AUTO_OPT: add a bit of flexibility for future porting, Mac OS X support

Signed-off-by: Steven Noonan <steven@uplinklabs.net>

1 files changed, 104 insertions, 0 deletions

diff --git a/crawl-ref/source/util/gcc-opt-x86.pl b/crawl-ref/source/util/gcc-opt-x86.pl
new file mode 100755
index 0000000000..808eecac2d
--- /dev/null
+++ b/crawl-ref/source/util/gcc-opt-x86.pl
@@ -0,0 +1,104 @@
+#!/usr/bin/perl
+#
+# GCC optimization flag generator
+#
+
+use strict;
+use warnings;
+
+my $gcc = $ARGV[0];
+my $cpuinfo = $ARGV[1];
+
+if ( ! $gcc ) {
+	die "Can't generate optimization flags (no compiler specified)\n";
+}
+
+if ( ! `which $gcc 2> /dev/null` ) {
+	die "Can't generate optimization flags ($gcc is missing?)\n";
+}
+
+#
+# We allow people to provide their own cpuinfo-compatible
+# descriptor. This may be useful later if we want to have
+# specific architecture-specific optimizations for release
+# builds or something.
+#
+if ( ! $cpuinfo ) {
+	$cpuinfo = "/proc/cpuinfo";
+}
+
+my %features;
+my $family;
+my $uname_S = `uname -s`;
+
+#
+# Collect CPU feature list
+#
+
+# The Linux way
+if ( -e $cpuinfo ) {
+	open(FH, "< $cpuinfo");
+	my @cpuinfo = <FH>;
+	close FH;
+
+	my @familyline = grep(/^cpu family/, @cpuinfo);
+	$familyline[0] =~ s/^cpu[ ]family[ \t]*[:][ ]*//;
+	$family = $familyline[0];
+
+	my @flags = grep(/^flags/, @cpuinfo);
+	$flags[0] =~ s/^flags[ \t]*[:][ \t]*//;
+	@flags = split(' ',$flags[0]);
+	foreach (@flags) {
+		$features{$_} = 1;
+	}
+}
+
+# The Mac OS X way
+if ( $uname_S =~ /^Darwin/ ) {
+	# All released Intel macs have CMOV, and
+	# sysctl doesn't provide this one.
+	$features{"cmov"} = 1;
+
+	$features{"mmx"} = `sysctl -n hw.optional.mmx`;
+	$features{"sse"} = `sysctl -n hw.optional.sse`;
+	$features{"sse2"} = `sysctl -n hw.optional.sse2`;
+	$features{"pni"} = `sysctl -n hw.optional.sse3`;
+	$features{"ssse3"} = `sysctl -n hw.optional.supplementalsse3`;
+}
+
+#
+# Check the minimum march/mtune value
+#
+my $march = "i386";
+my $fpmath;
+
+if ( $features{"cmov"} && $features{"mmx"} ) {
+	$march = "pentium2";
+}
+if ( $features{"sse"} ) {
+	$march = "pentium3";
+	$fpmath = "sse"
+}
+if ( $features{"sse2"} ) {
+	$march = "pentium-m";
+}
+if ( $features{"pni"} ) {
+	$march = "prescott";
+}
+
+# It's important to specify 'march=pentium4' for the
+# Pentium 4, because it has vastly different optimization
+# rules than other x86 processors. What's optimal for the
+# Pentium 3 is extremely sub-optimal for the Pentium 4.
+if ( $family == 15 ) {
+	$march = "pentium4";
+}
+
+print "-march=$march -mtune=$march";
+if ( $fpmath ) {
+	print " -mfpmath=$fpmath";
+}
+
+print "\n";
+
+exit 0