#!/bin/sh
# SPDX-License-Identifier: GPL-2.0
#
# Author: Steve Sistare <steven.sistare@oracle.com>
#
# Usage: hackdiff
#   Print difference between 2 identical series of hackbench runs
#
# Reads lines from stdin of this form (eg, from runmany):
#  hackbench 1 process 100000
#  5.753  5.421  5.254  6.044  5.989     Average 5.692   stdev 6.1%
#
# The first occurrence of a hackbench group line is the base series, and the
# next occurrence with identical parameters is the new series.

# Convert float $1 to integral fixed-point value with $2 decimal places
#
ftoi()
{
        declare -i tens=10**$2
        echo $(echo "scale=0; ($tens * $1) / 1" | bc -q)
}

# Convert integral fixed-point $1 with $2 decimal places to floating point
# string
#
itof()
{
        declare -i i frac tens x=$1
        tens=10**$2
	[[ $x -lt 0 ]] && sign='-' x=(-$x)
        i=$x/tens
        frac=$x%tens
        printf "%s%d.%0${2}d" "$sign" $i $frac
}

declare -a t1 t2 t3 groups
declare -a words
declare -a t1  t2  d1  d2 words groups seen_group
declare -i i t1d t2d t3 n=0

after=false

while read buf ; do
	if [[ ${buf:0:9} == "hackbench" ]]; then
		words=($buf)
		group=${words[1]}
		if [[ ${seen_group[$group]} == true ]]; then
			if [[ $after == false ]]; then
				n=0
				after=true
			fi
			if [[ ${groups[$n]} != $group ]]; then
				echo "expected group ${groups[$n]} " \
				     "but found $group"
				exit 1
			fi
		fi
		seen_group[$group]=true
		groups[$n]=$group

	elif $(echo $buf | grep -q Average) ; then
		words=($(echo $buf | sed ' s/^.*Average *//'))
		if [[ $after == true ]]; then
			t2[$n]=${words[0]}
			d=${words[2]}
			d2[$n]=${d%\%}
		else
			t1[$n]=${words[0]}
			d=${words[2]}
			d1[$n]=${d%\%}
		fi
		n=($n+1)
	fi
done

printf "%21s  %13s\n" "--- base --" "--- new ---"
printf "%6s  %6s %6s  %6s %6s  %8s\n" \
    groups  time \%stdev  time \%stdev  \%speedup

for ((i=0; i<$n; i++)) ; do
	t1d=$(ftoi ${t1[$i]} 3)
	t2d=$(ftoi ${t2[$i]} 3)
        t3=($t1d*1000/$t2d-1000)
        t3=($t3*100)
        speedup=$(itof $t3 3)
	printf "%6d  %6.3f %6.1f  %6.3f %6.1f  %8.1f\n" \
	    ${groups[$i]} ${t1[$i]} ${d1[$i]} ${t2[$i]} ${d2[$i]} $speedup
done