test/bench/shootout: more speedups Most significant in mandelbrot, from avoiding MOVSD between registers, but there are others.
test/bench/shootout: more speedups
Most significant in mandelbrot, from avoiding MOVSD between registers,
but there are others.

R=golang-dev, rsc
CC=golang-dev
http://codereview.appspot.com/6258063

d0f/go-zh,scirelli/scirelli-go,mhennings/marcohennings-go,rdp/rogerpack2005-golang,d0f/go-zh,webfd/go-zh,rflanagan/reginaldflanagan-project1,mhennings/marcohennings-go,glycerine/jeaten-go-arrayof-structof,Triskite/willstone-goclone,scirelli/scirelli-go,rflanagan/reginaldflanagan-project1,rdp/rogerpack2005-golang,mhennings/marcohennings-go,mhennings/marcohennings-go,bryanxu/go-zh,rflanagan/reginaldflanagan-project1,sanjosh/sanjos100-tipc,scirelli/scirelli-go,sanjosh/sanjos100-tipc,scirelli/scirelli-go,bryanxu/go-zh,sanjosh/sanjos100-tipc,rflanagan/reginaldflanagan-project1,sanjosh/sanjos100-tipc,bryanxu/go-zh,webfd/go-zh,rdp/rogerpack2005-golang,rdp/rogerpack2005-golang,bryanxu/go-zh,d0f/go-zh,rdp/rogerpack2005-golang,scirelli/scirelli-go,scirelli/scirelli-go,rflanagan/reginaldflanagan-project1,mhennings/marcohennings-go,Triskite/willstone-goclone,scirelli/scirelli-go,rdp/rogerpack2005-golang,Triskite/willstone-goclone,webfd/go-zh,bryanxu/go-zh,mhennings/marcohennings-go,rflanagan/reginaldflanagan-project1,sanjosh/sanjos100-tipc,rflanagan/reginaldflanagan-project1,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,Triskite/willstone-goclone,Triskite/willstone-goclone,d0f/go-zh,Triskite/willstone-goclone,bryanxu/go-zh,glycerine/jeaten-go-arrayof-structof,Triskite/willstone-goclone,webfd/go-zh,d0f/go-zh,Triskite/willstone-goclone,rflanagan/reginaldflanagan-project1,d0f/go-zh,mhennings/marcohennings-go,bryanxu/go-zh,d0f/go-zh,sanjosh/sanjos100-tipc,d0f/go-zh,rdp/rogerpack2005-golang,webfd/go-zh,scirelli/scirelli-go,sanjosh/sanjos100-tipc,mhennings/marcohennings-go,bryanxu/go-zh,rdp/rogerpack2005-golang,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,sanjosh/sanjos100-tipc,glycerine/jeaten-go-arrayof-structof,webfd/go-zh,glycerine/jeaten-go-arrayof-structof,glycerine/jeaten-go-arrayof-structof,glycerine/jeaten-go-arrayof-structof