ARM: Always enable ARMv7 when VFPv3 is enabled.

R=vegorov@chromium.org, rodolph.perfetta@gmail.com

BUG=v8:1317
TEST=

Review URL: http://codereview.chromium.org//6825037

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@7580 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

src/arm/assembler-arm.cc

@@ -59,12 +59,12 @@ static uint64_t CpuFeaturesImpliedByCompiler() {
 #endif  // def CAN_USE_ARMV7_INSTRUCTIONS
   // If the compiler is allowed to use VFP then we can use VFP too in our code
   // generation even when generating snapshots.  This won't work for cross
-  // compilation.
+  // compilation. VFPv3 implies ARMv7, see ARM DDI 0406B, page A1-6.
 #if defined(__VFP_FP__) && !defined(__SOFTFP__)
-  answer |= 1u << VFP3;
+  answer |= 1u << VFP3 | 1u << ARMv7;
 #endif  // defined(__VFP_FP__) && !defined(__SOFTFP__)
 #ifdef CAN_USE_VFP_INSTRUCTIONS
-  answer |= 1u << VFP3;
+  answer |= 1u << VFP3 | 1u << ARMv7;
 #endif  // def CAN_USE_VFP_INSTRUCTIONS
   return answer;
 }
@@ -77,9 +77,10 @@ void CpuFeatures::Probe() {
   initialized_ = true;
 #endif
 #ifndef __arm__
-  // For the simulator=arm build, use VFP when FLAG_enable_vfp3 is enabled.
+  // For the simulator=arm build, use VFP when FLAG_enable_vfp3 is
+  // enabled. VFPv3 implies ARMv7, see ARM DDI 0406B, page A1-6.
   if (FLAG_enable_vfp3) {
-    supported_ |= 1u << VFP3;
+    supported_ |= 1u << VFP3 | 1u << ARMv7;
   }
   // For the simulator=arm build, use ARMv7 when FLAG_enable_armv7 is enabled
   if (FLAG_enable_armv7) {
@@ -93,10 +94,11 @@ void CpuFeatures::Probe() {
   }
 
   if (OS::ArmCpuHasFeature(VFP3)) {
-    // This implementation also sets the VFP flags if
-    // runtime detection of VFP returns true.
-    supported_ |= 1u << VFP3;
-    found_by_runtime_probing_ |= 1u << VFP3;
+    // This implementation also sets the VFP flags if runtime
+    // detection of VFP returns true. VFPv3 implies ARMv7, see ARM DDI
+    // 0406B, page A1-6.
+    supported_ |= 1u << VFP3 | 1u << ARMv7;
+    found_by_runtime_probing_ |= 1u << VFP3 | 1u << ARMv7;
   }
 
   if (OS::ArmCpuHasFeature(ARMv7)) {

src/flag-definitions.h

@@ -162,7 +162,8 @@ DEFINE_bool(enable_rdtsc, true,
 DEFINE_bool(enable_sahf, true,
             "enable use of SAHF instruction if available (X64 only)")
 DEFINE_bool(enable_vfp3, true,
-            "enable use of VFP3 instructions if available (ARM only)")
+            "enable use of VFP3 instructions if available - this implies "
+            "enabling ARMv7 instructions (ARM only)")
 DEFINE_bool(enable_armv7, true,
             "enable use of ARMv7 instructions if available (ARM only)")
 DEFINE_bool(enable_fpu, true,

src/platform-linux.cc

@@ -92,9 +92,10 @@ void OS::Setup() {
 
 uint64_t OS::CpuFeaturesImpliedByPlatform() {
 #if (defined(__VFP_FP__) && !defined(__SOFTFP__))
-  // Here gcc is telling us that we are on an ARM and gcc is assuming that we
-  // have VFP3 instructions.  If gcc can assume it then so can we.
-  return 1u << VFP3;
+  // Here gcc is telling us that we are on an ARM and gcc is assuming
+  // that we have VFP3 instructions.  If gcc can assume it then so can
+  // we. VFPv3 implies ARMv7, see ARM DDI 0406B, page A1-6.
+  return 1u << VFP3 | 1u << ARMv7;
 #elif CAN_USE_ARMV7_INSTRUCTIONS
   return 1u << ARMv7;
 #elif(defined(__mips_hard_float) && __mips_hard_float != 0)