imac2% time zcat /Volumes/Programs/Archives/b/old/jpegsrc.v6b.tar.gz | tar -xf -
zcat /Volumes/Programs/Archives/b/old/jpegsrc.v6b.tar.gz  0.14s user 0.06s system 24% cpu 0.807 total
tar -xf -  0.04s user 0.28s system 44% cpu 0.722 total
imac2% cd jpeg-6b 
imac2% ls
README        jchuff.c      jdapistd.c    jidctint.c    makeapps.ds   rdswitch.c
ansi2knr.1    jchuff.h      jdatadst.c    jidctred.c    makefile.ansi rdtarga.c
ansi2knr.c    jcinit.c      jdatasrc.c    jinclude.h    makefile.bcc  structure.doc
cderror.h     jcmainct.c    jdcoefct.c    jmemansi.c    makefile.cfg  testimg.bmp
cdjpeg.c      jcmarker.c    jdcolor.c     jmemdos.c     makefile.dj   testimg.jpg
cdjpeg.h      jcmaster.c    jdct.h        jmemdosa.asm  makefile.manx testimg.ppm
change.log    jcomapi.c     jddctmgr.c    jmemmac.c     makefile.mc6  testimgp.jpg
cjpeg.1       jconfig.bcc   jdhuff.c      jmemmgr.c     makefile.mms  testorig.jpg
cjpeg.c       jconfig.cfg   jdhuff.h      jmemname.c    makefile.sas  testprog.jpg
ckconfig.c    jconfig.dj    jdinput.c     jmemnobs.c    makefile.unix transupp.c
coderules.doc jconfig.doc   jdmainct.c    jmemsys.h     makefile.vc   transupp.h
config.guess  jconfig.mac   jdmarker.c    jmorecfg.h    makefile.vms  usage.doc
config.sub    jconfig.manx  jdmaster.c    jpegint.h     makefile.wat  wizard.doc
configure     jconfig.mc6   jdmerge.c     jpeglib.h     makelib.ds    wrbmp.c
djpeg.1       jconfig.sas   jdphuff.c     jpegtran.1    makeproj.mac  wrgif.c
djpeg.c       jconfig.st    jdpostct.c    jpegtran.c    makljpeg.st   wrjpgcom.1
example.c     jconfig.vc    jdsample.c    jquant1.c     maktjpeg.st   wrjpgcom.c
filelist.doc  jconfig.vms   jdtrans.c     jquant2.c     makvms.opt    wrppm.c
install-sh    jconfig.wat   jerror.c      jutils.c      rdbmp.c       wrrle.c
install.doc   jcparam.c     jerror.h      jversion.h    rdcolmap.c    wrtarga.c
jcapimin.c    jcphuff.c     jfdctflt.c    libjpeg.doc   rdgif.c
jcapistd.c    jcprepct.c    jfdctfst.c    ltconfig      rdjpgcom.1
jccoefct.c    jcsample.c    jfdctint.c    ltmain.sh     rdjpgcom.c
jccolor.c     jctrans.c     jidctflt.c    makcjpeg.st   rdppm.c
jcdctmgr.c    jdapimin.c    jidctfst.c    makdjpeg.st   rdrle.c
imac2% time CFLAGS=-Os ./configure 
checking for gcc... gcc
checking whether the C compiler (gcc -Os ) works... yes
checking whether the C compiler (gcc -Os ) is a cross-compiler... no
checking whether we are using GNU C... yes
checking how to run the C preprocessor... gcc -E
checking for function prototypes... yes
checking for stddef.h... yes
checking for stdlib.h... yes
checking for string.h... yes
checking for size_t... yes
checking for type unsigned char... yes
checking for type unsigned short... yes
checking for type void... yes
checking for working const... yes
