On Fri, 19 Mar 2021, YunQiang Su wrote: > > what about just rebuilding them ? They are broken, so why should we fix > > broken user binaries with kernel hacks ? > > > > In fact without O32_FP64_SUPPORT option is enabled, the FP=0 mode is > always used for FPXX. As I noted in the discussion the choice of the FR mode for FPXX binaries is neutral performance-wise for R2 through R5, so as I previously stated it would be fine with me to use FR=0 rather than FR=1 for FPXX binaries with these architecture levels. > In fact it doesn't change the behaviour of kernel. That is not true for R6. The use of the FRE mode with R6 does regress support for FPXX binaries performance-wise, which makes it unacceptable. And O32_FP64_SUPPORT is unconditionally selected for R6, so FR=0 (or FRE) is currently not used for FPXX with R6. Maciej
