RFR(S): Bugfix: Clear High Word in Integer.bitCount() Intrinsic on SparcV9

[John Rose]

On Dec 14, 2012, at 6:03 PM, David Chase wrote:

> There is also the possibility of a peephole-ish optimization (that can be informed by general flow analysis) that keeps track of zero bits in a word -- for instance, if the source of the data was a LDUW, there's no need to clear the bits.

We do some really hacky stuff in that vein; see the flag SparcV9RegsHiBitsZero.

The bug 8001436 requests a less hacky infrastructure for doing bitwise type propagation.

http://bugs.sun.com/bugdatabase/view_bug.do?bug_id=8001436

— John
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