Compare golang benchmarks between working copy and pristine

benchwc.sh

#!/bin/bash
# Usage: benchwc.sh "path/to/package" "-build flags"
# e.g. benchwc.sh ./mypkg "-cpu=1,2,4 -tags=debug -benchtime=2s"
DIR=${1:-.}
BFLAGS=$2
git stash save || exit 1
cd $DIR && go test -run=^$ -bench=. -benchmem $BFLAGS | tee old.out
git stash pop || exit 1
cd $DIR && go test -run=^$ -bench=. -benchmem $BFLAGS | tee new.out
benchcmp old.out new.out | tee comparison.out

Note this requires benchcmp to be installed:
go get golang.org/x/tools/cmd/benchcmp