checking for inline... __inline__
checking for broken incomplete types... ok
checking for short external names... ok
checking to see if char is signed... yes
checking to see if right shift is signed... yes
checking to see if fopen accepts b spec... yes
checking for a BSD compatible install... /usr/bin/install -c
checking for ranlib... ranlib
checking libjpeg version number... 62
creating ./config.status
creating Makefile
creating jconfig.h
CFLAGS=-Os ./configure  1.95s user 5.79s system 58% cpu 13.201 total
imac2% time make -j  
gcc -Os  -I.   -c -o jcapimin.o jcapimin.c
gcc -Os  -I.   -c -o jcapistd.o jcapistd.c
gcc -Os  -I.   -c -o jctrans.o jctrans.c
gcc -Os  -I.   -c -o jcparam.o jcparam.c
gcc -Os  -I.   -c -o jdatadst.o jdatadst.c
gcc -Os  -I.   -c -o jcinit.o jcinit.c
gcc -Os  -I.   -c -o jcmaster.o jcmaster.c
gcc -Os  -I.   -c -o jcmarker.o jcmarker.c
gcc -Os  -I.   -c -o jcmainct.o jcmainct.c
gcc -Os  -I.   -c -o jcprepct.o jcprepct.c
gcc -Os  -I.   -c -o jccoefct.o jccoefct.c
gcc -Os  -I.   -c -o jccolor.o jccolor.c
^Cmake: *** [jccoefct.o] Interrupt
make: *** [jcprepct.o] Interrupt
make: *** [jcmainct.o] Interrupt
make: *** [jcmarker.o] Interrupt
make: *** [jcmaster.o] Interrupt
make: *** [jcinit.o] Interrupt
make: *** [jdatadst.o] Interrupt
make: *** [jcparam.o] Interrupt
make: *** [jctrans.o] Interrupt
make: *** [jcapistd.o] Interrupt
make: *** [jcapimin.o] Interrupt
make: *** [jccolor.o] Interrupt

make -j  0.11s user 0.22s system 22% cpu 1.474 total
imac2% rm *.o
zsh: no matches found: *.o
imac2% make clean
rm -f *.o *.lo libjpeg.a libjpeg.la
rm -f cjpeg djpeg jpegtran rdjpgcom wrjpgcom
rm -f ansi2knr core testout* config.log config.status
rm -f -r knr .libs _libs
imac2% time make -j 4
gcc -Os  -I.   -c -o jcapimin.o jcapimin.c
gcc -Os  -I.   -c -o jcapistd.o jcapistd.c
gcc -Os  -I.   -c -o jctrans.o jctrans.c
gcc -Os  -I.   -c -o jcparam.o jcparam.c
gcc -Os  -I.   -c -o jdatadst.o jdatadst.c
gcc -Os  -I.   -c -o jcinit.o jcinit.c
gcc -Os  -I.   -c -o jcmaster.o jcmaster.c
gcc -Os  -I.   -c -o jcmarker.o jcmarker.c
gcc -Os  -I.   -c -o jcmainct.o jcmainct.c
gcc -Os  -I.   -c -o jcprepct.o jcprepct.c
gcc -Os  -I.   -c -o jccoefct.o jccoefct.c
gcc -Os  -I.   -c -o jccolor.o jccolor.c
gcc -Os  -I.   -c -o jcsample.o jcsample.c
gcc -Os  -I.   -c -o jchuff.o jchuff.c
gcc -Os  -I.   -c -o jcphuff.o jcphuff.c
gcc -Os  -I.   -c -o jcdctmgr.o jcdctmgr.c
gcc -Os  -I.   -c -o jfdctfst.o jfdctfst.c
gcc -Os  -I.   -c -o jfdctflt.o jfdctflt.c
gcc -Os  -I.   -c -o jfdctint.o jfdctint.c
gcc -Os  -I.   -c -o jdapimin.o jdapimin.c
gcc -Os  -I.   -c -o jdapistd.o jdapistd.c
gcc -Os  -I.   -c -o jdtrans.o jdtrans.c
gcc -Os  -I.   -c -o jdatasrc.o jdatasrc.c
gcc -Os  -I.   -c -o jdmaster.o jdmaster.c
gcc -Os  -I.   -c -o jdinput.o jdinput.c
