RFR : [XS] 8209942: [epsilon] range function for EpsilonTLABElasticity causes compiler warning
matthias.baesken at sap.com
Wed Sep 5 11:03:05 UTC 2018
Hello, when compiling jdk/jdk on Windows, (with VS2017 update level 15.8 and not disabling warnings as errors )
I came across this warning leading to build error :
C:/jdk-just-clone/src/hotspot/share/runtime/flags/jvmFlagRangeList.cpp(341): error C2220: warning treated as error - no 'object' file generated
C:/jdk-just-clone/src/hotspot/share/runtime/flags/jvmFlagRangeList.cpp(341): warning C4305: 'argument': truncation from 'const intx' to 'double'
Would have been helpful to have a compiler flag set that really ***shows the code*** leading to the warning/error (because it comes from heavy macro expansion).
The following CR , Reported by ralf.schmelter at sap.com<mailto:ralf.schmelter at sap.com> , fixes the issue :
The flag -XX:EpsilonTLABElasticity (epsilon_globals.hpp, line 77) expects a double value, but uses max_intx in the allowed range.
This leads to a truncation warning in the Windows build. If the value should only be guaranteed to be >= 1, then DBL_MAX should have been used instead.
Please review .
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