ARM: Always enable ARMv7 when VFPv3 is enabled.

src/arm/assembler-arm.cc

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions
 // are met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 41 matching lines @@
 
 
 #ifdef __arm__
 static uint64_t CpuFeaturesImpliedByCompiler() {
   uint64_t answer = 0;
 #ifdef CAN_USE_ARMV7_INSTRUCTIONS
   answer |= 1u << ARMv7;
 #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__)

[Rodolph Perfetta, 2011/04/11 12:48:55]

This would be true for VFPv2 too.

[Søren Thygesen Gjesse, 2011/04/11 14:10:25]

I see, but that was what we had before. I can't seem to find any way to see from
gcc to distinguish.

-  answer |= 1u << VFP3;
+  answer |= 1u << VFP3 | 1u << ARMv7;
 #endif  // defined(__VFP_FP__) && !defined(__SOFTFP__)
 #ifdef CAN_USE_VFP_INSTRUCTIONS

[Rodolph Perfetta, 2011/04/11 12:48:55]

I can't find where CAN_USE_VFP_INSTRUCTIONS is defined.

[Søren Thygesen Gjesse, 2011/04/11 14:10:25]

This is defined in the SConstruct file when compiling for Android (maybe the gcc
used for compiling for Android did not define __VFP_FP__). We could consider
removing it, as the SCons based Android build is broken, and the Android
repository has a v8_shell target now.

-  answer |= 1u << VFP3;
+  answer |= 1u << VFP3 | 1u << ARMv7;
 #endif  // def CAN_USE_VFP_INSTRUCTIONS
   return answer;
 }
 #endif  // def __arm__
 
 
 void CpuFeatures::Probe() {
   ASSERT(!initialized_);
 #ifdef DEBUG
   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) {
     supported_ |= 1u << ARMv7;
   }
 #else  // def __arm__
   if (Serializer::enabled()) {
     supported_ |= OS::CpuFeaturesImpliedByPlatform();
     supported_ |= CpuFeaturesImpliedByCompiler();
     return;  // No features if we might serialize.
   }
 
   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)) {
     supported_ |= 1u << ARMv7;
     found_by_runtime_probing_ |= 1u << ARMv7;
   }
 #endif
 }
 
 
@@ skipping 2719 matching lines @@
 
   // Since a constant pool was just emitted, move the check offset forward by
   // the standard interval.
   next_buffer_check_ = pc_offset() + kCheckConstInterval;
 }
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_TARGET_ARCH_ARM