Building GHC in under /8/ minutes

In response to my last post, Simon Marlow suggested building the first GHC stage with -O, hoping that an optimised GHC in turn will be faster compiling the libraries and second stage. Here’s the result:

With the following build.mk:

SRC_HC_OPTS     = -H64m -Onot -fasm
GhcStage1HcOpts = -O -fasm
GhcStage2HcOpts = -Onot -fasm
GhcLibHcOpts    = -Onot -fasm
GhcLibWays      =
SplitObjs       = NO

On a 2 processor, 4 core linux machine, running with -j10:

make -j10 > /dev/null  1015.77s user 155.19s system 249% cpu 7:49.50 total

Great! A new GHC build record (I think). Can’t wait till the 16 core machine arrives…