Hello, For 32-bit mode there's no __popcnt64 instruction, so replace number of set bit calculation in 64b mask with two invocations of _popcnt32. Test started to pass for me under SDE. gcc/testsuite/ * gcc.target/i386/avx512f-vpcompressb-2.c: Fix popcnt for 32-bit mode. Checked into main trunk. -- Thanks, K