Make FlushICache NOP for Nvidia Denver CPU's.

src/base/cpu.cc

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "src/base/cpu.h"
 
 #if V8_LIBC_MSVCRT
 #include <intrin.h>  // __cpuid()
 #endif
 #if V8_OS_LINUX
@@ skipping 282 matching lines @@
 
 CPU::CPU()
     : stepping_(0),
       model_(0),
       ext_model_(0),
       family_(0),
       ext_family_(0),
       type_(0),
       implementer_(0),
       architecture_(0),
+      variant_(0),

[Benedikt Meurer, 2014/12/19 06:32:09]

The 0 default is not safe as we would default to denver if there is no variant
in cpuinfo, please change it back to -1, sorry for the confusion from my earlier
comment.

[arajp, 2014/12/19 10:45:31]

Done.

       part_(0),
       has_fpu_(false),
       has_cmov_(false),
       has_sahf_(false),
       has_mmx_(false),
       has_sse_(false),
       has_sse2_(false),
       has_sse3_(false),
       has_ssse3_(false),
       has_sse41_(false),
@@ skipping 76 matching lines @@
   char* implementer = cpu_info.ExtractField("CPU implementer");
   if (implementer != NULL) {
     char* end ;
     implementer_ = strtol(implementer, &end, 0);
     if (end == implementer) {
       implementer_ = 0;
     }
     delete[] implementer;
   }
 
+  char* variant = cpu_info.ExtractField("CPU variant");
+  if (variant != NULL) {
+    char* end ;
+    variant_ = strtol(variant, &end, 0);
+    if (end == variant) {
+      variant_ = -1;
+    }
+    delete[] variant;
+  }
+
   // Extract part number from the "CPU part" field.
   char* part = cpu_info.ExtractField("CPU part");
   if (part != NULL) {
     char* end ;
     part_ = strtol(part, &end, 0);
     if (end == part) {
       part_ = 0;
     }
     delete[] part;
   }
@@ skipping 132 matching lines @@
   char* implementer = cpu_info.ExtractField("CPU implementer");
   if (implementer != NULL) {
     char* end ;
     implementer_ = strtol(implementer, &end, 0);
     if (end == implementer) {
       implementer_ = 0;
     }
     delete[] implementer;
   }
 
+  char* variant = cpu_info.ExtractField("CPU variant");
+  if (variant != NULL) {
+    char* end ;
+    variant_ = strtol(variant, &end, 0);
+    if (end == variant) {
+      variant_ = -1;
+    }
+    delete[] variant;
+  }
+
   // Extract part number from the "CPU part" field.
   char* part = cpu_info.ExtractField("CPU part");
   if (part != NULL) {
     char* end ;
     part_ = strtol(part, &end, 0);
     if (end == part) {
       part_ = 0;
     }
     delete[] part;
   }
 
 #endif
 }
 
 } }  // namespace v8::base