#!/bin/bash --noprofile
#########################################################################
# Called by the makefile if AUTO_OPT_GCC is true, outputs the list of CPU
# specific optimization flags that should be used.
#########################################################################
#TODO: Detect extra compiler options for:
#
# * Non-gcc compilers.
# * CYGWIN.
# * Mac OS X.
# * Non-x86 Linux systems.
#########################################################################
# This line makes GCC automatically detect the CPU architecture to use.  Also
# might cause the use of some of the "-m" options we use down below,
# but GCC doesn't complain about an "-m" option being used repeatedly.
OUT="-mtune=native -march=native"
if [ -f /proc/cpuinfo ]; then
    # On Linux system, the "flags: " line of /proc/cpuinfo indicates which
    # extended instruction sets are available (among other things), so we
    # can use that to detect what to use.
    # Only get info for the first CPU; assumes that all CPUs in the system
    # are the same
    INFO=`cat /proc/cpuinfo | grep '^flags.*:' | head -n 1`
    # These are currently all x86 specific.
    for flag in cx16 mmx sse sse2 sse3 sse4.1 sse4.2 sse4 sse4a 3dnow abm; do
        # Put a space on either side of the flag name, so that it won't
        # match in the middle of a flag.
        if [[ $INFO == *\ $flag\ * ]] ; then
            OUT="$OUT -m$flag"
        fi
    done
    if [[ $INFO == *\ lahf_lm\ * ]]; then
        OUT="$OUT -msahf"
    fi
    # Any available SSE lets us use -mfpmath=sse
    if [[ $INFO == *\ sse* ]]; then
        OUT="$OUT -mfpmath=sse"
    fi
fi
echo "$OUT"

# These are good optimizations for a Pentium M or better:
#CFOPTIMIZE := -O2 -march=i686 -mtune=i686 -mmmx -msse -msse2 -mfpmath=sse -funroll-all-loops

CFOPTIMIZE := -O2

# Define this to automatically generate code optimized for your machine
# (GCC only as of now).
#
# NOTE: Don't use this with a release build, since the generated code
# won't work for all machines.
ifdef AUTO_OPT_GCC
ifdef CROSSHOST
error Can not do AUTO_OPT_GCC with CROSSHOST
endif
ifdef HURRY
error Can not do AUTO_OPT_GCC with HURRY
endif
AUTO_OPT_FLAGS := $(shell util/auto-opt.sh)
endif
CFOPTIMIZE := -O2 $(AUTO_OPT_FLAGS)