FP Registers in SPARC Intrinsic

Vladimir Kozlov vladimir.kozlov at oracle.com
Wed Jun 17 21:15:25 UTC 2015

Context switching should preserve FP, otherwise float point arithmetic 
will not work. Something else may be happened. We need more details.
Removing RC_NO_FP is good because register allocator should know that FP 
regs are used.


On 6/17/15 1:30 PM, Ahmed Khawaja wrote:
> I am working on adding some intrinsics that mostly benefit from the lack
> of a JNI call. One strategy I am using is to free up some registers by
> moving them into FP registers and restoring them later. One issue I am
> running into is I believe if the thread gets unscheduled, the FP
> registers are being trashed and then upon resume my code tries to reload
> the integer registers with the now garbage FP registers. When invoking
> the intrinsic, I removed RC_NO_FP, but this does not seem to indict to
> the JVM that the FP registers need to be saved on a context switch. Has
> anyone run into something similar?
> Thank you,
>     Ahmed Khawaja

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