diff --git a/Eigen/src/Core/util/Memory.h b/Eigen/src/Core/util/Memory.h
index 30d9b2377..83b2dd90d 100644
--- a/Eigen/src/Core/util/Memory.h
+++ b/Eigen/src/Core/util/Memory.h
@@ -614,6 +614,7 @@ inline void ei_queryCacheSizes_intel(int& l1, int& l2, int& l3)
   int cache_id = 0;
   int cache_type = 0;
   do {
+    abcd[0] = abcd[1] = abcd[2] = abcd[3] = 0;
     EIGEN_CPUID(abcd,0x4,cache_id);
     cache_type  = (abcd[0] & 0x0F) >> 0;
     if(cache_type==1||cache_type==3) // data or unified cache
@@ -641,8 +642,10 @@ inline void ei_queryCacheSizes_intel(int& l1, int& l2, int& l3)
 inline void ei_queryCacheSizes_amd(int& l1, int& l2, int& l3)
 {
   int abcd[4];
+  abcd[0] = abcd[1] = abcd[2] = abcd[3] = 0;
   EIGEN_CPUID(abcd,0x80000005,0);
   l1 = (abcd[2] >> 24) * 1024; // C[31:24] = L1 size in KB
+  abcd[0] = abcd[1] = abcd[2] = abcd[3] = 0;
   EIGEN_CPUID(abcd,0x80000006,0);
   l2 = (abcd[2] >> 16) * 1024; // C[31;16] = l2 cache size in KB
   l3 = ((abcd[3] & 0xFFFC000) >> 18) * 512 * 1024; // D[31;18] = l3 cache size in 512KB
diff --git a/bench/check_cache_queries.cpp b/bench/check_cache_queries.cpp
new file mode 100644
index 000000000..ca5bbf9a0
--- /dev/null
+++ b/bench/check_cache_queries.cpp
@@ -0,0 +1,129 @@
+
+#define EIGEN_INTERNAL_DEBUG_CACHE_QUERY
+#include <iostream>
+#include "../Eigen/Core"
+
+using namespace Eigen;
+using namespace std;
+
+#define DUMP_CPUID(CODE) {\
+  int abcd[4]; \
+  abcd[0] = abcd[1] = abcd[2] = abcd[3] = 0;\
+  EIGEN_CPUID(abcd, CODE, 0); \
+  std::cout << "The code " << CODE << " gives " \
+              << (int*)(abcd[0]) << " " << (int*)(abcd[1]) << " " \
+              << (int*)(abcd[2]) << " " << (int*)(abcd[3]) << " " << std::endl; \
+  }
+  
+int main()
+{
+  cout << "Eigen's L1    = " << ei_queryL1CacheSize() << endl;
+  cout << "Eigen's L2/L3 = " << ei_queryTopLevelCacheSize() << endl;
+  int l1, l2, l3;
+  ei_queryCacheSizes(l1, l2, l3);
+  cout << "Eigen's L1, L2, L3       = " << l1 << " " << l2 << " " << l3 << endl;
+  
+  #ifdef EIGEN_CPUID
+
+  ei_queryCacheSizes_intel(l1, l2, l3);
+  cout << "Eigen's intel L1, L2, L3 = " << l1 << " " << l2 << " " << l3 << endl;
+  ei_queryCacheSizes_amd(l1, l2, l3);
+  cout << "Eigen's amd L1, L2, L3   = " << l1 << " " << l2 << " " << l3 << endl;
+
+  int abcd[4];
+  int string[8];
+  char* string_char = (char*)(string);
+
+  // vendor ID
+  EIGEN_CPUID(abcd,0x0,0);
+  string[0] = abcd[1];
+  string[1] = abcd[3];
+  string[2] = abcd[2];
+  string[3] = 0;
+  cout << "vendor id = " << string_char << endl;
+
+  // dump Intel direct method
+  {
+    l1 = l2 = l3 = 0;
+    int cache_id = 0;
+    int cache_type = 0;
+    do {
+      abcd[0] = abcd[1] = abcd[2] = abcd[3] = 0;
+      EIGEN_CPUID(abcd,0x4,cache_id);
+      cache_type  = (abcd[0] & 0x0F) >> 0;
