AX_CACHE_SIZE: new submission to detect L1 and L2 cache sizes

1 files changed, 86 insertions, 0 deletions

diff --git a/m4/ax_cache_size.m4 b/m4/ax_cache_size.m4
new file mode 100644
index 0000000..af5d4d3
--- /dev/null
+++ b/m4/ax_cache_size.m4
@@ -0,0 +1,86 @@
+##### http://autoconf-archive.cryp.to/ax_cache_size.html
+#
+# SYNOPSIS
+#
+#   AX_CACHE_SIZE
+#
+# DESCRIPTION
+#
+#   Find L1 and L2 caches size by reading the corresponding file on
+#   UNIX or by requesting cpuid. The results are available in the
+#   defines CPU_L1_CACHE and CPU_L2_CACHE.
+#
+#   This macro depends on AX_GCC_X86_CPUID, AC_PROG_SED, AX_COUNT_CPUS,
+#   and AX_CPU_VENDOR.
+#
+# LAST MODIFICATION
+#
+#   2007-11-28
+#
+# COPYLEFT
+#
+#   Copyright (c) 2007 Christophe Tournayre <turn3r@users.sourceforge.net>
+#
+#   Copying and distribution of this file, with or without
+#   modification, are permitted in any medium without royalty provided
+#   the copyright notice and this notice are preserved.
+
+AC_DEFUN([AX_CACHE_SIZE],
+[
+  AC_REQUIRE([AC_PROG_SED])
+  AC_REQUIRE([AX_COUNT_CPUS])
+  AC_REQUIRE([AX_GCC_X86_CPUID])
+  AC_REQUIRE([AX_CPU_VENDOR])
+
+  AX_COUNT_CPUS
+  AX_CPU_VENDOR
+
+    ax_l1_size=unknown
+    ax_l2_size=unknown
+
+    #Check if the variable is present
+    if test -e /sys/devices/system/cpu/cpu0/cache/index0/size; then
+      for ncpu in `seq 0 $(($CPU_COUNT-1))`; do
+        for idx in `seq 0 3`; do
+          if test -e /sys/devices/system/cpu/cpu$ncpu/cache/index$idx/size ; then
+            level=`cat /sys/devices/system/cpu/cpu$ncpu/cache/index$idx/level`
+            size=`cat /sys/devices/system/cpu/cpu$ncpu/cache/index$idx/size`
+            eval CPU$ncpu\_L$level\_CACHE="$size"
+          fi
+        done
+      done
+
+      # This part can (must !!!) be optimized, because we know all caches per proc but
+      # we only take care about the first proc
+      ax_l1_size=$CPU0_L1_CACHE
+      ax_l2_size=$CPU0_L2_CACHE
+
+    else
+      #Or use CPUID
+      if test $ax_xpu_vendor != "Intel"; then
+        AX_GCC_X86_CPUID(0x80000005) # For L1 cache (not available on intel !!!)
+
+        l1_hexval=$(( 16#`echo $ax_cv_gcc_x86_cpuid_0x80000005 | cut -d ":" -f 4`))
+        ax_l1_size=$(($l1_hexval >> 24))
+      fi
+
+      AX_GCC_X86_CPUID(0x80000006) # For L2 cache
+
+      l2_hexval=$(( 16#`echo $ax_cv_gcc_x86_cpuid_0x80000006 | cut -d ":" -f 3`))
+      ax_l2_size=$(($l2_hexval >> 16))
+    fi
+
+    # Keep only digits if there is a unit (ie 1024K -> 1024) and convert in Bytes
+    AC_MSG_CHECKING(the L1 cache size)
+    ax_l1_size=`echo $ax_l1_size | $SED 's/\([[0-9]]\)[[A-Za-z]]$/\1/g'`
+    ax_l1_size=$(($ax_l1_size*1024))
+    AC_MSG_RESULT( $ax_l1_size Bytes)
+
+    AC_MSG_CHECKING(the L2 cache size)
+    ax_l2_size=`echo $ax_l2_size | $SED 's/\([[0-9]]\)[[A-Za-z]]$/\1/g'`
+    ax_l2_size=$(($ax_l2_size*1024))
+    AC_MSG_RESULT( $ax_l2_size Bytes)
+
+    AC_DEFINE_UNQUOTED([CPU_L1_CACHE], ${ax_l1_size}, [L1 cache size (in Bytes)])
+    AC_DEFINE_UNQUOTED([CPU_L2_CACHE], ${ax_l2_size}, [L2 cache size (in Bytes)])
+])