.com
Mon Oct 9 07:54:33 UTC 2017
unsigned multiplyHigh would definitely help [s390]. Think of just one instruction instead of seven. You could even get the full length product at the same cost.
On 07.10.2017, 11:09, "Andrew Haley" <aph at redhat.com> wrote:
One thought about this: we might generate better code on these
machines if we had an unsigned multiplyHigh intrinsic and did the
adjustment for signed arithmetic in Java code, where the sign
adjustment could be scheduled separately by C2.
OK, I'll get on with implementing unsignedMultiplyHigh!
Java Platform Lead Engineer
Red Hat UK Ltd. <https://www.redhat.com>
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