+      int cache_level = (abcd[0] & 0xE0) >> 5;  // A[7:5]
+      int ways        = (abcd[1] & 0xFFC00000) >> 22; // B[31:22]
+      int partitions  = (abcd[1] & 0x003FF000) >> 12; // B[21:12]
+      int line_size   = (abcd[1] & 0x00000FFF) >>  0; // B[11:0]
+      int sets        = (abcd[2]);                    // C[31:0]
+      int cache_size = (ways+1) * (partitions+1) * (line_size+1) * (sets+1);
+      
+      cout << "cache[" << cache_id << "].type       = " << cache_type << "\n";
+      cout << "cache[" << cache_id << "].level      = " << cache_level << "\n";
+      cout << "cache[" << cache_id << "].ways       = " << ways << "\n";
+      cout << "cache[" << cache_id << "].partitions = " << partitions << "\n";
+      cout << "cache[" << cache_id << "].line_size  = " << line_size << "\n";
+      cout << "cache[" << cache_id << "].sets       = " << sets << "\n";
+      cout << "cache[" << cache_id << "].size       = " << cache_size << "\n";
+      
+      cache_id++;
+    } while(cache_type>0);
+  }
+  
+  
+  // dump everything
+  std::cout << endl <<"Raw dump:" << endl;
+  DUMP_CPUID(0x0);
+  DUMP_CPUID(0x1);
+  DUMP_CPUID(0x2);
+  DUMP_CPUID(0x3);
+  DUMP_CPUID(0x4);
+  DUMP_CPUID(0x5);
+  DUMP_CPUID(0x6);
+  DUMP_CPUID(0x80000000);
+  DUMP_CPUID(0x80000001);
+  DUMP_CPUID(0x80000002);
+  DUMP_CPUID(0x80000003);
+  DUMP_CPUID(0x80000004);
+  DUMP_CPUID(0x80000005);
+  DUMP_CPUID(0x80000006);
+  DUMP_CPUID(0x80000007);
+  DUMP_CPUID(0x80000008);
+  #else
+  cout << "EIGEN_CPUID is not defined" << endl;
+  #endif
+  return 0;
+}
+#if 0
+#define FOO(CODE) { \
+  EIGEN_CPUID(abcd, CODE); \
+  std::cout << "The code " << CODE << " gives " \
+              << (int*)(abcd[0]) << " " << (int*)(abcd[1]) << " " \
+              << (int*)(abcd[2]) << " " << (int*)(abcd[3]) << " " << std::endl; \
+ }
+
+
+ int abcd[5];
+  abcd[4] = 0;
+//   for (int a = 0; a < 5; a++) {
+//     cpuid(abcd,a);
+//     std::cout << "The code " << a << " gives "
+//               << abcd[0] << " " << abcd[1] << " "
+//               << abcd[2] << " " << abcd[3] << " " << abcd[4] << std::endl;
+//   }
+
+  FOO(0x1); std::cerr << (char*)abcd << "\n";
+  FOO(0x2);
+  FOO(0x2);
+  FOO(0x2);
+  FOO(0x3); std::cerr << (char*)abcd << "\n";
+  FOO(0x80000002); std::cerr << (char*)abcd << "\n";
+  FOO(0x80000003); std::cerr << (char*)abcd << "\n";
+  FOO(0x80000004); std::cerr << (char*)abcd << "\n";
+  FOO(0x80000005); std::cerr << (char*)abcd << "\n";
+  FOO(0x80000006); std::cerr << (char*)(abcd) << "\n";
+  std::cerr << "L2 : " << (abcd[2] >> 16) << "KB\n";
+//   FOO(0x80000019); std::cerr << (char*)(abcd) << "\n";
+  FOO(0x8000001A); std::cerr << (char*)(abcd) << "\n";
+
+  #endif
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