From: Martin Mares <mj@ucw.cz>
Date: Tue, 11 Sep 2007 13:26:48 +0000 (+0200)
Subject: Auto-tune radix-sort width according to CPU type.
X-Git-Tag: holmes-import~506^2~13^2~17
X-Git-Url: http://mj.ucw.cz/gitweb/?a=commitdiff_plain;h=abba1591284f92182b86d5e430472c62a73a70ad;p=libucw.git

Auto-tune radix-sort width according to CPU type.
---

diff --git a/lib/autoconf.cfg b/lib/autoconf.cfg
index 4bd16617..b0e3c536 100644
--- a/lib/autoconf.cfg
+++ b/lib/autoconf.cfg
@@ -259,8 +259,14 @@ Set("PARTMAP_IS_MMAP") if IsSet("CPU_64BIT_POINTERS");
 # Option for lib/mempool.c
 Set("POOL_IS_MMAP");
 
-# FIXME
-Set("CONFIG_UCW_RADIX_SORTER_BITS" => 12);
+# Guess optimal bit width of the radix-sorter
+if (Get("CPU_ARCH") eq "default" || Get("CPU_ARCH") =~ /^i[345]86$/) {
+	# This should be safe everywhere
+	Set("CONFIG_UCW_RADIX_SORTER_BITS" => 10);
+} else {
+	# Use this on modern CPU's
+	Set("CONFIG_UCW_RADIX_SORTER_BITS" => 12);
+}
 
 # If debugging memory allocations:
 #LIBS+=-lefence