Emulate MLS on pre-ARMv6T2. Cleaned up thumbee vs. thumb2 confusion.

src/cpu.cc

Index: src/cpu.cc
diff --git a/src/cpu.cc b/src/cpu.cc
index bdc65aa20e61d5fd4d3627451bd38e08cfa688d2..01c1036db26b69a3ec2af35e8666f05f04751fed 100644
--- a/src/cpu.cc
+++ b/src/cpu.cc
@@ -259,7 +259,7 @@ CPU::CPU() : stepping_(0),
              has_sse42_(false),
              has_idiva_(false),
              has_neon_(false),
-             has_thumbee_(false),
+             has_thumb2_(false),
              has_vfp_(false),
              has_vfp3_(false),
              has_vfp3_d32_(false) {
@@ -383,7 +383,6 @@ CPU::CPU() : stepping_(0),
   if (hwcaps != 0) {
     has_idiva_ = (hwcaps & HWCAP_IDIVA) != 0;
     has_neon_ = (hwcaps & HWCAP_NEON) != 0;
-    has_thumbee_ = (hwcaps & HWCAP_THUMBEE) != 0;
     has_vfp_ = (hwcaps & HWCAP_VFP) != 0;
     has_vfp3_ = (hwcaps & (HWCAP_VFPv3 | HWCAP_VFPv3D16 | HWCAP_VFPv4)) != 0;
     has_vfp3_d32_ = (has_vfp3_ && ((hwcaps & HWCAP_VFPv3D16) == 0 ||
@@ -393,7 +392,7 @@ CPU::CPU() : stepping_(0),
     char* features = cpu_info.ExtractField("Features");
     has_idiva_ = HasListItem(features, "idiva");
     has_neon_ = HasListItem(features, "neon");
-    has_thumbee_ = HasListItem(features, "thumbee");
+    has_thumb2_ = HasListItem(features, "thumb2");

[Rodolph Perfetta, 2014/06/13 10:38:23]

thumb2 doesn't get reported as such in cpuinfo:
 * ARMv7 (or higher) => thumb2
 * ARMv6T2 => thumb2
I only know of one ARMv6T2 cpu and it doesn't have an MMU so we could simplify
to ARMv7

[Sven Panne, 2014/06/13 10:49:57]

This was proposed by Benedikt. We can simplify this in another CL if both of you
come to an agreement what the test should look like. :-)

     has_vfp_ = HasListItem(features, "vfp");
     if (HasListItem(features, "vfpv3d16")) {
       has_vfp3_ = true;
@@ -417,13 +416,13 @@ CPU::CPU() : stepping_(0),
     architecture_ = 7;
   }
 
-  // ARMv7 implies ThumbEE.
+  // ARMv7 implies Thumb2.
   if (architecture_ >= 7) {
-    has_thumbee_ = true;
+    has_thumb2_ = true;
   }
 
-  // The earliest architecture with ThumbEE is ARMv6T2.
-  if (has_thumbee_ && architecture_ < 6) {
+  // The earliest architecture with Thumb2 is ARMv6T2.
+  if (has_thumb2_ && architecture_ < 6) {
     architecture_ = 6;
   }
 
@@ -435,10 +434,10 @@ CPU::CPU() : stepping_(0),
   uint32_t cpu_flags = SYSPAGE_ENTRY(cpuinfo)->flags;
   if (cpu_flags & ARM_CPU_FLAG_V7) {
     architecture_ = 7;
-    has_thumbee_ = true;
+    has_thumb2_ = true;
   } else if (cpu_flags & ARM_CPU_FLAG_V6) {
     architecture_ = 6;
-    // QNX doesn't say if ThumbEE is available.
+    // QNX doesn't say if Thumb2 is available.
     // Assume false for the architectures older than ARMv7.
   }
   ASSERT(architecture_ >= 6);