SPARC: unsigned vs. signed int loads

Christian Thalinger Christian.Thalinger at Sun.COM
Wed Feb 11 08:35:38 PST 2009

Hi all!

Still working on 6797305, I recently was looking (again) closer at the
load instructions in and I noticed that byte and short loads do
a sign extend (ldsb and ldsh) while int loads do not (lduw).

In CACAO we did fully 64-bit signed extended loads on Alpha and SPARC64
so we could omit I2L conversions.

Is there a reason why HotSpot does zero-extended int loads?

-- Christian

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