Configure: Simplified radix sorter configuration

Originally, we guessed based on CPU model, but as I have ripped out
model detection, we cannot do that any longer; besides, it was very
much out of date.

Now, we use simple heuristics: anybody caring about performance
runs on amd64 and all amd64 processors have large enough L1 cache
to use 12-bit bucket width.

diff --git a/ucw/perl/UCW/Configure/LibUCW.pm b/ucw/perl/UCW/Configure/LibUCW.pm
index 46cac732aaf3d9c4eeb53c20e717e6da7db33a93..eda1d259d19b607e1d4126780ae247aa095259c2 100644 (file)
--- a/ucw/perl/UCW/Configure/LibUCW.pm
+++ b/ucw/perl/UCW/Configure/LibUCW.pm
@@ -35,13 +35,15 @@ Set("CONFIG_UCW_PARTMAP_IS_MMAP") if IsSet("CPU_64BIT_POINTERS");
 Set("CONFIG_UCW_POOL_IS_MMAP");
 
 # 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);
-}
+Test("CONFIG_UCW_RADIX_SORTER_BITS", "Determining radix sorter bucket width", sub {
+       if (Get("CPU_AMD64")) {
+               # All amd64 CPUs have large enough L1 cache
+               return 12;
+       } else {
+               # This should be safe everywhere
+               return 10;
+       }
+});
 
 # Detect if thread-local storage is supported
 if (Get("CONFIG_UCW_THREADS")) {