On Mon, 27 Nov 2023 01:06:21 GMT, Xiaohong Gong <xg...@openjdk.org> wrote:
>> make/autoconf/lib-vmath.m4 line 94: >> >>> 92: # Check the ARM SVE feature >>> 93: SVE_CFLAGS="-march=armv8-a+sve" >>> 94: >> >> What's this about? We're building a standard binary, and all SVE detection >> is to be deferred to runtime. > > We have to use this c-compiler option to build out the SVE ABIs (e.g. > `svfloat32_t sinfx_u10sve(svfloat32_t input)`) in `libvmath.so`. Without this > option, at build time, all the sve related featues like `arm_sve.h / > __ARM_FEATURE_SVE` are missing, together with the sve symbols in > `libvmath.so` we needed at runtime. That means at runtime, hotspot cannot > find out the sve symbols and the vector operations will fall back to the > default java implementation. That's fine, but we must make sure that SVE is not used by the compiler in any other places. If you've already built on non-SVE and tested the result on both SVE and non-SVE, I'm happy. ------------- PR Review Comment: https://git.openjdk.org/jdk/pull/16234#discussion_r1405950723
