check-sse4_2.sh

#!/bin/bash
#
# This script makes sure that the tikv-server executables in the target
# directory enables intel® sse4.2 extensions. It is suitable to run as part of
# CI.

dirs="./target/debug ./target/release"

errors=0

# These need to check sse4.2.
targets="tikv-server tikv-importer"

if [[ "`uname`" != "Linux" ]]; then
    echo "skipping sse4.2 check - not on Linux"
    exit 0
fi

echo "checking bins for sse4.2"

for dir in $dirs; do
    for file in $targets; do
        
        dirfile="$dir/$file"
        if [[ -x "$dirfile" && ! -d "$dirfile" ]]; then
            
            echo "checking binary $dirfile for sse4.2"
            
            # RocksDB uses sse4.2 in the `Fast_CRC32` function
            fast_crc32=$(nm "$dirfile" | grep -o " _.*Fast_CRC32.*")
            if [[ ! $fast_crc32 ]]; then
                echo "error: $dirfile does not contain rocksdb::crc32c::Fast_CRC32 function"
                errors=1
                continue
            fi
            
            # Make sure the `Fast_CRC32` uses the sse4.2 instruction `crc32`
            # f2.*0f 38 is the opcode of `crc32`, see Intel® SSE4 Programming Reference
            found=0
            for sym in $fast_crc32; do
                echo $sym
                if [[ `gdb -batch -ex "disass/r $sym" $dirfile 2> /dev/null | grep ">:.*f2.*0f 38.*crc32"` ]]; then
                    found=1
                    break
                fi
            done
            if [[ "$found" -ne 1 ]]; then
                echo "error: $dirfile does not enable sse4.2"
                errors=1
            fi
        fi
    done
done

if [[ "$errors" -ne 0 ]]; then
    echo "some binaries do not enable sse4.2"
    echo "fix this by building tikv with ROCKSDB_SYS_SSE=1"
    exit 1
fi