gcc -Os  -I.   -c -o jdmarker.o jdmarker.c
gcc -Os  -I.   -c -o jdhuff.o jdhuff.c
gcc -Os  -I.   -c -o jdphuff.o jdphuff.c
gcc -Os  -I.   -c -o jdmainct.o jdmainct.c
gcc -Os  -I.   -c -o jdcoefct.o jdcoefct.c
gcc -Os  -I.   -c -o jdpostct.o jdpostct.c
gcc -Os  -I.   -c -o jddctmgr.o jddctmgr.c
gcc -Os  -I.   -c -o jidctfst.o jidctfst.c
gcc -Os  -I.   -c -o jidctflt.o jidctflt.c
gcc -Os  -I.   -c -o jidctint.o jidctint.c
gcc -Os  -I.   -c -o jidctred.o jidctred.c
gcc -Os  -I.   -c -o jdsample.o jdsample.c
gcc -Os  -I.   -c -o jdcolor.o jdcolor.c
gcc -Os  -I.   -c -o jquant1.o jquant1.c
gcc -Os  -I.   -c -o jquant2.o jquant2.c
gcc -Os  -I.   -c -o jdmerge.o jdmerge.c
gcc -Os  -I.   -c -o jcomapi.o jcomapi.c
gcc -Os  -I.   -c -o jutils.o jutils.c
gcc -Os  -I.   -c -o jerror.o jerror.c
gcc -Os  -I.   -c -o jmemmgr.o jmemmgr.c
gcc -Os  -I.   -c -o jmemnobs.o jmemnobs.c
gcc -Os  -I.   -c -o cjpeg.o cjpeg.c
gcc -Os  -I.   -c -o rdppm.o rdppm.c
gcc -Os  -I.   -c -o rdgif.o rdgif.c
gcc -Os  -I.   -c -o rdtarga.o rdtarga.c
gcc -Os  -I.   -c -o rdrle.o rdrle.c
gcc -Os  -I.   -c -o rdbmp.o rdbmp.c
gcc -Os  -I.   -c -o rdswitch.o rdswitch.c
gcc -Os  -I.   -c -o cdjpeg.o cdjpeg.c
gcc -Os  -I.   -c -o djpeg.o djpeg.c
gcc -Os  -I.   -c -o wrppm.o wrppm.c
gcc -Os  -I.   -c -o wrgif.o wrgif.c
gcc -Os  -I.   -c -o wrtarga.o wrtarga.c
gcc -Os  -I.   -c -o wrrle.o wrrle.c
gcc -Os  -I.   -c -o wrbmp.o wrbmp.c
gcc -Os  -I.   -c -o rdcolmap.o rdcolmap.c
gcc -Os  -I.   -c -o jpegtran.o jpegtran.c
gcc -Os  -I.   -c -o transupp.o transupp.c
gcc -Os  -I.   -c -o rdjpgcom.o rdjpgcom.c
gcc -Os  -I.   -c -o wrjpgcom.o wrjpgcom.c
rm -f libjpeg.a
ar rc libjpeg.a  jcapimin.o jcapistd.o jctrans.o jcparam.o jdatadst.o jcinit.o jcmaster.o jcmarker.o jcmainct.o jcprepct.o jccoefct.o jccolor.o jcsample.o jchuff.o jcphuff.o jcdctmgr.o jfdctfst.o jfdctflt.o jfdctint.o jdapimin.o jdapistd.o jdtrans.o jdatasrc.o jdmaster.o jdinput.o jdmarker.o jdhuff.o jdphuff.o jdmainct.o jdcoefct.o jdpostct.o jddctmgr.o jidctfst.o jidctflt.o jidctint.o jidctred.o jdsample.o jdcolor.o jquant1.o jquant2.o jdmerge.o jcomapi.o jutils.o jerror.o jmemmgr.o jmemnobs.o
ranlib libjpeg.a
gcc  -o rdjpgcom rdjpgcom.o 
gcc  -o cjpeg cjpeg.o rdppm.o rdgif.o rdtarga.o rdrle.o rdbmp.o rdswitch.o cdjpeg.o libjpeg.a 
gcc  -o djpeg djpeg.o wrppm.o wrgif.o wrtarga.o wrrle.o wrbmp.o rdcolmap.o cdjpeg.o libjpeg.a 
gcc  -o wrjpgcom wrjpgcom.o 
gcc  -o jpegtran jpegtran.o rdswitch.o cdjpeg.o transupp.o libjpeg.a 
make -j 4  55.85s user 13.25s system 85% cpu 1:20.74 total
imac2% bc -l
bc 1.05
Copyright 1991, 1992, 1993, 1994, 1997, 1998 Free Software Foundation, Inc.
This is free software with ABSOLUTELY NO WARRANTY.
For details type `warranty'. 
60+20.74
80.74
80.74/2
40.37000000000000000000