RFR(M): 8213528: fp registers should not need to be saved around a CallLeafNoFP

Roland Westrelin rwestrel at redhat.com
Mon Nov 12 09:01:26 UTC 2018

> Looking on all .ad files I see difference only for x86_32:

I missed that.

> http://hg.openjdk.java.net/jdk/jdk/file/13266dac5fdb/src/hotspot/cpu/x86/x86_32.ad#l13326
> And I surprise we don't have difference for SPARC.
> Your change make code in x86_32 be unused. The only drawback to always use CallLeaf there is empty_FPU_stack() when cpu 
> does not have SSE2 (such CPUs should disappear already) and reset FPU control word when it is in special 24BitFPMode 
> mode. The 24bit mode most likely is not used any more (requires not presence SSE and other conditions):
> http://hg.openjdk.java.net/jdk/jdk/file/13266dac5fdb/src/hotspot/share/opto/compile.cpp#l3678
> Based on this I think we need purge all this vary outdated code as separate RFE.
> Lets first push your changes.

Ok. Thanks. So you're ok with this?


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